AVR Freaks

I am working on reading BMP images on a USB and displaying them on a SSD1963 TFT.  The below code will read the bmp header, then parse the image data to display on a TFT (BMP565 format). The issue I am having is the code works if  the image is 100px X 100px. But it the height and width are not the same, it doesn't display correctly. e.g. the image is not recognizable, but the height and width are correct. From reading online, I need to calculate the number of pixels in each row, which I do, but I suspect how I am not iterating over the rows correctly.

void display_bmp(int x1, int y1, char *bitmap){

	uint32_t bmpWidth  = 0;
	uint32_t bmpHeight = 0;
	uint16_t bmpImageoffset;
	uint16_t rowSize;
	uint8_t header_buff[60];
	uint16_t position = 0;
	uint8_t numberOfPixels = 0;
	uint32_t commpression = 0;
	uint32_t imageSize = 0;
	unsigned int byte_read;
	uint16_t bmpSig;
	volatile uint8_t lun = LUN_ID_USB;

	/* Mount drive */
	memset(&fs, 0, sizeof(FATFS));
	FRESULT res = f_mount(lun, &fs);
	if (FR_INVALID_DRIVE == res) {
		printf("Mount Failed!\n\r");
		return;
	}

	printf("loading  %s\n\r", (char *)bitmap);
	res = f_open(&file_object,(char *)bitmap, FA_OPEN_EXISTING | FA_READ);
	if (res == FR_NOT_READY || res != FR_OK) {
		/* LUN not ready or LUN test error */
		printf("File open failed!\n\r");
		f_close(&file_object);
		return;
	}

	// Read the bmp header
	res = f_read(&file_object, header_buff, sizeof header_buff, &byte_read); 

	if(res != FR_OK){
		print_fs_result(res);
		return;
	}
	bmpSig = (header_buff[1] << 8) | header_buff[0];
	printf("Signature:\t0x%X\n", bmpSig);
	if(bmpSig != 0x4D42){
		return; // not a bmp
	}
	bmpImageoffset =  header_buff[7] * 256 + header_buff[6];
	bmpHeight =  (header_buff[25] << 24) | (header_buff[24] << 16) | (header_buff[23] << 8) | header_buff[22];
	bmpWidth = (header_buff[15] << 24) |  (header_buff[16] << 16) | (header_buff[17] << 8) | header_buff[18];
	position = header_buff[10]; // starting point in file
	numberOfPixels = header_buff[29] * 256 + header_buff[28];
	commpression = (header_buff[30] << 24) |  (header_buff[31] << 16) | (header_buff[32] << 8) | header_buff[33];
	imageSize = (header_buff[37] << 24) |  (header_buff[36] << 16) | (header_buff[35] << 8) | header_buff[34];
	if(tft_conf.orient == LANDSCAPE){
		swap(uint32_t, bmpWidth, bmpHeight);
	}
	rowSize = ((numberOfPixels * bmpWidth + 31) /32 ) * 4;
	printf("Offset:\t%d\n", bmpImageoffset);
	printf("Height:\t%ld\n", bmpHeight);
	printf("Width:\t\t%ld\n", bmpWidth);
	printf("Row Size:\t%d\n", rowSize);
	printf("Start Index:\t%d\n", position);
	printf("# of Pixels:\t%d\n", numberOfPixels);
	printf("Compression:\t%ld\n", commpression);
	printf("Image Size:\t%ld\n", imageSize);
	// end header read

	sam_clearCs();
	sam_setXY(x1, y1,(bmpWidth + x1) -1, (bmpHeight + y1)-1);

	uint8_t row_buff[rowSize]; // only read 1 row at a time	

	res = f_lseek(&file_object, position); // start at beginning of image data

	for(uint32_t row = 0; row < bmpHeight; row++){ // read 1 row at a time

		res = f_read(&file_object, row_buff, sizeof row_buff, &byte_read); // read 1 row

		if(res != FR_OK){
			print_fs_result(res);
			return;
		}

		position = position + rowSize; // calculate next position on disk to read
		res = f_lseek(&file_object, position); // set next position

		if(res != FR_OK){
			print_fs_result(res);
			return;
		}
		// read the buffer and send to TFT
		for (int x = rowSize; x > 0 ; x -= 3) {

			uint16_t colorbyte = sam_color565(row_buff[x + 2], row_buff[x + 1], row_buff[x]);
			sam_writeData(colorbyte >> 8, colorbyte & 0xFF);
		}			

	} // end while

	sam_setCs();
	sam_clrXY();

	f_close(&file_object);
}