Function LoadPixelDataRLE4

Dependencies/FreeImage/Source/FreeImage/PluginBMP.cpp:207–339

Load image pixels for 4-bit RLE compressed dib @param io FreeImage IO @param handle FreeImage IO handle @param width Image width @param height Image height @param dib Image to be loaded @return Returns TRUE if successful, returns FALSE otherwise */

@return Returns TRUE if successful, returns FALSE otherwise
*/
static BOOL 
LoadPixelDataRLE4(FreeImageIO *io, fi_handle handle, int width, int height, FIBITMAP *dib) {
	int status_byte = 0;
	BYTE second_byte = 0;
	int bits = 0;

	BYTE *pixels = NULL;	// temporary 8-bit buffer

	try {
		height = abs(height);

		pixels = (BYTE*)malloc(width * height * sizeof(BYTE));
		if(!pixels) throw(1);
		memset(pixels, 0, width * height * sizeof(BYTE));

		BYTE *q = pixels;
		BYTE *end = pixels + height * width;

		for (int scanline = 0; scanline < height; ) {
			if (q < pixels || q  >= end) {
				break;
			}
			if(io->read_proc(&status_byte, sizeof(BYTE), 1, handle) != 1) {
				throw(1);
			}
			if (status_byte != 0)	{
				status_byte = (int)MIN((size_t)status_byte, (size_t)(end - q));
				// Encoded mode
				if(io->read_proc(&second_byte, sizeof(BYTE), 1, handle) != 1) {
					throw(1);
				}
				for (int i = 0; i < status_byte; i++)	{
					*q++=(BYTE)((i & 0x01) ? (second_byte & 0x0f) : ((second_byte >> 4) & 0x0f));
				}
				bits += status_byte;
			}
			else {
				// Escape mode
				if(io->read_proc(&status_byte, sizeof(BYTE), 1, handle) != 1) {
					throw(1);
				}
				switch (status_byte) {
					case RLE_ENDOFLINE:
					{
						// End of line
						bits = 0;
						scanline++;
						q = pixels + scanline*width;
					}
					break;

					case RLE_ENDOFBITMAP:
						// End of bitmap
						q = end;
						break;

					case RLE_DELTA:
					{