godot/core/image_quantize.cpp

/*************************************************************************/
/*  image_quantize.cpp                                                   */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2016 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       */
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/* distribute, sublicense, and/or sell copies of the Software, and to    */
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/* the following conditions:                                             */
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/* The above copyright notice and this permission notice shall be        */
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/* 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.h"
#include <stdio.h>
#include "print_string.h"
#ifdef TOOLS_ENABLED
#include "set.h"
#include "sort.h"
#include "os/os.h"

//#define QUANTIZE_SPEED_OVER_QUALITY


Image::MCBlock::MCBlock() {


}

Image::MCBlock::MCBlock(BColorPos *p_colors,int p_color_count) {

	colors=p_colors;
	color_count=p_color_count;
	min_color.color=BColor(255,255,255,255);
	max_color.color=BColor(0,0,0,0);
	shrink();
}

int Image::MCBlock::get_longest_axis_index() const {

	int max_dist=-1;
	int max_index=0;

	for(int i=0;i<4;i++) {

		int d = max_color.color.col[i]-min_color.color.col[i];
		//printf(" ai:%i - %i\n",i,d);
		if (d>max_dist) {
			max_index=i;
			max_dist=d;
		}
	}

	return max_index;
}
int Image::MCBlock::get_longest_axis_length() const {

	int max_dist=-1;
	int max_index=0;

	for(int i=0;i<4;i++) {

		int d = max_color.color.col[i]-min_color.color.col[i];
		if (d>max_dist) {
			max_index=i;
			max_dist=d;
		}
	}

	return max_dist;
}

bool Image::MCBlock::operator<(const MCBlock& p_block) const {

	int alen = get_longest_axis_length();
	int blen = p_block.get_longest_axis_length();
	if (alen==blen) {

		return colors < p_block.colors;
	} else
		return alen < blen;

}

void Image::MCBlock::shrink() {

	min_color=colors[0];
	max_color=colors[0];

	for(int i=1;i<color_count;i++) {

		for(int j=0;j<4;j++) {

			min_color.color.col[j]=MIN(min_color.color.col[j],colors[i].color.col[j]);
			max_color.color.col[j]=MAX(max_color.color.col[j],colors[i].color.col[j]);
		}
	}
}




void Image::quantize() {

	Image::Format orig_format=format;

	bool has_alpha = detect_alpha()!=ALPHA_NONE;

	bool quantize_fast=OS::get_singleton()->has_environment("QUANTIZE_FAST");

	convert(FORMAT_RGBA);

	ERR_FAIL_COND( format!=FORMAT_RGBA );

	DVector<uint8_t> indexed_data;


	{
		int color_count = data.size()/4;

		ERR_FAIL_COND(color_count==0);

		Set<MCBlock> block_queue;

		DVector<BColorPos> data_colors;
		data_colors.resize(color_count);

		DVector<BColorPos>::Write dcw=data_colors.write();

		DVector<uint8_t>::Read dr = data.read();
		const BColor * drptr=(const BColor*)&dr[0];
		BColorPos *bcptr=&dcw[0];



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

				//uint32_t data_ofs=i<<2;
				bcptr[i].color=drptr[i];//BColor(drptr[data_ofs+0],drptr[data_ofs+1],drptr[data_ofs+2],drptr[data_ofs+3]);
				bcptr[i].index=i;
			}

		}

		//printf("color count: %i\n",color_count);
		/*
		for(int i=0;i<color_count;i++) {

			BColor bc = ((BColor*)&wb[0])[i];
			printf("%i - %i,%i,%i,%i\n",i,bc.r,bc.g,bc.b,bc.a);
		}*/

		MCBlock initial_block((BColorPos*)&dcw[0],color_count);

		block_queue.insert(initial_block);

		while( block_queue.size() < 256 && block_queue.back()->get().color_count > 1 ) {

			MCBlock longest = block_queue.back()->get();
			//printf("longest: %i (%i)\n",longest.get_longest_axis_index(),longest.get_longest_axis_length());

			block_queue.erase(block_queue.back());

			BColorPos *first = longest.colors;
			BColorPos *median = longest.colors + (longest.color_count+1)/2;
			BColorPos *end = longest.colors + longest.color_count;

#if 0
			int lai =longest.get_longest_axis_index();
			switch(lai) {
#if 0
				case 0: { SortArray<BColorPos,BColorPos::SortR> sort; sort.sort(first,end-first); } break;
				case 1: { SortArray<BColorPos,BColorPos::SortG> sort; sort.sort(first,end-first); } break;
				case 2: { SortArray<BColorPos,BColorPos::SortB> sort; sort.sort(first,end-first); } break;
				case 3: { SortArray<BColorPos,BColorPos::SortA> sort; sort.sort(first,end-first); } break;
#else
				case 0: { SortArray<BColorPos,BColorPos::SortR> sort; sort.nth_element(0,end-first,median-first,first); } break;
				case 1: { SortArray<BColorPos,BColorPos::SortG> sort; sort.nth_element(0,end-first,median-first,first); } break;
				case 2: { SortArray<BColorPos,BColorPos::SortB> sort; sort.nth_element(0,end-first,median-first,first); } break;
				case 3: { SortArray<BColorPos,BColorPos::SortA> sort; sort.nth_element(0,end-first,median-first,first); } break;
#endif

