Add ETC1/ETC2 compression support though etc2comp.

Remove rg-etc1 code. Also updated travis to use ubuntu 14.04.

Fixes #8457.

.travis.yml

@@ -1,5 +1,7 @@
 language: cpp
 
+dist: trusty
+
 sudo: false
 
 compiler:
@@ -73,7 +75,6 @@ addons:
       # For style checks.
       - clang-format-3.9
 
-
 before_script:
   - if [ "$TRAVIS_OS_NAME" = "osx" ]; then brew update; brew install scons; fi
   - if [ "$TRAVIS_OS_NAME" = "osx" ] && [ "$GODOT_TARGET" = "android" ]; then
@@ -86,5 +87,9 @@ script:
   - if [ "$STATIC_CHECKS" = "yes" ]; then
       sh ./misc/travis/clang-format.sh;
     else
+      if [ "$TRAVIS_OS_NAME" = "windows" ]; then
         scons platform=$GODOT_TARGET CXX=$CXX openssl=builtin;
+      else
+        scons platform=$GODOT_TARGET bits=64 CXX=$CXX openssl=builtin;
+      fi
     fi

core/image.cpp

@@ -1483,16 +1483,16 @@ Error Image::decompress() {
 		_image_decompress_bc(this);
 	else if (format >= FORMAT_PVRTC2 && format <= FORMAT_PVRTC4A && _image_decompress_pvrtc)
 		_image_decompress_pvrtc(this);
-	else if (format == FORMAT_ETC && _image_decompress_etc)
-		_image_decompress_etc(this);
-	else if (format >= FORMAT_ETC2_R11 && format <= FORMAT_ETC2_RGB8A1 && _image_decompress_etc)
+	else if (format == FORMAT_ETC && _image_decompress_etc1)
+		_image_decompress_etc1(this);
+	else if (format >= FORMAT_ETC2_R11 && format <= FORMAT_ETC2_RGB8A1 && _image_decompress_etc1)
 		_image_decompress_etc2(this);
 	else
 		return ERR_UNAVAILABLE;
 	return OK;
 }
 
-Error Image::compress(CompressMode p_mode, bool p_for_srgb) {
+Error Image::compress(CompressMode p_mode, bool p_for_srgb, float p_lossy_quality) {
 
 	switch (p_mode) {
 
@@ -1513,13 +1513,13 @@ Error Image::compress(CompressMode p_mode, bool p_for_srgb) {
 		} break;
 		case COMPRESS_ETC: {
 
-			ERR_FAIL_COND_V(!_image_compress_etc_func, ERR_UNAVAILABLE);
-			_image_compress_etc_func(this);
+			ERR_FAIL_COND_V(!_image_compress_etc1_func, ERR_UNAVAILABLE);
+			_image_compress_etc1_func(this, p_lossy_quality);
 		} break;
 		case COMPRESS_ETC2: {
 
-			ERR_FAIL_COND_V(!_image_compress_etc_func, ERR_UNAVAILABLE);
-			_image_compress_etc_func(this);
+			ERR_FAIL_COND_V(!_image_compress_etc2_func, ERR_UNAVAILABLE);
+			_image_compress_etc2_func(this, p_lossy_quality);
 		} break;
 	}
 
@@ -1652,11 +1652,11 @@ Ref<Image> (*Image::_jpg_mem_loader_func)(const uint8_t *, int) = NULL;
 void (*Image::_image_compress_bc_func)(Image *, bool) = NULL;
 void (*Image::_image_compress_pvrtc2_func)(Image *) = NULL;
 void (*Image::_image_compress_pvrtc4_func)(Image *) = NULL;
-void (*Image::_image_compress_etc_func)(Image *) = NULL;
-void (*Image::_image_compress_etc2_func)(Image *) = NULL;
+void (*Image::_image_compress_etc1_func)(Image *, float) = NULL;
+void (*Image::_image_compress_etc2_func)(Image *, float) = NULL;
 void (*Image::_image_decompress_pvrtc)(Image *) = NULL;
 void (*Image::_image_decompress_bc)(Image *) = NULL;
-void (*Image::_image_decompress_etc)(Image *) = NULL;
+void (*Image::_image_decompress_etc1)(Image *) = NULL;
 void (*Image::_image_decompress_etc2)(Image *) = NULL;
 
 PoolVector<uint8_t> (*Image::lossy_packer)(const Ref<Image> &, float) = NULL;

core/image.h

@@ -117,12 +117,12 @@ public:
 	static void (*_image_compress_bc_func)(Image *, bool p_srgb);
 	static void (*_image_compress_pvrtc2_func)(Image *);
 	static void (*_image_compress_pvrtc4_func)(Image *);
-	static void (*_image_compress_etc_func)(Image *);
-	static void (*_image_compress_etc2_func)(Image *);
+	static void (*_image_compress_etc1_func)(Image *, float);
+	static void (*_image_compress_etc2_func)(Image *, float);
 
 	static void (*_image_decompress_pvrtc)(Image *);
 	static void (*_image_decompress_bc)(Image *);
-	static void (*_image_decompress_etc)(Image *);
+	static void (*_image_decompress_etc1)(Image *);
 	static void (*_image_decompress_etc2)(Image *);
 
 	static PoolVector<uint8_t> (*lossy_packer)(const Ref<Image> &p_image, float p_quality);
@@ -267,7 +267,7 @@ public:
 		COMPRESS_ETC2,
 	};
 
-	Error compress(CompressMode p_mode = COMPRESS_S3TC, bool p_for_srgb = false);
+	Error compress(CompressMode p_mode = COMPRESS_S3TC, bool p_for_srgb = false, float p_lossy_quality = 0.7);
 	Error decompress();
 	bool is_compressed() const;
 

core/math/math_funcs.h

@@ -112,6 +112,15 @@ public:
 	static _ALWAYS_INLINE_ bool is_inf(double p_val) {
 #ifdef _MSC_VER
 		return !_finite(p_val);
+// workaround for mingw builds on travis
+#elif defined(__MINGW32__) || defined(__MINGW64__)
+		union {
+			uint64_t u;
+			double f;
+		} ieee754;
+		ieee754.f = p_val;
+		return ((unsigned)(ieee754.u >> 32) & 0x7fffffff) == 0x7ff00000 &&
+			   ((unsigned)ieee754.u == 0);
 #else
 		return isinf(p_val);
 #endif
@@ -120,6 +129,14 @@ public:
 	static _ALWAYS_INLINE_ bool is_inf(float p_val) {
 #ifdef _MSC_VER
 		return !_finite(p_val);
+// workaround for mingw builds on travis
+#elif defined(__MINGW32__) || defined(__MINGW64__)
+		union {
+			uint32_t u;
+			float f;
+		} ieee754;
+		ieee754.f = p_val;
+		return (ieee754.u & 0x7fffffff) == 0x7f800000;
 #else
 		return isinf(p_val);
 #endif

doc/base/classes.xml

@@ -18490,8 +18490,10 @@
 			</return>
 			<argument index="0" name="format" type="int" default="0">
 			</argument>
+			<argument index="0" name="quality" type="float" default="0">
+			</argument>
 			<description>
-				Return a new compressed [Image] from this [Image] using one of [Image].COMPRESS_*.
+				Return a new compressed [Image] from this [Image] using one of [Image].COMPRESS_*. Quality only affects ETC1 and ETC2 encoding.
 			</description>
 		</method>
 		<method name="converted">

editor/import/resource_importer_texture.cpp

@@ -144,8 +144,12 @@ String ResourceImporterTexture::get_resource_type() const {
 
 bool ResourceImporterTexture::get_option_visibility(const String &p_option, const Map<StringName, Variant> &p_options) const {
 
-	if (p_option == "compress/lossy_quality" && int(p_options["compress/mode"]) != COMPRESS_LOSSY)
+	if (p_option == "compress/lossy_quality") {
+		int compress_mode = int(p_options["compress/mode"]);
+		if (compress_mode != COMPRESS_LOSSY && compress_mode != COMPRESS_VIDEO_RAM) {
 			return false;
+		}
+	}
 
 	return true;
 }
@@ -277,7 +281,7 @@ void ResourceImporterTexture::_save_stex(const Ref<Image> &p_image, const String
 			if (p_force_rgbe && image->get_format() >= Image::FORMAT_R8 && image->get_format() <= Image::FORMAT_RGBE9995) {
 				image->convert(Image::FORMAT_RGBE9995);
 			} else {
-				image->compress(p_vram_compression, p_texture_flags & VS::TEXTURE_FLAG_CONVERT_TO_LINEAR);
+				image->compress(p_vram_compression, p_texture_flags & VS::TEXTURE_FLAG_CONVERT_TO_LINEAR, p_lossy_quality);
 			}
 
 			format |= image->get_format();
@@ -382,8 +386,8 @@ Error ResourceImporterTexture::import(const String &p_source_file, const String
 		//Android, GLES 2.x
 		_save_stex(image, p_save_path + ".etc.stex", compress_mode, lossy, Image::COMPRESS_ETC, mipmaps, tex_flags, stream, detect_3d, detect_srgb, force_rgbe);
 		r_platform_variants->push_back("etc");
-		//_save_stex(image,p_save_path+".etc2.stex",compress_mode,lossy,Image::COMPRESS_ETC2,mipmaps,tex_flags,stream);
-		//r_platform_variants->push_back("etc2");
+		_save_stex(image, p_save_path + ".etc2.stex", compress_mode, lossy, Image::COMPRESS_ETC2, mipmaps, tex_flags, stream, detect_3d, detect_srgb, force_rgbe);
+		r_platform_variants->push_back("etc2");
 		_save_stex(image, p_save_path + ".s3tc.stex", compress_mode, lossy, Image::COMPRESS_S3TC, mipmaps, tex_flags, stream, detect_3d, detect_srgb, force_rgbe);
 		r_platform_variants->push_back("s3tc");
 

modules/etc/SCsub

@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+
+Import('env')
+Import('env_modules')
+
+env_etc = env_modules.Clone()
+
+# Thirdparty source files
+# Not unbundled so far since not widespread as shared library
+thirdparty_dir = "#thirdparty/etc2comp/"
+thirdparty_sources = [
+	"EtcBlock4x4.cpp",
+	"EtcBlock4x4Encoding.cpp",
+	"EtcBlock4x4Encoding_ETC1.cpp",
+	"EtcBlock4x4Encoding_R11.cpp",
+	"EtcBlock4x4Encoding_RG11.cpp",
+	"EtcBlock4x4Encoding_RGB8A1.cpp",
+	"EtcBlock4x4Encoding_RGB8.cpp",
+	"EtcBlock4x4Encoding_RGBA8.cpp",
+	"Etc.cpp",
+	"EtcDifferentialTrys.cpp",
+	"EtcFilter.cpp",
+	"EtcImage.cpp",
+	"EtcIndividualTrys.cpp",
+	"EtcMath.cpp",
+	"EtcSortedBlockList.cpp",
+]
+thirdparty_sources = [thirdparty_dir + file for file in thirdparty_sources]
+
+env_etc.add_source_files(env.modules_sources, thirdparty_sources)
+env_etc.Append(CPPPATH=[thirdparty_dir])
+
+# Godot source files
+env_etc.add_source_files(env.modules_sources, "*.cpp")
+
+# upstream uses c++11
+env_etc.Append(CXXFLAGS="-std=gnu++11")

modules/etc/image_etc.cpp

@@ -0,0 +1,181 @@
+/*************************************************************************/
+/*  image_etc.cpp                                                        */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                    http://www.godotengine.org                         */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md)    */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+#include "image_etc.h"
+#include "Etc.h"
+#include "EtcFilter.h"
+#include "image.h"
+#include "os/copymem.h"
+#include "os/os.h"
+#include "print_string.h"
+
+static Image::Format _get_etc2_mode(Image::DetectChannels format) {
+	switch (format) {
+		case Image::DETECTED_L:
+		case Image::DETECTED_R:
+			return Image::FORMAT_ETC2_R11;
+
+		case Image::DETECTED_RG:
+			return Image::FORMAT_ETC2_RG11;
+
+		case Image::DETECTED_RGB:
+			return Image::FORMAT_ETC2_RGB8;
+
+		case Image::DETECTED_RGBA:
+			return Image::FORMAT_ETC2_RGBA8;
+
+			// TODO: would be nice if we could use FORMAT_ETC2_RGB8A1 for FORMAT_RGBA5551
+	}
+
+	ERR_FAIL_COND_V(true, Image::FORMAT_MAX);
+}
+
+static Etc::Image::Format _image_format_to_etc2comp_format(Image::Format format) {
+	switch (format) {
+		case Image::FORMAT_ETC:
+			return Etc::Image::Format::ETC1;
+
+		case Image::FORMAT_ETC2_R11:
+			return Etc::Image::Format::R11;
+
+		case Image::FORMAT_ETC2_R11S:
+			return Etc::Image::Format::SIGNED_R11;
+
+		case Image::FORMAT_ETC2_RG11:
+			return Etc::Image::Format::RG11;
+
+		case Image::FORMAT_ETC2_RG11S:
+			return Etc::Image::Format::SIGNED_RG11;
+
+		case Image::FORMAT_ETC2_RGB8:
+			return Etc::Image::Format::RGB8;
+
+		case Image::FORMAT_ETC2_RGBA8:
+			return Etc::Image::Format::RGBA8;
+
+		case Image::FORMAT_ETC2_RGB8A1:
+			return Etc::Image::Format::RGB8A1;
+	}
+
+	ERR_FAIL_COND_V(true, Etc::Image::Format::UNKNOWN);
+}
+
+static void _decompress_etc1(Image *p_img) {
+	// not implemented, to be removed
+}
+
+static void _decompress_etc2(Image *p_img) {
+	// not implemented, to be removed
+}
+
+static void _compress_etc(Image *p_img, float p_lossy_quality, bool force_etc1_format) {
+	Image::Format img_format = p_img->get_format();
+	Image::DetectChannels detected_channels = p_img->get_detected_channels();
+
+	if (img_format >= Image::FORMAT_DXT1) {
+		return; //do not compress, already compressed
+	}
+
+	if (img_format > Image::FORMAT_RGBA8) {
+		// TODO: we should be able to handle FORMAT_RGBA4444 and FORMAT_RGBA5551 eventually
+		return;
+	}
+
+	int imgw = p_img->get_width(), imgh = p_img->get_height();
+	ERR_FAIL_COND(nearest_power_of_2(imgw) != imgw || nearest_power_of_2(imgh) != imgh);
+
+	Image::Format etc_format = force_etc1_format ? Image::FORMAT_ETC : _get_etc2_mode(detected_channels);
+
+	Ref<Image> img = p_img->duplicate();
+
+	if (img->get_format() != Image::FORMAT_RGBA8)
+		img->convert(Image::FORMAT_RGBA8); //still uses RGBA to convert
+
+	PoolVector<uint8_t>::Read r = img->get_data().read();
+
+	int target_size = Image::get_image_data_size(imgw, imgh, etc_format, p_img->has_mipmaps() ? -1 : 0);
+	int mmc = p_img->has_mipmaps() ? Image::get_image_required_mipmaps(imgw, imgh, etc_format) : 0;
+
+	PoolVector<uint8_t> dst_data;
+	dst_data.resize(target_size);
+
+	PoolVector<uint8_t>::Write w = dst_data.write();
+
+	// prepare parameters to be passed to etc2comp
+	int num_cpus = OS::get_singleton()->get_processor_count();
+	int encoding_time = 0;
+	float effort = CLAMP(p_lossy_quality * 100, 0, 100);
+	Etc::ErrorMetric error_metric = Etc::ErrorMetric::BT709; // NOTE: we can experiment with other error metrics
+	Etc::Image::Format etc2comp_etc_format = _image_format_to_etc2comp_format(etc_format);
+
+	int wofs = 0;
+	for (int i = 0; i < mmc + 1; i++) {
+		// convert source image to internal etc2comp format (which is equivalent to Image::FORMAT_RGBAF)
+		// NOTE: We can alternatively add a case to Image::convert to handle Image::FORMAT_RGBAF conversion.
+		int mipmap_ofs = 0, mipmap_size = 0, mipmap_w = 0, mipmap_h = 0;
+		img->get_mipmap_offset_size_and_dimensions(i, mipmap_ofs, mipmap_size, mipmap_w, mipmap_h);
+		const uint8_t *src = &r[mipmap_ofs];
+
+		Etc::ColorFloatRGBA *src_rgba_f = new Etc::ColorFloatRGBA[mipmap_w * mipmap_h];
+		for (int i = 0; i < mipmap_w * mipmap_h; i++) {
+			int si = i * 4; // RGBA8
+			src_rgba_f[i] = Etc::ColorFloatRGBA::ConvertFromRGBA8(src[si], src[si + 1], src[si + 2], src[si + 3]);
+		}
+
+		unsigned char *etc_data = NULL;
+		unsigned int etc_data_len = 0;
+		unsigned int extended_width = 0, extended_height = 0;
+		Etc::Encode((float *)src_rgba_f, mipmap_w, mipmap_h, etc2comp_etc_format, error_metric, effort, num_cpus, num_cpus, &etc_data, &etc_data_len, &extended_width, &extended_height, &encoding_time);
+
+		memcpy(&w[wofs], etc_data, etc_data_len);
+		wofs += etc_data_len;
+
+		delete[] etc_data;
+		delete[] src_rgba_f;
+	}
+
+	p_img->create(imgw, imgh, mmc > 1 ? true : false, etc_format, dst_data);
+}
+
+static void _compress_etc1(Image *p_img, float p_lossy_quality) {
+	_compress_etc(p_img, p_lossy_quality, true);
+}
+
+static void _compress_etc2(Image *p_img, float p_lossy_quality) {
+	_compress_etc(p_img, p_lossy_quality, false);
+}
+
+void _register_etc_compress_func() {
+
+	Image::_image_compress_etc1_func = _compress_etc1;
+	//Image::_image_decompress_etc1 = _decompress_etc1;
+
+	Image::_image_compress_etc2_func = _compress_etc2;
+	//Image::_image_decompress_etc2 = _decompress_etc2;
+}

modules/etc/image_etc.h

@@ -30,6 +30,6 @@
 #ifndef IMAGE_ETC1_H
 #define IMAGE_ETC1_H
 
-void _register_etc1_compress_func();
+void _register_etc_compress_func();
 
 #endif // IMAGE_ETC_H

modules/etc/register_types.cpp

@@ -34,15 +34,15 @@
 
 static ResourceFormatPKM *resource_loader_pkm = NULL;
 
-void register_etc1_types() {
+void register_etc_types() {
 
 	resource_loader_pkm = memnew(ResourceFormatPKM);
 	ResourceLoader::add_resource_format_loader(resource_loader_pkm);
 
-	_register_etc1_compress_func();
+	_register_etc_compress_func();
 }
 
-void unregister_etc1_types() {
+void unregister_etc_types() {
 
 	memdelete(resource_loader_pkm);
 }

modules/etc/register_types.h

@@ -27,5 +27,5 @@
 /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
 /*************************************************************************/
-void register_etc1_types();
-void unregister_etc1_types();
+void register_etc_types();
+void unregister_etc_types();

modules/etc1/SCsub

@@ -1,20 +0,0 @@
-#!/usr/bin/env python
-
-Import('env')
-Import('env_modules')
-
-env_etc1 = env_modules.Clone()
-
-# Thirdparty source files
-# Not unbundled so far since not widespread as shared library
-thirdparty_dir = "#thirdparty/rg-etc1/"
-thirdparty_sources = [
-    "rg_etc1.cpp",
-]
-thirdparty_sources = [thirdparty_dir + file for file in thirdparty_sources]
-
-env_etc1.add_source_files(env.modules_sources, thirdparty_sources)
-env_etc1.Append(CPPPATH=[thirdparty_dir])
-
-# Godot source files
-env_etc1.add_source_files(env.modules_sources, "*.cpp")

modules/etc1/image_etc.cpp

@@ -1,183 +0,0 @@
-/*************************************************************************/
-/*  image_etc.cpp                                                        */
-/*************************************************************************/
-/*                       This file is part of:                           */
-/*                           GODOT ENGINE                                */
-/*                    http://www.godotengine.org                         */
-/*************************************************************************/
-/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
-/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md)    */
-/*                                                                       */
-/* Permission is hereby granted, free of charge, to any person obtaining */
-/* a copy of this software and associated documentation files (the       */
-/* "Software"), to deal in the Software without restriction, including   */
-/* without limitation the rights to use, copy, modify, merge, publish,   */
-/* distribute, sublicense, and/or sell copies of the Software, and to    */
-/* permit persons to whom the Software is furnished to do so, subject to */
-/* the following conditions:                                             */
-/*                                                                       */
-/* The above copyright notice and this permission notice shall be        */
-/* included in all copies or substantial portions of the Software.       */
-/*                                                                       */
-/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
-/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
-/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
-/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
-/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
-/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
-/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
-/*************************************************************************/
-#include "image_etc.h"
-#include "image.h"
-#include "os/copymem.h"
-#include "print_string.h"
-#include "rg_etc1.h"
-static void _decompress_etc(Image *p_img) {
-
-	ERR_FAIL_COND(p_img->get_format() != Image::FORMAT_ETC);
-
-	int imgw = p_img->get_width();
-	int imgh = p_img->get_height();
-	PoolVector<uint8_t> src = p_img->get_data();
-	PoolVector<uint8_t> dst;
-
-	PoolVector<uint8_t>::Read r = src.read();
-
-	int mmc = p_img->get_mipmap_count();
-
-	for (int i = 0; i <= mmc; i++) {
-
-		dst.resize(dst.size() + imgw * imgh * 3);
-		const uint8_t *srcbr = &r[p_img->get_mipmap_offset(i)];
-		PoolVector<uint8_t>::Write w = dst.write();
-
-		uint8_t *wptr = &w[dst.size() - imgw * imgh * 3];
-
-		int bw = MAX(imgw / 4, 1);
-		int bh = MAX(imgh / 4, 1);
-
-		for (int y = 0; y < bh; y++) {
-
-			for (int x = 0; x < bw; x++) {
-
-				uint8_t block[4 * 4 * 4];
-
-				rg_etc1::unpack_etc1_block(srcbr, (unsigned int *)block);
-				srcbr += 8;
-
-				int maxx = MIN(imgw, 4);
-				int maxy = MIN(imgh, 4);
-
-				for (int yy = 0; yy < maxy; yy++) {
-
-					for (int xx = 0; xx < maxx; xx++) {
-
-						uint32_t src_ofs = (yy * 4 + xx) * 4;
-						uint32_t dst_ofs = ((y * 4 + yy) * imgw + x * 4 + xx) * 3;
-						wptr[dst_ofs + 0] = block[src_ofs + 0];
-						wptr[dst_ofs + 1] = block[src_ofs + 1];
-						wptr[dst_ofs + 2] = block[src_ofs + 2];
-					}
-				}
-			}
-		}
-
-		imgw = MAX(1, imgw / 2);
-		imgh = MAX(1, imgh / 2);
-	}
-
-	r = PoolVector<uint8_t>::Read();
-	//print_line("Re Creating ETC into regular image: w "+itos(p_img->get_width())+" h "+itos(p_img->get_height())+" mm "+itos(p_img->get_mipmaps()));
-	bool needs_mipmaps = p_img->has_mipmaps();
-	p_img->create(p_img->get_width(), p_img->get_height(), p_img->has_mipmaps(), Image::FORMAT_RGB8, dst);
-	if (needs_mipmaps)
-		p_img->generate_mipmaps();
-}
-
-static void _compress_etc(Image *p_img) {
-
-	Ref<Image> img = p_img->duplicate();
-
-	int imgw = img->get_width(), imgh = img->get_height();
-
-	ERR_FAIL_COND(nearest_power_of_2(imgw) != imgw || nearest_power_of_2(imgh) != imgh);
-
-	if (img->get_format() != Image::FORMAT_RGB8)
-		img->convert(Image::FORMAT_RGB8);
-
-	PoolVector<uint8_t> res_data;
-	PoolVector<uint8_t> dst_data;
-	PoolVector<uint8_t>::Read r = img->get_data().read();
-
-	int target_size = Image::get_image_data_size(p_img->get_width(), p_img->get_height(), Image::FORMAT_ETC, p_img->has_mipmaps() ? -1 : 0);
-	int mmc = p_img->has_mipmaps() ? Image::get_image_required_mipmaps(p_img->get_width(), p_img->get_height(), Image::FORMAT_ETC) : 0;
-
-	dst_data.resize(target_size);
-	int mc = 0;
-	int ofs = 0;
-	PoolVector<uint8_t>::Write w = dst_data.write();
-
-	rg_etc1::etc1_pack_params pp;
-	pp.m_quality = rg_etc1::cLowQuality;
-	for (int i = 0; i <= mmc; i++) {
-
-		int bw = MAX(imgw / 4, 1);
-		int bh = MAX(imgh / 4, 1);
-		const uint8_t *src = &r[img->get_mipmap_offset(i)];
-		int mmsize = MAX(bw, 1) * MAX(bh, 1) * 8;
-
-		uint8_t *dst = &w[ofs];
-		ofs += mmsize;
-
-		//print_line("bh: "+itos(bh)+" bw: "+itos(bw));
-
-		for (int y = 0; y < bh; y++) {
-
-			for (int x = 0; x < bw; x++) {
-
-				//print_line("x: "+itos(x)+" y: "+itos(y));
-
-				uint8_t block[4 * 4 * 4];
-				zeromem(block, 4 * 4 * 4);
-				uint8_t cblock[8];
-
-				int maxy = MIN(imgh, 4);
-				int maxx = MIN(imgw, 4);
-
-				for (int yy = 0; yy < maxy; yy++) {
-
-					for (int xx = 0; xx < maxx; xx++) {
-
-						uint32_t dst_ofs = (yy * 4 + xx) * 4;
-						uint32_t src_ofs = ((y * 4 + yy) * imgw + x * 4 + xx) * 3;
-						block[dst_ofs + 0] = src[src_ofs + 0];
-						block[dst_ofs + 1] = src[src_ofs + 1];
-						block[dst_ofs + 2] = src[src_ofs + 2];
-						block[dst_ofs + 3] = 255;
-					}
-				}
-
-				rg_etc1::pack_etc1_block(cblock, (const unsigned int *)block, pp);
-				for (int j = 0; j < 8; j++) {
-
-					dst[j] = cblock[j];
-				}
-
-				dst += 8;
-			}
-		}
-
-		imgw = MAX(1, imgw / 2);
-		imgh = MAX(1, imgh / 2);
-		mc++;
-	}
-
-	p_img->create(p_img->get_width(), p_img->get_height(), (mc - 1) ? true : false, Image::FORMAT_ETC, dst_data);
-}
-
-void _register_etc1_compress_func() {
-
-	rg_etc1::pack_etc1_block_init();
-	Image::_image_compress_etc_func = _compress_etc;
-	Image::_image_decompress_etc = _decompress_etc;
-}

thirdparty/README.md

@@ -37,6 +37,18 @@ Check the diff of enet.h, protocol.c, and host.c with the 1.3.13
 tarball before the next update.
 
 
+## etc2comp
+
+- Upstream: https://github.com/google/etc2comp
+- Version: 9cd0f9c (git)
+- License: Apache
+
+Files extracted from upstream source:
+
+- all .cpp and .h files in EtcLib/
+- README.md, LICENSE, AUTHORS
+
+
 ## fonts
 
 - Upstream: ?
@@ -296,17 +308,6 @@ Files extracted from upstream source:
 - LICENSE.TXT
 
 
-## rg-etc1
-
-- Upstream: https://github.com/richgel999/rg-etc1
-- Version: 1.04
-- License: zlib
-
-Files extracted from upstream source:
-
-- `rg_etc1.{cpp,h}`
-
-
 ## rtaudio
 
 - Upstream: http://www.music.mcgill.ca/~gary/rtaudio/

thirdparty/etc2comp/AUTHORS

@@ -0,0 +1,7 @@
+# This is the list of Etc2Comp authors for copyright purposes.
+#
+# This does not necessarily list everyone who has contributed code, since in
+# some cases, their employer may be the copyright holder.  To see the full list
+# of contributors, see the revision history in source control.
+Google Inc.
+Blue Shift Inc.

thirdparty/etc2comp/Etc.cpp

@@ -0,0 +1,128 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "EtcConfig.h"
+#include "Etc.h"
+#include "EtcFilter.h"
+
+#include <string.h>
+
+namespace Etc
+{
+	// ----------------------------------------------------------------------------------------------------
+	// C-style inteface to the encoder
+	//
+	void Encode(float *a_pafSourceRGBA,
+				unsigned int a_uiSourceWidth, 
+				unsigned int a_uiSourceHeight,
+				Image::Format a_format,
+				ErrorMetric a_eErrMetric,
+				float a_fEffort,
+				unsigned int a_uiJobs,
+				unsigned int a_uiMaxJobs,
+				unsigned char **a_ppaucEncodingBits,
+				unsigned int *a_puiEncodingBitsBytes,
+				unsigned int *a_puiExtendedWidth,
+				unsigned int *a_puiExtendedHeight, 
+				int *a_piEncodingTime_ms, bool a_bVerboseOutput)
+	{
+
+		Image image(a_pafSourceRGBA, a_uiSourceWidth,
+					a_uiSourceHeight,
+					a_eErrMetric);
+		image.m_bVerboseOutput = a_bVerboseOutput;
+		image.Encode(a_format, a_eErrMetric, a_fEffort, a_uiJobs, a_uiMaxJobs);
+
+		*a_ppaucEncodingBits = image.GetEncodingBits();
+		*a_puiEncodingBitsBytes = image.GetEncodingBitsBytes();
+		*a_puiExtendedWidth = image.GetExtendedWidth();
+		*a_puiExtendedHeight = image.GetExtendedHeight();
+		*a_piEncodingTime_ms = image.GetEncodingTimeMs();
+	}
+
+	void EncodeMipmaps(float *a_pafSourceRGBA,
+		unsigned int a_uiSourceWidth,
+		unsigned int a_uiSourceHeight,
+		Image::Format a_format,
+		ErrorMetric a_eErrMetric,
+		float a_fEffort,
+		unsigned int a_uiJobs,
+		unsigned int a_uiMaxJobs,
+		unsigned int a_uiMaxMipmaps,
+		unsigned int a_uiMipFilterFlags,
+		RawImage* a_pMipmapImages,
+		int *a_piEncodingTime_ms, 
+		bool a_bVerboseOutput)
+	{
+		auto mipWidth = a_uiSourceWidth;
+		auto mipHeight = a_uiSourceHeight;
+		int totalEncodingTime = 0;
+		for(unsigned int mip = 0; mip < a_uiMaxMipmaps && mipWidth >= 1 && mipHeight >= 1; mip++)
+		{
+			float* pImageData = nullptr;
+			float* pMipImage = nullptr;
+
+			if(mip == 0)
+			{
+				pImageData = a_pafSourceRGBA;
+			}
+			else
+			{
+				pMipImage = new float[mipWidth*mipHeight*4];
+				if(FilterTwoPass(a_pafSourceRGBA, a_uiSourceWidth, a_uiSourceHeight, pMipImage, mipWidth, mipHeight, a_uiMipFilterFlags, Etc::FilterLanczos3) )
+				{
+					pImageData = pMipImage;
+				}
+			}
+
+			if ( pImageData )
+			{
+			
+				Image image(pImageData, mipWidth, mipHeight,	a_eErrMetric);
+
+			image.m_bVerboseOutput = a_bVerboseOutput;
+			image.Encode(a_format, a_eErrMetric, a_fEffort, a_uiJobs, a_uiMaxJobs);
+
+			a_pMipmapImages[mip].paucEncodingBits = std::shared_ptr<unsigned char>(image.GetEncodingBits(), [](unsigned char *p) { delete[] p; });
+			a_pMipmapImages[mip].uiEncodingBitsBytes = image.GetEncodingBitsBytes();
+			a_pMipmapImages[mip].uiExtendedWidth = image.GetExtendedWidth();
+			a_pMipmapImages[mip].uiExtendedHeight = image.GetExtendedHeight();
+
+			totalEncodingTime += image.GetEncodingTimeMs();
+			}
+
+			if(pMipImage)
+			{
+				delete[] pMipImage;
+			}
+
+			if (!pImageData)
+			{
+				break;
+			}
+
+			mipWidth >>= 1;
+			mipHeight >>= 1;
+		}
+
+		*a_piEncodingTime_ms = totalEncodingTime;
+	}
+
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+}

thirdparty/etc2comp/Etc.h

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcConfig.h"
+#include "EtcImage.h"
+#include "EtcColor.h"
+#include "EtcErrorMetric.h"
+#include <memory>
+
+#define ETCCOMP_MIN_EFFORT_LEVEL (0.0f)
+#define ETCCOMP_DEFAULT_EFFORT_LEVEL (40.0f)
+#define ETCCOMP_MAX_EFFORT_LEVEL (100.0f)
+
+namespace Etc
+{
+	class Block4x4EncodingBits;
+
+	struct RawImage
+	{
+		int uiExtendedWidth;
+		int uiExtendedHeight;
+		unsigned int uiEncodingBitsBytes;
+		std::shared_ptr<unsigned char> paucEncodingBits;
+	};
+
+
+
+	// C-style inteface to the encoder
+	void Encode(float *a_pafSourceRGBA,
+				unsigned int a_uiSourceWidth,
+				unsigned int a_uiSourceHeight,
+				Image::Format a_format,
+				ErrorMetric a_eErrMetric,
+				float a_fEffort,
+				unsigned int a_uiJobs,
+				unsigned int a_uimaxJobs,
+				unsigned char **a_ppaucEncodingBits,
+				unsigned int *a_puiEncodingBitsBytes,
+				unsigned int *a_puiExtendedWidth,
+				unsigned int *a_puiExtendedHeight,
+				int *a_piEncodingTime_ms, bool a_bVerboseOutput = false);
+
+	void EncodeMipmaps(float *a_pafSourceRGBA,
+		unsigned int a_uiSourceWidth,
+		unsigned int a_uiSourceHeight,
+		Image::Format a_format,
+		ErrorMetric a_eErrMetric,
+		float a_fEffort,
+		unsigned int a_uiJobs,
+		unsigned int a_uiMaxJobs,
+		unsigned int a_uiMaxMipmaps,
+		unsigned int a_uiMipFilterFlags,
+		RawImage* a_pMipmaps,
+		int *a_piEncodingTime_ms, bool a_bVerboseOutput = false);
+
+}

