2dutils.hpp

#ifndef DUTILS_HEADER
#define DUTILS_HEADER

size_t tileIndexFromPixel(
	size_t pixel,
	uint32_t width,
	uint32_t b_width,
	size_t blockSize_w,
	size_t blockSize_h
){
	uint32_t y = pixel / width;
	uint32_t x = pixel % width;
	uint32_t b_y = y / blockSize_h;
	uint32_t b_x = x / blockSize_w;
	return b_y * b_width + b_x;
}

uint8_t* bitmap_expander(uint8_t* bitmap,uint32_t width,uint32_t height){
	uint8_t* bitmap_expanded = new uint8_t[width*height*4];
	for(size_t i=0;i<width*height;i++){
		bitmap_expanded[i*4 + 0] = bitmap[i];
		bitmap_expanded[i*4 + 1] = bitmap[i];
		bitmap_expanded[i*4 + 2] = bitmap[i];
		bitmap_expanded[i*4 + 3] = 255;
	}
	return bitmap_expanded;
}

uint8_t* alpha_expander(uint8_t* bitmap,uint32_t width,uint32_t height){
	uint8_t* bitmap_expanded = new uint8_t[width*height*4];
	for(size_t i=0;i<width*height;i++){
		//note: switches GRB to RGB
		bitmap_expanded[i*4 + 0] = bitmap[i*3 + 1];
		bitmap_expanded[i*4 + 1] = bitmap[i*3 + 0];
		bitmap_expanded[i*4 + 2] = bitmap[i*3 + 2];
		bitmap_expanded[i*4 + 3] = 255;
	}
	return bitmap_expanded;
}

uint8_t* full_expander(uint8_t* bitmap,uint32_t width,uint32_t height){
	uint8_t* bitmap_expanded = new uint8_t[width*height*4];
	for(size_t i=0;i<width*height;i++){
		//note: switches GRB to RGB
		bitmap_expanded[i*4 + 0] = bitmap[i];
		bitmap_expanded[i*4 + 1] = bitmap[i];
		bitmap_expanded[i*4 + 2] = bitmap[i];
		bitmap_expanded[i*4 + 3] = 255;
	}
	return bitmap_expanded;
}

bool greyscale_test(uint8_t* RGBA,uint32_t width,uint32_t height){
	for(size_t i=0;i<width*height;i+=4){
		if(
			RGBA[i] != RGBA[i+1]
			|| RGBA[i] != RGBA[i+2]
		){
			return false;
		}
	}
	return true;
}

size_t greyscale_counter(uint8_t* grey, uint32_t width,uint32_t height, uint8_t* palette, size_t limit){
	bool found[256];	
	for(size_t i=0;i<256;i++){
		found[i] = false;
	}
	size_t count = 0;
	for(size_t i=0;i<width*height;i++){
		if(!found[grey[i]]){
			found[grey[i]] = true;
			palette[count++] = grey[i];
			if(count > limit){
				return 0;
			}
		}
	}
	return count;
}

size_t colour_counter(uint8_t* in_bytes, uint32_t width,uint32_t height, uint8_t* palette, size_t limit){
	size_t count = 0;
	for(size_t i=0;i<width*height;i++){
		bool found = false;
		for(size_t j=0;j<count;j++){
			if(
				palette[j*3] == in_bytes[i*3]
				&& palette[j*3+1] == in_bytes[i*3+1]
				&& palette[j*3+2] == in_bytes[i*3+2]
			){
				found = true;
				break;
			}
		}
		if(!found){
			palette[count*3] = in_bytes[i*3];
			palette[count*3+1] = in_bytes[i*3+1];
			palette[count*3+2] = in_bytes[i*3+2];
			count++;
			if(count > limit){
				return 0;
			}
		}
	}
	return count;
}

double synthness(uint8_t* decoded,uint32_t width,uint32_t height){
	size_t repeat = 0;
	size_t matches = 0;

	for(size_t i=1;i<width*height;i++){
		if(
			   decoded[i*3 + 0] == decoded[(i - 1)*3 + 0]
			&& decoded[i*3 + 1] == decoded[(i - 1)*3 + 1]
			&& decoded[i*3 + 2] == decoded[(i - 1)*3 + 2]
		){
			repeat++;
			if(repeat == 4){
				matches++;
				repeat = 0;
			}
		}
	}

	return (double)matches*4/(width*height);
}

double synthness_grey(uint8_t* decoded,uint32_t width,uint32_t height){
	size_t repeat = 0;
	size_t matches = 0;

	for(size_t i=1;i<width*height;i++){
		if(
			   decoded[i] == decoded[(i - 1)]
		){
			repeat++;
			if(repeat == 8){
				matches++;
				repeat = 0;
			}
		}
	}

	return (double)matches*8/(width*height);
}

#endif //DUTILS_HEADER