virtualx-engine/thirdparty/etc2comp/EtcBlock4x4Encoding_RGBA8.cpp

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/*
* 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;
}
// ----------------------------------------------------------------------------------------------------
//
}