thirdparty/etc2comp/EtcBlock4x4.cpp

@@ -0,0 +1,425 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* 
+EtcBlock4x4.cpp
+
+Implements the state associated with each 4x4 block of pixels in an image
+
+Source images that are not a multiple of 4x4 are extended to fill the Block4x4 using pixels with an 
+alpha of NAN
+
+*/
+
+#include "EtcConfig.h"
+#include "EtcBlock4x4.h"
+
+#include "EtcBlock4x4EncodingBits.h"
+#include "EtcColor.h"
+#include "EtcImage.h"
+#include "EtcColorFloatRGBA.h"
+#include "EtcBlock4x4Encoding_RGB8.h"
+#include "EtcBlock4x4Encoding_RGBA8.h"
+#include "EtcBlock4x4Encoding_RGB8A1.h"
+#include "EtcBlock4x4Encoding_R11.h"
+#include "EtcBlock4x4Encoding_RG11.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+namespace Etc
+{
+	// ETC pixels are scanned vertically.  
+	// this mapping is for when someone wants to scan the ETC pixels horizontally
+	const unsigned int Block4x4::s_auiPixelOrderHScan[PIXELS] = { 0, 4, 8, 12, 1, 5, 9, 13, 2, 6, 10, 14, 3, 7, 11, 15 };
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	Block4x4::Block4x4(void)
+	{
+		m_pimageSource = nullptr;
+		m_uiSourceH = 0;
+		m_uiSourceV = 0;
+
+		m_sourcealphamix = SourceAlphaMix::UNKNOWN;
+		m_boolBorderPixels = false;
+		m_boolPunchThroughPixels = false;
+
+		m_pencoding = nullptr;
+
+		m_errormetric = ErrorMetric::NUMERIC;
+
+	}
+	Block4x4::~Block4x4()
+	{
+		m_pimageSource = nullptr;
+		if (m_pencoding)
+		{
+			delete m_pencoding;
+			m_pencoding = nullptr;
+		}
+	}
+	// ----------------------------------------------------------------------------------------------------
+	// initialization prior to encoding from a source image
+	// [a_uiSourceH,a_uiSourceV] is the location of the block in a_pimageSource
+	// a_paucEncodingBits is the place to store the final encoding
+	// a_errormetric is used for finding the best encoding
+	//
+	void Block4x4::InitFromSource(Image *a_pimageSource, 
+									unsigned int a_uiSourceH, unsigned int a_uiSourceV,
+									unsigned char *a_paucEncodingBits,
+									ErrorMetric a_errormetric)
+	{
+
+		Block4x4();
+
+		m_pimageSource = a_pimageSource;
+		m_uiSourceH = a_uiSourceH;
+		m_uiSourceV = a_uiSourceV;
+		m_errormetric = a_errormetric;
+
+		SetSourcePixels();
+
+		// set block encoder function
+		switch (m_pimageSource->GetFormat())
+		{
+		case Image::Format::ETC1:
+			m_pencoding = new Block4x4Encoding_ETC1;
+			break;
+
+		case Image::Format::RGB8:
+		case Image::Format::SRGB8:
+			m_pencoding = new Block4x4Encoding_RGB8;
+			break;
+
+		case Image::Format::RGBA8:
+		case Image::Format::SRGBA8:
+			if (a_errormetric == RGBX)
+			{
+				m_pencoding = new Block4x4Encoding_RGBA8;
+			}
+			else
+			{
+				switch (m_sourcealphamix)
+				{
+				case SourceAlphaMix::OPAQUE:
+					m_pencoding = new Block4x4Encoding_RGBA8_Opaque;
+					break;
+
+				case SourceAlphaMix::TRANSPARENT:
+					m_pencoding = new Block4x4Encoding_RGBA8_Transparent;
+					break;
+
+				case SourceAlphaMix::TRANSLUCENT:
+					m_pencoding = new Block4x4Encoding_RGBA8;
+					break;
+
+				default:
+					assert(0);
+					break;
+				}
+				break;
+			}
+			break;
+
+		case Image::Format::RGB8A1:
+		case Image::Format::SRGB8A1:
+			switch (m_sourcealphamix)
+			{
+			case SourceAlphaMix::OPAQUE:
+				m_pencoding = new Block4x4Encoding_RGB8A1_Opaque;
+				break;
+
+			case SourceAlphaMix::TRANSPARENT:
+				m_pencoding = new Block4x4Encoding_RGB8A1_Transparent;
+				break;
+
+			case SourceAlphaMix::TRANSLUCENT:
+				if (m_boolPunchThroughPixels)
+				{
+					m_pencoding = new Block4x4Encoding_RGB8A1;
+				}
+				else
+				{
+					m_pencoding = new Block4x4Encoding_RGB8A1_Opaque;
+				}
+				break;
+
+			default:
+				assert(0);
+				break;
+			}
+			break;
+
+		case Image::Format::R11:
+		case Image::Format::SIGNED_R11:
+			m_pencoding = new Block4x4Encoding_R11;
+			break;
+		case Image::Format::RG11:
+		case Image::Format::SIGNED_RG11:
+			m_pencoding = new Block4x4Encoding_RG11;
+			break;
+		default:
+			assert(0);
+			break;
+		}
+
+		m_pencoding->InitFromSource(this, m_afrgbaSource,
+									a_paucEncodingBits, a_errormetric);
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// initialization of encoding state from a prior encoding using encoding bits
+	// [a_uiSourceH,a_uiSourceV] is the location of the block in a_pimageSource
+	// a_paucEncodingBits is the place to read the prior encoding
+	// a_imageformat is used to determine how to interpret a_paucEncodingBits
+	// a_errormetric was used for the prior encoding
+	//
+	void Block4x4::InitFromEtcEncodingBits(Image::Format a_imageformat,
+											unsigned int a_uiSourceH, unsigned int a_uiSourceV,
+											unsigned char *a_paucEncodingBits,
+											Image *a_pimageSource,
+											ErrorMetric a_errormetric)
+	{
+		Block4x4();
+
+		m_pimageSource = a_pimageSource;
+		m_uiSourceH = a_uiSourceH;
+		m_uiSourceV = a_uiSourceV;
+		m_errormetric = a_errormetric;
+
+		SetSourcePixels();
+
+		// set block encoder function
+		switch (a_imageformat)
+		{
+		case Image::Format::ETC1:
+			m_pencoding = new Block4x4Encoding_ETC1;
+			break;
+
+		case Image::Format::RGB8:
+		case Image::Format::SRGB8:
+			m_pencoding = new Block4x4Encoding_RGB8;
+			break;
+
+		case Image::Format::RGBA8:
+		case Image::Format::SRGBA8:
+			m_pencoding = new Block4x4Encoding_RGBA8;
+			break;
+
+		case Image::Format::RGB8A1:
+		case Image::Format::SRGB8A1:
+			m_pencoding = new Block4x4Encoding_RGB8A1;
+			break;
+
+		case Image::Format::R11:
+		case Image::Format::SIGNED_R11:
+			m_pencoding = new Block4x4Encoding_R11;
+			break;
+		case Image::Format::RG11:
+		case Image::Format::SIGNED_RG11:
+			m_pencoding = new Block4x4Encoding_RG11;
+			break;
+		default:
+			assert(0);
+			break;
+		}
+
+		m_pencoding->InitFromEncodingBits(this, a_paucEncodingBits, m_afrgbaSource,
+										m_pimageSource->GetErrorMetric());
+
+	}
+	
+	// ----------------------------------------------------------------------------------------------------
+	// set source pixels from m_pimageSource
+	// set m_alphamix
+	//
+	void Block4x4::SetSourcePixels(void)
+	{
+
+		Image::Format imageformat = m_pimageSource->GetFormat();
+
+		// alpha census
+		unsigned int uiTransparentSourcePixels = 0;
+		unsigned int uiOpaqueSourcePixels = 0;
+
+		// copy source to consecutive memory locations
+		// convert from image horizontal scan to block vertical scan
+		unsigned int uiPixel = 0;
+		for (unsigned int uiBlockPixelH = 0; uiBlockPixelH < Block4x4::COLUMNS; uiBlockPixelH++)
+		{
+			unsigned int uiSourcePixelH = m_uiSourceH + uiBlockPixelH;
+
+			for (unsigned int uiBlockPixelV = 0; uiBlockPixelV < Block4x4::ROWS; uiBlockPixelV++)
+			{
+				unsigned int uiSourcePixelV = m_uiSourceV + uiBlockPixelV;
+
+				ColorFloatRGBA *pfrgbaSource = m_pimageSource->GetSourcePixel(uiSourcePixelH, uiSourcePixelV);
+
+				// if pixel extends beyond source image because of block padding
+				if (pfrgbaSource == nullptr)
+				{
+					m_afrgbaSource[uiPixel] = ColorFloatRGBA(0.0f, 0.0f, 0.0f, NAN);	// denotes border pixel
+					m_boolBorderPixels = true;
+					uiTransparentSourcePixels++;
+				}
+				else
+				{
+					//get teh current pixel data, and store some of the attributes
+					//before capping values to fit the encoder type
+					
+					m_afrgbaSource[uiPixel] = (*pfrgbaSource).ClampRGBA();
+
+					if (m_afrgbaSource[uiPixel].fA == 1.0f || m_errormetric == RGBX)
+					{
+						m_pimageSource->m_iNumOpaquePixels++;
+					}
+					else if (m_afrgbaSource[uiPixel].fA == 0.0f)
+					{
+						m_pimageSource->m_iNumTransparentPixels++;
+					}
+					else if(m_afrgbaSource[uiPixel].fA > 0.0f && m_afrgbaSource[uiPixel].fA < 1.0f)
+					{
+						m_pimageSource->m_iNumTranslucentPixels++;
+					}
+					else
+					{
+						m_pimageSource->m_numOutOfRangeValues.fA++;
+					}
+
+					if (m_afrgbaSource[uiPixel].fR != 0.0f)
+					{
+						m_pimageSource->m_numColorValues.fR++;
+						//make sure we are getting a float between 0-1
+						if (m_afrgbaSource[uiPixel].fR - 1.0f > 0.0f)
+						{
+							m_pimageSource->m_numOutOfRangeValues.fR++;
+						}
+					}
+
+					if (m_afrgbaSource[uiPixel].fG != 0.0f)
+					{
+						m_pimageSource->m_numColorValues.fG++;
+						if (m_afrgbaSource[uiPixel].fG - 1.0f > 0.0f)
+						{
+							m_pimageSource->m_numOutOfRangeValues.fG++;
+						}
+					}
+					if (m_afrgbaSource[uiPixel].fB != 0.0f)
+					{
+						m_pimageSource->m_numColorValues.fB++;
+						if (m_afrgbaSource[uiPixel].fB - 1.0f > 0.0f)
+						{
+							m_pimageSource->m_numOutOfRangeValues.fB++;
+						}
+					}
+					// for formats with no alpha, set source alpha to 1
+					if (imageformat == Image::Format::ETC1 ||
+						imageformat == Image::Format::RGB8 ||
+						imageformat == Image::Format::SRGB8)
+					{
+						m_afrgbaSource[uiPixel].fA = 1.0f;
+					}
+
+					if (imageformat == Image::Format::R11 ||
+						imageformat == Image::Format::SIGNED_R11)
+					{
+						m_afrgbaSource[uiPixel].fA = 1.0f;
+						m_afrgbaSource[uiPixel].fG = 0.0f;
+						m_afrgbaSource[uiPixel].fB = 0.0f;
+					}
+
+					if (imageformat == Image::Format::RG11 ||
+						imageformat == Image::Format::SIGNED_RG11)
+					{
+						m_afrgbaSource[uiPixel].fA = 1.0f;
+						m_afrgbaSource[uiPixel].fB = 0.0f;
+					}
+
+				
+					// for RGB8A1, set source alpha to 0.0 or 1.0
+					// set punch through flag
+					if (imageformat == Image::Format::RGB8A1 ||
+						imageformat == Image::Format::SRGB8A1)
+					{
+						if (m_afrgbaSource[uiPixel].fA >= 0.5f)
+						{
+							m_afrgbaSource[uiPixel].fA = 1.0f;
+						}
+						else
+						{
+							m_afrgbaSource[uiPixel].fA = 0.0f;
+							m_boolPunchThroughPixels = true;
+						}
+					}
+
+					if (m_afrgbaSource[uiPixel].fA == 1.0f || m_errormetric == RGBX)
+					{
+						uiOpaqueSourcePixels++;
+					}
+					else if (m_afrgbaSource[uiPixel].fA == 0.0f)
+					{
+						uiTransparentSourcePixels++;
+					}
+
+				}
+
+				uiPixel += 1;
+			}
+		}
+
+		if (uiOpaqueSourcePixels == PIXELS)
+		{
+			m_sourcealphamix = SourceAlphaMix::OPAQUE;
+		}
+		else if (uiTransparentSourcePixels == PIXELS)
+		{
+			m_sourcealphamix = SourceAlphaMix::TRANSPARENT;
+		}
+		else
+		{
+			m_sourcealphamix = SourceAlphaMix::TRANSLUCENT;
+		}
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// return a name for the encoding mode
+	//
+	const char * Block4x4::GetEncodingModeName(void)
+	{
+
+		switch (m_pencoding->GetMode())
+		{
+		case Block4x4Encoding::MODE_ETC1:
+			return "ETC1";
+		case Block4x4Encoding::MODE_T:
+			return "T";
+		case Block4x4Encoding::MODE_H:
+			return "H";
+		case Block4x4Encoding::MODE_PLANAR:
+			return "PLANAR";
+		default:
+			return "???";
+		}
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+}

thirdparty/etc2comp/EtcBlock4x4.h

@@ -0,0 +1,172 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcColor.h"
+#include "EtcColorFloatRGBA.h"
+#include "EtcErrorMetric.h"
+#include "EtcImage.h"
+#include "EtcBlock4x4Encoding.h"
+
+namespace Etc
+{
+	class Block4x4EncodingBits;
+
+	class Block4x4
+	{
+	public:
+
+		static const unsigned int ROWS = 4;
+		static const unsigned int COLUMNS = 4;
+		static const unsigned int PIXELS = ROWS * COLUMNS;
+
+		// the alpha mix for a 4x4 block of pixels
+		enum class SourceAlphaMix
+		{
+			UNKNOWN,
+			//
+			OPAQUE,			// all 1.0
+			TRANSPARENT,	// all 0.0 or NAN
+			TRANSLUCENT		// not all opaque or transparent
+		};
+
+		typedef void (Block4x4::*EncoderFunctionPtr)(void);
+
+		Block4x4(void);
+		~Block4x4();
+		void InitFromSource(Image *a_pimageSource,
+							unsigned int a_uiSourceH,
+							unsigned int a_uiSourceV,
+							unsigned char *a_paucEncodingBits,
+							ErrorMetric a_errormetric);
+
+		void InitFromEtcEncodingBits(Image::Format a_imageformat,
+										unsigned int a_uiSourceH,
+										unsigned int a_uiSourceV,
+										unsigned char *a_paucEncodingBits,
+										Image *a_pimageSource,
+										ErrorMetric a_errormetric);
+
+		// return true if final iteration was performed
+		inline void PerformEncodingIteration(float a_fEffort)
+		{
+			m_pencoding->PerformIteration(a_fEffort);
+		}
+
+		inline void SetEncodingBitsFromEncoding(void)
+		{
+			m_pencoding->SetEncodingBits();
+		}
+
+		inline unsigned int GetSourceH(void)
+		{
+			return m_uiSourceH;
+		}
+
+		inline unsigned int GetSourceV(void)
+		{
+			return m_uiSourceV;
+		}
+
+		inline float GetError(void)
+		{
+			return m_pencoding->GetError();
+		}
+
+		static const unsigned int s_auiPixelOrderHScan[PIXELS];
+
+		inline ColorFloatRGBA * GetDecodedColors(void)
+		{
+			return m_pencoding->GetDecodedColors();
+		}
+
+		inline float * GetDecodedAlphas(void)
+		{
+			return m_pencoding->GetDecodedAlphas();
+		}
+
+		inline Block4x4Encoding::Mode GetEncodingMode(void)
+		{
+			return m_pencoding->GetMode();
+		}
+
+		inline bool GetFlip(void)
+		{
+			return m_pencoding->GetFlip();
+		}
+
+		inline bool IsDifferential(void)
+		{
+			return m_pencoding->IsDifferential();
+		}
+
+		inline ColorFloatRGBA * GetSource()
+		{
+			return m_afrgbaSource;
+		}
+
+		inline ErrorMetric GetErrorMetric()
+		{
+			return m_errormetric;
+		}
+
+		const char * GetEncodingModeName(void);
+
+		inline Block4x4Encoding * GetEncoding(void)
+		{
+			return m_pencoding;
+		}
+
+		inline SourceAlphaMix GetSourceAlphaMix(void)
+		{
+			return m_sourcealphamix;
+		}
+
+		inline Image * GetImageSource(void)
+		{
+			return m_pimageSource;
+		}
+
+		inline bool HasBorderPixels(void)
+		{
+			return m_boolBorderPixels;
+		}
+
+		inline bool HasPunchThroughPixels(void)
+		{
+			return m_boolPunchThroughPixels;
+		}
+
+	private:
+
+		void SetSourcePixels(void);
+
+		Image				*m_pimageSource;
+		unsigned int		m_uiSourceH;
+		unsigned int		m_uiSourceV;
+		ErrorMetric			m_errormetric;
+		ColorFloatRGBA		m_afrgbaSource[PIXELS];		// vertical scan
+
+		SourceAlphaMix		m_sourcealphamix;
+		bool				m_boolBorderPixels;			// marked as rgba(NAN, NAN, NAN, NAN)
+		bool				m_boolPunchThroughPixels;	// RGB8A1 or SRGB8A1 with any pixels with alpha < 0.5
+
+		Block4x4Encoding	*m_pencoding;
+
+	};
+
+} // namespace Etc

thirdparty/etc2comp/EtcBlock4x4Encoding.cpp

@@ -0,0 +1,261 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+EtcBlock4x4Encoding.cpp
+
+Block4x4Encoding is the abstract base class for the different encoders.  Each encoder targets a 
+particular file format (e.g. ETC1, RGB8, RGBA8, R11)
+
+*/
+
+#include "EtcConfig.h"
+#include "EtcBlock4x4Encoding.h"
+
+#include "EtcBlock4x4EncodingBits.h"
+#include "EtcBlock4x4.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+namespace Etc
+{
+	// ----------------------------------------------------------------------------------------------------
+	//
+	const float Block4x4Encoding::LUMA_WEIGHT = 3.0f;
+	const float Block4x4Encoding::CHROMA_BLUE_WEIGHT = 0.5f;
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	Block4x4Encoding::Block4x4Encoding(void)
+	{
+
+		m_pblockParent = nullptr;
+
+		m_pafrgbaSource = nullptr;
+
+		m_boolBorderPixels = false;
+
+		m_fError = -1.0f;
+
+		m_mode = MODE_UNKNOWN;
+
+		m_uiEncodingIterations = 0;
+		m_boolDone = false;
+
+		for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+		{
+			m_afrgbaDecodedColors[uiPixel] = ColorFloatRGBA(-1.0f, -1.0f, -1.0f, -1.0f);
+			m_afDecodedAlphas[uiPixel] = -1.0f;
+		}
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// initialize the generic encoding for a 4x4 block
+	// a_pblockParent points to the block associated with this encoding
+	// a_errormetric is used to choose the best encoding
+	// init the decoded pixels to -1 to mark them as undefined
+	// init the error to -1 to mark it as undefined
+	//
+	void Block4x4Encoding::Init(Block4x4 *a_pblockParent,
+								ColorFloatRGBA *a_pafrgbaSource,
+								ErrorMetric a_errormetric)
+	{
+
+		m_pblockParent = a_pblockParent;
+
+		m_pafrgbaSource = a_pafrgbaSource;
+
+		m_boolBorderPixels = m_pblockParent->HasBorderPixels();
+
+		m_fError = -1.0f;
+
+		m_uiEncodingIterations = 0;
+
+		m_errormetric = a_errormetric;
+
+		for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+		{
+			m_afrgbaDecodedColors[uiPixel] = ColorFloatRGBA(-1.0f, -1.0f, -1.0f, -1.0f);
+			m_afDecodedAlphas[uiPixel] = -1.0f;
+		}
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// calculate the error for the block by summing the pixel errors
+	//
+	void Block4x4Encoding::CalcBlockError(void)
+	{
+		m_fError = 0.0f;
+
+		for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+		{
+			m_fError += CalcPixelError(m_afrgbaDecodedColors[uiPixel], m_afDecodedAlphas[uiPixel],
+										m_pafrgbaSource[uiPixel]);
+		}
+		
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// calculate the error between the source pixel and the decoded pixel
+	// the error amount is base on the error metric
+	//
+	float Block4x4Encoding::CalcPixelError(ColorFloatRGBA a_frgbaDecodedColor, float a_fDecodedAlpha,
+											ColorFloatRGBA a_frgbaSourcePixel)
+	{
+
+		// if a border pixel
+		if (isnan(a_frgbaSourcePixel.fA))
+		{
+			return 0.0f;
+		}
+
+		if (m_errormetric == ErrorMetric::RGBA)
+		{
+			assert(a_fDecodedAlpha >= 0.0f);
+
+			float fDRed = (a_fDecodedAlpha * a_frgbaDecodedColor.fR) -
+							(a_frgbaSourcePixel.fA * a_frgbaSourcePixel.fR);
+			float fDGreen = (a_fDecodedAlpha * a_frgbaDecodedColor.fG) -
+							(a_frgbaSourcePixel.fA * a_frgbaSourcePixel.fG);
+			float fDBlue = (a_fDecodedAlpha * a_frgbaDecodedColor.fB) -
+							(a_frgbaSourcePixel.fA * a_frgbaSourcePixel.fB);
+
+			float fDAlpha = a_fDecodedAlpha - a_frgbaSourcePixel.fA;
+
+			return fDRed*fDRed + fDGreen*fDGreen + fDBlue*fDBlue + fDAlpha*fDAlpha;
+		}
+		else if (m_errormetric == ErrorMetric::RGBX)
+		{
+			assert(a_fDecodedAlpha >= 0.0f);
+
+			float fDRed = a_frgbaDecodedColor.fR - a_frgbaSourcePixel.fR;
+			float fDGreen = a_frgbaDecodedColor.fG - a_frgbaSourcePixel.fG;
+			float fDBlue = a_frgbaDecodedColor.fB - a_frgbaSourcePixel.fB;
+			float fDAlpha = a_fDecodedAlpha - a_frgbaSourcePixel.fA;
+
+			return fDRed*fDRed + fDGreen*fDGreen + fDBlue*fDBlue + fDAlpha*fDAlpha;
+		}
+		else if (m_errormetric == ErrorMetric::REC709)
+		{
+			assert(a_fDecodedAlpha >= 0.0f);
+
+			float fLuma1 = a_frgbaSourcePixel.fR*0.2126f + a_frgbaSourcePixel.fG*0.7152f + a_frgbaSourcePixel.fB*0.0722f;
+			float fChromaR1 = 0.5f * ((a_frgbaSourcePixel.fR - fLuma1) * (1.0f / (1.0f - 0.2126f)));
+			float fChromaB1 = 0.5f * ((a_frgbaSourcePixel.fB - fLuma1) * (1.0f / (1.0f - 0.0722f)));
+
+			float fLuma2 = a_frgbaDecodedColor.fR*0.2126f +
+							a_frgbaDecodedColor.fG*0.7152f +
+							a_frgbaDecodedColor.fB*0.0722f;
+			float fChromaR2 = 0.5f * ((a_frgbaDecodedColor.fR - fLuma2) * (1.0f / (1.0f - 0.2126f)));
+			float fChromaB2 = 0.5f * ((a_frgbaDecodedColor.fB - fLuma2) * (1.0f / (1.0f - 0.0722f)));
+
+			float fDeltaL = a_frgbaSourcePixel.fA * fLuma1 - a_fDecodedAlpha * fLuma2;
+			float fDeltaCr = a_frgbaSourcePixel.fA * fChromaR1 - a_fDecodedAlpha * fChromaR2;
+			float fDeltaCb = a_frgbaSourcePixel.fA * fChromaB1 - a_fDecodedAlpha * fChromaB2;
+
+			float fDAlpha = a_fDecodedAlpha - a_frgbaSourcePixel.fA;
+
+			// Favor Luma accuracy over Chroma, and Red over Blue 
+			return LUMA_WEIGHT*fDeltaL*fDeltaL +
+					fDeltaCr*fDeltaCr +
+					CHROMA_BLUE_WEIGHT*fDeltaCb*fDeltaCb +
+					fDAlpha*fDAlpha;
+	#if 0
+			float fDRed = a_frgbaDecodedPixel.fR - a_frgbaSourcePixel.fR;
+			float fDGreen = a_frgbaDecodedPixel.fG - a_frgbaSourcePixel.fG;
+			float fDBlue = a_frgbaDecodedPixel.fB - a_frgbaSourcePixel.fB;
+			return 2.0f * 3.0f * fDeltaL * fDeltaL + fDRed*fDRed + fDGreen*fDGreen + fDBlue*fDBlue;
+#endif
+		}
+		else if (m_errormetric == ErrorMetric::NORMALXYZ)
+		{
+			float fDecodedX = 2.0f * a_frgbaDecodedColor.fR - 1.0f;
+			float fDecodedY = 2.0f * a_frgbaDecodedColor.fG - 1.0f;
+			float fDecodedZ = 2.0f * a_frgbaDecodedColor.fB - 1.0f;
+
+			float fDecodedLength = sqrtf(fDecodedX*fDecodedX + fDecodedY*fDecodedY + fDecodedZ*fDecodedZ);
+
+			if (fDecodedLength < 0.5f)
+			{
+				return 1.0f;
+			}
+			else if (fDecodedLength == 0.0f)
+			{
+				fDecodedX = 1.0f;
+				fDecodedY = 0.0f;
+				fDecodedZ = 0.0f;
+			}
+			else
+			{
+				fDecodedX /= fDecodedLength;
+				fDecodedY /= fDecodedLength;
+				fDecodedZ /= fDecodedLength;
+			}
+
+			float fSourceX = 2.0f * a_frgbaSourcePixel.fR - 1.0f;
+			float fSourceY = 2.0f * a_frgbaSourcePixel.fG - 1.0f;
+			float fSourceZ = 2.0f * a_frgbaSourcePixel.fB - 1.0f;
+
+			float fSourceLength = sqrtf(fSourceX*fSourceX + fSourceY*fSourceY + fSourceZ*fSourceZ);
+
+			if (fSourceLength == 0.0f)
+			{
+				fSourceX = 1.0f;
+				fSourceY = 0.0f;
+				fSourceZ = 0.0f;
+			}
+			else
+			{
+				fSourceX /= fSourceLength;
+				fSourceY /= fSourceLength;
+				fSourceZ /= fSourceLength;
+			}
+
+			float fDotProduct = fSourceX*fDecodedX + fSourceY*fDecodedY + fSourceZ*fDecodedZ;
+			float fNormalizedDotProduct = 1.0f - 0.5f * (fDotProduct + 1.0f);
+			float fDotProductError = fNormalizedDotProduct * fNormalizedDotProduct;
+			
+			float fLength2 = fDecodedX*fDecodedX + fDecodedY*fDecodedY + fDecodedZ*fDecodedZ;
+			float fLength2Error = fabsf(1.0f - fLength2);
+
+			float fDeltaW = a_frgbaDecodedColor.fA - a_frgbaSourcePixel.fA;
+			float fErrorW = fDeltaW * fDeltaW;
+
+			return fDotProductError + fLength2Error + fErrorW;
+		}
+		else // ErrorMetric::NUMERIC
+		{
+			assert(a_fDecodedAlpha >= 0.0f);
+
+			float fDX = a_frgbaDecodedColor.fR - a_frgbaSourcePixel.fR;
+			float fDY = a_frgbaDecodedColor.fG - a_frgbaSourcePixel.fG;
+			float fDZ = a_frgbaDecodedColor.fB - a_frgbaSourcePixel.fB;
+			float fDW = a_frgbaDecodedColor.fA - a_frgbaSourcePixel.fA;
+
+			return fDX*fDX + fDY*fDY + fDZ*fDZ + fDW*fDW;
+		}
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+} // namespace Etc
+

thirdparty/etc2comp/EtcBlock4x4Encoding.h

@@ -0,0 +1,148 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcColorFloatRGBA.h"
+
+#include "EtcErrorMetric.h"
+
+#include <assert.h>
+#include <float.h>
+
+namespace Etc
+{
+	class Block4x4;
+
+	// abstract base class for specific encodings
+	class Block4x4Encoding
+	{
+	public:
+
+		static const unsigned int ROWS = 4;
+		static const unsigned int COLUMNS = 4;
+		static const unsigned int PIXELS = ROWS * COLUMNS;
+		static const float LUMA_WEIGHT;
+		static const float CHROMA_BLUE_WEIGHT;
+
+		typedef enum
+		{
+			MODE_UNKNOWN,
+			//
+			MODE_ETC1,
+			MODE_T,
+			MODE_H,
+			MODE_PLANAR,
+			MODE_R11,
+			MODE_RG11,
+			//
+			MODES
+		} Mode;
+
+		Block4x4Encoding(void);
+		//virtual ~Block4x4Encoding(void) =0;
+		virtual ~Block4x4Encoding(void) {}
+		virtual void InitFromSource(Block4x4 *a_pblockParent,
+									ColorFloatRGBA *a_pafrgbaSource,
+
+									unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric) = 0;
+
+		virtual void InitFromEncodingBits(Block4x4 *a_pblockParent,
+											unsigned char *a_paucEncodingBits,
+											ColorFloatRGBA *a_pafrgbaSource,
+
+											ErrorMetric a_errormetric) = 0;
+
+		// perform an iteration of the encoding
+		// the first iteration must generate a complete, valid (if poor) encoding
+		virtual void PerformIteration(float a_fEffort) = 0;
+
+		void CalcBlockError(void);
+
+		inline float GetError(void)
+		{
+			assert(m_fError >= 0.0f);
+
+			return m_fError;
+		}
+
+		inline ColorFloatRGBA * GetDecodedColors(void)
+		{
+			return m_afrgbaDecodedColors;
+		}
+
+		inline float * GetDecodedAlphas(void)
+		{
+			return m_afDecodedAlphas;
+		}
+
+		virtual void SetEncodingBits(void) = 0;
+
+		virtual bool GetFlip(void) = 0;
+
+		virtual bool IsDifferential(void) = 0;
+
+		virtual bool HasSeverelyBentDifferentialColors(void) const = 0;
+
+		inline Mode GetMode(void)
+		{
+			return m_mode;
+		}
+
+		inline bool IsDone(void)
+		{
+			return m_boolDone;
+		}
+
+		inline void SetDoneIfPerfect()
+		{
+			if (GetError() == 0.0f)
+			{
+				m_boolDone = true;
+			}
+		}
+
+		float CalcPixelError(ColorFloatRGBA a_frgbaDecodedColor, float a_fDecodedAlpha,
+								ColorFloatRGBA a_frgbaSourcePixel);
+
+	protected:
+
+		void Init(Block4x4 *a_pblockParent,
+					ColorFloatRGBA *a_pafrgbaSource,
+
+					ErrorMetric a_errormetric);
+
+		Block4x4		*m_pblockParent;
+		ColorFloatRGBA	*m_pafrgbaSource;
+
+		bool			m_boolBorderPixels;				// if block has any border pixels
+
+		ColorFloatRGBA	m_afrgbaDecodedColors[PIXELS];	// decoded RGB components, ignore Alpha
+		float			m_afDecodedAlphas[PIXELS];		// decoded alpha component
+		float			m_fError;						// error for RGBA relative to m_pafrgbaSource
+
+		// intermediate encoding
+		Mode			m_mode;
+
+		unsigned int	m_uiEncodingIterations;
+		bool			m_boolDone;						// all iterations have been done
+		ErrorMetric		m_errormetric;
+
+	private:
+
+	};
+
+} // namespace Etc

thirdparty/etc2comp/EtcBlock4x4EncodingBits.h

@@ -0,0 +1,315 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <assert.h>
+
+namespace Etc
+{
+
+	// ################################################################################
+	// Block4x4EncodingBits
+	// Base class for Block4x4EncodingBits_XXXX
+	// ################################################################################
+
+	class Block4x4EncodingBits
+	{
+	public:
+
+		enum class Format
+		{
+			UNKNOWN,
+			//
+			RGB8,
+			RGBA8,
+			R11,
+			RG11,
+			RGB8A1,
+			//
+			FORMATS
+		};
+
+		static unsigned int GetBytesPerBlock(Format a_format)
+		{
+			switch (a_format)
+			{
+			case Format::RGB8:
+			case Format::R11:
+			case Format::RGB8A1:
+				return 8;
+				break;
+
+			case Format::RGBA8:
+			case Format::RG11:
+				return 16;
+				break;
+
+			default:
+				return 0;
+				break;
+			}
+
+		}
+
+	};
+
+	// ################################################################################
+	// Block4x4EncodingBits_RGB8
+	// Encoding bits for the RGB portion of ETC1, RGB8, RGB8A1 and RGBA8
+	// ################################################################################
+
+	class Block4x4EncodingBits_RGB8
+	{
+	public:
+
+		static const unsigned int BYTES_PER_BLOCK = 8;
+
+		inline Block4x4EncodingBits_RGB8(void)
+		{
+			assert(sizeof(Block4x4EncodingBits_RGB8) == BYTES_PER_BLOCK);
+
+			for (unsigned int uiByte = 0; uiByte < BYTES_PER_BLOCK; uiByte++)
+			{
+				auc[uiByte] = 0;
+			}
+
+		}
+
+		typedef struct
+		{
+			unsigned red2 : 4;
+			unsigned red1 : 4;
+			//
+			unsigned green2 : 4;
+			unsigned green1 : 4;
+			//
+			unsigned blue2 : 4;
+			unsigned blue1 : 4;
+			//
+			unsigned flip : 1;
+			unsigned diff : 1;
+			unsigned cw2 : 3;
+			unsigned cw1 : 3;
+			//
+			unsigned int selectors;
+		} Individual;
+
+		typedef struct
+		{
+			signed dred2 : 3;
+			unsigned red1 : 5;
+			//
+			signed dgreen2 : 3;
+			unsigned green1 : 5;
+			//
+			signed dblue2 : 3;
+			unsigned blue1 : 5;
+			//
+			unsigned flip : 1;
+			unsigned diff : 1;
+			unsigned cw2 : 3;
+			unsigned cw1 : 3;
+			//
+			unsigned int selectors;
+		} Differential;
+
+		typedef struct
+		{
+			unsigned red1b : 2;
+			unsigned detect2 : 1;
+			unsigned red1a : 2;
+			unsigned detect1 : 3;
+			//
+			unsigned blue1 : 4;
+			unsigned green1 : 4;
+			//
+			unsigned green2 : 4;
+			unsigned red2 : 4;
+			//
+			unsigned db : 1;
+			unsigned diff : 1;
+			unsigned da : 2;
+			unsigned blue2 : 4;
+			//
+			unsigned int selectors;
+		} T;
+
+		typedef struct
+		{
+			unsigned green1a : 3;
+			unsigned red1 : 4;
+			unsigned detect1 : 1;
+			//
+			unsigned blue1b : 2;
+			unsigned detect3 : 1;
+			unsigned blue1a : 1;
+			unsigned green1b : 1;
+			unsigned detect2 : 3;
+			//
+			unsigned green2a : 3;
+			unsigned red2 : 4;
+			unsigned blue1c : 1;
+			//
+			unsigned db : 1;
+			unsigned diff : 1;
+			unsigned da : 1;
+			unsigned blue2 : 4;
+			unsigned green2b : 1;
+			//
+			unsigned int selectors;
+		} H;
+
+		typedef struct
+		{
+			unsigned originGreen1 : 1;
+			unsigned originRed : 6;
+			unsigned detect1 : 1;
+			//
+			unsigned originBlue1 : 1;
+			unsigned originGreen2 : 6;
+			unsigned detect2 : 1;
+			//
+			unsigned originBlue3 : 2;
+			unsigned detect4 : 1;
+			unsigned originBlue2 : 2;
+			unsigned detect3 : 3;
+			//
+			unsigned horizRed2 : 1;
+			unsigned diff : 1;
+			unsigned horizRed1 : 5;
+			unsigned originBlue4 : 1;
+			//
+			unsigned horizBlue1: 1;
+			unsigned horizGreen : 7;
+			//
+			unsigned vertRed1 : 3;
+			unsigned horizBlue2 : 5;
+			//
+			unsigned vertGreen1 : 5;
+			unsigned vertRed2 : 3;
+			//
+			unsigned vertBlue : 6;
+			unsigned vertGreen2 : 2;
+		} Planar;
+
+		union
+		{
+			unsigned char auc[BYTES_PER_BLOCK];
+			unsigned long int ul;
+			Individual individual;
+			Differential differential;
+			T t;
+			H h;
+			Planar planar;
+		};
+
+	};
+
+	// ################################################################################
+	// Block4x4EncodingBits_A8
+	// Encoding bits for the A portion of RGBA8
+	// ################################################################################
+
+	class Block4x4EncodingBits_A8
+	{
+	public:
+
+		static const unsigned int BYTES_PER_BLOCK = 8;
+		static const unsigned int SELECTOR_BYTES = 6;
+
+		typedef struct
+		{
+			unsigned base : 8;
+			unsigned table : 4;
+			unsigned multiplier : 4;
+			unsigned selectors0 : 8;
+			unsigned selectors1 : 8;
+			unsigned selectors2 : 8;
+			unsigned selectors3 : 8;
+			unsigned selectors4 : 8;
+			unsigned selectors5 : 8;
+		} Data;
+
+		Data data;
+
+	};
+
+	// ################################################################################
+	// Block4x4EncodingBits_R11
+	// Encoding bits for the R portion of R11
+	// ################################################################################
+
+	class Block4x4EncodingBits_R11
+	{
+	public:
+
+		static const unsigned int BYTES_PER_BLOCK = 8;
+		static const unsigned int SELECTOR_BYTES = 6;
+
+		typedef struct
+		{
+			unsigned base : 8;
+			unsigned table : 4;
+			unsigned multiplier : 4;
+			unsigned selectors0 : 8;
+			unsigned selectors1 : 8;
+			unsigned selectors2 : 8;
+			unsigned selectors3 : 8;
+			unsigned selectors4 : 8;
+			unsigned selectors5 : 8;
+		} Data;
+
+		Data data;
+
+	};
+
+	class Block4x4EncodingBits_RG11
+	{
+	public:
+
+		static const unsigned int BYTES_PER_BLOCK = 16;
+		static const unsigned int SELECTOR_BYTES = 12;
+
+		typedef struct
+		{
+			//Red portion
+			unsigned baseR : 8;
+			unsigned tableIndexR : 4;
+			unsigned multiplierR : 4;
+			unsigned selectorsR0 : 8;
+			unsigned selectorsR1 : 8;
+			unsigned selectorsR2 : 8;
+			unsigned selectorsR3 : 8;
+			unsigned selectorsR4 : 8;
+			unsigned selectorsR5 : 8;
+			//Green portion
+			unsigned baseG : 8;
+			unsigned tableIndexG : 4;
+			unsigned multiplierG : 4;
+			unsigned selectorsG0 : 8;
+			unsigned selectorsG1 : 8;
+			unsigned selectorsG2 : 8;
+			unsigned selectorsG3 : 8;
+			unsigned selectorsG4 : 8;
+			unsigned selectorsG5 : 8;
+		} Data;
+
+		Data data;
+
+	};
+
+}

