/*************************************************************************/
/*  image_compress_squish.cpp                                            */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* 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:                                             */
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/* 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.*/
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/*************************************************************************/
#include "image_compress_squish.h"

#include "print_string.h"

#include <squish.h>

void image_compress_squish(Image *p_image) {

	int w=p_image->get_width();
	int h=p_image->get_height();

	if (p_image->get_mipmaps() == 0) {
		ERR_FAIL_COND( !w || w % 4 != 0);
		ERR_FAIL_COND( !h || h % 4 != 0);
	} else {
		ERR_FAIL_COND( !w || w !=nearest_power_of_2(w) );
		ERR_FAIL_COND( !h || h !=nearest_power_of_2(h) );
	};

	if (p_image->get_format()>=Image::FORMAT_BC1)
		return; //do not compress, already compressed

	int shift=0;
	int squish_comp=squish::kColourRangeFit;
	Image::Format target_format;

	if (p_image->get_format()==Image::FORMAT_GRAYSCALE_ALPHA) {
		//compressed normalmap
		target_format = Image::FORMAT_BC3; squish_comp|=squish::kDxt5;
	} else if (p_image->detect_alpha()!=Image::ALPHA_NONE) {

		target_format = Image::FORMAT_BC2; squish_comp|=squish::kDxt3;
	} else {
		target_format = Image::FORMAT_BC1; shift=1; squish_comp|=squish::kDxt1;
	}

	p_image->convert(Image::FORMAT_RGBA); //always expects rgba

	int mm_count = p_image->get_mipmaps();

	DVector<uint8_t> data;
	int target_size = Image::get_image_data_size(w,h,target_format,mm_count);
	data.resize(target_size);

	DVector<uint8_t>::Read rb = p_image->get_data().read();
	DVector<uint8_t>::Write wb = data.write();

	int dst_ofs=0;

	for(int i=0;i<=mm_count;i++) {

		int src_ofs = p_image->get_mipmap_offset(i);
		squish::CompressImage( &rb[src_ofs],w,h,&wb[dst_ofs],squish_comp);
		dst_ofs+=(MAX(4,w)*MAX(4,h))>>shift;
		w>>=1;
		h>>=1;
	}

	rb = DVector<uint8_t>::Read();
	wb = DVector<uint8_t>::Write();

	p_image->create(p_image->get_width(),p_image->get_height(),p_image->get_mipmaps(),target_format,data);

}