Function WSA_LoadFile

src/wsa.c:192–321

* Load a WSA file. * @param filename Name of the file. * @param wsa Data buffer for the WSA. * @param wsaSize Current size of buffer. * @param reserveDisplayFrame True if we need to reserve the display frame. * @return Address of loaded WSA file, or NULL. */

 * @return Address of loaded WSA file, or NULL.
 */
void *WSA_LoadFile(const char *filename, void *wsa, uint32 wsaSize, bool reserveDisplayFrame)
{
	WSAFlags flags;
	WSAFileHeader fileheader;
	WSAHeader *header;
	uint32 bufferSizeMinimal;
	uint32 bufferSizeOptimal;
	uint16 lengthHeader;
	uint8 fileno;
	uint16 lengthPalette;
	uint16 lengthFirstFrame;
	uint32 lengthFileContent;
	uint32 displaySize;
	uint8 *buffer;

	memset(&flags, 0, sizeof(flags));

	fileno = File_Open(filename, FILE_MODE_READ);
	fileheader.frames = File_Read_LE16(fileno);
	fileheader.width = File_Read_LE16(fileno);
	fileheader.height = File_Read_LE16(fileno);
	fileheader.requiredBufferSize = File_Read_LE16(fileno);
	fileheader.hasPalette = File_Read_LE16(fileno);		/* has palette */
	fileheader.firstFrameOffset = File_Read_LE32(fileno);	/* Offset of 1st frame */
	fileheader.secondFrameOffset = File_Read_LE32(fileno);	/* Offset of 2nd frame (end of 1st frame) */

	lengthPalette = 0;
	if (fileheader.hasPalette) {
		flags.hasPalette = true;

		lengthPalette = 0x300;	/* length of a 256 color RGB palette */
	}

	lengthFileContent = File_Seek(fileno, 0, 2);

	lengthFirstFrame = 0;
	if (fileheader.firstFrameOffset != 0) {
		lengthFirstFrame = fileheader.secondFrameOffset - fileheader.firstFrameOffset;
	} else {
		flags.hasNoFirstFrame = true;	/* is the continuation of another WSA */
	}

	lengthFileContent -= lengthPalette + lengthFirstFrame + 10;

	displaySize = 0;
	if (reserveDisplayFrame) {
		flags.displayInBuffer = true;
		displaySize = fileheader.width * fileheader.height;
	}

	bufferSizeMinimal = displaySize + fileheader.requiredBufferSize - 33 + sizeof(WSAHeader);
	bufferSizeOptimal = bufferSizeMinimal + lengthFileContent;

	if (wsaSize > 1 && wsaSize < bufferSizeMinimal) {
		File_Close(fileno);

		return NULL;
	}