thirdparty/etc2comp/EtcBlock4x4Encoding_ETC1.h

@@ -0,0 +1,186 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcBlock4x4Encoding.h"
+#include "EtcBlock4x4EncodingBits.h"
+#include "EtcDifferentialTrys.h"
+#include "EtcIndividualTrys.h"
+
+namespace Etc
+{
+
+	// base class for Block4x4Encoding_RGB8
+	class Block4x4Encoding_ETC1 : public Block4x4Encoding
+	{
+	public:
+
+		Block4x4Encoding_ETC1(void);
+		virtual ~Block4x4Encoding_ETC1(void);
+
+		virtual void InitFromSource(Block4x4 *a_pblockParent,
+									ColorFloatRGBA *a_pafrgbaSource,
+
+									unsigned char *a_paucEncodingBits,
+									ErrorMetric a_errormetric);
+
+		virtual void InitFromEncodingBits(Block4x4 *a_pblockParent,
+											unsigned char *a_paucEncodingBits,
+											ColorFloatRGBA *a_pafrgbaSource, 
+
+											ErrorMetric a_errormetric);
+
+		virtual void PerformIteration(float a_fEffort);
+
+		inline virtual bool GetFlip(void)
+		{
+			return m_boolFlip;
+		}
+
+		inline virtual bool IsDifferential(void)
+		{
+			return m_boolDiff;
+		}
+
+		virtual void SetEncodingBits(void);
+
+		void Decode(void);
+
+		inline ColorFloatRGBA GetColor1(void) const
+		{
+			return m_frgbaColor1;
+		}
+
+		inline ColorFloatRGBA GetColor2(void) const
+		{
+			return m_frgbaColor2;
+		}
+
+		inline const unsigned int * GetSelectors(void) const
+		{
+			return m_auiSelectors;
+		}
+
+		inline unsigned int GetCW1(void) const
+		{
+			return m_uiCW1;
+		}
+
+		inline unsigned int GetCW2(void) const
+		{
+			return m_uiCW2;
+		}
+
+		inline bool HasSeverelyBentDifferentialColors(void) const
+		{
+			return m_boolSeverelyBentDifferentialColors;
+		}
+
+	protected:
+
+		static const unsigned int s_auiPixelOrderFlip0[PIXELS];
+		static const unsigned int s_auiPixelOrderFlip1[PIXELS];
+		static const unsigned int s_auiPixelOrderHScan[PIXELS];
+
+		static const unsigned int s_auiLeftPixelMapping[8];
+		static const unsigned int s_auiRightPixelMapping[8];
+		static const unsigned int s_auiTopPixelMapping[8];
+		static const unsigned int s_auiBottomPixelMapping[8];
+
+		static const unsigned int SELECTOR_BITS = 2;
+		static const unsigned int SELECTORS = 1 << SELECTOR_BITS;
+
+		static const unsigned int CW_BITS = 3;
+		static const unsigned int CW_RANGES = 1 << CW_BITS;
+
+		static float s_aafCwTable[CW_RANGES][SELECTORS];
+		static unsigned char s_aucDifferentialCwRange[256];
+
+		static const int MAX_DIFFERENTIAL = 3;
+		static const int MIN_DIFFERENTIAL = -4;
+
+		void InitFromEncodingBits_Selectors(void);
+
+		void PerformFirstIteration(void);
+		void CalculateMostLikelyFlip(void);
+
+		void TryDifferential(bool a_boolFlip, unsigned int a_uiRadius,
+								int a_iGrayOffset1, int a_iGrayOffset2);
+		void TryDifferentialHalf(DifferentialTrys::Half *a_phalf);
+
+		void TryIndividual(bool a_boolFlip, unsigned int a_uiRadius);
+		void TryIndividualHalf(IndividualTrys::Half *a_phalf);
+
+		void TryDegenerates1(void);
+		void TryDegenerates2(void);
+		void TryDegenerates3(void);
+		void TryDegenerates4(void);
+
+		void CalculateSelectors();
+		void CalculateHalfOfTheSelectors(unsigned int a_uiHalf,
+											const unsigned int *pauiPixelMapping);
+
+		// calculate the distance2 of r_frgbaPixel from r_frgbaTarget's gray line
+		inline float CalcGrayDistance2(ColorFloatRGBA &r_frgbaPixel, 
+										ColorFloatRGBA &r_frgbaTarget)
+		{
+			float fDeltaGray = ((r_frgbaPixel.fR - r_frgbaTarget.fR) +
+								(r_frgbaPixel.fG - r_frgbaTarget.fG) +
+								(r_frgbaPixel.fB - r_frgbaTarget.fB)) / 3.0f;
+
+			ColorFloatRGBA frgbaPointOnGrayLine = (r_frgbaTarget + fDeltaGray).ClampRGB();
+
+			float fDR = r_frgbaPixel.fR - frgbaPointOnGrayLine.fR;
+			float fDG = r_frgbaPixel.fG - frgbaPointOnGrayLine.fG;
+			float fDB = r_frgbaPixel.fB - frgbaPointOnGrayLine.fB;
+
+			return (fDR*fDR) + (fDG*fDG) + (fDB*fDB);
+		}
+
+		void SetEncodingBits_Selectors(void);
+
+		// intermediate encoding
+		bool			m_boolDiff;
+		bool			m_boolFlip;
+		ColorFloatRGBA	m_frgbaColor1;
+		ColorFloatRGBA	m_frgbaColor2;
+		unsigned int	m_uiCW1;
+		unsigned int	m_uiCW2;
+		unsigned int	m_auiSelectors[PIXELS];
+
+		// state shared between iterations
+		ColorFloatRGBA	m_frgbaSourceAverageLeft;
+		ColorFloatRGBA	m_frgbaSourceAverageRight;
+		ColorFloatRGBA	m_frgbaSourceAverageTop;
+		ColorFloatRGBA	m_frgbaSourceAverageBottom;
+		bool			m_boolMostLikelyFlip;
+
+		// stats
+		float			m_fError1;	// error for Etc1 half 1
+		float			m_fError2;	// error for Etc1 half 2
+		bool			m_boolSeverelyBentDifferentialColors;	// only valid if m_boolDiff;
+
+		// final encoding
+		Block4x4EncodingBits_RGB8 *m_pencodingbitsRGB8;		// or RGB8 portion of Block4x4EncodingBits_RGB8A8
+
+		private:
+
+		void CalculateSourceAverages(void);
+
+	};
+
+} // namespace Etc

thirdparty/etc2comp/EtcBlock4x4Encoding_R11.cpp

@@ -0,0 +1,429 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+EtcBlock4x4Encoding_R11.cpp
+
+Block4x4Encoding_R11 is the encoder to use when targetting file format R11 and SR11 (signed R11).  
+
+*/
+
+#include "EtcConfig.h"
+#include "EtcBlock4x4Encoding_R11.h"
+
+#include "EtcBlock4x4EncodingBits.h"
+#include "EtcBlock4x4.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <float.h>
+#include <limits>
+
+namespace Etc
+{
+
+	// modifier values to use for R11, SR11, RG11 and SRG11
+	float Block4x4Encoding_R11::s_aafModifierTable[MODIFIER_TABLE_ENTRYS][SELECTORS]
+	{
+		{ -3.0f / 255.0f, -6.0f / 255.0f,  -9.0f / 255.0f, -15.0f / 255.0f, 2.0f / 255.0f, 5.0f / 255.0f, 8.0f / 255.0f, 14.0f / 255.0f },
+		{ -3.0f / 255.0f, -7.0f / 255.0f, -10.0f / 255.0f, -13.0f / 255.0f, 2.0f / 255.0f, 6.0f / 255.0f, 9.0f / 255.0f, 12.0f / 255.0f },
+		{ -2.0f / 255.0f, -5.0f / 255.0f,  -8.0f / 255.0f, -13.0f / 255.0f, 1.0f / 255.0f, 4.0f / 255.0f, 7.0f / 255.0f, 12.0f / 255.0f },
+		{ -2.0f / 255.0f, -4.0f / 255.0f,  -6.0f / 255.0f, -13.0f / 255.0f, 1.0f / 255.0f, 3.0f / 255.0f, 5.0f / 255.0f, 12.0f / 255.0f },
+
+		{ -3.0f / 255.0f, -6.0f / 255.0f,  -8.0f / 255.0f, -12.0f / 255.0f, 2.0f / 255.0f, 5.0f / 255.0f, 7.0f / 255.0f, 11.0f / 255.0f },
+		{ -3.0f / 255.0f, -7.0f / 255.0f,  -9.0f / 255.0f, -11.0f / 255.0f, 2.0f / 255.0f, 6.0f / 255.0f, 8.0f / 255.0f, 10.0f / 255.0f },
+		{ -4.0f / 255.0f, -7.0f / 255.0f,  -8.0f / 255.0f, -11.0f / 255.0f, 3.0f / 255.0f, 6.0f / 255.0f, 7.0f / 255.0f, 10.0f / 255.0f },
+		{ -3.0f / 255.0f, -5.0f / 255.0f,  -8.0f / 255.0f, -11.0f / 255.0f, 2.0f / 255.0f, 4.0f / 255.0f, 7.0f / 255.0f, 10.0f / 255.0f },
+
+		{ -2.0f / 255.0f, -6.0f / 255.0f,  -8.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 5.0f / 255.0f, 7.0f / 255.0f,  9.0f / 255.0f },
+		{ -2.0f / 255.0f, -5.0f / 255.0f,  -8.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 4.0f / 255.0f, 7.0f / 255.0f,  9.0f / 255.0f },
+		{ -2.0f / 255.0f, -4.0f / 255.0f,  -8.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 3.0f / 255.0f, 7.0f / 255.0f,  9.0f / 255.0f },
+		{ -2.0f / 255.0f, -5.0f / 255.0f,  -7.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 4.0f / 255.0f, 6.0f / 255.0f,  9.0f / 255.0f },
+
+		{ -3.0f / 255.0f, -4.0f / 255.0f,  -7.0f / 255.0f, -10.0f / 255.0f, 2.0f / 255.0f, 3.0f / 255.0f, 6.0f / 255.0f,  9.0f / 255.0f },
+		{ -1.0f / 255.0f, -2.0f / 255.0f,  -3.0f / 255.0f, -10.0f / 255.0f, 0.0f / 255.0f, 1.0f / 255.0f, 2.0f / 255.0f,  9.0f / 255.0f },
+		{ -4.0f / 255.0f, -6.0f / 255.0f,  -8.0f / 255.0f,  -9.0f / 255.0f, 3.0f / 255.0f, 5.0f / 255.0f, 7.0f / 255.0f,  8.0f / 255.0f },
+		{ -3.0f / 255.0f, -5.0f / 255.0f,  -7.0f / 255.0f,  -9.0f / 255.0f, 2.0f / 255.0f, 4.0f / 255.0f, 6.0f / 255.0f,  8.0f / 255.0f }
+	};
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	Block4x4Encoding_R11::Block4x4Encoding_R11(void)
+	{
+
+		m_pencodingbitsR11 = nullptr;
+
+	}
+
+	Block4x4Encoding_R11::~Block4x4Encoding_R11(void) {}
+	// ----------------------------------------------------------------------------------------------------
+	// initialization prior to encoding
+	// a_pblockParent points to the block associated with this encoding
+	// a_errormetric is used to choose the best encoding
+	// a_pafrgbaSource points to a 4x4 block subset of the source image
+	// a_paucEncodingBits points to the final encoding bits
+	//
+	void Block4x4Encoding_R11::InitFromSource(Block4x4 *a_pblockParent,
+		ColorFloatRGBA *a_pafrgbaSource,
+		unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric)
+	{
+		Block4x4Encoding::Init(a_pblockParent, a_pafrgbaSource,a_errormetric);
+
+		m_pencodingbitsR11 = (Block4x4EncodingBits_R11 *)a_paucEncodingBits;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// initialization from the encoding bits of a previous encoding
+	// a_pblockParent points to the block associated with this encoding
+	// a_errormetric is used to choose the best encoding
+	// a_pafrgbaSource points to a 4x4 block subset of the source image
+	// a_paucEncodingBits points to the final encoding bits of a previous encoding
+	//
+	void Block4x4Encoding_R11::InitFromEncodingBits(Block4x4 *a_pblockParent,
+		unsigned char *a_paucEncodingBits,
+		ColorFloatRGBA *a_pafrgbaSource,
+		ErrorMetric a_errormetric)
+	{
+		m_pencodingbitsR11 = (Block4x4EncodingBits_R11 *)a_paucEncodingBits;
+
+		// init RGB portion
+		Block4x4Encoding_RGB8::InitFromEncodingBits(a_pblockParent,
+			(unsigned char *)m_pencodingbitsR11,
+			a_pafrgbaSource,
+			a_errormetric);
+
+		// init R11 portion
+		{
+			m_mode = MODE_R11;
+			if (a_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_R11 || a_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
+			{
+				m_fRedBase = (float)(signed char)m_pencodingbitsR11->data.base;
+			}
+			else
+			{
+				m_fRedBase = (float)(unsigned char)m_pencodingbitsR11->data.base;
+			}
+			m_fRedMultiplier = (float)m_pencodingbitsR11->data.multiplier;
+			m_uiRedModifierTableIndex = m_pencodingbitsR11->data.table;
+
+			unsigned long long int ulliSelectorBits = 0;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors0 << 40;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors1 << 32;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors2 << 24;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors3 << 16;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors4 << 8;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors5;
+			for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+			{
+				unsigned int uiShift = 45 - (3 * uiPixel);
+				m_auiRedSelectors[uiPixel] = (ulliSelectorBits >> uiShift) & (SELECTORS - 1);
+			}
+
+			// decode the red channel
+			// calc red error
+			for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+			{
+				float fDecodedPixelData = 0.0f;
+				if (a_pblockParent->GetImageSource()->GetFormat() == Image::Format::R11 || a_pblockParent->GetImageSource()->GetFormat() == Image::Format::RG11)
+				{
+					fDecodedPixelData = DecodePixelRed(m_fRedBase, m_fRedMultiplier,
+						m_uiRedModifierTableIndex,
+						m_auiRedSelectors[uiPixel]);
+				}
+				else if (a_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_R11 || a_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
+				{
+					fDecodedPixelData = DecodePixelRed(m_fRedBase + 128, m_fRedMultiplier,
+						m_uiRedModifierTableIndex,
+						m_auiRedSelectors[uiPixel]);
+				}
+				else
+				{
+					assert(0);
+				}
+				m_afrgbaDecodedColors[uiPixel] = ColorFloatRGBA(fDecodedPixelData, 0.0f, 0.0f, 1.0f);
+			}
+			CalcBlockError();
+		}
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// perform a single encoding iteration
+	// replace the encoding if a better encoding was found
+	// subsequent iterations generally take longer for each iteration
+	// set m_boolDone if encoding is perfect or encoding is finished based on a_fEffort
+	//
+	void Block4x4Encoding_R11::PerformIteration(float a_fEffort)
+	{
+		assert(!m_boolDone);
+		m_mode = MODE_R11;
+
+		switch (m_uiEncodingIterations)
+		{
+		case 0:
+			m_fError = FLT_MAX;
+			m_fRedBlockError = FLT_MAX;		// artificially high value
+			CalculateR11(8, 0.0f, 0.0f);
+			m_fError = m_fRedBlockError;
+			break;
+
+		case 1:
+			CalculateR11(8, 2.0f, 1.0f);
+			m_fError = m_fRedBlockError;
+			if (a_fEffort <= 24.5f)
+			{
+				m_boolDone = true;
+			}
+			break;
+
+		case 2:
+			CalculateR11(8, 12.0f, 1.0f);
+			m_fError = m_fRedBlockError;
+			if (a_fEffort <= 49.5f)
+			{
+				m_boolDone = true;
+			}
+			break;
+
+		case 3:
+			CalculateR11(7, 6.0f, 1.0f);
+			m_fError = m_fRedBlockError;
+			break;
+
+		case 4:
+			CalculateR11(6, 3.0f, 1.0f);
+			m_fError = m_fRedBlockError;
+			break;
+
+		case 5:
+			CalculateR11(5, 1.0f, 0.0f);
+			m_fError = m_fRedBlockError;
+			m_boolDone = true;
+			break;
+
+		default:
+			assert(0);
+			break;
+		}
+
+		m_uiEncodingIterations++;
+		SetDoneIfPerfect();
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// find the best combination of base color, multiplier and selectors
+	//
+	// a_uiSelectorsUsed limits the number of selector combinations to try
+	// a_fBaseRadius limits the range of base colors to try
+	// a_fMultiplierRadius limits the range of multipliers to try
+	//
+	void Block4x4Encoding_R11::CalculateR11(unsigned int a_uiSelectorsUsed, 
+												float a_fBaseRadius, float a_fMultiplierRadius)
+	{
+		// maps from virtual (monotonic) selector to ETC selector
+		static const unsigned int auiVirtualSelectorMap[8] = {3, 2, 1, 0, 4, 5, 6, 7};
+
+		// find min/max red
+		float fMinRed = 1.0f;
+		float fMaxRed = 0.0f;
+		for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+		{
+			// ignore border pixels
+			float fAlpha = m_pafrgbaSource[uiPixel].fA;
+			if (isnan(fAlpha))
+			{
+				continue;
+			}
+
+			float fRed = m_pafrgbaSource[uiPixel].fR;
+
+			if (fRed < fMinRed)
+			{
+				fMinRed = fRed;
+			}
+			if (fRed > fMaxRed)
+			{
+				fMaxRed = fRed;
+			}
+		}
+		assert(fMinRed <= fMaxRed);
+
+		float fRedRange = (fMaxRed - fMinRed);
+
+		// try each modifier table entry							  
+		for (unsigned int uiTableEntry = 0; uiTableEntry < MODIFIER_TABLE_ENTRYS; uiTableEntry++)
+		{
+			for (unsigned int uiMinVirtualSelector = 0; 
+					uiMinVirtualSelector <= (8- a_uiSelectorsUsed); 
+					uiMinVirtualSelector++)
+			{
+				unsigned int uiMaxVirtualSelector = uiMinVirtualSelector + a_uiSelectorsUsed - 1;
+
+				unsigned int uiMinSelector = auiVirtualSelectorMap[uiMinVirtualSelector];
+				unsigned int uiMaxSelector = auiVirtualSelectorMap[uiMaxVirtualSelector];
+
+				float fTableEntryCenter = -s_aafModifierTable[uiTableEntry][uiMinSelector];
+
+				float fTableEntryRange = s_aafModifierTable[uiTableEntry][uiMaxSelector] -
+											s_aafModifierTable[uiTableEntry][uiMinSelector];
+
+				float fCenterRatio = fTableEntryCenter / fTableEntryRange;
+
+				float fCenter = fMinRed + fCenterRatio*fRedRange;
+				fCenter = roundf(255.0f * fCenter) / 255.0f;
+
+				float fMinBase = fCenter - (a_fBaseRadius / 255.0f);
+				if (fMinBase < 0.0f)
+				{
+					fMinBase = 0.0f;
+				}
+
+				float fMaxBase = fCenter + (a_fBaseRadius / 255.0f);
+				if (fMaxBase > 1.0f)
+				{
+					fMaxBase = 1.0f;
+				}
+
+				for (float fBase = fMinBase; fBase <= fMaxBase; fBase += (0.999999f / 255.0f))
+				{
+					float fRangeMultiplier = roundf(fRedRange / fTableEntryRange);
+
+					float fMinMultiplier = fRangeMultiplier - a_fMultiplierRadius;
+					if (fMinMultiplier < 1.0f)
+					{
+						fMinMultiplier = 0.0f;
+					}
+					else if (fMinMultiplier > 15.0f)
+					{
+						fMinMultiplier = 15.0f;
+					}
+
+					float fMaxMultiplier = fRangeMultiplier + a_fMultiplierRadius;
+					if (fMaxMultiplier < 1.0f)
+					{
+						fMaxMultiplier = 1.0f;
+					}
+					else if (fMaxMultiplier > 15.0f)
+					{
+						fMaxMultiplier = 15.0f;
+					}
+
+					for (float fMultiplier = fMinMultiplier; fMultiplier <= fMaxMultiplier; fMultiplier += 1.0f)
+					{
+						// find best selector for each pixel
+						unsigned int auiBestSelectors[PIXELS];
+						float afBestRedError[PIXELS];
+						float afBestPixelRed[PIXELS];
+
+						for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+						{
+							float fBestPixelRedError = FLT_MAX;
+
+							for (unsigned int uiSelector = 0; uiSelector < SELECTORS; uiSelector++)
+							{
+								float fPixelRed = DecodePixelRed(fBase * 255.0f, fMultiplier, uiTableEntry, uiSelector);
+
+								ColorFloatRGBA frgba(fPixelRed, m_pafrgbaSource[uiPixel].fG,0.0f,1.0f);
+
+								float fPixelRedError = CalcPixelError(frgba, 1.0f, m_pafrgbaSource[uiPixel]);
+
+								if (fPixelRedError < fBestPixelRedError)
+								{
+									fBestPixelRedError = fPixelRedError;
+									auiBestSelectors[uiPixel] = uiSelector;
+									afBestRedError[uiPixel] = fBestPixelRedError;
+									afBestPixelRed[uiPixel] = fPixelRed;
+								}
+							}
+						}
+						float fBlockError = 0.0f;  
+						for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+						{
+							fBlockError += afBestRedError[uiPixel];
+						}
+						if (fBlockError < m_fRedBlockError)
+						{
+							m_fRedBlockError = fBlockError;
+
+							if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::R11 || m_pblockParent->GetImageSource()->GetFormat() == Image::Format::RG11)
+							{
+								m_fRedBase = 255.0f * fBase;
+							}
+							else if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_R11 || m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
+							{
+								m_fRedBase = (fBase * 255) - 128;
+							}
+							else
+							{
+								assert(0);
+							}
+							m_fRedMultiplier = fMultiplier;
+							m_uiRedModifierTableIndex = uiTableEntry;
+
+							for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+							{
+								m_auiRedSelectors[uiPixel] = auiBestSelectors[uiPixel];
+								float fBestPixelRed = afBestPixelRed[uiPixel];
+								m_afrgbaDecodedColors[uiPixel] = ColorFloatRGBA(fBestPixelRed, 0.0f, 0.0f, 1.0f);
+								m_afDecodedAlphas[uiPixel] = 1.0f;
+							}
+						}
+					}
+				}
+
+			}
+		}
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// set the encoding bits based on encoding state
+	//
+	void Block4x4Encoding_R11::SetEncodingBits(void)
+	{
+		if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::R11 || m_pblockParent->GetImageSource()->GetFormat() == Image::Format::RG11)
+		{
+			m_pencodingbitsR11->data.base = (unsigned char)roundf(m_fRedBase);
+		}
+		else if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_R11 || m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
+		{
+			m_pencodingbitsR11->data.base = (signed char)roundf(m_fRedBase);
+		}
+		else
+		{
+			assert(0);
+		}
+		m_pencodingbitsR11->data.table = m_uiRedModifierTableIndex;
+		m_pencodingbitsR11->data.multiplier = (unsigned char)roundf(m_fRedMultiplier);
+
+		unsigned long long int ulliSelectorBits = 0;
+		for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+		{
+			unsigned int uiShift = 45 - (3 * uiPixel);
+			ulliSelectorBits |= ((unsigned long long int)m_auiRedSelectors[uiPixel]) << uiShift;
+		}
+
+		m_pencodingbitsR11->data.selectors0 = ulliSelectorBits >> 40;
+		m_pencodingbitsR11->data.selectors1 = ulliSelectorBits >> 32;
+		m_pencodingbitsR11->data.selectors2 = ulliSelectorBits >> 24;
+		m_pencodingbitsR11->data.selectors3 = ulliSelectorBits >> 16;
+		m_pencodingbitsR11->data.selectors4 = ulliSelectorBits >> 8;
+		m_pencodingbitsR11->data.selectors5 = ulliSelectorBits;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+}

thirdparty/etc2comp/EtcBlock4x4Encoding_R11.h

@@ -0,0 +1,122 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcBlock4x4Encoding_RGB8.h"
+
+namespace Etc
+{
+	class Block4x4EncodingBits_R11;
+
+	// ################################################################################
+	// Block4x4Encoding_R11
+	// ################################################################################
+
+	class Block4x4Encoding_R11 : public Block4x4Encoding_RGB8
+	{
+	public:
+
+		Block4x4Encoding_R11(void);
+		virtual ~Block4x4Encoding_R11(void);
+
+		virtual void InitFromSource(Block4x4 *a_pblockParent,
+			ColorFloatRGBA *a_pafrgbaSource,
+			unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric);
+
+		virtual void InitFromEncodingBits(Block4x4 *a_pblockParent,
+			unsigned char *a_paucEncodingBits,
+			ColorFloatRGBA *a_pafrgbaSource,
+			ErrorMetric a_errormetric);
+
+		virtual void PerformIteration(float a_fEffort);
+
+		virtual void SetEncodingBits(void);
+
+		inline float GetRedBase(void) const
+		{
+			return m_fRedBase;
+		}
+
+		inline float GetRedMultiplier(void) const
+		{
+			return m_fRedMultiplier;
+		}
+
+		inline int GetRedTableIndex(void) const
+		{
+			return m_uiRedModifierTableIndex;
+		}
+
+		inline const unsigned int * GetRedSelectors(void) const
+		{
+			return m_auiRedSelectors;
+		}
+
+	protected:
+
+		static const unsigned int MODIFIER_TABLE_ENTRYS = 16;
+		static const unsigned int SELECTOR_BITS = 3;
+		static const unsigned int SELECTORS = 1 << SELECTOR_BITS;
+
+		static float s_aafModifierTable[MODIFIER_TABLE_ENTRYS][SELECTORS];
+
+		void CalculateR11(unsigned int a_uiSelectorsUsed, 
+							float a_fBaseRadius, float a_fMultiplierRadius);
+
+		
+
+	
+		inline float DecodePixelRed(float a_fBase, float a_fMultiplier,
+			unsigned int a_uiTableIndex, unsigned int a_uiSelector)
+		{
+			float fMultiplier = a_fMultiplier;
+			if (fMultiplier <= 0.0f)
+			{
+				fMultiplier = 1.0f / 8.0f;
+			}
+
+			float fPixelRed = a_fBase * 8 + 4 +
+				8 * fMultiplier*s_aafModifierTable[a_uiTableIndex][a_uiSelector]*255;
+			fPixelRed /= 2047.0f;
+
+			if (fPixelRed < 0.0f)
+			{
+				fPixelRed = 0.0f;
+			}
+			else if (fPixelRed > 1.0f)
+			{
+				fPixelRed = 1.0f;
+			}
+
+			return fPixelRed;
+		}
+
+		Block4x4EncodingBits_R11 *m_pencodingbitsR11;
+
+		float m_fRedBase;
+		float m_fRedMultiplier;
+		float m_fRedBlockError;
+		unsigned int m_uiRedModifierTableIndex;
+		unsigned int m_auiRedSelectors[PIXELS];
+
+		
+	};
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+} // namespace Etc