			}

			//avoid same color from being split in 2
			//search forward and flip
			BColorPos *median_end=median;
			BColorPos *p=median_end+1;

			while(p!=end) {
				if (median_end->color==p->color) {
					SWAP(*(median_end+1),*p);
					median_end++;
				}
				p++;
			}

			//search backward and flip
			BColorPos *median_begin=median;
			p=median_begin-1;

			while(p!=(first-1)) {
				if (median_begin->color==p->color) {
					SWAP(*(median_begin-1),*p);
					median_begin--;
				}
				p--;
			}


			if (first < median_begin) {
				median=median_begin;
			} else if (median_end < end-1) {
				median=median_end+1;
			} else {
				break; //shouldn't have arrived here, since it means all pixels are equal, but wathever
			}

			MCBlock left(first,median-first);
			MCBlock right(median,end-median);

			block_queue.insert(left);
			block_queue.insert(right);

#else
			switch(longest.get_longest_axis_index()) {
				case 0: { SortArray<BColorPos,BColorPos::SortR> sort; sort.nth_element(0,end-first,median-first,first); } break;
				case 1: { SortArray<BColorPos,BColorPos::SortG> sort; sort.nth_element(0,end-first,median-first,first); } break;
				case 2: { SortArray<BColorPos,BColorPos::SortB> sort; sort.nth_element(0,end-first,median-first,first); } break;
				case 3: { SortArray<BColorPos,BColorPos::SortA> sort; sort.nth_element(0,end-first,median-first,first); } break;

			}

			MCBlock left(first,median-first);
			MCBlock right(median,end-median);

			block_queue.insert(left);
			block_queue.insert(right);


#endif


		}

		while(block_queue.size() > 256) {

			block_queue.erase(block_queue.front());// erase least significant
		}

		int res_colors=0;

		int comp_size = (has_alpha?4:3);
		indexed_data.resize(color_count + 256*comp_size);

		DVector<uint8_t>::Write iw = indexed_data.write();
		uint8_t *iwptr=&iw[0];
		BColor pallete[256];

	//	print_line("applying quantization - res colors "+itos(block_queue.size()));

		while(block_queue.size()) {

			const MCBlock &b = block_queue.back()->get();

			uint64_t sum[4]={0,0,0,0};

			for(int i=0;i<b.color_count;i++) {

				sum[0]+=b.colors[i].color.col[0];
				sum[1]+=b.colors[i].color.col[1];
				sum[2]+=b.colors[i].color.col[2];
				sum[3]+=b.colors[i].color.col[3];
			}

			BColor c( sum[0]/b.color_count, sum[1]/b.color_count, sum[2]/b.color_count, sum[3]/b.color_count );



			//printf(" %i: %i,%i,%i,%i out of %i\n",res_colors,c.r,c.g,c.b,c.a,b.color_count);



			for(int i=0;i<comp_size;i++) {
				iwptr[ color_count + res_colors * comp_size + i ] = c.col[i];
			}

			if (quantize_fast) {
				for(int i=0;i<b.color_count;i++) {
					iwptr[b.colors[i].index]=res_colors;
				}
			} else {

				pallete[res_colors]=c;
			}


			res_colors++;

			block_queue.erase(block_queue.back());

		}


		if (!quantize_fast) {

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

				const BColor &c=drptr[i];
				uint8_t best_dist_idx=0;
				uint32_t dist=0xFFFFFFFF;

				for(int j=0;j<res_colors;j++) {

					const BColor &pc=pallete[j];
					uint32_t d = 0;
					{ int16_t v = (int16_t)c.r-(int16_t)pc.r; d+=v*v; }
					{ int16_t v = (int16_t)c.g-(int16_t)pc.g; d+=v*v; }
					{ int16_t v = (int16_t)c.b-(int16_t)pc.b; d+=v*v; }
					{ int16_t v = (int16_t)c.a-(int16_t)pc.a; d+=v*v; }

					if (d<=dist) {
						best_dist_idx=j;
						dist=d;
					}
				}


				iwptr[ i ] = best_dist_idx;

			}
		}

		//iw = DVector<uint8_t>::Write();
		//dr = DVector<uint8_t>::Read();
		//wb = DVector<uint8_t>::Write();
	}

	print_line(itos(indexed_data.size()));
	data=indexed_data;
	format=has_alpha?FORMAT_INDEXED_ALPHA:FORMAT_INDEXED;


} //do none



#else


void Image::quantize() {} //do none


#endif