thirdparty/etc2comp/EtcBlock4x4Encoding_RG11.cpp

@@ -0,0 +1,447 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+EtcBlock4x4Encoding_RG11.cpp
+
+Block4x4Encoding_RG11 is the encoder to use when targetting file format RG11 and SRG11 (signed RG11).
+
+*/
+
+#include "EtcConfig.h"
+#include "EtcBlock4x4Encoding_RG11.h"
+
+#include "EtcBlock4x4EncodingBits.h"
+#include "EtcBlock4x4.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <float.h>
+#include <limits>
+
+namespace Etc
+{
+	// ----------------------------------------------------------------------------------------------------
+	//
+	Block4x4Encoding_RG11::Block4x4Encoding_RG11(void)
+	{
+		m_pencodingbitsRG11 = nullptr;
+	}
+
+	Block4x4Encoding_RG11::~Block4x4Encoding_RG11(void) {}
+	// ----------------------------------------------------------------------------------------------------
+	// initialization prior to encoding
+	// a_pblockParent points to the block associated with this encoding
+	// a_errormetric is used to choose the best encoding
+	// a_pafrgbaSource points to a 4x4 block subset of the source image
+	// a_paucEncodingBits points to the final encoding bits
+	//
+	void Block4x4Encoding_RG11::InitFromSource(Block4x4 *a_pblockParent,
+		ColorFloatRGBA *a_pafrgbaSource,
+		unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric)
+	{
+		Block4x4Encoding::Init(a_pblockParent, a_pafrgbaSource,a_errormetric);
+
+		m_pencodingbitsRG11 = (Block4x4EncodingBits_RG11 *)a_paucEncodingBits;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// initialization from the encoding bits of a previous encoding
+	// a_pblockParent points to the block associated with this encoding
+	// a_errormetric is used to choose the best encoding
+	// a_pafrgbaSource points to a 4x4 block subset of the source image
+	// a_paucEncodingBits points to the final encoding bits of a previous encoding
+	//
+	void Block4x4Encoding_RG11::InitFromEncodingBits(Block4x4 *a_pblockParent,
+		unsigned char *a_paucEncodingBits,
+		ColorFloatRGBA *a_pafrgbaSource,
+		ErrorMetric a_errormetric)
+	{
+
+		m_pencodingbitsRG11 = (Block4x4EncodingBits_RG11 *)a_paucEncodingBits;
+
+		// init RGB portion
+		Block4x4Encoding_RGB8::InitFromEncodingBits(a_pblockParent,
+			(unsigned char *)m_pencodingbitsRG11,
+			a_pafrgbaSource,
+			a_errormetric);
+		m_fError = 0.0f;
+
+		{
+			m_mode = MODE_RG11;
+			if (a_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
+			{
+				m_fRedBase = (float)(signed char)m_pencodingbitsRG11->data.baseR;
+				m_fGrnBase = (float)(signed char)m_pencodingbitsRG11->data.baseG;
+			}
+			else
+			{
+				m_fRedBase = (float)(unsigned char)m_pencodingbitsRG11->data.baseR;
+				m_fGrnBase = (float)(unsigned char)m_pencodingbitsRG11->data.baseG;
+			}
+			m_fRedMultiplier = (float)m_pencodingbitsRG11->data.multiplierR;
+			m_fGrnMultiplier = (float)m_pencodingbitsRG11->data.multiplierG;
+			m_uiRedModifierTableIndex = m_pencodingbitsRG11->data.tableIndexR;
+			m_uiGrnModifierTableIndex = m_pencodingbitsRG11->data.tableIndexG;
+
+			unsigned long long int ulliSelectorBitsR = 0;
+			ulliSelectorBitsR |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsR0 << 40;
+			ulliSelectorBitsR |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsR1 << 32;
+			ulliSelectorBitsR |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsR2 << 24;
+			ulliSelectorBitsR |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsR3 << 16;
+			ulliSelectorBitsR |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsR4 << 8;
+			ulliSelectorBitsR |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsR5;
+
+			unsigned long long int ulliSelectorBitsG = 0;
+			ulliSelectorBitsG |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsG0 << 40;
+			ulliSelectorBitsG |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsG1 << 32;
+			ulliSelectorBitsG |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsG2 << 24;
+			ulliSelectorBitsG |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsG3 << 16;
+			ulliSelectorBitsG |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsG4 << 8;
+			ulliSelectorBitsG |= (unsigned long long int)m_pencodingbitsRG11->data.selectorsG5;
+
+			
+			for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+			{
+				unsigned int uiShift = 45 - (3 * uiPixel);
+				m_auiRedSelectors[uiPixel] = (ulliSelectorBitsR >> uiShift) & (SELECTORS - 1);
+				m_auiGrnSelectors[uiPixel] = (ulliSelectorBitsG >> uiShift) & (SELECTORS - 1);
+			}
+
+			
+			for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+			{
+				float fRedDecodedData = 0.0f;
+				float fGrnDecodedData = 0.0f;
+				if (a_pblockParent->GetImageSource()->GetFormat() == Image::Format::RG11)
+				{
+					fRedDecodedData = DecodePixelRed(m_fRedBase, m_fRedMultiplier, m_uiRedModifierTableIndex, m_auiRedSelectors[uiPixel]);
+					fGrnDecodedData = DecodePixelRed(m_fGrnBase, m_fGrnMultiplier, m_uiGrnModifierTableIndex, m_auiGrnSelectors[uiPixel]);
+				}
+				else if (a_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
+				{
+					fRedDecodedData = DecodePixelRed(m_fRedBase + 128, m_fRedMultiplier, m_uiRedModifierTableIndex, m_auiRedSelectors[uiPixel]);
+					fGrnDecodedData = DecodePixelRed(m_fGrnBase + 128, m_fGrnMultiplier, m_uiGrnModifierTableIndex, m_auiGrnSelectors[uiPixel]);
+				}
+				else
+				{
+					assert(0);
+				}
+				m_afrgbaDecodedColors[uiPixel] = ColorFloatRGBA(fRedDecodedData, fGrnDecodedData, 0.0f, 1.0f);
+			}
+
+		}
+
+		CalcBlockError();
+ 	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// perform a single encoding iteration
+	// replace the encoding if a better encoding was found
+	// subsequent iterations generally take longer for each iteration
+	// set m_boolDone if encoding is perfect or encoding is finished based on a_fEffort
+	//
+	void Block4x4Encoding_RG11::PerformIteration(float a_fEffort)
+	{
+		assert(!m_boolDone);
+
+		switch (m_uiEncodingIterations)
+		{
+		case 0:
+			m_fError = FLT_MAX;
+			m_fGrnBlockError = FLT_MAX;		// artificially high value
+			m_fRedBlockError = FLT_MAX;
+			CalculateR11(8, 0.0f, 0.0f);
+			CalculateG11(8, 0.0f, 0.0f);
+			m_fError = (m_fGrnBlockError + m_fRedBlockError);
+			break;
+
+		case 1:
+			CalculateR11(8, 2.0f, 1.0f);
+			CalculateG11(8, 2.0f, 1.0f);
+			m_fError = (m_fGrnBlockError + m_fRedBlockError);
+			if (a_fEffort <= 24.5f)
+			{
+				m_boolDone = true;
+			}
+			break;
+
+		case 2:
+			CalculateR11(8, 12.0f, 1.0f);
+			CalculateG11(8, 12.0f, 1.0f);
+			m_fError = (m_fGrnBlockError + m_fRedBlockError);
+			if (a_fEffort <= 49.5f)
+			{
+				m_boolDone = true;
+			}
+			break;
+
+		case 3:
+			CalculateR11(7, 6.0f, 1.0f);
+			CalculateG11(7, 6.0f, 1.0f);
+			m_fError = (m_fGrnBlockError + m_fRedBlockError);
+			break;
+
+		case 4:
+			CalculateR11(6, 3.0f, 1.0f);
+			CalculateG11(6, 3.0f, 1.0f);
+			m_fError = (m_fGrnBlockError + m_fRedBlockError);
+			break;
+
+		case 5:
+			CalculateR11(5, 1.0f, 0.0f);
+			CalculateG11(5, 1.0f, 0.0f);
+			m_fError = (m_fGrnBlockError + m_fRedBlockError);
+			m_boolDone = true;
+			break;
+
+		default:
+			assert(0);
+			break;
+		}
+
+		m_uiEncodingIterations++;
+		SetDoneIfPerfect();
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// find the best combination of base color, multiplier and selectors
+	//
+	// a_uiSelectorsUsed limits the number of selector combinations to try
+	// a_fBaseRadius limits the range of base colors to try
+	// a_fMultiplierRadius limits the range of multipliers to try
+	//
+	void Block4x4Encoding_RG11::CalculateG11(unsigned int a_uiSelectorsUsed,
+		float a_fBaseRadius, float a_fMultiplierRadius)
+	{
+		// maps from virtual (monotonic) selector to etc selector
+		static const unsigned int auiVirtualSelectorMap[8] = { 3, 2, 1, 0, 4, 5, 6, 7 };
+
+		// find min/max Grn
+		float fMinGrn = 1.0f;
+		float fMaxGrn = 0.0f;
+		for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+		{
+			// ignore border pixels
+			float fAlpha = m_pafrgbaSource[uiPixel].fA;
+			if (isnan(fAlpha))
+			{
+				continue;
+			}
+
+			float fGrn = m_pafrgbaSource[uiPixel].fG;
+
+			if (fGrn < fMinGrn)
+			{
+				fMinGrn = fGrn;
+			}
+			if (fGrn > fMaxGrn)
+			{
+				fMaxGrn = fGrn;
+			}
+		}
+		assert(fMinGrn <= fMaxGrn);
+
+		float fGrnRange = (fMaxGrn - fMinGrn);
+
+		// try each modifier table entry							  
+		for (unsigned int uiTableEntry = 0; uiTableEntry < MODIFIER_TABLE_ENTRYS; uiTableEntry++)
+		{
+			for (unsigned int uiMinVirtualSelector = 0;
+			uiMinVirtualSelector <= (8 - a_uiSelectorsUsed);
+				uiMinVirtualSelector++)
+			{
+				unsigned int uiMaxVirtualSelector = uiMinVirtualSelector + a_uiSelectorsUsed - 1;
+
+				unsigned int uiMinSelector = auiVirtualSelectorMap[uiMinVirtualSelector];
+				unsigned int uiMaxSelector = auiVirtualSelectorMap[uiMaxVirtualSelector];
+
+				float fTableEntryCenter = -s_aafModifierTable[uiTableEntry][uiMinSelector];
+
+				float fTableEntryRange = s_aafModifierTable[uiTableEntry][uiMaxSelector] -
+					s_aafModifierTable[uiTableEntry][uiMinSelector];
+
+				float fCenterRatio = fTableEntryCenter / fTableEntryRange;
+
+				float fCenter = fMinGrn + fCenterRatio*fGrnRange;
+				fCenter = roundf(255.0f * fCenter) / 255.0f;
+
+				float fMinBase = fCenter - (a_fBaseRadius / 255.0f);
+				if (fMinBase < 0.0f)
+				{
+					fMinBase = 0.0f;
+				}
+
+				float fMaxBase = fCenter + (a_fBaseRadius / 255.0f);
+				if (fMaxBase > 1.0f)
+				{
+					fMaxBase = 1.0f;
+				}
+
+				for (float fBase = fMinBase; fBase <= fMaxBase; fBase += (0.999999f / 255.0f))
+				{
+					float fRangeMultiplier = roundf(fGrnRange / fTableEntryRange);
+
+					float fMinMultiplier = fRangeMultiplier - a_fMultiplierRadius;
+					if (fMinMultiplier < 1.0f)
+					{
+						fMinMultiplier = 0.0f;
+					}
+					else if (fMinMultiplier > 15.0f)
+					{
+						fMinMultiplier = 15.0f;
+					}
+
+					float fMaxMultiplier = fRangeMultiplier + a_fMultiplierRadius;
+					if (fMaxMultiplier < 1.0f)
+					{
+						fMaxMultiplier = 1.0f;
+					}
+					else if (fMaxMultiplier > 15.0f)
+					{
+						fMaxMultiplier = 15.0f;
+					}
+
+					for (float fMultiplier = fMinMultiplier; fMultiplier <= fMaxMultiplier; fMultiplier += 1.0f)
+					{
+						// find best selector for each pixel
+						unsigned int auiBestSelectors[PIXELS];
+						float afBestGrnError[PIXELS];
+						float afBestPixelGrn[PIXELS];
+
+						for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+						{
+							float fBestPixelGrnError = FLT_MAX;
+
+							for (unsigned int uiSelector = 0; uiSelector < SELECTORS; uiSelector++)
+							{
+								//DecodePixelRed is not red channel specific
+								float fPixelGrn = DecodePixelRed(fBase * 255.0f, fMultiplier, uiTableEntry, uiSelector);
+								
+								ColorFloatRGBA frgba(m_pafrgbaSource[uiPixel].fR, fPixelGrn, 0.0f, 1.0f);
+									
+								float fPixelGrnError = CalcPixelError(frgba, 1.0f, m_pafrgbaSource[uiPixel]);
+
+								if (fPixelGrnError < fBestPixelGrnError)
+								{
+									fBestPixelGrnError = fPixelGrnError;
+									auiBestSelectors[uiPixel] = uiSelector;
+									afBestGrnError[uiPixel] = fBestPixelGrnError;
+									afBestPixelGrn[uiPixel] = fPixelGrn;
+								}
+							}
+						}
+						float fBlockError = 0.0f;
+						for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+						{
+							fBlockError += afBestGrnError[uiPixel];
+						}
+
+						if (fBlockError < m_fGrnBlockError)
+						{
+							m_fGrnBlockError = fBlockError;
+
+							if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::RG11)
+							{
+								m_fGrnBase = 255.0f * fBase;
+							}
+							else if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
+							{
+								m_fGrnBase = (fBase * 255) - 128;
+							}
+							else
+							{
+								assert(0);
+							}
+							m_fGrnMultiplier = fMultiplier;
+							m_uiGrnModifierTableIndex = uiTableEntry;
+							for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+							{
+								m_auiGrnSelectors[uiPixel] = auiBestSelectors[uiPixel];
+								m_afrgbaDecodedColors[uiPixel].fG = afBestPixelGrn[uiPixel];
+								m_afDecodedAlphas[uiPixel] = 1.0f;
+							}
+						}
+					}
+				}
+
+			}
+		}
+	}
+	
+	// ----------------------------------------------------------------------------------------------------
+	// set the encoding bits based on encoding state
+	//
+	void Block4x4Encoding_RG11::SetEncodingBits(void)
+	{
+		unsigned long long int ulliSelectorBitsR = 0;
+		unsigned long long int ulliSelectorBitsG = 0;
+		for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+		{
+			unsigned int uiShift = 45 - (3 * uiPixel);
+			ulliSelectorBitsR |= ((unsigned long long int)m_auiRedSelectors[uiPixel]) << uiShift;
+			ulliSelectorBitsG |= ((unsigned long long int)m_auiGrnSelectors[uiPixel]) << uiShift;
+		}
+		if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::RG11)
+		{
+			m_pencodingbitsRG11->data.baseR = (unsigned char)roundf(m_fRedBase);
+		}
+		else if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
+		{
+			m_pencodingbitsRG11->data.baseR = (signed char)roundf(m_fRedBase);
+		}
+		else
+		{
+			assert(0);
+		}
+		m_pencodingbitsRG11->data.tableIndexR = m_uiRedModifierTableIndex;
+		m_pencodingbitsRG11->data.multiplierR = (unsigned char)roundf(m_fRedMultiplier);
+
+		m_pencodingbitsRG11->data.selectorsR0 = ulliSelectorBitsR >> 40;
+		m_pencodingbitsRG11->data.selectorsR1 = ulliSelectorBitsR >> 32;
+		m_pencodingbitsRG11->data.selectorsR2 = ulliSelectorBitsR >> 24;
+		m_pencodingbitsRG11->data.selectorsR3 = ulliSelectorBitsR >> 16;
+		m_pencodingbitsRG11->data.selectorsR4 = ulliSelectorBitsR >> 8;
+		m_pencodingbitsRG11->data.selectorsR5 = ulliSelectorBitsR;
+
+		if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::RG11)
+		{
+			m_pencodingbitsRG11->data.baseG = (unsigned char)roundf(m_fGrnBase);
+		}
+		else if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
+		{
+			m_pencodingbitsRG11->data.baseG = (signed char)roundf(m_fGrnBase);
+		}
+		else
+		{
+			assert(0);
+		}
+		m_pencodingbitsRG11->data.tableIndexG = m_uiGrnModifierTableIndex;
+		m_pencodingbitsRG11->data.multiplierG = (unsigned char)roundf(m_fGrnMultiplier);
+
+		m_pencodingbitsRG11->data.selectorsG0 = ulliSelectorBitsG >> 40;
+		m_pencodingbitsRG11->data.selectorsG1 = ulliSelectorBitsG >> 32;
+		m_pencodingbitsRG11->data.selectorsG2 = ulliSelectorBitsG >> 24;
+		m_pencodingbitsRG11->data.selectorsG3 = ulliSelectorBitsG >> 16;
+		m_pencodingbitsRG11->data.selectorsG4 = ulliSelectorBitsG >> 8;
+		m_pencodingbitsRG11->data.selectorsG5 = ulliSelectorBitsG;
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+}

thirdparty/etc2comp/EtcBlock4x4Encoding_RG11.h

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcBlock4x4Encoding_RGB8.h"
+#include "EtcBlock4x4Encoding_R11.h"
+
+namespace Etc
+{
+	class Block4x4EncodingBits_RG11;
+
+	// ################################################################################
+	// Block4x4Encoding_RG11
+	// ################################################################################
+
+	class Block4x4Encoding_RG11 : public Block4x4Encoding_R11
+	{
+		float m_fGrnBase;
+		float m_fGrnMultiplier;
+		float m_fGrnBlockError;
+		unsigned int m_auiGrnSelectors[PIXELS];
+		unsigned int m_uiGrnModifierTableIndex;
+	public:
+
+		Block4x4Encoding_RG11(void);
+		virtual ~Block4x4Encoding_RG11(void);
+
+		virtual void InitFromSource(Block4x4 *a_pblockParent,
+			ColorFloatRGBA *a_pafrgbaSource,
+
+			unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric);
+
+		virtual void InitFromEncodingBits(Block4x4 *a_pblockParent,
+			unsigned char *a_paucEncodingBits,
+			ColorFloatRGBA *a_pafrgbaSource,
+
+			ErrorMetric a_errormetric);
+
+		virtual void PerformIteration(float a_fEffort);
+
+		virtual void SetEncodingBits(void);
+
+		Block4x4EncodingBits_RG11 *m_pencodingbitsRG11;
+
+		void CalculateG11(unsigned int a_uiSelectorsUsed, float a_fBaseRadius, float a_fMultiplierRadius);
+
+		inline float GetGrnBase(void) const
+		{
+			return m_fGrnBase;
+		}
+
+		inline float GetGrnMultiplier(void) const
+		{
+			return m_fGrnMultiplier;
+		}
+
+		inline int GetGrnTableIndex(void) const
+		{
+			return m_uiGrnModifierTableIndex;
+		}
+
+		inline const unsigned int * GetGrnSelectors(void) const
+		{
+			return m_auiGrnSelectors;
+		}
+
+	};
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+} // namespace Etc

thirdparty/etc2comp/EtcBlock4x4Encoding_RGB8.h

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcBlock4x4Encoding_ETC1.h"
+
+namespace Etc
+{
+
+	class Block4x4Encoding_RGB8 : public Block4x4Encoding_ETC1
+	{
+	public:
+
+		Block4x4Encoding_RGB8(void);
+		virtual ~Block4x4Encoding_RGB8(void);
+
+		virtual void InitFromEncodingBits(Block4x4 *a_pblockParent,
+											unsigned char *a_paucEncodingBits,
+											ColorFloatRGBA *a_pafrgbaSource,
+
+											ErrorMetric a_errormetric);
+
+		virtual void PerformIteration(float a_fEffort);
+		
+		virtual void SetEncodingBits(void);
+
+		inline ColorFloatRGBA GetColor3(void) const
+		{
+			return m_frgbaColor3;
+		}
+
+	protected:
+
+		static const unsigned int PLANAR_CORNER_COLORS = 3;
+		static const unsigned int MAX_PLANAR_REGRESSION_SIZE = 4;
+		static const unsigned int TH_DISTANCES = 8;
+
+		static float s_afTHDistanceTable[TH_DISTANCES];
+
+		void TryPlanar(unsigned int a_uiRadius);
+		void TryTAndH(unsigned int a_uiRadius);
+
+		void InitFromEncodingBits_Planar(void);
+
+		ColorFloatRGBA	m_frgbaColor3;		// used for planar
+
+		void SetEncodingBits_T(void);
+		void SetEncodingBits_H(void);
+		void SetEncodingBits_Planar(void);
+
+		// state shared between iterations
+		ColorFloatRGBA	m_frgbaOriginalColor1_TAndH;
+		ColorFloatRGBA	m_frgbaOriginalColor2_TAndH;
+
+		void CalculateBaseColorsForTAndH(void);
+		void TryT(unsigned int a_uiRadius);
+		void TryT_BestSelectorCombination(void);
+		void TryH(unsigned int a_uiRadius);
+		void TryH_BestSelectorCombination(void);
+
+	private:
+
+		void InitFromEncodingBits_T(void);
+		void InitFromEncodingBits_H(void);
+
+		void CalculatePlanarCornerColors(void);
+
+		void ColorRegression(ColorFloatRGBA *a_pafrgbaPixels, unsigned int a_uiPixels,
+			ColorFloatRGBA *a_pfrgbaSlope, ColorFloatRGBA *a_pfrgbaOffset);
+
+		bool TwiddlePlanar(void);
+		bool TwiddlePlanarR();
+		bool TwiddlePlanarG();
+		bool TwiddlePlanarB();
+
+		void DecodePixels_T(void);
+		void DecodePixels_H(void);
+		void DecodePixels_Planar(void);
+
+	};
+
+} // namespace Etc

thirdparty/etc2comp/EtcBlock4x4Encoding_RGB8A1.h

@@ -0,0 +1,129 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcBlock4x4Encoding_RGB8.h"
+#include "EtcErrorMetric.h"
+#include "EtcBlock4x4EncodingBits.h"
+
+namespace Etc
+{
+
+	// ################################################################################
+	// Block4x4Encoding_RGB8A1
+	// RGB8A1 if not completely opaque or transparent
+	// ################################################################################
+
+	class Block4x4Encoding_RGB8A1 : public Block4x4Encoding_RGB8
+	{
+	public:
+
+		static const unsigned int TRANSPARENT_SELECTOR = 2;
+
+		Block4x4Encoding_RGB8A1(void);
+		virtual ~Block4x4Encoding_RGB8A1(void);
+
+		virtual void InitFromSource(Block4x4 *a_pblockParent,
+									ColorFloatRGBA *a_pafrgbaSource,
+									unsigned char *a_paucEncodingBits,
+									ErrorMetric a_errormetric);
+
+		virtual void InitFromEncodingBits(Block4x4 *a_pblockParent,
+											unsigned char *a_paucEncodingBits,
+											ColorFloatRGBA *a_pafrgbaSource,
+											ErrorMetric a_errormetric);
+
+		virtual void PerformIteration(float a_fEffort);
+
+		virtual void SetEncodingBits(void);
+
+		void InitFromEncodingBits_ETC1(Block4x4 *a_pblockParent,
+										unsigned char *a_paucEncodingBits,
+										ColorFloatRGBA *a_pafrgbaSource,
+										ErrorMetric a_errormetric);
+
+		void InitFromEncodingBits_T(void);
+		void InitFromEncodingBits_H(void);
+
+		void PerformFirstIteration(void);
+
+		void Decode_ETC1(void);
+		void DecodePixels_T(void);
+		void DecodePixels_H(void);
+		void SetEncodingBits_ETC1(void);
+		void SetEncodingBits_T(void);
+		void SetEncodingBits_H(void);
+
+	protected:
+
+		bool m_boolOpaque;				// all source pixels have alpha >= 0.5
+		bool m_boolTransparent;			// all source pixels have alpha < 0.5
+		bool m_boolPunchThroughPixels;	// some source pixels have alpha < 0.5
+
+		static float s_aafCwOpaqueUnsetTable[CW_RANGES][SELECTORS];
+
+	private:
+
+		void TryDifferential(bool a_boolFlip, unsigned int a_uiRadius,
+								int a_iGrayOffset1, int a_iGrayOffset2);
+		void TryDifferentialHalf(DifferentialTrys::Half *a_phalf);
+
+		void TryT(unsigned int a_uiRadius);
+		void TryT_BestSelectorCombination(void);
+		void TryH(unsigned int a_uiRadius);
+		void TryH_BestSelectorCombination(void);
+
+		void TryDegenerates1(void);
+		void TryDegenerates2(void);
+		void TryDegenerates3(void);
+		void TryDegenerates4(void);
+
+	};
+
+	// ################################################################################
+	// Block4x4Encoding_RGB8A1_Opaque
+	// RGB8A1 if all pixels have alpha==1
+	// ################################################################################
+
+	class Block4x4Encoding_RGB8A1_Opaque : public Block4x4Encoding_RGB8A1
+	{
+	public:
+
+		virtual void PerformIteration(float a_fEffort);
+
+		void PerformFirstIteration(void);
+
+	private:
+
+	};
+
+	// ################################################################################
+	// Block4x4Encoding_RGB8A1_Transparent
+	// RGB8A1 if all pixels have alpha==0
+	// ################################################################################
+
+	class Block4x4Encoding_RGB8A1_Transparent : public Block4x4Encoding_RGB8A1
+	{
+	public:
+
+		virtual void PerformIteration(float a_fEffort);
+
+	private:
+
+	};
+
+} // namespace Etc

thirdparty/etc2comp/EtcBlock4x4Encoding_RGBA8.cpp

@@ -0,0 +1,474 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+EtcBlock4x4Encoding_RGBA8.cpp contains:
+	Block4x4Encoding_RGBA8
+	Block4x4Encoding_RGBA8_Opaque
+	Block4x4Encoding_RGBA8_Transparent
+
+These encoders are used when targetting file format RGBA8.
+
+Block4x4Encoding_RGBA8_Opaque is used when all pixels in the 4x4 block are opaque
+Block4x4Encoding_RGBA8_Transparent is used when all pixels in the 4x4 block are transparent
+Block4x4Encoding_RGBA8 is used when there is a mixture of alphas in the 4x4 block
+
+*/
+
+#include "EtcConfig.h"
+#include "EtcBlock4x4Encoding_RGBA8.h"
+
+#include "EtcBlock4x4EncodingBits.h"
+#include "EtcBlock4x4.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <float.h>
+#include <limits>
+
+namespace Etc
+{
+
+	// ####################################################################################################
+	// Block4x4Encoding_RGBA8
+	// ####################################################################################################
+
+	float Block4x4Encoding_RGBA8::s_aafModifierTable[MODIFIER_TABLE_ENTRYS][ALPHA_SELECTORS]
+	{
+		{ -3.0f / 255.0f, -6.0f / 255.0f,  -9.0f / 255.0f, -15.0f / 255.0f, 2.0f / 255.0f, 5.0f / 255.0f, 8.0f / 255.0f, 14.0f / 255.0f },
+		{ -3.0f / 255.0f, -7.0f / 255.0f, -10.0f / 255.0f, -13.0f / 255.0f, 2.0f / 255.0f, 6.0f / 255.0f, 9.0f / 255.0f, 12.0f / 255.0f },
+		{ -2.0f / 255.0f, -5.0f / 255.0f,  -8.0f / 255.0f, -13.0f / 255.0f, 1.0f / 255.0f, 4.0f / 255.0f, 7.0f / 255.0f, 12.0f / 255.0f },
+		{ -2.0f / 255.0f, -4.0f / 255.0f,  -6.0f / 255.0f, -13.0f / 255.0f, 1.0f / 255.0f, 3.0f / 255.0f, 5.0f / 255.0f, 12.0f / 255.0f },
+
+		{ -3.0f / 255.0f, -6.0f / 255.0f,  -8.0f / 255.0f, -12.0f / 255.0f, 2.0f / 255.0f, 5.0f / 255.0f, 7.0f / 255.0f, 11.0f / 255.0f },
+		{ -3.0f / 255.0f, -7.0f / 255.0f,  -9.0f / 255.0f, -11.0f / 255.0f, 2.0f / 255.0f, 6.0f / 255.0f, 8.0f / 255.0f, 10.0f / 255.0f },
+		{ -4.0f / 255.0f, -7.0f / 255.0f,  -8.0f / 255.0f, -11.0f / 255.0f, 3.0f / 255.0f, 6.0f / 255.0f, 7.0f / 255.0f, 10.0f / 255.0f },
+		{ -3.0f / 255.0f, -5.0f / 255.0f,  -8.0f / 255.0f, -11.0f / 255.0f, 2.0f / 255.0f, 4.0f / 255.0f, 7.0f / 255.0f, 10.0f / 255.0f },
+
+		{ -2.0f / 255.0f, -6.0f / 255.0f,  -8.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 5.0f / 255.0f, 7.0f / 255.0f,  9.0f / 255.0f },
+		{ -2.0f / 255.0f, -5.0f / 255.0f,  -8.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 4.0f / 255.0f, 7.0f / 255.0f,  9.0f / 255.0f },
+		{ -2.0f / 255.0f, -4.0f / 255.0f,  -8.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 3.0f / 255.0f, 7.0f / 255.0f,  9.0f / 255.0f },
+		{ -2.0f / 255.0f, -5.0f / 255.0f,  -7.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 4.0f / 255.0f, 6.0f / 255.0f,  9.0f / 255.0f },
+
+		{ -3.0f / 255.0f, -4.0f / 255.0f,  -7.0f / 255.0f, -10.0f / 255.0f, 2.0f / 255.0f, 3.0f / 255.0f, 6.0f / 255.0f,  9.0f / 255.0f },
+		{ -1.0f / 255.0f, -2.0f / 255.0f,  -3.0f / 255.0f, -10.0f / 255.0f, 0.0f / 255.0f, 1.0f / 255.0f, 2.0f / 255.0f,  9.0f / 255.0f },
+		{ -4.0f / 255.0f, -6.0f / 255.0f,  -8.0f / 255.0f,  -9.0f / 255.0f, 3.0f / 255.0f, 5.0f / 255.0f, 7.0f / 255.0f,  8.0f / 255.0f },
+		{ -3.0f / 255.0f, -5.0f / 255.0f,  -7.0f / 255.0f,  -9.0f / 255.0f, 2.0f / 255.0f, 4.0f / 255.0f, 6.0f / 255.0f,  8.0f / 255.0f }
+	};
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	Block4x4Encoding_RGBA8::Block4x4Encoding_RGBA8(void)
+	{
+
+		m_pencodingbitsA8 = nullptr;
+
+	}
+	Block4x4Encoding_RGBA8::~Block4x4Encoding_RGBA8(void) {}
+	// ----------------------------------------------------------------------------------------------------
+	// initialization prior to encoding
+	// a_pblockParent points to the block associated with this encoding
+	// a_errormetric is used to choose the best encoding
+	// a_pafrgbaSource points to a 4x4 block subset of the source image
+	// a_paucEncodingBits points to the final encoding bits
+	//
+	void Block4x4Encoding_RGBA8::InitFromSource(Block4x4 *a_pblockParent,
+												ColorFloatRGBA *a_pafrgbaSource,
+												unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric)
+	{
+		Block4x4Encoding::Init(a_pblockParent, a_pafrgbaSource,a_errormetric);
+
+		m_pencodingbitsA8 = (Block4x4EncodingBits_A8 *)a_paucEncodingBits;
+		m_pencodingbitsRGB8 = (Block4x4EncodingBits_RGB8 *)(a_paucEncodingBits + sizeof(Block4x4EncodingBits_A8));
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// initialization from the encoding bits of a previous encoding
+	// a_pblockParent points to the block associated with this encoding
+	// a_errormetric is used to choose the best encoding
+	// a_pafrgbaSource points to a 4x4 block subset of the source image
+	// a_paucEncodingBits points to the final encoding bits of a previous encoding
+	//
+	void Block4x4Encoding_RGBA8::InitFromEncodingBits(Block4x4 *a_pblockParent,
+														unsigned char *a_paucEncodingBits,
+														ColorFloatRGBA *a_pafrgbaSource,
+														ErrorMetric a_errormetric)
+	{
+
+		m_pencodingbitsA8 = (Block4x4EncodingBits_A8 *)a_paucEncodingBits;
+		m_pencodingbitsRGB8 = (Block4x4EncodingBits_RGB8 *)(a_paucEncodingBits + sizeof(Block4x4EncodingBits_A8));
+
+		// init RGB portion
+		Block4x4Encoding_RGB8::InitFromEncodingBits(a_pblockParent,
+													(unsigned char *) m_pencodingbitsRGB8,
+													a_pafrgbaSource,
+													a_errormetric);
+
+		// init A8 portion
+		// has to be done after InitFromEncodingBits()
+		{
+			m_fBase = m_pencodingbitsA8->data.base / 255.0f;
+			m_fMultiplier = (float)m_pencodingbitsA8->data.multiplier;
+			m_uiModifierTableIndex = m_pencodingbitsA8->data.table;
+
+			unsigned long long int ulliSelectorBits = 0;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors0 << 40;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors1 << 32;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors2 << 24;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors3 << 16;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors4 << 8;
+			ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors5;
+			for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+			{
+				unsigned int uiShift = 45 - (3 * uiPixel);
+				m_auiAlphaSelectors[uiPixel] = (ulliSelectorBits >> uiShift) & (ALPHA_SELECTORS - 1);
+			}
+
+			// decode the alphas
+			// calc alpha error
+			m_fError = 0.0f;
+			for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+			{
+				m_afDecodedAlphas[uiPixel] = DecodePixelAlpha(m_fBase, m_fMultiplier,
+					m_uiModifierTableIndex,
+					m_auiAlphaSelectors[uiPixel]);
+
+				float fDeltaAlpha = m_afDecodedAlphas[uiPixel] - m_pafrgbaSource[uiPixel].fA;
+				m_fError += fDeltaAlpha * fDeltaAlpha;
+			}
+		}
+
+		// redo error calc to include alpha
+		CalcBlockError();
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// perform a single encoding iteration
+	// replace the encoding if a better encoding was found
+	// subsequent iterations generally take longer for each iteration
+	// set m_boolDone if encoding is perfect or encoding is finished based on a_fEffort
+	//
+	// similar to Block4x4Encoding_RGB8_Base::Encode_RGB8(), but with alpha added
+	//
+	void Block4x4Encoding_RGBA8::PerformIteration(float a_fEffort)
+	{
+		assert(!m_boolDone);
+
+		if (m_uiEncodingIterations == 0)
+		{
+			if (a_fEffort < 24.9f)
+			{
+				CalculateA8(0.0f);
+			}
+			else if (a_fEffort < 49.9f)
+			{
+				CalculateA8(1.0f);
+			}
+			else
+			{
+				CalculateA8(2.0f);
+			}
+		}
+
+		Block4x4Encoding_RGB8::PerformIteration(a_fEffort);
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// find the best combination of base alpga, multiplier and selectors
+	//
+	// a_fRadius limits the range of base alpha to try
+	//
+	void Block4x4Encoding_RGBA8::CalculateA8(float a_fRadius)
+	{
+
+		// find min/max alpha
+		float fMinAlpha = 1.0f;
+		float fMaxAlpha = 0.0f;
+		for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+		{
+			float fAlpha = m_pafrgbaSource[uiPixel].fA;
+
+			// ignore border pixels
+			if (isnan(fAlpha))
+			{
+				continue;
+			}
+
+			if (fAlpha < fMinAlpha)
+			{
+				fMinAlpha = fAlpha;
+			}
+			if (fAlpha > fMaxAlpha)
+			{
+				fMaxAlpha = fAlpha;
+			}
+		}
+		assert(fMinAlpha <= fMaxAlpha);
+
+		float fAlphaRange = fMaxAlpha - fMinAlpha;
+
+		// try each modifier table entry
+		m_fError = FLT_MAX;		// artificially high value
+		for (unsigned int uiTableEntry = 0; uiTableEntry < MODIFIER_TABLE_ENTRYS; uiTableEntry++)
+		{
+			static const unsigned int MIN_VALUE_SELECTOR = 3;
+			static const unsigned int MAX_VALUE_SELECTOR = 7;
+
+			float fTableEntryCenter = -s_aafModifierTable[uiTableEntry][MIN_VALUE_SELECTOR];
+
+			float fTableEntryRange = s_aafModifierTable[uiTableEntry][MAX_VALUE_SELECTOR] -
+				s_aafModifierTable[uiTableEntry][MIN_VALUE_SELECTOR];
+
+			float fCenterRatio = fTableEntryCenter / fTableEntryRange;
+
+			float fCenter = fMinAlpha + fCenterRatio*fAlphaRange;
+			fCenter = roundf(255.0f * fCenter) / 255.0f;
+
+			float fMinBase = fCenter - (a_fRadius / 255.0f);
+			if (fMinBase < 0.0f)
+			{
+				fMinBase = 0.0f;
+			}
+
+			float fMaxBase = fCenter + (a_fRadius / 255.0f);
+			if (fMaxBase > 1.0f)
+			{
+				fMaxBase = 1.0f;
+			}
+
+			for (float fBase = fMinBase; fBase <= fMaxBase; fBase += (0.999999f / 255.0f))
+			{
+
+				float fRangeMultiplier = roundf(fAlphaRange / fTableEntryRange);
+
+				float fMinMultiplier = fRangeMultiplier - a_fRadius;
+				if (fMinMultiplier < 1.0f)
+				{
+					fMinMultiplier = 1.0f;
+				}
+				else if (fMinMultiplier > 15.0f)
+				{
+					fMinMultiplier = 15.0f;
+				}
+
+				float fMaxMultiplier = fRangeMultiplier + a_fRadius;
+				if (fMaxMultiplier < 1.0f)
+				{
+					fMaxMultiplier = 1.0f;
+				}
+				else if (fMaxMultiplier > 15.0f)
+				{
+					fMaxMultiplier = 15.0f;
+				}
+
+				for (float fMultiplier = fMinMultiplier; fMultiplier <= fMaxMultiplier; fMultiplier += 1.0f)
+				{
+					// find best selector for each pixel
+					unsigned int auiBestSelectors[PIXELS];
+					float afBestAlphaError[PIXELS];
+					float afBestDecodedAlphas[PIXELS];
+					for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+					{
+						float fBestPixelAlphaError = FLT_MAX;
+						for (unsigned int uiSelector = 0; uiSelector < ALPHA_SELECTORS; uiSelector++)
+						{
+							float fDecodedAlpha = DecodePixelAlpha(fBase, fMultiplier, uiTableEntry, uiSelector);
+
+							// border pixels (NAN) should have zero error
+							float fPixelDeltaAlpha = isnan(m_pafrgbaSource[uiPixel].fA) ?
+															0.0f :
+															fDecodedAlpha - m_pafrgbaSource[uiPixel].fA;
+
+							float fPixelAlphaError = fPixelDeltaAlpha * fPixelDeltaAlpha;
+
+							if (fPixelAlphaError < fBestPixelAlphaError)
+							{
+								fBestPixelAlphaError = fPixelAlphaError;
+								auiBestSelectors[uiPixel] = uiSelector;
+								afBestAlphaError[uiPixel] = fBestPixelAlphaError;
+								afBestDecodedAlphas[uiPixel] = fDecodedAlpha;
+							}
+						}
+					}
+
+					float fBlockError = 0.0f;
+					for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+					{
+						fBlockError += afBestAlphaError[uiPixel];
+					}
+
+					if (fBlockError < m_fError)
+					{
+						m_fError = fBlockError;
+
+						m_fBase = fBase;
+						m_fMultiplier = fMultiplier;
+						m_uiModifierTableIndex = uiTableEntry;
+						for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+						{
+							m_auiAlphaSelectors[uiPixel] = auiBestSelectors[uiPixel];
+							m_afDecodedAlphas[uiPixel] = afBestDecodedAlphas[uiPixel];
+						}
+					}
+				}
+			}
+
+		}
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// set the encoding bits based on encoding state
+	//
+	void Block4x4Encoding_RGBA8::SetEncodingBits(void)
+	{
+
+		// set the RGB8 portion
+		Block4x4Encoding_RGB8::SetEncodingBits();
+
+		// set the A8 portion
+		{
+			m_pencodingbitsA8->data.base = (unsigned char)roundf(255.0f * m_fBase);
+			m_pencodingbitsA8->data.table = m_uiModifierTableIndex;
+			m_pencodingbitsA8->data.multiplier = (unsigned char)roundf(m_fMultiplier);
+
+			unsigned long long int ulliSelectorBits = 0;
+			for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+			{
+				unsigned int uiShift = 45 - (3 * uiPixel);
+				ulliSelectorBits |= ((unsigned long long int)m_auiAlphaSelectors[uiPixel]) << uiShift;
+			}
+
+			m_pencodingbitsA8->data.selectors0 = ulliSelectorBits >> 40;
+			m_pencodingbitsA8->data.selectors1 = ulliSelectorBits >> 32;
+			m_pencodingbitsA8->data.selectors2 = ulliSelectorBits >> 24;
+			m_pencodingbitsA8->data.selectors3 = ulliSelectorBits >> 16;
+			m_pencodingbitsA8->data.selectors4 = ulliSelectorBits >> 8;
+			m_pencodingbitsA8->data.selectors5 = ulliSelectorBits;
+		}
+
+	}
+
+	// ####################################################################################################
+	// Block4x4Encoding_RGBA8_Opaque
+	// ####################################################################################################
+
+	// ----------------------------------------------------------------------------------------------------
+	// perform a single encoding iteration
+	// replace the encoding if a better encoding was found
+	// subsequent iterations generally take longer for each iteration
+	// set m_boolDone if encoding is perfect or encoding is finished based on a_fEffort
+	//
+	void Block4x4Encoding_RGBA8_Opaque::PerformIteration(float a_fEffort)
+	{
+		assert(!m_boolDone);
+
+		if (m_uiEncodingIterations == 0)
+		{
+			m_fError = 0.0f;
+
+			for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+			{
+				m_afDecodedAlphas[uiPixel] = 1.0f;
+			}
+		}
+
+		Block4x4Encoding_RGB8::PerformIteration(a_fEffort);
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// set the encoding bits based on encoding state
+	//
+	void Block4x4Encoding_RGBA8_Opaque::SetEncodingBits(void)
+	{
+
+		// set the RGB8 portion
+		Block4x4Encoding_RGB8::SetEncodingBits();
+
+		// set the A8 portion
+		m_pencodingbitsA8->data.base = 255;
+		m_pencodingbitsA8->data.table = 15;
+		m_pencodingbitsA8->data.multiplier = 15;
+		m_pencodingbitsA8->data.selectors0 = 0xFF;
+		m_pencodingbitsA8->data.selectors1 = 0xFF;
+		m_pencodingbitsA8->data.selectors2 = 0xFF;
+		m_pencodingbitsA8->data.selectors3 = 0xFF;
+		m_pencodingbitsA8->data.selectors4 = 0xFF;
+		m_pencodingbitsA8->data.selectors5 = 0xFF;
+
+	}
+
+	// ####################################################################################################
+	// Block4x4Encoding_RGBA8_Transparent
+	// ####################################################################################################
+
+	// ----------------------------------------------------------------------------------------------------
+	// perform a single encoding iteration
+	// replace the encoding if a better encoding was found
+	// subsequent iterations generally take longer for each iteration
+	// set m_boolDone if encoding is perfect or encoding is finished based on a_fEffort
+	//
+	void Block4x4Encoding_RGBA8_Transparent::PerformIteration(float )
+	{
+		assert(!m_boolDone);
+		assert(m_uiEncodingIterations == 0);
+
+		m_mode = MODE_ETC1;
+		m_boolDiff = true;
+		m_boolFlip = false;
+
+		for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
+		{
+			m_afrgbaDecodedColors[uiPixel] = ColorFloatRGBA();
+			m_afDecodedAlphas[uiPixel] = 0.0f;
+		}
+
+		m_fError = 0.0f;
+
+		m_boolDone = true;
+		m_uiEncodingIterations++;
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// set the encoding bits based on encoding state
+	//
+	void Block4x4Encoding_RGBA8_Transparent::SetEncodingBits(void)
+	{
+
+		Block4x4Encoding_RGB8::SetEncodingBits();
+
+		// set the A8 portion
+		m_pencodingbitsA8->data.base = 0;
+		m_pencodingbitsA8->data.table = 0;
+		m_pencodingbitsA8->data.multiplier = 1;
+		m_pencodingbitsA8->data.selectors0 = 0;
+		m_pencodingbitsA8->data.selectors1 = 0;
+		m_pencodingbitsA8->data.selectors2 = 0;
+		m_pencodingbitsA8->data.selectors3 = 0;
+		m_pencodingbitsA8->data.selectors4 = 0;
+		m_pencodingbitsA8->data.selectors5 = 0;
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+}

thirdparty/etc2comp/EtcBlock4x4Encoding_RGBA8.h

@@ -0,0 +1,121 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcBlock4x4Encoding_RGB8.h"
+
+namespace Etc
+{
+	class Block4x4EncodingBits_A8;
+
+	// ################################################################################
+	// Block4x4Encoding_RGBA8
+	// RGBA8 if not completely opaque or transparent
+	// ################################################################################
+
+	class Block4x4Encoding_RGBA8 : public Block4x4Encoding_RGB8
+	{
+	public:
+
+		Block4x4Encoding_RGBA8(void);
+		virtual ~Block4x4Encoding_RGBA8(void);
+
+		virtual void InitFromSource(Block4x4 *a_pblockParent,
+									ColorFloatRGBA *a_pafrgbaSource,
+									unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric);
+
+		virtual void InitFromEncodingBits(Block4x4 *a_pblockParent,
+											unsigned char *a_paucEncodingBits,
+											ColorFloatRGBA *a_pafrgbaSource,
+											ErrorMetric a_errormetric);
+
+		virtual void PerformIteration(float a_fEffort);
+
+		virtual void SetEncodingBits(void);
+
+	protected:
+
+		static const unsigned int MODIFIER_TABLE_ENTRYS = 16;
+		static const unsigned int ALPHA_SELECTOR_BITS = 3;
+		static const unsigned int ALPHA_SELECTORS = 1 << ALPHA_SELECTOR_BITS;
+
+		static float s_aafModifierTable[MODIFIER_TABLE_ENTRYS][ALPHA_SELECTORS];
+
+		void CalculateA8(float a_fRadius);
+
+		Block4x4EncodingBits_A8 *m_pencodingbitsA8;	// A8 portion of Block4x4EncodingBits_RGBA8
+
+		float m_fBase;
+		float m_fMultiplier;
+		unsigned int m_uiModifierTableIndex;
+		unsigned int m_auiAlphaSelectors[PIXELS];
+
+	private:
+
+		inline float DecodePixelAlpha(float a_fBase, float a_fMultiplier,
+										unsigned int a_uiTableIndex, unsigned int a_uiSelector)
+		{
+			float fPixelAlpha = a_fBase + 
+								a_fMultiplier*s_aafModifierTable[a_uiTableIndex][a_uiSelector];
+			if (fPixelAlpha < 0.0f)
+			{
+				fPixelAlpha = 0.0f;
+			}
+			else if (fPixelAlpha > 1.0f)
+			{
+				fPixelAlpha = 1.0f;
+			}
+
+			return fPixelAlpha;
+		}
+
+	};
+
+	// ################################################################################
+	// Block4x4Encoding_RGBA8_Opaque
+	// RGBA8 if all pixels have alpha==1
+	// ################################################################################
+
+	class Block4x4Encoding_RGBA8_Opaque : public Block4x4Encoding_RGBA8
+	{
+	public:
+
+		virtual void PerformIteration(float a_fEffort);
+
+		virtual void SetEncodingBits(void);
+
+	};
+
+	// ################################################################################
+	// Block4x4Encoding_RGBA8_Transparent
+	// RGBA8 if all pixels have alpha==0
+	// ################################################################################
+
+	class Block4x4Encoding_RGBA8_Transparent : public Block4x4Encoding_RGBA8
+	{
+	public:
+
+		virtual void PerformIteration(float a_fEffort);
+
+		virtual void SetEncodingBits(void);
+
+	};
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+} // namespace Etc

thirdparty/etc2comp/EtcColor.h

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <math.h>
+
+namespace Etc
+{
+
+	inline float LogToLinear(float a_fLog)
+	{
+		static const float ALPHA = 0.055f;
+		static const float ONE_PLUS_ALPHA = 1.0f + ALPHA;
+
+		if (a_fLog <= 0.04045f)
+		{
+			return a_fLog / 12.92f;
+		}
+		else
+		{
+			return powf((a_fLog + ALPHA) / ONE_PLUS_ALPHA, 2.4f);
+		}
+	}
+
+	inline float LinearToLog(float &a_fLinear)
+	{
+		static const float ALPHA = 0.055f;
+		static const float ONE_PLUS_ALPHA = 1.0f + ALPHA;
+
+		if (a_fLinear <= 0.0031308f)
+		{
+			return 12.92f * a_fLinear;
+		}
+		else
+		{
+			return ONE_PLUS_ALPHA * powf(a_fLinear, (1.0f/2.4f)) - ALPHA;
+		}
+	}
+
+	class ColorR8G8B8A8
+	{
+	public:
+
+		unsigned char ucR;
+		unsigned char ucG;
+		unsigned char ucB;
+		unsigned char ucA;
+
+	};
+}

thirdparty/etc2comp/EtcColorFloatRGBA.h

@@ -0,0 +1,321 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcConfig.h"
+#include "EtcColor.h"
+
+#include <math.h>
+
+namespace Etc
+{
+
+	class ColorFloatRGBA
+    {
+    public:
+
+		ColorFloatRGBA(void)
+        {
+            fR = fG = fB = fA = 0.0f;
+        }
+
+		ColorFloatRGBA(float a_fR, float a_fG, float a_fB, float a_fA)
+        {
+            fR = a_fR;
+            fG = a_fG;
+            fB = a_fB;
+            fA = a_fA;
+        }
+
+		inline ColorFloatRGBA operator+(ColorFloatRGBA& a_rfrgba)
+		{
+			ColorFloatRGBA frgba;
+			frgba.fR = fR + a_rfrgba.fR;
+			frgba.fG = fG + a_rfrgba.fG;
+			frgba.fB = fB + a_rfrgba.fB;
+			frgba.fA = fA + a_rfrgba.fA;
+			return frgba;
+		}
+
+		inline ColorFloatRGBA operator+(float a_f)
+		{
+			ColorFloatRGBA frgba;
+			frgba.fR = fR + a_f;
+			frgba.fG = fG + a_f;
+			frgba.fB = fB + a_f;
+			frgba.fA = fA;
+			return frgba;
+		}
+
+		inline ColorFloatRGBA operator-(float a_f)
+		{
+			ColorFloatRGBA frgba;
+			frgba.fR = fR - a_f;
+			frgba.fG = fG - a_f;
+			frgba.fB = fB - a_f;
+			frgba.fA = fA;
+			return frgba;
+		}
+
+		inline ColorFloatRGBA operator-(ColorFloatRGBA& a_rfrgba)
+		{
+			ColorFloatRGBA frgba;
+			frgba.fR = fR - a_rfrgba.fR;
+			frgba.fG = fG - a_rfrgba.fG;
+			frgba.fB = fB - a_rfrgba.fB;
+			frgba.fA = fA - a_rfrgba.fA;
+			return frgba;
+		}
+
+		inline ColorFloatRGBA operator*(float a_f)
+		{
+			ColorFloatRGBA frgba;
+			frgba.fR = fR * a_f;
+			frgba.fG = fG * a_f;
+			frgba.fB = fB * a_f;
+			frgba.fA = fA;
+
+			return frgba;
+		}
+
+		inline ColorFloatRGBA ScaleRGB(float a_f)
+		{
+			ColorFloatRGBA frgba;
+			frgba.fR = a_f * fR;
+			frgba.fG = a_f * fG;
+			frgba.fB = a_f * fB;
+			frgba.fA = fA;
+
+			return frgba;
+		}
+
+		inline ColorFloatRGBA RoundRGB(void)
+		{
+			ColorFloatRGBA frgba;
+			frgba.fR = roundf(fR);
+			frgba.fG = roundf(fG);
+			frgba.fB = roundf(fB);
+
+			return frgba;
+		}
+
+		inline ColorFloatRGBA ToLinear()
+		{
+			ColorFloatRGBA frgbaLinear;
+			frgbaLinear.fR = LogToLinear(fR);
+			frgbaLinear.fG = LogToLinear(fG);
+			frgbaLinear.fB = LogToLinear(fB);
+			frgbaLinear.fA = fA;
+
+			return frgbaLinear;
+		}
+
+		inline ColorFloatRGBA ToLog(void)
+		{
+			ColorFloatRGBA frgbaLog;
+			frgbaLog.fR = LinearToLog(fR);
+			frgbaLog.fG = LinearToLog(fG);
+			frgbaLog.fB = LinearToLog(fB);
+			frgbaLog.fA = fA;
+
+			return frgbaLog;
+		}
+
+		inline static ColorFloatRGBA ConvertFromRGBA8(unsigned char a_ucR, 
+			unsigned char a_ucG, unsigned char a_ucB, unsigned char a_ucA)
+		{
+			ColorFloatRGBA frgba;
+
+			frgba.fR = (float)a_ucR / 255.0f;
+			frgba.fG = (float)a_ucG / 255.0f;
+			frgba.fB = (float)a_ucB / 255.0f;
+			frgba.fA = (float)a_ucA / 255.0f;
+
+			return frgba;
+		}
+
+		inline static ColorFloatRGBA ConvertFromRGB4(unsigned char a_ucR4,
+														unsigned char a_ucG4,
+														unsigned char a_ucB4)
+		{
+			ColorFloatRGBA frgba;
+
+			unsigned char ucR8 = (unsigned char)((a_ucR4 << 4) + a_ucR4);
+			unsigned char ucG8 = (unsigned char)((a_ucG4 << 4) + a_ucG4);
+			unsigned char ucB8 = (unsigned char)((a_ucB4 << 4) + a_ucB4);
+
+			frgba.fR = (float)ucR8 / 255.0f;
+			frgba.fG = (float)ucG8 / 255.0f;
+			frgba.fB = (float)ucB8 / 255.0f;
+			frgba.fA = 1.0f;
+
+			return frgba;
+		}
+
+		inline static ColorFloatRGBA ConvertFromRGB5(unsigned char a_ucR5,
+			unsigned char a_ucG5,
+			unsigned char a_ucB5)
+		{
+			ColorFloatRGBA frgba;
+
+			unsigned char ucR8 = (unsigned char)((a_ucR5 << 3) + (a_ucR5 >> 2));
+			unsigned char ucG8 = (unsigned char)((a_ucG5 << 3) + (a_ucG5 >> 2));
+			unsigned char ucB8 = (unsigned char)((a_ucB5 << 3) + (a_ucB5 >> 2));
+
+			frgba.fR = (float)ucR8 / 255.0f;
+			frgba.fG = (float)ucG8 / 255.0f;
+			frgba.fB = (float)ucB8 / 255.0f;
+			frgba.fA = 1.0f;
+
+			return frgba;
+		}
+
+		inline static ColorFloatRGBA ConvertFromR6G7B6(unsigned char a_ucR6,
+			unsigned char a_ucG7,
+			unsigned char a_ucB6)
+		{
+			ColorFloatRGBA frgba;
+
+			unsigned char ucR8 = (unsigned char)((a_ucR6 << 2) + (a_ucR6 >> 4));
+			unsigned char ucG8 = (unsigned char)((a_ucG7 << 1) + (a_ucG7 >> 6));
+			unsigned char ucB8 = (unsigned char)((a_ucB6 << 2) + (a_ucB6 >> 4));
+
+			frgba.fR = (float)ucR8 / 255.0f;
+			frgba.fG = (float)ucG8 / 255.0f;
+			frgba.fB = (float)ucB8 / 255.0f;
+			frgba.fA = 1.0f;
+
+			return frgba;
+		}
+
+		// quantize to 4 bits, expand to 8 bits
+		inline ColorFloatRGBA QuantizeR4G4B4(void) const
+		{
+			ColorFloatRGBA frgba = *this;
+
+			// quantize to 4 bits
+			frgba = frgba.ClampRGB().ScaleRGB(15.0f).RoundRGB();
+			unsigned int uiR4 = (unsigned int)frgba.fR;
+			unsigned int uiG4 = (unsigned int)frgba.fG;
+			unsigned int uiB4 = (unsigned int)frgba.fB;
+
+			// expand to 8 bits
+			frgba.fR = (float) ((uiR4 << 4) + uiR4);
+			frgba.fG = (float) ((uiG4 << 4) + uiG4);
+			frgba.fB = (float) ((uiB4 << 4) + uiB4);
+
+			frgba = frgba.ScaleRGB(1.0f/255.0f);
+
+			return frgba;
+		}
+
+		// quantize to 5 bits, expand to 8 bits
+		inline ColorFloatRGBA QuantizeR5G5B5(void) const
+		{
+			ColorFloatRGBA frgba = *this;
+
+			// quantize to 5 bits
+			frgba = frgba.ClampRGB().ScaleRGB(31.0f).RoundRGB();
+			unsigned int uiR5 = (unsigned int)frgba.fR;
+			unsigned int uiG5 = (unsigned int)frgba.fG;
+			unsigned int uiB5 = (unsigned int)frgba.fB;
+
+			// expand to 8 bits
+			frgba.fR = (float)((uiR5 << 3) + (uiR5 >> 2));
+			frgba.fG = (float)((uiG5 << 3) + (uiG5 >> 2));
+			frgba.fB = (float)((uiB5 << 3) + (uiB5 >> 2));
+
+			frgba = frgba.ScaleRGB(1.0f / 255.0f);
+
+			return frgba;
+		}
+
+		// quantize to 6/7/6 bits, expand to 8 bits
+		inline ColorFloatRGBA QuantizeR6G7B6(void) const
+		{
+			ColorFloatRGBA frgba = *this;
+
+			// quantize to 6/7/6 bits
+			ColorFloatRGBA frgba6 = frgba.ClampRGB().ScaleRGB(63.0f).RoundRGB();
+			ColorFloatRGBA frgba7 = frgba.ClampRGB().ScaleRGB(127.0f).RoundRGB();
+			unsigned int uiR6 = (unsigned int)frgba6.fR;
+			unsigned int uiG7 = (unsigned int)frgba7.fG;
+			unsigned int uiB6 = (unsigned int)frgba6.fB;
+
+			// expand to 8 bits
+			frgba.fR = (float)((uiR6 << 2) + (uiR6 >> 4));
+			frgba.fG = (float)((uiG7 << 1) + (uiG7 >> 6));
+			frgba.fB = (float)((uiB6 << 2) + (uiB6 >> 4));
+
+			frgba = frgba.ScaleRGB(1.0f / 255.0f);
+
+			return frgba;
+		}
+
+		inline ColorFloatRGBA ClampRGB(void)
+		{
+			ColorFloatRGBA frgba = *this;
+			if (frgba.fR < 0.0f) { frgba.fR = 0.0f; }
+			if (frgba.fR > 1.0f) { frgba.fR = 1.0f; }
+			if (frgba.fG < 0.0f) { frgba.fG = 0.0f; }
+			if (frgba.fG > 1.0f) { frgba.fG = 1.0f; }
+			if (frgba.fB < 0.0f) { frgba.fB = 0.0f; }
+			if (frgba.fB > 1.0f) { frgba.fB = 1.0f; }
+
+			return frgba;
+		}
+
+		inline ColorFloatRGBA ClampRGBA(void)
+		{
+			ColorFloatRGBA frgba = *this;
+			if (frgba.fR < 0.0f) { frgba.fR = 0.0f; }
+			if (frgba.fR > 1.0f) { frgba.fR = 1.0f; }
+			if (frgba.fG < 0.0f) { frgba.fG = 0.0f; }
+			if (frgba.fG > 1.0f) { frgba.fG = 1.0f; }
+			if (frgba.fB < 0.0f) { frgba.fB = 0.0f; }
+			if (frgba.fB > 1.0f) { frgba.fB = 1.0f; }
+			if (frgba.fA < 0.0f) { frgba.fA = 0.0f; }
+			if (frgba.fA > 1.0f) { frgba.fA = 1.0f; }
+
+			return frgba;
+		}
+
+		inline int IntRed(float a_fScale)
+		{
+			return (int)roundf(fR * a_fScale);
+		}
+
+		inline int IntGreen(float a_fScale)
+		{
+			return (int)roundf(fG * a_fScale);
+		}
+
+		inline int IntBlue(float a_fScale)
+		{
+			return (int)roundf(fB * a_fScale);
+		}
+
+		inline int IntAlpha(float a_fScale)
+		{
+			return (int)roundf(fA * a_fScale);
+		}
+
+		float	fR, fG, fB, fA;
+    };
+
+}
+

thirdparty/etc2comp/EtcConfig.h

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#ifdef _WIN32
+#define ETC_WINDOWS (1)
+#else
+#define ETC_WINDOWS (0)
+#endif
+
+#if __APPLE__
+#define ETC_OSX (1)
+#else
+#define ETC_OSX (0)
+#endif
+
+#if __unix__
+#define ETC_UNIX (1)
+#else
+#define ETC_UNIX (0)
+#endif
+
+
+// short names for common types
+#include <stdint.h>
+typedef int8_t i8;
+typedef int16_t i16;
+typedef int32_t i32;
+typedef int64_t i64;
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+typedef float	f32;
+typedef double	f64;
+
+// Keep asserts enabled in release builds during development
+#undef NDEBUG
+
+// 0=disable. stb_image can be used if you need to compress
+//other image formats like jpg
+#define USE_STB_IMAGE_LOAD 0
+
+#if ETC_WINDOWS
+#include <sdkddkver.h>
+#define _CRT_SECURE_NO_WARNINGS (1)
+#include <tchar.h>
+#endif
+
+#include <stdio.h>
+

thirdparty/etc2comp/EtcDifferentialTrys.cpp

@@ -0,0 +1,173 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+EtcDifferentialTrys.cpp
+
+Gathers the results of the various encoding trys for both halves of a 4x4 block for Differential mode
+
+*/
+
+#include "EtcConfig.h"
+#include "EtcDifferentialTrys.h"
+
+#include <assert.h>
+
+namespace Etc
+{
+
+	// ----------------------------------------------------------------------------------------------------
+	// construct a list of trys (encoding attempts)
+	//
+	// a_frgbaColor1 is the basecolor for the first half
+	// a_frgbaColor2 is the basecolor for the second half
+	// a_pauiPixelMapping1 is the pixel order for the first half
+	// a_pauiPixelMapping2 is the pixel order for the second half
+	// a_uiRadius is the amount to vary the base colors
+	//
+	DifferentialTrys::DifferentialTrys(ColorFloatRGBA a_frgbaColor1, ColorFloatRGBA a_frgbaColor2,
+										const unsigned int *a_pauiPixelMapping1,
+										const unsigned int *a_pauiPixelMapping2,
+										unsigned int a_uiRadius,
+										int a_iGrayOffset1, int a_iGrayOffset2)
+	{
+		assert(a_uiRadius <= MAX_RADIUS);
+
+		m_boolSeverelyBentColors = false;
+
+		ColorFloatRGBA frgbaQuantizedColor1 = a_frgbaColor1.QuantizeR5G5B5();
+		ColorFloatRGBA frgbaQuantizedColor2 = a_frgbaColor2.QuantizeR5G5B5();
+
+		// quantize base colors
+		// ensure that trys with a_uiRadius don't overflow
+		int iRed1 = MoveAwayFromEdge(frgbaQuantizedColor1.IntRed(31.0f)+a_iGrayOffset1, a_uiRadius);
+		int iGreen1 = MoveAwayFromEdge(frgbaQuantizedColor1.IntGreen(31.0f) + a_iGrayOffset1, a_uiRadius);
+		int iBlue1 = MoveAwayFromEdge(frgbaQuantizedColor1.IntBlue(31.0f) + a_iGrayOffset1, a_uiRadius);
+		int iRed2 = MoveAwayFromEdge(frgbaQuantizedColor2.IntRed(31.0f) + a_iGrayOffset2, a_uiRadius);
+		int iGreen2 = MoveAwayFromEdge(frgbaQuantizedColor2.IntGreen(31.0f) + a_iGrayOffset2, a_uiRadius);
+		int iBlue2 = MoveAwayFromEdge(frgbaQuantizedColor2.IntBlue(31.0f) + a_iGrayOffset2, a_uiRadius);
+
+		int iDeltaRed = iRed2 - iRed1;
+		int iDeltaGreen = iGreen2 - iGreen1;
+		int iDeltaBlue = iBlue2 - iBlue1;
+
+		// make sure components are within range
+		{
+			if (iDeltaRed > 3)
+			{
+				if (iDeltaRed > 7)
+				{
+					m_boolSeverelyBentColors = true;
+				}
+
+				iRed1 += (iDeltaRed - 3) / 2;
+				iRed2 = iRed1 + 3;
+				iDeltaRed = 3;
+			}
+			else if (iDeltaRed < -4)
+			{
+				if (iDeltaRed < -8)
+				{
+					m_boolSeverelyBentColors = true;
+				}
+
+				iRed1 += (iDeltaRed + 4) / 2;
+				iRed2 = iRed1 - 4;
+				iDeltaRed = -4;
+			}
+			assert(iRed1 >= (signed)(0 + a_uiRadius) && iRed1 <= (signed)(31 - a_uiRadius));
+			assert(iRed2 >= (signed)(0 + a_uiRadius) && iRed2 <= (signed)(31 - a_uiRadius));
+			assert(iDeltaRed >= -4 && iDeltaRed <= 3);
+
+			if (iDeltaGreen > 3)
+			{
+				if (iDeltaGreen > 7)
+				{
+					m_boolSeverelyBentColors = true;
+				}
+
+				iGreen1 += (iDeltaGreen - 3) / 2;
+				iGreen2 = iGreen1 + 3;
+				iDeltaGreen = 3;
+			}
+			else if (iDeltaGreen < -4)
+			{
+				if (iDeltaGreen < -8)
+				{
+					m_boolSeverelyBentColors = true;
+				}
+
+				iGreen1 += (iDeltaGreen + 4) / 2;
+				iGreen2 = iGreen1 - 4;
+				iDeltaGreen = -4;
+			}
+			assert(iGreen1 >= (signed)(0 + a_uiRadius) && iGreen1 <= (signed)(31 - a_uiRadius));
+			assert(iGreen2 >= (signed)(0 + a_uiRadius) && iGreen2 <= (signed)(31 - a_uiRadius));
+			assert(iDeltaGreen >= -4 && iDeltaGreen <= 3);
+
+			if (iDeltaBlue > 3)
+			{
+				if (iDeltaBlue > 7)
+				{
+					m_boolSeverelyBentColors = true;
+				}
+
+				iBlue1 += (iDeltaBlue - 3) / 2;
+				iBlue2 = iBlue1 + 3;
+				iDeltaBlue = 3;
+			}
+			else if (iDeltaBlue < -4)
+			{
+				if (iDeltaBlue < -8)
+				{
+					m_boolSeverelyBentColors = true;
+				}
+
+				iBlue1 += (iDeltaBlue + 4) / 2;
+				iBlue2 = iBlue1 - 4;
+				iDeltaBlue = -4;
+			}
+			assert(iBlue1 >= (signed)(0+a_uiRadius) && iBlue1 <= (signed)(31 - a_uiRadius));
+			assert(iBlue2 >= (signed)(0 + a_uiRadius) && iBlue2 <= (signed)(31 - a_uiRadius));
+			assert(iDeltaBlue >= -4 && iDeltaBlue <= 3);
+		}
+
+		m_half1.Init(iRed1, iGreen1, iBlue1, a_pauiPixelMapping1, a_uiRadius);
+		m_half2.Init(iRed2, iGreen2, iBlue2, a_pauiPixelMapping2, a_uiRadius);
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	void DifferentialTrys::Half::Init(int a_iRed, int a_iGreen, int a_iBlue, 
+										const unsigned int *a_pauiPixelMapping, unsigned int a_uiRadius)
+	{
+
+		m_iRed = a_iRed;
+		m_iGreen = a_iGreen;
+		m_iBlue = a_iBlue;
+
+		m_pauiPixelMapping = a_pauiPixelMapping;
+		m_uiRadius = a_uiRadius;
+
+		m_uiTrys = 0;
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+} // namespace Etc

thirdparty/etc2comp/EtcDifferentialTrys.h

@@ -0,0 +1,97 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcColorFloatRGBA.h"
+
+namespace Etc
+{
+
+	class DifferentialTrys
+	{
+	public:
+
+		static const unsigned int MAX_RADIUS = 2;
+
+		DifferentialTrys(ColorFloatRGBA a_frgbaColor1,
+							ColorFloatRGBA a_frgbaColor2,
+							const unsigned int *a_pauiPixelMapping1,
+							const unsigned int *a_pauiPixelMapping2,
+							unsigned int a_uiRadius,
+							int a_iGrayOffset1, int a_iGrayOffset2);
+
+		inline static int MoveAwayFromEdge(int a_i, int a_iDistance)
+		{
+			if (a_i < (0+ a_iDistance))
+			{
+				return (0 + a_iDistance);
+			}
+			else if (a_i > (31- a_iDistance))
+			{
+				return (31 - a_iDistance);
+			}
+
+			return a_i;
+		}
+
+		class Try
+		{
+        public :
+			static const unsigned int SELECTORS = 8;	// per half
+
+			int m_iRed;
+			int m_iGreen;
+			int m_iBlue;
+			unsigned int m_uiCW;
+			unsigned int m_auiSelectors[SELECTORS];
+			float m_fError;
+        };
+
+		class Half
+		{
+		public:
+
+			static const unsigned int MAX_TRYS = 125;
+
+			void Init(int a_iRed, int a_iGreen, int a_iBlue, 
+						const unsigned int *a_pauiPixelMapping,
+						unsigned int a_uiRadius);
+
+			// center of trys
+			int m_iRed;
+			int m_iGreen;
+			int m_iBlue;
+
+			const unsigned int *m_pauiPixelMapping;
+			unsigned int m_uiRadius;
+
+			unsigned int m_uiTrys;
+			Try m_atry[MAX_TRYS];
+
+			Try *m_ptryBest;
+		};
+
+		Half m_half1;
+		Half m_half2;
+
+		bool m_boolSeverelyBentColors;
+	};
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+} // namespace Etc

thirdparty/etc2comp/EtcErrorMetric.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+namespace Etc
+{
+
+	enum ErrorMetric
+	{
+		RGBA,
+		RGBX,
+		REC709,
+		NUMERIC,
+		NORMALXYZ,
+		//
+		ERROR_METRICS,
+		//
+		BT709 = REC709
+	};
+
+	inline const char *ErrorMetricToString(ErrorMetric errorMetric)
+	{
+		switch (errorMetric)
+		{
+		case RGBA:
+			return "RGBA";
+		case RGBX:
+			return "RGBX";
+		case REC709:
+			return "REC709";
+		case NUMERIC:
+			return "NUMERIC";
+		case NORMALXYZ:
+			return "NORMALXYZ";
+		case ERROR_METRICS:
+		default:
+			return "UNKNOWN";
+		}
+	}
+} // namespace Etc

thirdparty/etc2comp/EtcFile.cpp

@@ -0,0 +1,390 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifdef _WIN32
+#define _CRT_SECURE_NO_WARNINGS (1)
+#endif
+
+#include "EtcConfig.h"
+
+
+#include "EtcFile.h"
+
+#include "EtcFileHeader.h"
+#include "EtcColor.h"
+#include "Etc.h"
+#include "EtcBlock4x4EncodingBits.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <stdlib.h>
+
+using namespace Etc;
+
+// ----------------------------------------------------------------------------------------------------
+//
+File::File(const char *a_pstrFilename, Format a_fileformat, Image::Format a_imageformat,
+			unsigned char *a_paucEncodingBits, unsigned int a_uiEncodingBitsBytes,
+			unsigned int a_uiSourceWidth, unsigned int a_uiSourceHeight,
+			unsigned int a_uiExtendedWidth, unsigned int a_uiExtendedHeight)
+{
+	if (a_pstrFilename == nullptr)
+	{
+		m_pstrFilename = const_cast<char *>("");
+	}
+	else
+	{
+		m_pstrFilename = new char[strlen(a_pstrFilename) + 1];
+		strcpy(m_pstrFilename, a_pstrFilename);
+	}
+
+	m_fileformat = a_fileformat;
+	if (m_fileformat == Format::INFER_FROM_FILE_EXTENSION)
+	{
+		// ***** TODO: add this later *****
+		m_fileformat = Format::KTX;
+	}
+
+	m_imageformat = a_imageformat;
+
+	m_uiNumMipmaps = 1;
+	m_pMipmapImages = new RawImage[m_uiNumMipmaps];
+	m_pMipmapImages[0].paucEncodingBits = std::shared_ptr<unsigned char>(a_paucEncodingBits, [](unsigned char *p) { delete[] p; } );
+	m_pMipmapImages[0].uiEncodingBitsBytes = a_uiEncodingBitsBytes;
+	m_pMipmapImages[0].uiExtendedWidth = a_uiExtendedWidth;
+	m_pMipmapImages[0].uiExtendedHeight = a_uiExtendedHeight;
+
+	m_uiSourceWidth = a_uiSourceWidth;
+	m_uiSourceHeight = a_uiSourceHeight;
+
+	switch (m_fileformat)
+	{
+	case Format::PKM:
+		m_pheader = new FileHeader_Pkm(this);
+		break;
+
+	case Format::KTX:
+		m_pheader = new FileHeader_Ktx(this);
+		break;
+
+	default:
+		assert(0);
+		break;
+	}
+
+}
+
+// ----------------------------------------------------------------------------------------------------
+//
+File::File(const char *a_pstrFilename, Format a_fileformat, Image::Format a_imageformat,
+	unsigned int a_uiNumMipmaps, RawImage *a_pMipmapImages,
+	unsigned int a_uiSourceWidth, unsigned int a_uiSourceHeight)
+{
+	if (a_pstrFilename == nullptr)
+	{
+		m_pstrFilename = const_cast<char *>("");
+	}
+	else
+	{
+		m_pstrFilename = new char[strlen(a_pstrFilename) + 1];
+		strcpy(m_pstrFilename, a_pstrFilename);
+	}
+
+	m_fileformat = a_fileformat;
+	if (m_fileformat == Format::INFER_FROM_FILE_EXTENSION)
+	{
+		// ***** TODO: add this later *****
+		m_fileformat = Format::KTX;
+	}
+
+	m_imageformat = a_imageformat;
+
+	m_uiNumMipmaps = a_uiNumMipmaps;
+	m_pMipmapImages = new RawImage[m_uiNumMipmaps];
+
+	for(unsigned int mip = 0; mip < m_uiNumMipmaps; mip++)
+	{
+		m_pMipmapImages[mip] = a_pMipmapImages[mip];
+	}
+
+	m_uiSourceWidth = a_uiSourceWidth;
+	m_uiSourceHeight = a_uiSourceHeight;
+
+	switch (m_fileformat)
+	{
+	case Format::PKM:
+		m_pheader = new FileHeader_Pkm(this);
+		break;
+
+	case Format::KTX:
+		m_pheader = new FileHeader_Ktx(this);
+		break;
+
+	default:
+		assert(0);
+		break;
+	}
+
+}
+
+// ----------------------------------------------------------------------------------------------------
+//
+File::File(const char *a_pstrFilename, Format a_fileformat)
+{
+	if (a_pstrFilename == nullptr)
+	{
+		return;
+	}
+	else
+	{
+		m_pstrFilename = new char[strlen(a_pstrFilename) + 1];
+		strcpy(m_pstrFilename, a_pstrFilename);
+	}
+
+	m_fileformat = a_fileformat;
+	if (m_fileformat == Format::INFER_FROM_FILE_EXTENSION)
+	{
+		// ***** TODO: add this later *****
+		m_fileformat = Format::KTX;
+	}
+
+	FILE *pfile = fopen(m_pstrFilename, "rb");
+	if (pfile == nullptr)
+	{
+		printf("ERROR: Couldn't open %s", m_pstrFilename);
+		exit(1);
+	}
+	fseek(pfile, 0, SEEK_END);
+	unsigned int fileSize = ftell(pfile);
+	fseek(pfile, 0, SEEK_SET);
+	size_t szResult;
+
+	m_pheader = new FileHeader_Ktx(this);
+	szResult = fread( ((FileHeader_Ktx*)m_pheader)->GetData(), 1, sizeof(FileHeader_Ktx::Data), pfile);
+	assert(szResult > 0);
+
+	m_uiNumMipmaps = 1;
+	m_pMipmapImages = new RawImage[m_uiNumMipmaps];
+
+	if (((FileHeader_Ktx*)m_pheader)->GetData()->m_u32BytesOfKeyValueData > 0)
+		fseek(pfile, ((FileHeader_Ktx*)m_pheader)->GetData()->m_u32BytesOfKeyValueData, SEEK_CUR);
+	szResult = fread(&m_pMipmapImages->uiEncodingBitsBytes, 1, sizeof(unsigned int), pfile);
+	assert(szResult > 0);
+
+	m_pMipmapImages->paucEncodingBits = std::shared_ptr<unsigned char>(new unsigned char[m_pMipmapImages->uiEncodingBitsBytes], [](unsigned char *p) { delete[] p; } );
+	assert(ftell(pfile) + m_pMipmapImages->uiEncodingBitsBytes <= fileSize);
+	szResult = fread(m_pMipmapImages->paucEncodingBits.get(), 1, m_pMipmapImages->uiEncodingBitsBytes, pfile);
+	assert(szResult == m_pMipmapImages->uiEncodingBitsBytes);
+
+	uint32_t uiInternalFormat = ((FileHeader_Ktx*)m_pheader)->GetData()->m_u32GlInternalFormat;
+	uint32_t uiBaseInternalFormat = ((FileHeader_Ktx*)m_pheader)->GetData()->m_u32GlBaseInternalFormat;
+	
+	if (uiInternalFormat == (uint32_t)FileHeader_Ktx::InternalFormat::ETC1_RGB8 && uiBaseInternalFormat == (uint32_t)FileHeader_Ktx::BaseInternalFormat::ETC1_RGB8)
+	{
+		m_imageformat = Image::Format::ETC1;
+	}
+	else if (uiInternalFormat == (uint32_t)FileHeader_Ktx::InternalFormat::ETC2_RGB8 && uiBaseInternalFormat == (uint32_t)FileHeader_Ktx::BaseInternalFormat::ETC2_RGB8)
+	{
+		m_imageformat = Image::Format::RGB8;
+	}
+	else if (uiInternalFormat == (uint32_t)FileHeader_Ktx::InternalFormat::ETC2_RGB8A1 && uiBaseInternalFormat == (uint32_t)FileHeader_Ktx::BaseInternalFormat::ETC2_RGB8A1)
+	{
+		m_imageformat = Image::Format::RGB8A1;
+	}
+	else if (uiInternalFormat == (uint32_t)FileHeader_Ktx::InternalFormat::ETC2_RGBA8 && uiBaseInternalFormat == (uint32_t)FileHeader_Ktx::BaseInternalFormat::ETC2_RGBA8)
+	{
+		m_imageformat = Image::Format::RGBA8;
+	}
+	else if (uiInternalFormat == (uint32_t)FileHeader_Ktx::InternalFormat::ETC2_R11 && uiBaseInternalFormat == (uint32_t)FileHeader_Ktx::BaseInternalFormat::ETC2_R11)
+	{
+		m_imageformat = Image::Format::R11;
+	}
+	else if (uiInternalFormat == (uint32_t)FileHeader_Ktx::InternalFormat::ETC2_SIGNED_R11 && uiBaseInternalFormat == (uint32_t)FileHeader_Ktx::BaseInternalFormat::ETC2_R11)
+	{
+		m_imageformat = Image::Format::SIGNED_R11;
+	}
+	else if (uiInternalFormat == (uint32_t)FileHeader_Ktx::InternalFormat::ETC2_RG11 && uiBaseInternalFormat == (uint32_t)FileHeader_Ktx::BaseInternalFormat::ETC2_RG11)
+	{
+		m_imageformat = Image::Format::RG11;
+	}
+	else if (uiInternalFormat == (uint32_t)FileHeader_Ktx::InternalFormat::ETC2_SIGNED_RG11 && uiBaseInternalFormat == (uint32_t)FileHeader_Ktx::BaseInternalFormat::ETC2_RG11)
+	{
+		m_imageformat = Image::Format::SIGNED_RG11;
+	}
+	else
+	{
+		m_imageformat = Image::Format::UNKNOWN;
+	}
+
+	m_uiSourceWidth = ((FileHeader_Ktx*)m_pheader)->GetData()->m_u32PixelWidth;
+	m_uiSourceHeight = ((FileHeader_Ktx*)m_pheader)->GetData()->m_u32PixelHeight;
+	m_pMipmapImages->uiExtendedWidth = Image::CalcExtendedDimension((unsigned short)m_uiSourceWidth);
+	m_pMipmapImages->uiExtendedHeight = Image::CalcExtendedDimension((unsigned short)m_uiSourceHeight);
+
+	unsigned int uiBlocks = m_pMipmapImages->uiExtendedWidth * m_pMipmapImages->uiExtendedHeight / 16;
+	Block4x4EncodingBits::Format encodingbitsformat = Image::DetermineEncodingBitsFormat(m_imageformat);
+	unsigned int expectedbytes = uiBlocks * Block4x4EncodingBits::GetBytesPerBlock(encodingbitsformat);
+	assert(expectedbytes == m_pMipmapImages->uiEncodingBitsBytes);
+
+	fclose(pfile);
+}
+
+File::~File()
+{
+	if (m_pMipmapImages != nullptr)
+	{
+		delete [] m_pMipmapImages;
+	}
+
+	if(m_pstrFilename != nullptr)
+	{
+		delete[] m_pstrFilename;
+		m_pstrFilename = nullptr;
+	}
+	if (m_pheader != nullptr)
+	{
+		delete m_pheader;
+		m_pheader = nullptr;
+	}
+}
+
+void File::UseSingleBlock(int a_iPixelX, int a_iPixelY)
+{
+	if (a_iPixelX <= -1 || a_iPixelY <= -1)
+		return;
+	if (a_iPixelX >(int) m_uiSourceWidth)
+	{
+		//if we are using a ktx thats the size of a single block or less
+		//then make sure we use the 4x4 image as the single block
+		if (m_uiSourceWidth <= 4)
+		{
+			a_iPixelX = 0;
+		}
+		else
+		{
+			printf("blockAtHV: H coordinate out of range, capped to image width\n");
+			a_iPixelX = m_uiSourceWidth - 1;
+		}
+	}
+	if (a_iPixelY >(int) m_uiSourceHeight)
+	{
+		//if we are using a ktx thats the size of a single block or less
+		//then make sure we use the 4x4 image as the single block
+		if (m_uiSourceHeight <= 4)
+		{
+			a_iPixelY= 0;
+		}
+		else
+		{
+			printf("blockAtHV: V coordinate out of range, capped to image height\n");
+			a_iPixelY = m_uiSourceHeight - 1;
+		}
+	}
+
+	unsigned int origWidth = m_uiSourceWidth;
+	unsigned int origHeight = m_uiSourceHeight;
+
+	m_uiSourceWidth = 4;
+	m_uiSourceHeight = 4;
+
+	Block4x4EncodingBits::Format encodingbitsformat = Image::DetermineEncodingBitsFormat(m_imageformat);
+	unsigned int uiEncodingBitsBytesPerBlock = Block4x4EncodingBits::GetBytesPerBlock(encodingbitsformat);
+
+	int numMipmaps = 1;
+	RawImage* pMipmapImages = new RawImage[numMipmaps];
+	pMipmapImages[0].uiExtendedWidth = Image::CalcExtendedDimension((unsigned short)m_uiSourceWidth);
+	pMipmapImages[0].uiExtendedHeight = Image::CalcExtendedDimension((unsigned short)m_uiSourceHeight);
+	pMipmapImages[0].uiEncodingBitsBytes = 0;
+	pMipmapImages[0].paucEncodingBits = std::shared_ptr<unsigned char>(new unsigned char[uiEncodingBitsBytesPerBlock], [](unsigned char *p) { delete[] p; });
+
+	//block position in pixels
+	// remove the bottom 2 bits to get the block coordinates 
+	unsigned int iBlockPosX = (a_iPixelX & 0xFFFFFFFC);
+	unsigned int iBlockPosY = (a_iPixelY & 0xFFFFFFFC);
+
+	int numXBlocks = (origWidth / 4);
+	int numYBlocks = (origHeight / 4);
+	
+
+	// block location 
+	//int iBlockX = (a_iPixelX % 4) == 0 ? a_iPixelX / 4.0f : (a_iPixelX / 4) + 1;
+	//int iBlockY = (a_iPixelY % 4) == 0 ? a_iPixelY / 4.0f : (a_iPixelY / 4) + 1;
+	//m_paucEncodingBits += ((iBlockY * numXBlocks) + iBlockX) * uiEncodingBitsBytesPerBlock;
+
+	
+	unsigned int num = numXBlocks*numYBlocks;
+	unsigned int uiH = 0, uiV = 0;
+	unsigned char* pEncodingBits = m_pMipmapImages[0].paucEncodingBits.get();
+	for (unsigned int uiBlock = 0; uiBlock < num; uiBlock++)
+	{
+		if (uiH == iBlockPosX && uiV == iBlockPosY)
+		{
+			memcpy(pMipmapImages[0].paucEncodingBits.get(),pEncodingBits, uiEncodingBitsBytesPerBlock);
+			break;
+		}
+		pEncodingBits += uiEncodingBitsBytesPerBlock;
+		uiH += 4;
+
+		if (uiH >= origWidth)
+		{
+			uiH = 0;
+			uiV += 4;
+		}
+	}
+
+	delete [] m_pMipmapImages;
+	m_pMipmapImages = pMipmapImages;
+}
+// ----------------------------------------------------------------------------------------------------
+//
+void File::Write()
+{
+
+	FILE *pfile = fopen(m_pstrFilename, "wb");
+	if (pfile == nullptr)
+	{
+		printf("Error: couldn't open Etc file (%s)\n", m_pstrFilename);
+		exit(1);
+	}
+
+	m_pheader->Write(pfile);
+
+	for(unsigned int mip = 0; mip < m_uiNumMipmaps; mip++)
+	{
+		if(m_fileformat == Format::KTX)
+		{
+			// Write u32 image size
+			uint32_t u32ImageSize = m_pMipmapImages[mip].uiEncodingBitsBytes;
+			uint32_t szBytesWritten = fwrite(&u32ImageSize, 1, sizeof(u32ImageSize), pfile);
+			assert(szBytesWritten == sizeof(u32ImageSize));
+		}
+
+		unsigned int iResult = (int)fwrite(m_pMipmapImages[mip].paucEncodingBits.get(), 1, m_pMipmapImages[mip].uiEncodingBitsBytes, pfile);
+		if (iResult != m_pMipmapImages[mip].uiEncodingBitsBytes)
+	{
+		printf("Error: couldn't write Etc file (%s)\n", m_pstrFilename);
+		exit(1);
+		}
+	}
+
+	fclose(pfile);
+
+}
+
+// ----------------------------------------------------------------------------------------------------
+//
+

thirdparty/etc2comp/EtcFile.h

@@ -0,0 +1,136 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcColorFloatRGBA.h"
+#include "EtcImage.h"
+#include "Etc.h"
+
+namespace Etc
+{
+	class FileHeader;
+	class SourceImage;
+
+	class File
+	{
+	public:
+
+		enum class Format
+		{
+			INFER_FROM_FILE_EXTENSION,
+			PKM,
+			KTX,
+		};
+
+		File(const char *a_pstrFilename, Format a_fileformat, Image::Format a_imageformat,
+				unsigned char *a_paucEncodingBits, unsigned int a_uiEncodingBitsBytes,
+				unsigned int a_uiSourceWidth, unsigned int a_uiSourceHeight,
+				unsigned int a_uiExtendedWidth, unsigned int a_uiExtendedHeight);
+
+		File(const char *a_pstrFilename, Format a_fileformat, Image::Format a_imageformat,
+			unsigned int a_uiNumMipmaps, RawImage *pMipmapImages,
+			unsigned int a_uiSourceWidth, unsigned int a_uiSourceHeight );
+
+		File(const char *a_pstrFilename, Format a_fileformat);
+		~File();
+		const char *GetFilename(void) { return m_pstrFilename; }
+
+		void Read(const char *a_pstrFilename);
+		void Write(void);
+
+		inline unsigned int GetSourceWidth(void)
+		{
+			return m_uiSourceWidth;
+		}
+
+		inline unsigned int GetSourceHeight(void)
+		{
+			return m_uiSourceHeight;
+		}
+
+		inline unsigned int GetExtendedWidth(unsigned int mipmapIndex = 0)
+		{
+			if (mipmapIndex < m_uiNumMipmaps)
+			{
+				return m_pMipmapImages[mipmapIndex].uiExtendedWidth;
+			}
+			else
+			{
+				return 0;
+			}
+		}
+
+		inline unsigned int GetExtendedHeight(unsigned int mipmapIndex = 0)
+		{
+			if (mipmapIndex < m_uiNumMipmaps)
+			{
+				return m_pMipmapImages[mipmapIndex].uiExtendedHeight;
+			}
+			else
+			{
+				return 0;
+			}
+		}
+
+		inline Image::Format GetImageFormat()
+		{
+			return m_imageformat;
+		}
+
+		inline unsigned int GetEncodingBitsBytes(unsigned int mipmapIndex = 0)
+		{
+			if (mipmapIndex < m_uiNumMipmaps)
+			{
+				return m_pMipmapImages[mipmapIndex].uiEncodingBitsBytes;
+			}
+			else
+			{
+				return 0;
+			}
+		}
+
+		inline unsigned char*  GetEncodingBits(unsigned int mipmapIndex = 0)
+		{
+			if( mipmapIndex < m_uiNumMipmaps)
+			{
+				return m_pMipmapImages[mipmapIndex].paucEncodingBits.get();
+			}
+			else
+			{
+				return nullptr;
+			}
+		}
+
+		inline unsigned int GetNumMipmaps() 
+		{
+			return m_uiNumMipmaps; 
+		}
+
+		void UseSingleBlock(int a_iPixelX = -1, int a_iPixelY = -1);
+	private:
+
+		char *m_pstrFilename;               // includes directory path and file extension
+		Format m_fileformat;
+		Image::Format m_imageformat;
+		FileHeader *m_pheader;
+		unsigned int m_uiNumMipmaps;
+		RawImage*	 m_pMipmapImages;
+		unsigned int m_uiSourceWidth;
+		unsigned int m_uiSourceHeight;
+	};
+
+}

thirdparty/etc2comp/EtcFileHeader.cpp

@@ -0,0 +1,185 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "EtcFileHeader.h"
+
+#include "EtcBlock4x4EncodingBits.h"
+
+#include <assert.h>
+
+namespace Etc
+{
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	FileHeader_Pkm::FileHeader_Pkm(File *a_pfile)
+	{
+		m_pfile = a_pfile;
+
+		static const char s_acMagicNumberData[4] = { 'P', 'K', 'M', ' ' };
+		static const char s_acVersionData[2] = { '1', '0' };
+
+		for (unsigned int ui = 0; ui < sizeof(s_acMagicNumberData); ui++)
+		{
+			m_data.m_acMagicNumber[ui] = s_acMagicNumberData[ui];
+		}
+
+		for (unsigned int ui = 0; ui < sizeof(s_acVersionData); ui++)
+		{
+			m_data.m_acVersion[ui] = s_acVersionData[ui];
+		}
+
+		m_data.m_ucDataType_msb = 0;        // ETC1_RGB_NO_MIPMAPS
+		m_data.m_ucDataType_lsb = 0;
+
+		m_data.m_ucOriginalWidth_msb = (unsigned char)(m_pfile->GetSourceWidth() >> 8);
+		m_data.m_ucOriginalWidth_lsb = m_pfile->GetSourceWidth() & 0xFF;
+		m_data.m_ucOriginalHeight_msb = (unsigned char)(m_pfile->GetSourceHeight() >> 8);
+		m_data.m_ucOriginalHeight_lsb = m_pfile->GetSourceHeight() & 0xFF;
+
+		m_data.m_ucExtendedWidth_msb = (unsigned char)(m_pfile->GetExtendedWidth() >> 8);
+		m_data.m_ucExtendedWidth_lsb = m_pfile->GetExtendedWidth() & 0xFF;
+		m_data.m_ucExtendedHeight_msb = (unsigned char)(m_pfile->GetExtendedHeight() >> 8);
+		m_data.m_ucExtendedHeight_lsb = m_pfile->GetExtendedHeight() & 0xFF;
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	void FileHeader_Pkm::Write(FILE *a_pfile)
+	{
+
+		fwrite(&m_data, sizeof(Data), 1, a_pfile);
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	FileHeader_Ktx::FileHeader_Ktx(File *a_pfile)
+	{
+		m_pfile = a_pfile;
+
+		static const uint8_t s_au8Itentfier[12] =
+		{ 
+			0xAB, 0x4B, 0x54, 0x58, // first four bytes of Byte[12] identifier
+			0x20, 0x31, 0x31, 0xBB, // next four bytes of Byte[12] identifier
+			0x0D, 0x0A, 0x1A, 0x0A  // final four bytes of Byte[12] identifier
+		};
+
+		for (unsigned int ui = 0; ui < sizeof(s_au8Itentfier); ui++)
+		{
+			m_data.m_au8Identifier[ui] = s_au8Itentfier[ui];
+		}
+
+		m_data.m_u32Endianness				= 0x04030201;
+		m_data.m_u32GlType					= 0;
+		m_data.m_u32GlTypeSize				= 1;
+		m_data.m_u32GlFormat				= 0;
+
+		switch (m_pfile->GetImageFormat())
+		{
+		case Image::Format::RGB8:
+		case Image::Format::SRGB8:
+			m_data.m_u32GlInternalFormat = (unsigned int)InternalFormat::ETC2_RGB8;
+			m_data.m_u32GlBaseInternalFormat = (unsigned int)BaseInternalFormat::ETC2_RGB8;
+			break;
+
+		case Image::Format::RGBA8:
+		case Image::Format::SRGBA8:
+			m_data.m_u32GlInternalFormat = (unsigned int)InternalFormat::ETC2_RGBA8;
+			m_data.m_u32GlBaseInternalFormat = (unsigned int)BaseInternalFormat::ETC2_RGBA8;
+			break;
+
+		case Image::Format::RGB8A1:
+		case Image::Format::SRGB8A1:
+			m_data.m_u32GlInternalFormat = (unsigned int)InternalFormat::ETC2_RGB8A1;
+			m_data.m_u32GlBaseInternalFormat = (unsigned int)BaseInternalFormat::ETC2_RGB8A1;
+			break;
+		
+		case Image::Format::R11:
+			m_data.m_u32GlInternalFormat = (unsigned int)InternalFormat::ETC2_R11;
+			m_data.m_u32GlBaseInternalFormat = (unsigned int)BaseInternalFormat::ETC2_R11;
+			break;
+
+		case Image::Format::SIGNED_R11:
+			m_data.m_u32GlInternalFormat = (unsigned int)InternalFormat::ETC2_SIGNED_R11;
+			m_data.m_u32GlBaseInternalFormat = (unsigned int)BaseInternalFormat::ETC2_R11;
+			break;
+		
+		case Image::Format::RG11:
+			m_data.m_u32GlInternalFormat = (unsigned int)InternalFormat::ETC2_RG11;
+			m_data.m_u32GlBaseInternalFormat = (unsigned int)BaseInternalFormat::ETC2_RG11;
+			break;
+
+		case Image::Format::SIGNED_RG11:
+			m_data.m_u32GlInternalFormat = (unsigned int)InternalFormat::ETC2_SIGNED_RG11;
+			m_data.m_u32GlBaseInternalFormat = (unsigned int)BaseInternalFormat::ETC2_RG11;
+			break;
+
+		default:
+			m_data.m_u32GlInternalFormat = (unsigned int)InternalFormat::ETC1_RGB8;
+			m_data.m_u32GlBaseInternalFormat = (unsigned int)BaseInternalFormat::ETC1_RGB8;
+			break;
+		}
+
+		m_data.m_u32PixelWidth				= 0;
+		m_data.m_u32PixelHeight				= 0;
+		m_data.m_u32PixelDepth				= 0;
+		m_data.m_u32NumberOfArrayElements	= 0;
+		m_data.m_u32NumberOfFaces			= 0;
+		m_data.m_u32BytesOfKeyValueData		= 0;
+
+		m_pkeyvaluepair = nullptr;
+
+		m_u32Images = 0;
+		m_u32KeyValuePairs = 0;
+
+		m_data.m_u32PixelWidth = m_pfile->GetSourceWidth();
+		m_data.m_u32PixelHeight = m_pfile->GetSourceHeight();
+		m_data.m_u32PixelDepth = 0;
+		m_data.m_u32NumberOfArrayElements = 0;
+		m_data.m_u32NumberOfFaces = 1;
+		m_data.m_u32NumberOfMipmapLevels = m_pfile->GetNumMipmaps();
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	void FileHeader_Ktx::Write(FILE *a_pfile)
+	{
+		size_t szBytesWritten;
+
+		// Write header
+		szBytesWritten = fwrite(&m_data, 1, sizeof(Data), a_pfile);
+		assert(szBytesWritten == sizeof(Data));
+
+		// Write KeyAndValuePairs
+		if (m_u32KeyValuePairs)
+		{
+			fwrite(m_pkeyvaluepair, m_pkeyvaluepair->u32KeyAndValueByteSize, 1, a_pfile);
+		}
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	FileHeader_Ktx::Data *FileHeader_Ktx::GetData()
+	{
+		return &m_data;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+} // namespace Etc

thirdparty/etc2comp/EtcFileHeader.h

@@ -0,0 +1,146 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcFile.h"
+#include <stdio.h>
+#include <inttypes.h>
+
+namespace Etc
+{
+
+	class Image;
+
+	class FileHeader
+	{
+	public:
+
+		virtual void Write(FILE *a_pfile) = 0;
+		File GetFile();
+		virtual ~FileHeader(void) {}
+	protected:
+
+		File *m_pfile;
+	};
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+    class FileHeader_Pkm : public FileHeader
+    {
+    public:
+
+		FileHeader_Pkm(File *a_pfile);
+
+		virtual void Write(FILE *a_pfile);
+		virtual ~FileHeader_Pkm(void) {}
+	private:
+
+		typedef struct
+		{
+			char m_acMagicNumber[4];
+			char m_acVersion[2];
+			unsigned char m_ucDataType_msb;             // e.g. ETC1_RGB_NO_MIPMAPS
+			unsigned char m_ucDataType_lsb;
+			unsigned char m_ucExtendedWidth_msb;     //  padded to 4x4 blocks
+			unsigned char m_ucExtendedWidth_lsb;
+			unsigned char m_ucExtendedHeight_msb;    //  padded to 4x4 blocks
+			unsigned char m_ucExtendedHeight_lsb;
+			unsigned char m_ucOriginalWidth_msb;
+			unsigned char m_ucOriginalWidth_lsb;
+			unsigned char m_ucOriginalHeight_msb;
+			unsigned char m_ucOriginalHeight_lsb;
+		} Data;
+
+		Data m_data;
+	};
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+    class FileHeader_Ktx : public FileHeader
+    {
+    public:
+
+		typedef struct
+		{
+			uint32_t	u32KeyAndValueByteSize;
+		} KeyValuePair;
+
+		typedef struct
+		{
+			uint8_t m_au8Identifier[12];
+			uint32_t m_u32Endianness;
+			uint32_t m_u32GlType;
+			uint32_t m_u32GlTypeSize;
+			uint32_t m_u32GlFormat;
+			uint32_t m_u32GlInternalFormat;
+			uint32_t m_u32GlBaseInternalFormat;
+			uint32_t m_u32PixelWidth;
+			uint32_t m_u32PixelHeight;
+			uint32_t m_u32PixelDepth;
+			uint32_t m_u32NumberOfArrayElements;
+			uint32_t m_u32NumberOfFaces;
+			uint32_t m_u32NumberOfMipmapLevels;
+			uint32_t m_u32BytesOfKeyValueData;
+		} Data;
+
+		enum class InternalFormat
+		{
+			ETC1_RGB8 = 0x8D64,
+			ETC1_ALPHA8 = ETC1_RGB8,
+			//
+			ETC2_R11 = 0x9270,
+			ETC2_SIGNED_R11 = 0x9271,
+			ETC2_RG11 = 0x9272,
+			ETC2_SIGNED_RG11 = 0x9273,
+			ETC2_RGB8 = 0x9274,
+			ETC2_SRGB8 = 0x9275,
+			ETC2_RGB8A1 = 0x9276,
+			ETC2_SRGB8_PUNCHTHROUGH_ALPHA1 = 0x9277,
+			ETC2_RGBA8 = 0x9278
+		};
+
+		enum class BaseInternalFormat
+		{
+			ETC2_R11 = 0x1903,
+			ETC2_RG11 = 0x8227,
+			ETC1_RGB8 = 0x1907,
+			ETC1_ALPHA8 = ETC1_RGB8,
+			//
+			ETC2_RGB8 = 0x1907,
+			ETC2_RGB8A1 = 0x1908,
+			ETC2_RGBA8 = 0x1908,
+		};
+
+		FileHeader_Ktx(File *a_pfile);
+
+		virtual void Write(FILE *a_pfile);
+		virtual ~FileHeader_Ktx(void) {}
+
+		void AddKeyAndValue(KeyValuePair *a_pkeyvaluepair);
+
+		Data* GetData();
+
+	private:
+
+		Data m_data;
+		KeyValuePair *m_pkeyvaluepair;
+		
+		uint32_t m_u32Images;
+		uint32_t m_u32KeyValuePairs;
+	};
+
+} // namespace Etc

thirdparty/etc2comp/EtcFilter.cpp

@@ -0,0 +1,401 @@
+#include <stdlib.h>
+#include <math.h>
+#include "EtcFilter.h"
+
+
+namespace Etc
+{
+
+static const double PiConst = 3.14159265358979323846;
+
+inline double sinc(double x) 
+{
+    if ( x == 0.0 ) 
+    {
+        return 1.0;
+    }
+
+    return sin(PiConst * x) / (PiConst * x);
+}
+
+//inline float sincf( float x )
+//{
+//    x *= F_PI;
+//    if (x < 0.01f && x > -0.01f)
+//    {
+//        return 1.0f + x*x*(-1.0f/6.0f + x*x*1.0f/120.0f);
+//    }
+//
+//    return sinf(x)/x;
+//}
+//
+//double bessel0(double x) 
+//{
+//    const double EPSILON_RATIO = 1E-16;
+//    double xh, sum, pow, ds;
+//    int k;
+//
+//    xh = 0.5 * x;
+//    sum = 1.0;
+//    pow = 1.0;
+//    k = 0;
+//    ds = 1.0;
+//    while (ds > sum * EPSILON_RATIO) 
+//    {
+//        ++k;
+//        pow = pow * (xh / k);
+//        ds = pow * pow;
+//        sum = sum + ds;
+//    }
+//
+//    return sum;
+//}
+
+//**--------------------------------------------------------------------------
+//** Name: kaiser(double alpha, double half_width, double x) 
+//** Returns:
+//** Description: Alpha controls shape of filter.  We are using 4.
+//**--------------------------------------------------------------------------
+//inline double kaiser(double alpha, double half_width, double x) 
+//{
+//    double ratio = (x / half_width);
+//    return bessel0(alpha * sqrt(1 - ratio * ratio)) / bessel0(alpha);
+//}
+//
+//float Filter_Lanczos4Sinc(float x)
+//{
+//    if (x <= -4.0f || x >= 4.0f)    // half-width of 4
+//    {
+//        return 0.0;
+//    }
+//
+//    return sinc(0.875f * x) * sinc(0.25f * x);
+//}
+//
+//double Filter_Kaiser4( double t )
+//{
+//    return kaiser( 4.0, 3.0, t);
+//}
+//
+//double Filter_KaiserOptimal( double t )
+//{
+//    return kaiser( 8.93, 3.0f, t);
+//}                  
+
+double FilterLanczos3( double t )
+{
+	if ( t <= -3.0 || t >= 3.0 ) 
+    {
+        return 0.0;
+    }
+
+    return sinc( t ) * sinc( t / 3.0 );
+}
+
+double FilterBox( double t )
+{
+    return ( t > -0.5 && t < 0.5) ? 1.0 : 0.0;
+}
+
+double FilterLinear( double t )
+{
+	if (t < 0.0) t = -t;
+
+    return (t < 1.0) ? (1.0 - t) : 0.0;
+}
+
+
+//**--------------------------------------------------------------------------
+//** Name: CalcContributions( int srcSize, 
+//**                          int destSize, 
+//**                          double filterSize, 
+//**						  bool wrap,
+//**                          double (*FilterProc)(double), 
+//**                          FilterWeights contrib[] )
+//** Returns: void
+//** Description:
+//**--------------------------------------------------------------------------
+void CalcContributions( int srcSize, int destSize, double filterSize, bool wrap, double (*FilterProc)(double), FilterWeights contrib[] )
+{
+    double scale;
+    double filterScale;
+    double center;
+    double totalWeight;
+    double weight;
+    int   iRight;
+    int   iLeft;
+    int   iDest;
+
+    scale = (double)destSize / srcSize;
+    if ( scale < 1.0 )
+    {
+        filterSize = filterSize / scale;
+        filterScale = scale;
+    }
+    else
+    {
+        filterScale = 1.0;
+    }
+
+    if ( filterSize > (double)MaxFilterSize )
+    {
+        filterSize = (double)MaxFilterSize;
+    }
+
+    for ( iDest = 0; iDest < destSize; ++iDest )
+    {
+        center = (double)iDest / scale;
+
+        iLeft = (int)ceil(center - filterSize);
+		iRight = (int)floor(center + filterSize);
+
+		if ( !wrap )
+		{
+        if ( iLeft < 0 )
+        {
+            iLeft = 0;
+        }
+
+        if ( iRight >= srcSize )
+        {
+            iRight = srcSize - 1;
+        }
+		}
+
+		int numWeights = iRight - iLeft + 1;
+
+        contrib[iDest].first = iLeft;
+        contrib[iDest].numWeights = numWeights;
+
+        totalWeight = 0;
+		double t = ((double)iLeft - center) * filterScale;
+		for (int i = 0; i < numWeights; i++)
+        {
+			weight = (*FilterProc)(t) * filterScale;
+            totalWeight += weight;
+			contrib[iDest].weight[i] = weight;
+			t += filterScale;
+        }
+
+        //**--------------------------------------------------------
+        //** Normalize weights by dividing by the sum of the weights
+        //**--------------------------------------------------------
+        if ( totalWeight > 0.0 )
+        {   
+            for ( int i = 0; i < numWeights; i++)
+            {
+                contrib[iDest].weight[i] /= totalWeight;
+            }
+        }
+    }
+}
+
+//**-------------------------------------------------------------------------
+//** Name: Filter_TwoPass( RGBCOLOR *pSrcImage, 
+//**                       int srcWidth, int srcHeight, 
+//**                       RGBCOLOR *pDestImage, 
+//**                       int destWidth, int destHeight, 
+//**                       double (*FilterProc)(double) )
+//** Returns: 0 on failure and 1 on success
+//** Description: Filters a 2d image with a two pass filter by averaging the
+//**    weighted contributions of the pixels within the filter region.  The
+//**    contributions are determined by a weighting function parameter.
+//**-------------------------------------------------------------------------
+int FilterTwoPass( RGBCOLOR *pSrcImage, int srcWidth, int srcHeight, 
+                    RGBCOLOR *pDestImage, int destWidth, int destHeight, unsigned int wrapFlags, double (*FilterProc)(double) )
+{
+    FilterWeights *contrib;
+    RGBCOLOR *pPixel;
+    RGBCOLOR *pSrcPixel;
+    RGBCOLOR *pTempImage;
+    int iRow;
+    int iCol;
+    int iSrcCol;
+    int iSrcRow;
+    int iWeight;
+    double dRed;
+    double dGreen;
+    double dBlue;
+    double dAlpha;
+    double filterSize = 3.0;
+
+	int maxDim = (srcWidth>srcHeight)?srcWidth:srcHeight;
+	contrib = (FilterWeights*)malloc(maxDim * sizeof(FilterWeights));
+
+	//**------------------------------------------------------------------------
+    //** Need to create a temporary image to stuff the horizontally scaled image
+    //**------------------------------------------------------------------------
+    pTempImage = (RGBCOLOR *)malloc( destWidth * srcHeight * sizeof(RGBCOLOR) );
+    if ( pTempImage == NULL )
+    {
+        return 0;
+    }
+
+    //**-------------------------------------------------------
+    //** Horizontally filter the image into the temporary image
+    //**-------------------------------------------------------
+	bool bWrapHorizontal = !!(wrapFlags&FILTER_WRAP_X);
+	CalcContributions( srcWidth, destWidth, filterSize, bWrapHorizontal, FilterProc, contrib );
+    for ( iRow = 0; iRow < srcHeight; iRow++ )
+    {
+        for ( iCol = 0; iCol < destWidth; iCol++ )
+        {
+            dRed   = 0;
+            dGreen = 0;
+            dBlue  = 0;
+            dAlpha = 0;
+
+            for ( iWeight = 0; iWeight < contrib[iCol].numWeights; iWeight++ )
+            {
+                iSrcCol = iWeight + contrib[iCol].first;
+				if (bWrapHorizontal)
+				{
+					iSrcCol = (iSrcCol < 0) ? (srcWidth + iSrcCol) : (iSrcCol >= srcWidth) ? (iSrcCol - srcWidth) : iSrcCol;
+				}
+                pSrcPixel = pSrcImage + (iRow * srcWidth) + iSrcCol;
+                dRed   += contrib[iCol].weight[iWeight] * pSrcPixel->rgba[0];
+                dGreen += contrib[iCol].weight[iWeight] * pSrcPixel->rgba[1];
+                dBlue  += contrib[iCol].weight[iWeight] * pSrcPixel->rgba[2];
+                dAlpha += contrib[iCol].weight[iWeight] * pSrcPixel->rgba[3];
+            }
+
+            pPixel = pTempImage + (iRow * destWidth) + iCol;
+			pPixel->rgba[0] = static_cast<unsigned char>(std::max(0.0, std::min(255.0, dRed)));
+			pPixel->rgba[1] = static_cast<unsigned char>(std::max(0.0, std::min(255.0, dGreen)));
+			pPixel->rgba[2] = static_cast<unsigned char>(std::max(0.0, std::min(255.0, dBlue)));
+			pPixel->rgba[3] = static_cast<unsigned char>(std::max(0.0, std::min(255.0, dAlpha)));
+        }
+    }
+
+    //**-------------------------------------------------------
+    //** Vertically filter the image into the destination image
+    //**-------------------------------------------------------
+	bool bWrapVertical = !!(wrapFlags&FILTER_WRAP_Y);
+	CalcContributions(srcHeight, destHeight, filterSize, bWrapVertical, FilterProc, contrib);
+    for ( iCol = 0; iCol < destWidth; iCol++ )
+    {
+        for ( iRow = 0; iRow < destHeight; iRow++ )
+        {
+            dRed   = 0;
+            dGreen = 0;
+            dBlue  = 0;
+            dAlpha = 0;
+
+            for ( iWeight = 0; iWeight < contrib[iRow].numWeights; iWeight++ )
+            {
+                iSrcRow = iWeight + contrib[iRow].first;
+				if (bWrapVertical)
+				{
+					iSrcRow = (iSrcRow < 0) ? (srcHeight + iSrcRow) : (iSrcRow >= srcHeight) ? (iSrcRow - srcHeight) : iSrcRow;
+				}
+                pSrcPixel = pTempImage + (iSrcRow * destWidth) + iCol;
+                dRed   += contrib[iRow].weight[iWeight] * pSrcPixel->rgba[0];
+                dGreen += contrib[iRow].weight[iWeight] * pSrcPixel->rgba[1];
+                dBlue  += contrib[iRow].weight[iWeight] * pSrcPixel->rgba[2];
+                dAlpha += contrib[iRow].weight[iWeight] * pSrcPixel->rgba[3];
+            }
+
+            pPixel = pDestImage + (iRow * destWidth) + iCol;
+            pPixel->rgba[0]   = (unsigned char)(std::max( 0.0, std::min( 255.0, dRed)));
+            pPixel->rgba[1] = (unsigned char)(std::max( 0.0, std::min( 255.0, dGreen)));
+            pPixel->rgba[2]  = (unsigned char)(std::max( 0.0, std::min( 255.0, dBlue)));
+            pPixel->rgba[3] = (unsigned char)(std::max( 0.0, std::min( 255.0, dAlpha)));
+        }
+    }
+
+    free( pTempImage );
+	free( contrib );
+
+    return 1;
+}
+
+//**-------------------------------------------------------------------------
+//** Name: FilterResample(RGBCOLOR *pSrcImage, int srcWidth, int srcHeight, 
+//**                       RGBCOLOR *pDstImage, int dstWidth, int dstHeight)
+//** Returns: 1
+//** Description: This function runs a 2d box filter over the srouce image
+//** to produce the destination image.
+//**-------------------------------------------------------------------------
+void FilterResample( RGBCOLOR *pSrcImage, int srcWidth, int srcHeight, 
+                     RGBCOLOR *pDstImage, int dstWidth, int dstHeight )
+{
+    int iRow;
+    int iCol;
+    int iSampleRow;
+    int iSampleCol;
+    int iFirstSampleRow;
+    int iFirstSampleCol;
+    int iLastSampleRow;
+    int iLastSampleCol;
+    int red;
+    int green;
+    int blue;
+    int alpha;
+    int samples;
+    float xScale;
+    float yScale;
+
+    RGBCOLOR *pSrcPixel;
+    RGBCOLOR *pDstPixel;
+
+    xScale = (float)srcWidth / dstWidth;
+    yScale = (float)srcHeight / dstHeight;
+
+    for ( iRow = 0; iRow < dstHeight; iRow++ )
+    {
+        for ( iCol = 0; iCol < dstWidth; iCol++ )
+        {
+            iFirstSampleRow = (int)(iRow * yScale);
+            iLastSampleRow = (int)ceil(iFirstSampleRow + yScale - 1);
+            if ( iLastSampleRow >= srcHeight )
+            {
+                iLastSampleRow = srcHeight - 1;
+            }
+
+            iFirstSampleCol = (int)(iCol * xScale);
+            iLastSampleCol = (int)ceil(iFirstSampleCol + xScale - 1);
+            if ( iLastSampleCol >= srcWidth )
+            {
+                iLastSampleCol = srcWidth - 1;
+            }
+
+            samples = 0;
+            red     = 0;
+            green   = 0;
+            blue    = 0;
+            alpha   = 0;
+            for ( iSampleRow = iFirstSampleRow; iSampleRow <= iLastSampleRow; iSampleRow++ )
+            {
+                for ( iSampleCol = iFirstSampleCol; iSampleCol <= iLastSampleCol; iSampleCol++ )
+                {
+                    pSrcPixel = pSrcImage + iSampleRow * srcWidth + iSampleCol;
+                    red   += pSrcPixel->rgba[0];
+                    green += pSrcPixel->rgba[1];
+                    blue  += pSrcPixel->rgba[2];
+                    alpha += pSrcPixel->rgba[3];
+
+                    samples++;
+                }
+            }
+
+            pDstPixel = pDstImage + iRow * dstWidth + iCol;
+            if ( samples > 0 )
+            {
+                pDstPixel->rgba[0] = static_cast<uint8_t>(red / samples);
+                pDstPixel->rgba[1] = static_cast<uint8_t>(green / samples);
+                pDstPixel->rgba[2] = static_cast<uint8_t>(blue / samples);
+                pDstPixel->rgba[3] = static_cast<uint8_t>(alpha / samples);
+            }
+            else
+            {
+                pDstPixel->rgba[0] = static_cast<uint8_t>(red);
+                pDstPixel->rgba[1] = static_cast<uint8_t>(green);
+                pDstPixel->rgba[2] = static_cast<uint8_t>(blue);
+                pDstPixel->rgba[3] = static_cast<uint8_t>(alpha);
+            }
+        }
+    }
+}
+
+
+}

thirdparty/etc2comp/EtcFilter.h

@@ -0,0 +1,244 @@
+#pragma once
+#include <stdint.h>
+#include <algorithm>
+
+namespace Etc
+{
+
+enum FilterEnums
+{
+	MaxFilterSize = 32
+};
+
+enum WrapFlags
+{
+	FILTER_WRAP_NONE = 0,
+	FILTER_WRAP_X = 0x1,
+	FILTER_WRAP_Y = 0x2
+};
+
+typedef struct tagFilterWeights
+{
+	int   first;
+	int   numWeights;
+	double weight[MaxFilterSize * 2 + 1];
+} FilterWeights;
+
+typedef struct tagRGBCOLOR
+{
+	union
+	{
+		uint32_t ulColor;
+		uint8_t rgba[4];
+	};
+} RGBCOLOR;
+
+
+double FilterBox( double t );
+double FilterLinear( double t );
+double FilterLanczos3( double t );
+
+int FilterTwoPass( RGBCOLOR *pSrcImage, int srcWidth, int srcHeight, 
+                    RGBCOLOR *pDestImage, int destWidth, int destHeight, unsigned int wrapFlags, double (*FilterProc)(double) );
+void FilterResample( RGBCOLOR *pSrcImage, int srcWidth, int srcHeight, 
+                     RGBCOLOR *pDstImage, int dstWidth, int dstHeight );
+
+
+void CalcContributions(int srcSize, int destSize, double filterSize, bool wrap, double(*FilterProc)(double), FilterWeights contrib[]);
+
+template <typename T>
+void FilterResample(T *pSrcImage, int srcWidth, int srcHeight, T *pDstImage, int dstWidth, int dstHeight)
+{
+	float xScale;
+	float yScale;
+
+	T *pSrcPixel;
+	T *pDstPixel;
+
+	xScale = (float)srcWidth / dstWidth;
+	yScale = (float)srcHeight / dstHeight;
+
+	for (int iRow = 0; iRow < dstHeight; iRow++)
+	{
+		for (int iCol = 0; iCol < dstWidth; iCol++)
+		{
+			int samples;
+			int iFirstSampleRow;
+			int iFirstSampleCol;
+			int iLastSampleRow;
+			int iLastSampleCol;
+			float red;
+			float green;
+			float blue;
+			float alpha;
+
+			iFirstSampleRow = (int)(iRow * yScale);
+			iLastSampleRow = (int)ceil(iFirstSampleRow + yScale - 1);
+			if (iLastSampleRow >= srcHeight)
+			{
+				iLastSampleRow = srcHeight - 1;
+			}
+
+			iFirstSampleCol = (int)(iCol * xScale);
+			iLastSampleCol = (int)ceil(iFirstSampleCol + xScale - 1);
+			if (iLastSampleCol >= srcWidth)
+			{
+				iLastSampleCol = srcWidth - 1;
+			}
+
+			samples = 0;
+			red = 0.f;
+			green = 0.f;
+			blue = 0.f;
+			alpha = 0.f;
+			for (int iSampleRow = iFirstSampleRow; iSampleRow <= iLastSampleRow; iSampleRow++)
+			{
+				for (int iSampleCol = iFirstSampleCol; iSampleCol <= iLastSampleCol; iSampleCol++)
+				{
+					pSrcPixel = pSrcImage + (iSampleRow * srcWidth + iSampleCol) * 4;
+					red += static_cast<float>(pSrcPixel[0]);
+					green += static_cast<float>(pSrcPixel[1]);
+					blue += static_cast<float>(pSrcPixel[2]);
+					alpha += static_cast<float>(pSrcPixel[3]);
+
+					samples++;
+				}
+			}
+
+			pDstPixel = pDstImage + (iRow * dstWidth + iCol) * 4;
+			if (samples > 0)
+			{
+				pDstPixel[0] = static_cast<T>(red / samples);
+				pDstPixel[1] = static_cast<T>(green / samples);
+				pDstPixel[2] = static_cast<T>(blue / samples);
+				pDstPixel[3] = static_cast<T>(alpha / samples);
+			}
+			else
+			{
+				pDstPixel[0] = static_cast<T>(red);
+				pDstPixel[1] = static_cast<T>(green);
+				pDstPixel[2] = static_cast<T>(blue);
+				pDstPixel[3] = static_cast<T>(alpha);
+			}
+		}
+	}
+
+}
+
+//**-------------------------------------------------------------------------
+//** Name: Filter_TwoPass( RGBCOLOR *pSrcImage, 
+//**                       int srcWidth, int srcHeight, 
+//**                       RGBCOLOR *pDestImage, 
+//**                       int destWidth, int destHeight, 
+//**                       double (*FilterProc)(double) )
+//** Returns: 0 on failure and 1 on success
+//** Description: Filters a 2d image with a two pass filter by averaging the
+//**    weighted contributions of the pixels within the filter region.  The
+//**    contributions are determined by a weighting function parameter.
+//**-------------------------------------------------------------------------
+template <typename T>
+int FilterTwoPass(T *pSrcImage, int srcWidth, int srcHeight,
+	T *pDestImage, int destWidth, int destHeight, unsigned int wrapFlags, double(*FilterProc)(double))
+{
+	const int numComponents = 4;
+	FilterWeights *contrib;
+	T *pPixel;
+	T *pTempImage;
+	double dRed;
+	double dGreen;
+	double dBlue;
+	double dAlpha;
+	double filterSize = 3.0;
+
+	int maxDim = (srcWidth>srcHeight) ? srcWidth : srcHeight;
+	contrib = new FilterWeights[maxDim];
+
+	//**------------------------------------------------------------------------
+	//** Need to create a temporary image to stuff the horizontally scaled image
+	//**------------------------------------------------------------------------
+	pTempImage = new T[destWidth * srcHeight * numComponents];
+	if (pTempImage == NULL)
+	{
+		return 0;
+	}
+
+	//**-------------------------------------------------------
+	//** Horizontally filter the image into the temporary image
+	//**-------------------------------------------------------
+	bool bWrapHorizontal = !!(wrapFlags&FILTER_WRAP_X);
+	CalcContributions(srcWidth, destWidth, filterSize, bWrapHorizontal, FilterProc, contrib);
+	for (int iRow = 0; iRow < srcHeight; iRow++)
+	{
+		for (int iCol = 0; iCol < destWidth; iCol++)
+		{
+			dRed = 0;
+			dGreen = 0;
+			dBlue = 0;
+			dAlpha = 0;
+
+			for (int iWeight = 0; iWeight < contrib[iCol].numWeights; iWeight++)
+			{
+				int iSrcCol = iWeight + contrib[iCol].first;
+				if(bWrapHorizontal)
+				{
+					iSrcCol = (iSrcCol < 0)?(srcWidth+iSrcCol):(iSrcCol >= srcWidth)?(iSrcCol-srcWidth):iSrcCol;
+				}
+				T* pSrcPixel = pSrcImage + ((iRow * srcWidth) + iSrcCol)*numComponents;
+				dRed += contrib[iCol].weight[iWeight] * pSrcPixel[0];
+				dGreen += contrib[iCol].weight[iWeight] * pSrcPixel[1];
+				dBlue += contrib[iCol].weight[iWeight] * pSrcPixel[2];
+				dAlpha += contrib[iCol].weight[iWeight] * pSrcPixel[3];
+			}
+
+			pPixel = pTempImage + ((iRow * destWidth) + iCol)*numComponents;
+			pPixel[0] = static_cast<T>(std::max(0.0, std::min(255.0, dRed)));
+			pPixel[1] = static_cast<T>(std::max(0.0, std::min(255.0, dGreen)));
+			pPixel[2] = static_cast<T>(std::max(0.0, std::min(255.0, dBlue)));
+			pPixel[3] = static_cast<T>(std::max(0.0, std::min(255.0, dAlpha)));
+		}
+	}
+
+	//**-------------------------------------------------------
+	//** Vertically filter the image into the destination image
+	//**-------------------------------------------------------
+	bool bWrapVertical = !!(wrapFlags&FILTER_WRAP_Y);
+	CalcContributions(srcHeight, destHeight, filterSize, bWrapVertical, FilterProc, contrib);
+	for (int iCol = 0; iCol < destWidth; iCol++)
+	{
+		for (int iRow = 0; iRow < destHeight; iRow++)
+		{
+			dRed = 0;
+			dGreen = 0;
+			dBlue = 0;
+			dAlpha = 0;
+
+			for (int iWeight = 0; iWeight < contrib[iRow].numWeights; iWeight++)
+			{
+				int iSrcRow = iWeight + contrib[iRow].first;
+				if (bWrapVertical)
+				{
+					iSrcRow = (iSrcRow < 0) ? (srcHeight + iSrcRow) : (iSrcRow >= srcHeight) ? (iSrcRow - srcHeight) : iSrcRow;
+				}
+				T* pSrcPixel = pTempImage + ((iSrcRow * destWidth) + iCol)*numComponents;
+				dRed += contrib[iRow].weight[iWeight] * pSrcPixel[0];
+				dGreen += contrib[iRow].weight[iWeight] * pSrcPixel[1];
+				dBlue += contrib[iRow].weight[iWeight] * pSrcPixel[2];
+				dAlpha += contrib[iRow].weight[iWeight] * pSrcPixel[3];
+			}
+
+			pPixel = pDestImage + ((iRow * destWidth) + iCol)*numComponents;
+			pPixel[0] = static_cast<T>(std::max(0.0, std::min(255.0, dRed)));
+			pPixel[1] = static_cast<T>(std::max(0.0, std::min(255.0, dGreen)));
+			pPixel[2] = static_cast<T>(std::max(0.0, std::min(255.0, dBlue)));
+			pPixel[3] = static_cast<T>(std::max(0.0, std::min(255.0, dAlpha)));
+		}
+	}
+
+	delete[] pTempImage;
+	delete[] contrib;
+
+	return 1;
+}
+
+
+}

thirdparty/etc2comp/EtcImage.cpp

@@ -0,0 +1,685 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+EtcImage.cpp
+
+Image is an array of 4x4 blocks that represent the encoding of the source image
+
+*/
+
+#include "EtcConfig.h"
+
+#include <stdlib.h>
+
+#include "EtcImage.h"
+
+#include "Etc.h"
+#include "EtcBlock4x4.h"
+#include "EtcBlock4x4EncodingBits.h"
+#include "EtcSortedBlockList.h"
+
+#if ETC_WINDOWS
+#include <windows.h>
+#endif
+#include <ctime>
+#include <chrono>
+#include <future>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+// fix conflict with Block4x4::AlphaMix
+#ifdef OPAQUE
+#undef OPAQUE
+#endif
+#ifdef TRANSPARENT
+#undef TRANSPARENT
+#endif
+
+namespace Etc
+{
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	Image::Image(void)
+	{
+		m_encodingStatus = EncodingStatus::SUCCESS;
+		m_warningsToCapture = EncodingStatus::SUCCESS;
+		m_pafrgbaSource = nullptr;
+
+		m_pablock = nullptr;
+
+		m_encodingbitsformat = Block4x4EncodingBits::Format::UNKNOWN;
+		m_uiEncodingBitsBytes = 0;
+		m_paucEncodingBits = nullptr;
+
+		m_format = Format::UNKNOWN;
+		m_iNumOpaquePixels = 0;
+		m_iNumTranslucentPixels = 0;
+		m_iNumTransparentPixels = 0;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// constructor using source image
+	// used to set state before Encode() is called
+	//
+	Image::Image(float *a_pafSourceRGBA, unsigned int a_uiSourceWidth,
+					unsigned int a_uiSourceHeight, 
+					ErrorMetric a_errormetric)
+	{
+		m_encodingStatus = EncodingStatus::SUCCESS;
+		m_warningsToCapture = EncodingStatus::SUCCESS;
+		m_pafrgbaSource = (ColorFloatRGBA *) a_pafSourceRGBA;
+		m_uiSourceWidth = a_uiSourceWidth;
+		m_uiSourceHeight = a_uiSourceHeight;
+
+		m_uiExtendedWidth = CalcExtendedDimension((unsigned short)m_uiSourceWidth);
+		m_uiExtendedHeight = CalcExtendedDimension((unsigned short)m_uiSourceHeight);
+
+		m_uiBlockColumns = m_uiExtendedWidth >> 2;
+		m_uiBlockRows = m_uiExtendedHeight >> 2;
+
+		m_pablock = new Block4x4[GetNumberOfBlocks()];
+		assert(m_pablock);
+
+		m_format = Format::UNKNOWN;
+
+		m_encodingbitsformat = Block4x4EncodingBits::Format::UNKNOWN;
+		m_uiEncodingBitsBytes = 0;
+		m_paucEncodingBits = nullptr;
+
+		m_errormetric = a_errormetric;
+		m_fEffort = 0.0f;
+
+		m_iEncodeTime_ms = -1;
+
+		m_iNumOpaquePixels = 0;
+		m_iNumTranslucentPixels = 0;
+		m_iNumTransparentPixels = 0;
+		m_bVerboseOutput = false;
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// constructor using encoding bits
+	// recreates encoding state using a previously encoded image
+	//
+	Image::Image(Format a_format,
+					unsigned int a_uiSourceWidth, unsigned int a_uiSourceHeight,
+					unsigned char *a_paucEncidingBits, unsigned int a_uiEncodingBitsBytes,
+					Image *a_pimageSource, ErrorMetric a_errormetric)
+	{
+		m_encodingStatus = EncodingStatus::SUCCESS;
+		m_pafrgbaSource = nullptr;
+		m_uiSourceWidth = a_uiSourceWidth;
+		m_uiSourceHeight = a_uiSourceHeight;
+
+		m_uiExtendedWidth = CalcExtendedDimension((unsigned short)m_uiSourceWidth);
+		m_uiExtendedHeight = CalcExtendedDimension((unsigned short)m_uiSourceHeight);
+
+		m_uiBlockColumns = m_uiExtendedWidth >> 2;
+		m_uiBlockRows = m_uiExtendedHeight >> 2;
+
+		unsigned int uiBlocks = GetNumberOfBlocks();
+
+		m_pablock = new Block4x4[uiBlocks];
+		assert(m_pablock);
+
+		m_format = a_format;
+
+		m_iNumOpaquePixels = 0;
+		m_iNumTranslucentPixels = 0;
+		m_iNumTransparentPixels = 0;
+		
+		m_encodingbitsformat = DetermineEncodingBitsFormat(m_format);
+		if (m_encodingbitsformat == Block4x4EncodingBits::Format::UNKNOWN)
+		{
+			AddToEncodingStatus(ERROR_UNKNOWN_FORMAT);
+			return;
+		}
+		m_uiEncodingBitsBytes = a_uiEncodingBitsBytes;
+		m_paucEncodingBits = a_paucEncidingBits;
+
+		m_errormetric = a_errormetric;
+		m_fEffort = 0.0f;
+		m_bVerboseOutput = false;
+		m_iEncodeTime_ms = -1;
+		
+		unsigned char *paucEncodingBits = m_paucEncodingBits;
+		unsigned int uiEncodingBitsBytesPerBlock = Block4x4EncodingBits::GetBytesPerBlock(m_encodingbitsformat);
+
+		unsigned int uiH = 0;
+		unsigned int uiV = 0;
+		for (unsigned int uiBlock = 0; uiBlock < uiBlocks; uiBlock++)
+		{
+			m_pablock[uiBlock].InitFromEtcEncodingBits(a_format, uiH, uiV, paucEncodingBits, 
+														a_pimageSource, a_errormetric);
+			paucEncodingBits += uiEncodingBitsBytesPerBlock;
+			uiH += 4;
+			if (uiH >= m_uiSourceWidth)
+			{
+				uiH = 0;
+				uiV += 4;
+			}
+		}
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	Image::~Image(void)
+	{
+		if (m_pablock != nullptr)
+		{
+			delete[] m_pablock;
+			m_pablock = nullptr;
+		}
+
+		/*if (m_paucEncodingBits != nullptr)
+		{
+			delete[] m_paucEncodingBits;
+			m_paucEncodingBits = nullptr;
+		}*/
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// encode an image
+	// create a set of encoding bits that conforms to a_format
+	// find best fit using a_errormetric
+	// explore a range of possible encodings based on a_fEffort (range = [0:100])
+	// speed up process using a_uiJobs as the number of process threads (a_uiJobs must not excede a_uiMaxJobs)
+	//
+	Image::EncodingStatus Image::Encode(Format a_format, ErrorMetric a_errormetric, float a_fEffort, unsigned int a_uiJobs, unsigned int a_uiMaxJobs)
+	{
+
+		auto start = std::chrono::steady_clock::now();
+		
+		m_encodingStatus = EncodingStatus::SUCCESS;
+
+		m_format = a_format;
+		m_errormetric = a_errormetric;
+		m_fEffort = a_fEffort;
+
+		if (m_errormetric < 0 || m_errormetric > ERROR_METRICS)
+		{
+			AddToEncodingStatus(ERROR_UNKNOWN_ERROR_METRIC);
+			return m_encodingStatus;
+		}
+
+		if (m_fEffort < ETCCOMP_MIN_EFFORT_LEVEL)
+		{
+			AddToEncodingStatus(WARNING_EFFORT_OUT_OF_RANGE);
+			m_fEffort = ETCCOMP_MIN_EFFORT_LEVEL;
+		}
+		else if (m_fEffort > ETCCOMP_MAX_EFFORT_LEVEL)
+		{
+			AddToEncodingStatus(WARNING_EFFORT_OUT_OF_RANGE);
+			m_fEffort = ETCCOMP_MAX_EFFORT_LEVEL;
+		}
+		if (a_uiJobs < 1)
+		{
+			a_uiJobs = 1;
+			AddToEncodingStatus(WARNING_JOBS_OUT_OF_RANGE);
+		}
+		else if (a_uiJobs > a_uiMaxJobs)
+		{
+			a_uiJobs = a_uiMaxJobs;
+			AddToEncodingStatus(WARNING_JOBS_OUT_OF_RANGE);
+		}
+
+		m_encodingbitsformat = DetermineEncodingBitsFormat(m_format);
+
+		if (m_encodingbitsformat == Block4x4EncodingBits::Format::UNKNOWN)
+		{
+			AddToEncodingStatus(ERROR_UNKNOWN_FORMAT);
+			return m_encodingStatus;
+		}
+
+		assert(m_paucEncodingBits == nullptr);
+		m_uiEncodingBitsBytes = GetNumberOfBlocks() * Block4x4EncodingBits::GetBytesPerBlock(m_encodingbitsformat);
+		m_paucEncodingBits = new unsigned char[m_uiEncodingBitsBytes];
+
+		InitBlocksAndBlockSorter();
+
+
+		std::future<void> *handle = new std::future<void>[a_uiMaxJobs];
+
+		unsigned int uiNumThreadsNeeded = 0;
+		unsigned int uiUnfinishedBlocks = GetNumberOfBlocks();
+
+		uiNumThreadsNeeded = (uiUnfinishedBlocks < a_uiJobs) ? uiUnfinishedBlocks : a_uiJobs;
+			
+		for (int i = 0; i < (int)uiNumThreadsNeeded - 1; i++)
+		{
+			handle[i] = async(std::launch::async, &Image::RunFirstPass, this, i, uiNumThreadsNeeded);
+		}
+
+		RunFirstPass(uiNumThreadsNeeded - 1, uiNumThreadsNeeded);
+
+		for (int i = 0; i < (int)uiNumThreadsNeeded - 1; i++)
+		{
+			handle[i].get();
+		}
+
+		// perform effort-based encoding
+		if (m_fEffort > ETCCOMP_MIN_EFFORT_LEVEL)
+		{
+			unsigned int uiFinishedBlocks = 0;
+			unsigned int uiTotalEffortBlocks = static_cast<unsigned int>(roundf(0.01f * m_fEffort  * GetNumberOfBlocks()));
+
+			if (m_bVerboseOutput)
+			{
+				printf("effortblocks = %d\n", uiTotalEffortBlocks);
+			}
+			unsigned int uiPass = 0;
+			while (1)
+			{
+				if (m_bVerboseOutput)
+				{
+					uiPass++;
+					printf("pass %u\n", uiPass);
+				}
+				m_psortedblocklist->Sort();
+				uiUnfinishedBlocks = m_psortedblocklist->GetNumberOfSortedBlocks();
+				uiFinishedBlocks = GetNumberOfBlocks() - uiUnfinishedBlocks;
+				if (m_bVerboseOutput)
+				{
+					printf("    %u unfinished blocks\n", uiUnfinishedBlocks);
+					// m_psortedblocklist->Print();
+				}
+
+				
+
+				//stop enocding when we did enough to satify the effort percentage
+				if (uiFinishedBlocks >= uiTotalEffortBlocks)
+				{
+					if (m_bVerboseOutput)
+					{
+						printf("Finished %d Blocks out of %d\n", uiFinishedBlocks, uiTotalEffortBlocks);
+					}
+					break;
+				}
+
+				unsigned int uiIteratedBlocks = 0;
+				unsigned int blocksToIterateThisPass = (uiTotalEffortBlocks - uiFinishedBlocks);
+				uiNumThreadsNeeded = (uiUnfinishedBlocks < a_uiJobs) ? uiUnfinishedBlocks : a_uiJobs;
+
+				if (uiNumThreadsNeeded <= 1)
+				{
+					//since we already how many blocks each thread will process
+					//cap the thread limit to do the proper amount of work, and not more
+					uiIteratedBlocks = IterateThroughWorstBlocks(blocksToIterateThisPass, 0, 1);
+				}
+				else
+				{
+					//we have a lot of work to do, so lets multi thread it
+					std::future<unsigned int> *handleToBlockEncoders = new std::future<unsigned int>[uiNumThreadsNeeded-1];
+
+					for (int i = 0; i < (int)uiNumThreadsNeeded - 1; i++)
+					{
+						handleToBlockEncoders[i] = async(std::launch::async, &Image::IterateThroughWorstBlocks, this, blocksToIterateThisPass, i, uiNumThreadsNeeded);
+					}
+					uiIteratedBlocks = IterateThroughWorstBlocks(blocksToIterateThisPass, uiNumThreadsNeeded - 1, uiNumThreadsNeeded);
+
+					for (int i = 0; i < (int)uiNumThreadsNeeded - 1; i++)
+					{
+						uiIteratedBlocks += handleToBlockEncoders[i].get();
+					}
+
+					delete[] handleToBlockEncoders;
+				}
+
+				if (m_bVerboseOutput)
+				{
+					printf("    %u iterated blocks\n", uiIteratedBlocks);
+				}
+			}
+		}
+
+		// generate Etc2-compatible bit-format 4x4 blocks
+		for (int i = 0; i < (int)a_uiJobs - 1; i++)
+		{
+			handle[i] = async(std::launch::async, &Image::SetEncodingBits, this, i, a_uiJobs);
+		}
+		SetEncodingBits(a_uiJobs - 1, a_uiJobs);
+
+		for (int i = 0; i < (int)a_uiJobs - 1; i++)
+		{
+			handle[i].get();
+		}
+
+		auto end = std::chrono::steady_clock::now();
+		std::chrono::milliseconds elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
+		m_iEncodeTime_ms = (int)elapsed.count();
+
+		delete[] handle;
+		delete m_psortedblocklist;
+		return m_encodingStatus;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// iterate the encoding thru the blocks with the worst error
+	// stop when a_uiMaxBlocks blocks have been iterated
+	// split the blocks between the process threads using a_uiMultithreadingOffset and a_uiMultithreadingStride
+	//
+	unsigned int Image::IterateThroughWorstBlocks(unsigned int a_uiMaxBlocks, 
+													unsigned int a_uiMultithreadingOffset, 
+													unsigned int a_uiMultithreadingStride)
+	{
+		assert(a_uiMultithreadingStride > 0);
+		unsigned int uiIteratedBlocks = a_uiMultithreadingOffset;
+
+		SortedBlockList::Link *plink = m_psortedblocklist->GetLinkToFirstBlock();
+		for (plink = plink->Advance(a_uiMultithreadingOffset);
+				plink != nullptr;
+				plink = plink->Advance(a_uiMultithreadingStride) )
+		{
+			if (uiIteratedBlocks >= a_uiMaxBlocks)
+			{
+				break;
+			}
+
+			plink->GetBlock()->PerformEncodingIteration(m_fEffort);
+
+			uiIteratedBlocks += a_uiMultithreadingStride;	
+		}
+
+		return uiIteratedBlocks;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// determine which warnings to check for during Encode() based on encoding format
+	//
+	void Image::FindEncodingWarningTypesForCurFormat()
+	{
+		TrackEncodingWarning(WARNING_ALL_TRANSPARENT_PIXELS);
+		TrackEncodingWarning(WARNING_SOME_RGBA_NOT_0_TO_1);
+		switch (m_format)
+		{
+		case Image::Format::ETC1:
+		case Image::Format::RGB8:
+		case Image::Format::SRGB8:
+			TrackEncodingWarning(WARNING_SOME_NON_OPAQUE_PIXELS);
+			TrackEncodingWarning(WARNING_SOME_TRANSLUCENT_PIXELS);
+			break;
+
+		case Image::Format::RGB8A1:
+		case Image::Format::SRGB8A1:
+			TrackEncodingWarning(WARNING_SOME_TRANSLUCENT_PIXELS);
+			TrackEncodingWarning(WARNING_ALL_OPAQUE_PIXELS);
+			break;
+		case Image::Format::RGBA8:
+		case Image::Format::SRGBA8:
+			TrackEncodingWarning(WARNING_ALL_OPAQUE_PIXELS);
+			break;
+
+		case Image::Format::R11:
+		case Image::Format::SIGNED_R11:
+			TrackEncodingWarning(WARNING_SOME_NON_OPAQUE_PIXELS);
+			TrackEncodingWarning(WARNING_SOME_TRANSLUCENT_PIXELS);
+			TrackEncodingWarning(WARNING_SOME_GREEN_VALUES_ARE_NOT_ZERO);
+			TrackEncodingWarning(WARNING_SOME_BLUE_VALUES_ARE_NOT_ZERO);
+			break;
+
+		case Image::Format::RG11:
+		case Image::Format::SIGNED_RG11:
+			TrackEncodingWarning(WARNING_SOME_NON_OPAQUE_PIXELS);
+			TrackEncodingWarning(WARNING_SOME_TRANSLUCENT_PIXELS);
+			TrackEncodingWarning(WARNING_SOME_BLUE_VALUES_ARE_NOT_ZERO);
+			break;
+		case Image::Format::FORMATS:
+		case Image::Format::UNKNOWN:
+		default:
+			assert(0);
+			break;
+		}
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// examine source pixels to check for warnings
+	//
+	void Image::FindAndSetEncodingWarnings()
+	{
+		int numPixels = (m_uiBlockRows * 4) * (m_uiBlockColumns * 4);
+		if (m_iNumOpaquePixels == numPixels)
+		{
+			AddToEncodingStatusIfSignfigant(Image::EncodingStatus::WARNING_ALL_OPAQUE_PIXELS);
+		}
+		if (m_iNumOpaquePixels < numPixels)
+		{
+			AddToEncodingStatusIfSignfigant(Image::EncodingStatus::WARNING_SOME_NON_OPAQUE_PIXELS);
+		}
+		if (m_iNumTranslucentPixels > 0)
+		{
+			AddToEncodingStatusIfSignfigant(Image::EncodingStatus::WARNING_SOME_TRANSLUCENT_PIXELS);
+		}
+		if (m_iNumTransparentPixels == numPixels)
+		{
+			AddToEncodingStatusIfSignfigant(Image::EncodingStatus::WARNING_ALL_TRANSPARENT_PIXELS);
+		}
+		if (m_numColorValues.fB > 0.0f)
+		{
+			AddToEncodingStatusIfSignfigant(Image::EncodingStatus::WARNING_SOME_BLUE_VALUES_ARE_NOT_ZERO);
+		}
+		if (m_numColorValues.fG > 0.0f) 
+		{
+			AddToEncodingStatusIfSignfigant(Image::EncodingStatus::WARNING_SOME_GREEN_VALUES_ARE_NOT_ZERO);
+		}
+
+		if (m_numOutOfRangeValues.fR > 0.0f || m_numOutOfRangeValues.fG > 0.0f)
+		{
+			AddToEncodingStatusIfSignfigant(Image::EncodingStatus::WARNING_SOME_RGBA_NOT_0_TO_1);
+		}
+		if (m_numOutOfRangeValues.fB > 0.0f || m_numOutOfRangeValues.fA > 0.0f)
+		{
+			AddToEncodingStatusIfSignfigant(Image::EncodingStatus::WARNING_SOME_RGBA_NOT_0_TO_1);
+		}
+	}
+	
+	// ----------------------------------------------------------------------------------------------------
+	// return a string name for a given image format
+	//
+	const char * Image::EncodingFormatToString(Image::Format a_format)
+	{
+		switch (a_format)
+		{
+		case Image::Format::ETC1:
+			return "ETC1";
+		case Image::Format::RGB8:
+			return "RGB8";
+		case Image::Format::SRGB8:
+			return "SRGB8";
+
+		case Image::Format::RGB8A1:
+			return "RGB8A1";
+		case Image::Format::SRGB8A1:
+			return "SRGB8A1";
+		case Image::Format::RGBA8:
+			return "RGBA8";
+		case Image::Format::SRGBA8:
+			return "SRGBA8";
+
+		case Image::Format::R11:
+			return "R11";
+		case Image::Format::SIGNED_R11:
+			return "SIGNED_R11";
+
+		case Image::Format::RG11:
+			return "RG11";
+		case Image::Format::SIGNED_RG11:
+			return "SIGNED_RG11";
+		case Image::Format::FORMATS:
+		case Image::Format::UNKNOWN:
+		default:
+			return "UNKNOWN";
+		}
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// return a string name for the image's format
+	//
+	const char * Image::EncodingFormatToString(void)
+	{
+		return EncodingFormatToString(m_format);
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// init image blocks prior to encoding
+	// init block sorter for subsequent sortings
+	// check for encoding warnings
+	//
+	void Image::InitBlocksAndBlockSorter(void)
+	{
+		
+		FindEncodingWarningTypesForCurFormat();
+
+		// init each block
+		Block4x4 *pblock = m_pablock;
+		unsigned char *paucEncodingBits = m_paucEncodingBits;
+		for (unsigned int uiBlockRow = 0; uiBlockRow < m_uiBlockRows; uiBlockRow++)
+		{
+			unsigned int uiBlockV = uiBlockRow * 4;
+
+			for (unsigned int uiBlockColumn = 0; uiBlockColumn < m_uiBlockColumns; uiBlockColumn++)
+			{
+				unsigned int uiBlockH = uiBlockColumn * 4;
+
+				pblock->InitFromSource(this, uiBlockH, uiBlockV, paucEncodingBits, m_errormetric);
+
+				paucEncodingBits += Block4x4EncodingBits::GetBytesPerBlock(m_encodingbitsformat);
+
+				pblock++;
+			}
+		}
+
+		FindAndSetEncodingWarnings();
+
+		// init block sorter
+		{
+			m_psortedblocklist = new SortedBlockList(GetNumberOfBlocks(), 100);
+
+			for (unsigned int uiBlock = 0; uiBlock < GetNumberOfBlocks(); uiBlock++)
+			{
+				pblock = &m_pablock[uiBlock];
+				m_psortedblocklist->AddBlock(pblock);
+			}
+		}
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// run the first pass of the encoder
+	// the encoder generally finds a reasonable, fast encoding
+	// this is run on all blocks regardless of effort to ensure that all blocks have a valid encoding
+	//
+	void Image::RunFirstPass(unsigned int a_uiMultithreadingOffset, unsigned int a_uiMultithreadingStride)
+	{
+		assert(a_uiMultithreadingStride > 0);
+
+		for (unsigned int uiBlock = a_uiMultithreadingOffset;
+				uiBlock < GetNumberOfBlocks(); 
+				uiBlock += a_uiMultithreadingStride)
+		{
+			Block4x4 *pblock = &m_pablock[uiBlock];
+			pblock->PerformEncodingIteration(m_fEffort);
+		}
+	}
+
+    // ----------------------------------------------------------------------------------------------------
+	// set the encoding bits (for the output file) based on the best encoding for each block
+	//
+	void Image::SetEncodingBits(unsigned int a_uiMultithreadingOffset,
+								unsigned int a_uiMultithreadingStride)
+	{
+		assert(a_uiMultithreadingStride > 0);
+
+		for (unsigned int uiBlock = a_uiMultithreadingOffset; 
+				uiBlock < GetNumberOfBlocks(); 
+				uiBlock += a_uiMultithreadingStride)
+		{
+			Block4x4 *pblock = &m_pablock[uiBlock];
+			pblock->SetEncodingBitsFromEncoding();
+		}
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// return the image error
+	// image error is the sum of all block errors
+	//
+	float Image::GetError(void)
+	{
+		float fError = 0.0f;
+
+		for (unsigned int uiBlock = 0; uiBlock < GetNumberOfBlocks(); uiBlock++)
+		{
+			Block4x4 *pblock = &m_pablock[uiBlock];
+			fError += pblock->GetError();
+		}
+
+		return fError;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// determine the encoding bits format based on the encoding format
+	// the encoding bits format is a family of bit encodings that are shared across various encoding formats
+	//
+	Block4x4EncodingBits::Format Image::DetermineEncodingBitsFormat(Format a_format)
+	{
+		Block4x4EncodingBits::Format encodingbitsformat;
+
+		// determine encoding bits format from image format
+		switch (a_format)
+		{
+		case Format::ETC1:
+		case Format::RGB8:
+		case Format::SRGB8:
+			encodingbitsformat = Block4x4EncodingBits::Format::RGB8;
+			break;
+
+		case Format::RGBA8:
+		case Format::SRGBA8:
+			encodingbitsformat = Block4x4EncodingBits::Format::RGBA8;
+			break;
+
+		case Format::R11:
+		case Format::SIGNED_R11:
+			encodingbitsformat = Block4x4EncodingBits::Format::R11;
+			break;
+
+		case Format::RG11:
+		case Format::SIGNED_RG11:
+			encodingbitsformat = Block4x4EncodingBits::Format::RG11;
+			break;
+
+		case Format::RGB8A1:
+		case Format::SRGB8A1:
+			encodingbitsformat = Block4x4EncodingBits::Format::RGB8A1;
+			break;
+
+		default:
+			encodingbitsformat = Block4x4EncodingBits::Format::UNKNOWN;
+			break;
+		}
+
+		return encodingbitsformat;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+}	// namespace Etc

thirdparty/etc2comp/EtcImage.h

@@ -0,0 +1,249 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+//#include "Etc.h"
+#include "EtcColorFloatRGBA.h"
+#include "EtcBlock4x4EncodingBits.h"
+#include "EtcErrorMetric.h"
+
+
+namespace Etc
+{
+	class Block4x4;
+	class EncoderSpec;
+	class SortedBlockList;
+
+    class Image
+    {
+    public:
+
+		//the differnt warning and errors that can come up during encoding
+		enum  EncodingStatus
+		{
+			SUCCESS = 0,
+			//
+			WARNING_THRESHOLD = 1 << 0,
+			//
+			WARNING_EFFORT_OUT_OF_RANGE = 1 << 1,
+			WARNING_JOBS_OUT_OF_RANGE = 1 << 2,
+			WARNING_SOME_NON_OPAQUE_PIXELS = 1 << 3,//just for opaque formats, etc1, rgb8, r11, rg11
+			WARNING_ALL_OPAQUE_PIXELS = 1 << 4,
+			WARNING_ALL_TRANSPARENT_PIXELS = 1 << 5,
+			WARNING_SOME_TRANSLUCENT_PIXELS = 1 << 6,//just for rgb8A1
+			WARNING_SOME_RGBA_NOT_0_TO_1 = 1 << 7,
+			WARNING_SOME_BLUE_VALUES_ARE_NOT_ZERO = 1 << 8,
+			WARNING_SOME_GREEN_VALUES_ARE_NOT_ZERO = 1 << 9,
+			//
+			ERROR_THRESHOLD = 1 << 16,
+			//
+			ERROR_UNKNOWN_FORMAT = 1 << 17,
+			ERROR_UNKNOWN_ERROR_METRIC = 1 << 18,
+			ERROR_ZERO_WIDTH_OR_HEIGHT = 1 << 19,
+			//
+		};
+		
+		enum class Format
+		{
+			UNKNOWN,
+			//
+			ETC1,
+			//
+			// ETC2 formats
+			RGB8,
+			SRGB8,
+			RGBA8,
+			SRGBA8,
+			R11,
+			SIGNED_R11,
+			RG11,
+			SIGNED_RG11,
+			RGB8A1,
+			SRGB8A1,
+			//
+			FORMATS,
+			//
+			DEFAULT = SRGB8
+		};
+
+		// constructor using source image
+		Image(float *a_pafSourceRGBA, unsigned int a_uiSourceWidth,
+				unsigned int a_uiSourceHeight,
+				ErrorMetric a_errormetric);
+
+		// constructor using encoding bits
+		Image(Format a_format, 
+				unsigned int a_uiSourceWidth, unsigned int a_uiSourceHeight,
+				unsigned char *a_paucEncidingBits, unsigned int a_uiEncodingBitsBytes,
+				Image *a_pimageSource,
+				ErrorMetric a_errormetric);
+
+		~Image(void);
+
+		EncodingStatus Encode(Format a_format, ErrorMetric a_errormetric, float a_fEffort, 
+			unsigned int a_uiJobs, unsigned int a_uiMaxJobs);
+
+		inline void AddToEncodingStatus(EncodingStatus a_encStatus)
+		{
+			m_encodingStatus = (EncodingStatus)((unsigned int)m_encodingStatus | (unsigned int)a_encStatus);
+		}
+		
+		inline unsigned int GetSourceWidth(void)
+		{
+			return m_uiSourceWidth;
+		}
+
+		inline unsigned int GetSourceHeight(void)
+		{
+			return m_uiSourceHeight;
+		}
+
+		inline unsigned int GetExtendedWidth(void)
+		{
+			return m_uiExtendedWidth;
+		}
+
+		inline unsigned int GetExtendedHeight(void)
+		{
+			return m_uiExtendedHeight;
+		}
+
+		inline unsigned int GetNumberOfBlocks()
+		{
+			return m_uiBlockColumns * m_uiBlockRows;
+		}
+
+		inline Block4x4 * GetBlocks()
+		{
+			return m_pablock;
+		}
+
+		inline unsigned char * GetEncodingBits(void)
+		{
+			return m_paucEncodingBits;
+		}
+
+		inline unsigned int GetEncodingBitsBytes(void)
+		{
+			return m_uiEncodingBitsBytes;
+		}
+
+		inline int GetEncodingTimeMs(void)
+		{
+			return m_iEncodeTime_ms;
+		}
+
+		float GetError(void);
+
+		inline ColorFloatRGBA * GetSourcePixel(unsigned int a_uiH, unsigned int a_uiV)
+		{
+			if (a_uiH >= m_uiSourceWidth || a_uiV >= m_uiSourceHeight)
+			{
+				return nullptr;
+			}
+
+			return &m_pafrgbaSource[a_uiV*m_uiSourceWidth + a_uiH];
+		}
+
+		inline Format GetFormat(void)
+		{
+			return m_format;
+		}
+
+		static Block4x4EncodingBits::Format DetermineEncodingBitsFormat(Format a_format);
+
+		inline static unsigned short CalcExtendedDimension(unsigned short a_ushOriginalDimension)
+		{
+			return (unsigned short)((a_ushOriginalDimension + 3) & ~3);
+		}
+
+		inline ErrorMetric GetErrorMetric(void)
+		{
+			return m_errormetric;
+		}
+
+		static const char * EncodingFormatToString(Image::Format a_format);
+		const char * EncodingFormatToString(void);
+		//used to get basic information about the image data
+		int m_iNumOpaquePixels;
+		int m_iNumTranslucentPixels;
+		int m_iNumTransparentPixels;
+
+		ColorFloatRGBA m_numColorValues;
+		ColorFloatRGBA m_numOutOfRangeValues;
+
+		bool m_bVerboseOutput;
+	private:
+		//add a warning or error to check for while encoding
+		inline void TrackEncodingWarning(EncodingStatus a_encStatus)
+		{
+			m_warningsToCapture = (EncodingStatus)((unsigned int)m_warningsToCapture | (unsigned int)a_encStatus);
+		}
+
+		//report the warning if it is something we care about for this encoding
+		inline void AddToEncodingStatusIfSignfigant(EncodingStatus a_encStatus)
+		{
+			if ((EncodingStatus)((unsigned int)m_warningsToCapture & (unsigned int)a_encStatus) == a_encStatus)
+			{
+				AddToEncodingStatus(a_encStatus);
+			}
+		}
+
+		Image(void);
+		void FindEncodingWarningTypesForCurFormat();
+		void FindAndSetEncodingWarnings();
+
+		void InitBlocksAndBlockSorter(void);
+
+		void RunFirstPass(unsigned int a_uiMultithreadingOffset, 
+							unsigned int a_uiMultithreadingStride);
+
+		void SetEncodingBits(unsigned int a_uiMultithreadingOffset,
+								unsigned int a_uiMultithreadingStride);
+
+		unsigned int IterateThroughWorstBlocks(unsigned int a_uiMaxBlocks,
+												unsigned int a_uiMultithreadingOffset,
+												unsigned int a_uiMultithreadingStride);
+
+		// inputs
+		ColorFloatRGBA *m_pafrgbaSource;
+		unsigned int m_uiSourceWidth;
+		unsigned int m_uiSourceHeight;
+		unsigned int m_uiExtendedWidth;
+		unsigned int m_uiExtendedHeight;
+		unsigned int m_uiBlockColumns;
+		unsigned int m_uiBlockRows;
+		// intermediate data
+		Block4x4 *m_pablock;
+		// encoding
+		Format m_format;
+		Block4x4EncodingBits::Format m_encodingbitsformat;
+		unsigned int m_uiEncodingBitsBytes;		// for entire image
+		unsigned char *m_paucEncodingBits;
+		ErrorMetric m_errormetric;
+		float m_fEffort;
+		// stats
+		int m_iEncodeTime_ms;
+		
+		SortedBlockList *m_psortedblocklist;
+		//this will hold any warning or errors that happen during encoding
+		EncodingStatus m_encodingStatus;
+		//these will be the warnings we are tracking
+		EncodingStatus m_warningsToCapture;
+	};
+
+} // namespace Etc

thirdparty/etc2comp/EtcIndividualTrys.cpp

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+EtcIndividualTrys.cpp
+
+Gathers the results of the various encoding trys for both halves of a 4x4 block for Individual mode
+
+*/
+
+#include "EtcConfig.h"
+#include "EtcIndividualTrys.h"
+
+#include <assert.h>
+
+namespace Etc
+{
+
+	// ----------------------------------------------------------------------------------------------------
+	// construct a list of trys (encoding attempts)
+	//
+	// a_frgbaColor1 is the basecolor for the first half
+	// a_frgbaColor2 is the basecolor for the second half
+	// a_pauiPixelMapping1 is the pixel order for the first half
+	// a_pauiPixelMapping2 is the pixel order for the second half
+	// a_uiRadius is the amount to vary the base colors
+	//
+	IndividualTrys::IndividualTrys(ColorFloatRGBA a_frgbaColor1, ColorFloatRGBA a_frgbaColor2,
+									const unsigned int *a_pauiPixelMapping1,
+									const unsigned int *a_pauiPixelMapping2,
+									unsigned int a_uiRadius)
+	{
+		assert(a_uiRadius <= MAX_RADIUS);
+
+		ColorFloatRGBA frgbaQuantizedColor1 = a_frgbaColor1.QuantizeR4G4B4();
+		ColorFloatRGBA frgbaQuantizedColor2 = a_frgbaColor2.QuantizeR4G4B4();
+
+		// quantize base colors
+		// ensure that trys with a_uiRadius don't overflow
+		int iRed1 = MoveAwayFromEdge(frgbaQuantizedColor1.IntRed(15.0f), a_uiRadius);
+		int iGreen1 = MoveAwayFromEdge(frgbaQuantizedColor1.IntGreen(15.0f), a_uiRadius);
+		int iBlue1 = MoveAwayFromEdge(frgbaQuantizedColor1.IntBlue(15.0f), a_uiRadius);
+		int iRed2 = MoveAwayFromEdge(frgbaQuantizedColor2.IntRed(15.0f), a_uiRadius);
+		int iGreen2 = MoveAwayFromEdge(frgbaQuantizedColor2.IntGreen(15.0f), a_uiRadius);
+		int iBlue2 = MoveAwayFromEdge(frgbaQuantizedColor2.IntBlue(15.0f), a_uiRadius);
+
+		m_half1.Init(iRed1, iGreen1, iBlue1, a_pauiPixelMapping1, a_uiRadius);
+		m_half2.Init(iRed2, iGreen2, iBlue2, a_pauiPixelMapping2, a_uiRadius);
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	void IndividualTrys::Half::Init(int a_iRed, int a_iGreen, int a_iBlue,
+									const unsigned int *a_pauiPixelMapping, unsigned int a_uiRadius)
+	{
+
+		m_iRed = a_iRed;
+		m_iGreen = a_iGreen;
+		m_iBlue = a_iBlue;
+
+		m_pauiPixelMapping = a_pauiPixelMapping;
+		m_uiRadius = a_uiRadius;
+
+		m_uiTrys = 0;
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+} // namespace Etc

thirdparty/etc2comp/EtcIndividualTrys.h

@@ -0,0 +1,95 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "EtcColorFloatRGBA.h"
+
+namespace Etc
+{
+
+	class IndividualTrys
+	{
+	public:
+
+		static const unsigned int MAX_RADIUS = 1;
+
+		IndividualTrys(ColorFloatRGBA a_frgbaColor1,
+						ColorFloatRGBA a_frgbaColor2,
+						const unsigned int *a_pauiPixelMapping1,
+						const unsigned int *a_pauiPixelMapping2,
+						unsigned int a_uiRadius);
+
+		inline static int MoveAwayFromEdge(int a_i, int a_iDistance)
+		{
+			if (a_i < (0+ a_iDistance))
+			{
+				return (0 + a_iDistance);
+			}
+			else if (a_i > (15- a_iDistance))
+			{
+				return (15 - a_iDistance);
+			}
+
+			return a_i;
+		}
+
+		class Try
+		{
+        public :
+			static const unsigned int SELECTORS = 8;	// per half
+
+			int m_iRed;
+			int m_iGreen;
+			int m_iBlue;
+			unsigned int m_uiCW;
+			unsigned int m_auiSelectors[SELECTORS];
+			float m_fError;
+        };
+
+		class Half
+		{
+		public:
+
+			static const unsigned int MAX_TRYS = 27;
+
+			void Init(int a_iRed, int a_iGreen, int a_iBlue, 
+						const unsigned int *a_pauiPixelMapping,
+						unsigned int a_uiRadius);
+
+			// center of trys
+			int m_iRed;
+			int m_iGreen;
+			int m_iBlue;
+
+			const unsigned int *m_pauiPixelMapping;
+			unsigned int m_uiRadius;
+
+			unsigned int m_uiTrys;
+			Try m_atry[MAX_TRYS];
+
+			Try *m_ptryBest;
+		};
+
+		Half m_half1;
+		Half m_half2;
+
+	};
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+} // namespace Etc

thirdparty/etc2comp/EtcMath.cpp

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "EtcConfig.h"
+#include "EtcMath.h"
+
+namespace Etc
+{
+
+	// ----------------------------------------------------------------------------------------------------
+	// calculate the line that best fits the set of XY points contained in a_afX[] and a_afY[]
+	// use a_fSlope and a_fOffset to define that line
+	//
+	bool Regression(float a_afX[], float a_afY[], unsigned int a_Points,
+					float *a_fSlope, float *a_fOffset)
+	{
+		float fPoints = (float)a_Points;
+
+		float fSumX = 0.0f;
+		float fSumY = 0.0f;
+		float fSumXY = 0.0f;
+		float fSumX2 = 0.0f;
+
+		for (unsigned int uiPoint = 0; uiPoint < a_Points; uiPoint++)
+		{
+			fSumX += a_afX[uiPoint];
+			fSumY += a_afY[uiPoint];
+			fSumXY += a_afX[uiPoint] * a_afY[uiPoint];
+			fSumX2 += a_afX[uiPoint] * a_afX[uiPoint];
+		}
+
+		float fDivisor = fPoints*fSumX2 - fSumX*fSumX;
+
+		// if vertical line
+		if (fDivisor == 0.0f)
+		{
+			*a_fSlope = 0.0f;
+			*a_fOffset = 0.0f;
+			return true;
+		}
+
+		*a_fSlope = (fPoints*fSumXY - fSumX*fSumY) / fDivisor;
+		*a_fOffset = (fSumY - (*a_fSlope)*fSumX) / fPoints;
+
+		return false;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+
+} // namespace Etc

thirdparty/etc2comp/EtcMath.h

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <math.h>
+
+namespace Etc
+{
+
+	// ----------------------------------------------------------------------------------------------------
+	// return true if vertical line
+	bool Regression(float a_afX[], float a_afY[], unsigned int a_Points,
+					float *a_fSlope, float *a_fOffset);
+
+	inline float ConvertMSEToPSNR(float a_fMSE)
+	{
+		if (a_fMSE == 0.0f)
+		{
+			return INFINITY;
+		}
+
+		return 10.0f * log10f(1.0f / a_fMSE);
+	}
+
+
+}

thirdparty/etc2comp/EtcSortedBlockList.cpp

@@ -0,0 +1,228 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+EtcSortedBlockList.cpp
+
+SortedBlockList is a list of 4x4 blocks that can be used by the "effort" system to prioritize
+the encoding of the 4x4 blocks.
+
+The sorting is done with buckets, where each bucket is an indication of how much error each 4x4 block has
+
+*/
+
+#include "EtcConfig.h"
+#include "EtcSortedBlockList.h"
+
+#include "EtcBlock4x4.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+namespace Etc
+{
+
+	// ----------------------------------------------------------------------------------------------------
+	// construct an empty list
+	//
+	// allocate enough memory to add all of the image's 4x4 blocks later
+	// allocate enough buckets to sort the blocks
+	//
+	SortedBlockList::SortedBlockList(unsigned int a_uiImageBlocks, unsigned int a_uiBuckets)
+	{
+		m_uiImageBlocks = a_uiImageBlocks;
+		m_iBuckets = (int)a_uiBuckets;
+
+		m_uiAddedBlocks = 0;
+		m_uiSortedBlocks = 0;
+		m_palinkPool = new Link[m_uiImageBlocks];
+		m_pabucket = new Bucket[m_iBuckets];
+		m_fMaxError = 0.0f;
+
+		InitBuckets();
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	//
+	SortedBlockList::~SortedBlockList(void)
+	{
+		delete[] m_palinkPool;
+		delete[] m_pabucket;
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+    // add a 4x4 block to the list
+	// the 4x4 block will be sorted later
+	//
+    void SortedBlockList::AddBlock(Block4x4 *a_pblock)
+    {
+        assert(m_uiAddedBlocks < m_uiImageBlocks);
+        Link *plink = &m_palinkPool[m_uiAddedBlocks++];
+		plink->Init(a_pblock);
+    }
+
+	// ----------------------------------------------------------------------------------------------------
+	// sort all of the 4x4 blocks that have been added to the list
+	//
+	// first, determine the maximum error, then assign an error range to each bucket
+	// next, determine which bucket each 4x4 block belongs to based on the 4x4 block's error
+	// add the 4x4 block to the appropriate bucket
+	// lastly, walk thru the buckets and add each bucket to a sorted linked list
+	//
+	// the resultant sorting is an approximate sorting from most to least error
+	//
+    void SortedBlockList::Sort(void)
+    {
+		assert(m_uiAddedBlocks == m_uiImageBlocks);
+        InitBuckets();
+
+        // find max block error
+        m_fMaxError = -1.0f;
+
+        for (unsigned int uiLink = 0; uiLink < m_uiAddedBlocks; uiLink++)
+        {
+            Link *plinkBlock = &m_palinkPool[uiLink];
+
+            float fBlockError = plinkBlock->GetBlock()->GetError();
+            if (fBlockError > m_fMaxError)
+            {
+                m_fMaxError = fBlockError;
+            }
+        }
+        // prevent divide by zero or divide by negative
+        if (m_fMaxError <= 0.0f)
+        {
+            m_fMaxError = 1.0f;
+        }
+		//used for debugging
+		//int numDone = 0;
+        // put all of the blocks with unfinished encodings into the appropriate bucket
+		m_uiSortedBlocks = 0;
+        for (unsigned int uiLink = 0; uiLink < m_uiAddedBlocks; uiLink++)
+        {
+            Link *plinkBlock = &m_palinkPool[uiLink];
+
+			// if the encoding is done, don't add it to the list
+			if (plinkBlock->GetBlock()->GetEncoding()->IsDone())
+			{
+				//numDone++;
+				continue;
+			}
+
+            // calculate the appropriate sort bucket
+            float fBlockError = plinkBlock->GetBlock()->GetError();
+            int iBucket = (int) floorf(m_iBuckets * fBlockError / m_fMaxError);
+            // clamp to bucket index
+            iBucket = iBucket < 0 ? 0 : iBucket >= m_iBuckets ? m_iBuckets - 1 : iBucket;
+
+            // add block to bucket
+			{
+				Bucket *pbucket = &m_pabucket[iBucket];
+				if (pbucket->plinkLast)
+				{
+					pbucket->plinkLast->SetNext(plinkBlock);
+					pbucket->plinkLast = plinkBlock;
+				}
+				else
+				{
+					pbucket->plinkFirst = pbucket->plinkLast = plinkBlock;
+				}
+				plinkBlock->SetNext(nullptr);
+			}
+
+			m_uiSortedBlocks++;
+
+            if (0)
+            {
+                printf("%u: e=%.3f\n", uiLink, fBlockError);
+                Print();
+                printf("\n\n\n");
+            }
+        }
+		//printf("num blocks already done: %d\n",numDone);
+		//link the blocks together across buckets
+		m_plinkFirst = nullptr;
+		m_plinkLast = nullptr;
+		for (int iBucket = m_iBuckets - 1; iBucket >= 0; iBucket--)
+		{
+			Bucket *pbucket = &m_pabucket[iBucket];
+
+			if (pbucket->plinkFirst)
+			{
+				if (m_plinkFirst == nullptr)
+				{
+					m_plinkFirst = pbucket->plinkFirst;
+				}
+				else
+				{
+					assert(pbucket->plinkLast->GetNext() == nullptr);
+					m_plinkLast->SetNext(pbucket->plinkFirst);
+				}
+
+				m_plinkLast = pbucket->plinkLast;
+			}
+		}
+
+
+	}
+
+	// ----------------------------------------------------------------------------------------------------
+	// clear all of the buckets.  normally done in preparation for a sort
+	//
+	void SortedBlockList::InitBuckets(void)
+    {
+        for (int iBucket = 0; iBucket < m_iBuckets; iBucket++)
+        {
+            Bucket *pbucket = &m_pabucket[iBucket];
+
+            pbucket->plinkFirst = 0;
+            pbucket->plinkLast = 0;
+        }
+    }
+
+    // ----------------------------------------------------------------------------------------------------
+    // print out the list of sorted 4x4 blocks
+	// normally used for debugging
+	//
+    void SortedBlockList::Print(void)
+    {
+        for (int iBucket = m_iBuckets-1; iBucket >= 0; iBucket--)
+        {
+            Bucket *pbucket = &m_pabucket[iBucket];
+
+            unsigned int uiBlocks = 0;
+            for (Link *plink = pbucket->plinkFirst; plink != nullptr; plink = plink->GetNext() )
+            {
+                uiBlocks++;
+
+				if (plink == pbucket->plinkLast)
+				{
+					break;
+				}
+            }
+
+            float fBucketError = m_fMaxError * iBucket / m_iBuckets;
+            float fBucketRMS = sqrtf(fBucketError / (4.0f*16.0f) );
+            printf("%3d: e=%.3f rms=%.6f %u\n", iBucket, fBucketError, fBucketRMS, uiBlocks);
+        }
+    }
+
+    // ----------------------------------------------------------------------------------------------------
+    //
+
+}   // namespace Etc

thirdparty/etc2comp/EtcSortedBlockList.h

@@ -0,0 +1,124 @@
+/*
+ * Copyright 2015 The Etc2Comp Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+namespace Etc
+{
+	class Block4x4;
+
+    class SortedBlockList
+    {
+    public:
+
+		class Link
+		{
+		public:
+
+			inline void Init(Block4x4 *a_pblock)
+			{
+				m_pblock = a_pblock;
+				m_plinkNext = nullptr;
+			}
+
+			inline Block4x4 * GetBlock(void)
+			{
+				return m_pblock;
+			}
+
+			inline void SetNext(Link *a_plinkNext)
+			{
+				m_plinkNext = a_plinkNext;
+			}
+
+			inline Link * GetNext(void)
+			{
+				return m_plinkNext;
+			}
+
+			inline Link * Advance(unsigned int a_uiSteps = 1)
+			{
+				Link *plink = this;
+
+				for (unsigned int uiStep = 0; uiStep < a_uiSteps; uiStep++)
+				{
+					if (plink == nullptr)
+					{
+						break;
+					}
+
+					plink = plink->m_plinkNext;
+				}
+
+				return plink;
+			}
+
+		private:
+
+			Block4x4 *m_pblock;
+			Link *m_plinkNext;
+		};
+
+		SortedBlockList(unsigned int a_uiImageBlocks, unsigned int a_uiBuckets);
+		~SortedBlockList(void);
+
+        void AddBlock(Block4x4 *a_pblock);
+
+        void Sort(void);
+
+		inline Link * GetLinkToFirstBlock(void)
+		{
+			return m_plinkFirst;
+		}
+
+		inline unsigned int GetNumberOfAddedBlocks(void)
+		{
+			return m_uiAddedBlocks;
+		}
+
+		inline unsigned int GetNumberOfSortedBlocks(void)
+		{
+			return m_uiSortedBlocks;
+		}
+
+		void Print(void);
+
+	private:
+
+        void InitBuckets(void);
+
+        class Bucket
+        {
+        public:
+            Link *plinkFirst;
+            Link *plinkLast;
+        };
+
+        unsigned int m_uiImageBlocks;
+        int m_iBuckets;
+
+		unsigned int m_uiAddedBlocks;
+		unsigned int m_uiSortedBlocks;
+		Link *m_palinkPool;
+        Bucket *m_pabucket;
+        float m_fMaxError;
+
+		Link *m_plinkFirst;
+		Link *m_plinkLast;
+
+    };
+
+} // namespace Etc

thirdparty/etc2comp/LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
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+      and distribution as defined by Sections 1 through 9 of this document.
+
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+
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thirdparty/etc2comp/README.md

@@ -0,0 +1,197 @@
+# Etc2Comp - Texture to ETC2 compressor
+
+Etc2Comp is a command line tool that converts textures (e.g. bitmaps)
+into the [ETC2](https://en.wikipedia.org/wiki/Ericsson_Texture_Compression)
+format. The tool is built with a focus on encoding performance
+to reduce the amount of time required to compile asset heavy applications as
+well as reduce overall application size.
+
+This repo provides source code that can be compiled into a binary. The
+binary can then be used to convert textures to the ETC2 format.
+
+Important: This is not an official Google product. It is an experimental
+library published as-is. Please see the CONTRIBUTORS.md file for information
+about questions or issues.
+
+## Setup
+This project uses [CMake](https://cmake.org/) to generate platform-specific
+build files:
+ - Linux: make files
+ - OS X: Xcode workspace files
+ - Microsoft Windows: Visual Studio solution files
+ - Note: CMake supports other formats, but this doc only provides steps for
+ one of each platform for brevity.
+
+Refer to each platform's setup section to setup your environment and build
+an Etc2Comp binary. Then skip to the usage section of this page for examples
+of how to use the library.
+
+### Setup for OS X
+ build tested on this config:
+  OS X 10.9.5 i7 16GB RAM
+  Xcode 5.1.1
+  cmake 3.2.3
+  
+Start by downloading and installing the following components if they are not
+already installed on your development machine.
+ - *Xcode* version 5.1.1, or greater
+ - [CMake](https://cmake.org/download/) version 3.2.3, or greater
+
+To build the Etc2Comp binary:
+ 1. Open a *Terminal* window and navigate to the project directory.
+ 1. Run `mkdir build_xcode`
+ 1. Run `cd build_xcode`
+ 1. Run `cmake -G Xcode ../`
+ 1. Open *Xcode* and import the `build_xcode/EtcTest.xcodeproj` file.
+ 1. Open the Product menu and choose Build For -> Running.
+ 1. Once the build succeeds the binary located at `build_xcode/EtcTool/Debug/EtcTool`
+can be executed.
+
+Optional
+Xcode EtcTool ‘Run’ preferences
+note: if the build_xcode/EtcTest.xcodeproj is manually deleted then some Xcode preferences 
+will need to be set by hand after cmake is run (these prefs are retained across 
+cmake updates if the .xcodeproj is not deleted/removed)
+
+1. Set the active scheme to ‘EtcTool’
+1. Edit the scheme
+1. Select option ‘Run EtcTool’, then tab ‘Arguments’. 
+Add this launch argument: ‘-argfile ../../EtcTool/args.txt’
+1. Select tab ‘Options’ and set a custom working directory to: ‘$(SRCROOT)/Build_Xcode/EtcTool’
+
+### SetUp for Windows
+
+1. Open a *Terminal* window and navigate to the project directory.
+1. Run `mkdir build_vs`
+1. Run `cd build_vs`
+1. Run CMAKE, noting what build version you need, and pointing to the parent directory as the source root; 
+  For VS 2013 : `cmake -G "Visual Studio 12 2013 Win64" ../`
+  For VS 2015 : `cmake -G "Visual Studio 14 2015 Win64" ../`
+  NOTE: To see what supported Visual Studio outputs there are, run `cmake -G`
+1. open the 'EtcTest' solution
+1. make the 'EtcTool' project the start up project 
+1. (optional) in the project properties, under 'Debugging ->command arguments' 
+add the argfile textfile thats included in the EtcTool directory. 
+example: -argfile C:\etc2\EtcTool\Args.txt
+
+### Setup For Linux
+The Linux build was tested on this config:
+  Ubuntu desktop 14.04
+  gcc/g++ 4.8
+  cmake 2.8.12.2
+
+1. Verify linux has cmake and C++-11 capable g++ installed
+1. Open shell
+1. Run `mkdir build_linux`
+1. Run `cd build_linux`
+1. Run `cmake ../`
+1. Run `make`
+1. navigate to the newly created EtcTool directory `cd EtcTool`
+1. run the executable: `./EtcTool -argfile ../../EtcTool/args.txt`
+
+Skip to the <a href="#usage">Usage</a> section for more information about using the
+tool.
+
+## Usage
+
+### Command Line Usage
+EtcTool can be run from the command line with the following usage:
+    etctool.exe source_image [options ...] -output encoded_image
+
+The encoder will use an array of RGBA floats read from the source_image to create 
+an ETC1 or ETC2 encoded image in encoded_image.  The RGBA floats should be in the 
+range [0:1].
+
+Options:
+
+    -analyze <analysis_folder>
+    -argfile <arg_file>           additional command line arguments read from a file
+    -blockAtHV <H V>              encodes a single block that contains the
+                                  pixel specified by the H V coordinates
+    -compare <comparison_image>   compares source_image to comparison_image
+    -effort <amount>              number between 0 and 100 to specify the encoding quality 
+                                  (100 is the highest quality)
+    -errormetric <error_metric>   specify the error metric, the options are
+                                  rgba, rgbx, rec709, numeric and normalxyz
+    -format <etc_format>          ETC1, RGB8, SRGB8, RGBA8, SRGB8, RGB8A1,
+                                  SRGB8A1 or R11
+    -help                         prints this message
+    -jobs or -j <thread_count>    specifies the number of threads (default=1)
+    -normalizexyz                 normalize RGB to have a length of 1
+    -verbose or -v                shows status information during the encoding
+                                  process
+	-mipmaps or -m <mip_count>    sets the maximum number of mipaps to generate (default=1)
+	-mipwrap or -w <x|y|xy>       sets the mipmap filter wrap mode (default=clamp)
+
+* -analyze will run an analysis of the encoding and place it in folder 
+"analysis_folder" (e.g. ../analysis/kodim05).  within the analysis_folder, a folder 
+will be created with a name of the current date/time (e.g. 20151204_153306).  this 
+date/time folder is used to compare encodings of the same texture over time.  
+within the date/time folder is a text file with several encoding stats and a 2x png 
+image showing the encoding mode for each 4x4 block.
+
+* -argfile allows additional command line arguments to be placed in a text file
+
+* -blockAtHV selects the 4x4 pixel subset of the source image at position (H,V).  
+This is mainly used for debugging
+
+* -compare compares the source image to the created encoded image. The encoding
+will dictate what error analysis is used in the comparison.
+
+* -effort uses an "amount" between 0 and 100 to determine how much additional effort 
+to apply during the encoding.
+
+* -errormetric selects the fitting algorithm used by the encoder.  "rgba" calculates 
+RMS error using RGB components that are weighted by A.  "rgbx" calculates RMS error 
+using RGBA components, where A is treated as an additional data channel, instead of 
+as alpha.  "rec709" is similar to "rgba", except the RGB components are also weighted 
+according to Rec709.  "numeric" calculates RMS error using unweighted RGBA components.  
+"normalize" calculates error based on dot product and vector length for RGB and RMS 
+error for A.
+
+* -help prints out the usage message
+
+* -jobs enables multi-threading to speed up image encoding
+
+* -normalizexyz normalizes the source RGB to have a length of 1.
+
+* -verbose shows information on the current encoding process. It will then display the 
+PSNR and time time it took to encode the image.
+
+* -mipmaps takes an argument that specifies how many mipmaps to generate from the 
+source image.  The mipmaps are generated with a lanczos3 filter using edge clamping.
+If the mipmaps option is not specified no mipmaps are created.
+
+* -mipwrap takes an argument that specifies the mipmap filter wrap mode.  The options 
+are "x", "y" and "xy" which specify wrapping in x only, y only or x and y respectively.
+The default options are clamping in both x and y.
+
+Note: Path names can use slashes or backslashes.  The tool will convert the 
+slashes to the appropriate polarity for the current platform.
+
+
+## API
+
+The library supports two different APIs - a C-like API that is not heavily 
+class-based and a class-based API.
+
+main() in EtcTool.cpp contains an example of both APIs.
+
+The Encode() method now returns an EncodingStatus that contains bit flags for
+reporting various warnings and flags encountered when encoding.
+
+
+## Copyright
+Copyright 2015 Etc2Comp Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

thirdparty/rg-etc1/rg_etc1.h

@@ -1,76 +0,0 @@
-// File: rg_etc1.h - Fast, high quality ETC1 block packer/unpacker - Rich Geldreich <richgel99@gmail.com>
-// Please see ZLIB license at the end of this file.
-#pragma once
-
-namespace rg_etc1
-{
-   // Unpacks an 8-byte ETC1 compressed block to a block of 4x4 32bpp RGBA pixels.
-   // Returns false if the block is invalid. Invalid blocks will still be unpacked with clamping.
-   // This function is thread safe, and does not dynamically allocate any memory.
-   // If preserve_alpha is true, the alpha channel of the destination pixels will not be overwritten. Otherwise, alpha will be set to 255.
-   bool unpack_etc1_block(const void *pETC1_block, unsigned int* pDst_pixels_rgba, bool preserve_alpha = false);
-
-   // Quality setting = the higher the quality, the slower. 
-   // To pack large textures, it is highly recommended to call pack_etc1_block() in parallel, on different blocks, from multiple threads (particularly when using cHighQuality).
-   enum etc1_quality
-   { 
-      cLowQuality,
-      cMediumQuality,
-      cHighQuality,
-   };
-      
-   struct etc1_pack_params
-   {
-      etc1_quality m_quality;
-      bool m_dithering;
-                              
-      inline etc1_pack_params() 
-      {
-         clear();
-      }
-
-      void clear()
-      {
-         m_quality = cHighQuality;
-         m_dithering = false;
-      }
-   };
-
-   // Important: pack_etc1_block_init() must be called before calling pack_etc1_block().
-   void pack_etc1_block_init();
-
-   // Packs a 4x4 block of 32bpp RGBA pixels to an 8-byte ETC1 block.
-   // 32-bit RGBA pixels must always be arranged as (R,G,B,A) (R first, A last) in memory, independent of platform endianness. A should always be 255.
-   // Returns squared error of result.
-   // This function is thread safe, and does not dynamically allocate any memory.
-   // pack_etc1_block() does not currently support "perceptual" colorspace metrics - it primarily optimizes for RGB RMSE.
-   unsigned int pack_etc1_block(void* pETC1_block, const unsigned int* pSrc_pixels_rgba, etc1_pack_params& pack_params);
-            
-} // namespace rg_etc1
-
-//------------------------------------------------------------------------------
-//
-// rg_etc1 uses the ZLIB license:
-// http://opensource.org/licenses/Zlib
-//
-// Copyright (c) 2012 Rich Geldreich
-//
-// This software is provided 'as-is', without any express or implied
-// warranty.  In no event will the authors be held liable for any damages
-// arising from the use of this software.
-//
-// Permission is granted to anyone to use this software for any purpose,
-// including commercial applications, and to alter it and redistribute it
-// freely, subject to the following restrictions:
-//
-// 1. The origin of this software must not be misrepresented; you must not
-// claim that you wrote the original software. If you use this software
-// in a product, an acknowledgment in the product documentation would be
-// appreciated but is not required.
-//
-// 2. Altered source versions must be plainly marked as such, and must not be
-// misrepresented as being the original software.
-//
-// 3. This notice may not be removed or altered from any source distribution.
-//
-//------------------------------------------------------------------------------