[PATCH] Fix BMP display when the image stretches beyond border

[Heinrich Schuchardt]

On 4/7/22 15:42, Vitaly Wool wrote:
> When an image stretches beyond the display border, one still needs
> to seek to the next pixel line to display the visible part of that
> image correctly.
>
> Signed-off-by: Vitaly Wool <vitaly.wool at konsulko.com>
> ---
>   drivers/video/video_bmp.c | 15 +++++++--------
>   1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/video/video_bmp.c b/drivers/video/video_bmp.c
> index 4d2d961696..d0177daf58 100644
> --- a/drivers/video/video_bmp.c
> +++ b/drivers/video/video_bmp.c
> @@ -238,7 +238,7 @@ int video_bmp_display(struct udevice *dev, ulong bmp_image, int x, int y,
>   	struct bmp_image *bmp = map_sysmem(bmp_image, 0);
>   	uchar *bmap;
>   	ushort padded_width;
> -	unsigned long width, height, byte_width;
> +	unsigned long width, vis_width, height, byte_width;
>   	unsigned long pwidth = priv->xsize;
>   	unsigned colours, bpix, bmp_bpix;
>   	enum video_format eformat;
> @@ -297,8 +297,7 @@ int video_bmp_display(struct udevice *dev, ulong bmp_image, int x, int y,
>   		video_splash_align_axis(&y, priv->ysize, height);
>   	}
>
> -	if ((x + width) > pwidth)
> -		width = pwidth - x;
> +	vis_width = min(pwidth - x, width);

Where do we treat x > pwidth?

>   	if ((y + height) > priv->ysize)

Or y > priv->ysize?

Best regards

Heinrich

>   		height = priv->ysize - y;
>
> @@ -318,7 +317,7 @@ int video_bmp_display(struct udevice *dev, ulong bmp_image, int x, int y,
>   			debug("compressed %d %d\n", compression, BMP_BI_RLE8);
>   			if (compression == BMP_BI_RLE8) {
>   				video_display_rle8_bitmap(dev, bmp, bpix, palette, fb,
> -							  x, y, width, height);
> +							  x, y, vis_width, height);
>   				break;
>   			}
>   		}
> @@ -330,7 +329,7 @@ int video_bmp_display(struct udevice *dev, ulong bmp_image, int x, int y,
>
>   		for (i = 0; i < height; ++i) {
>   			WATCHDOG_RESET();
> -			for (j = 0; j < width; j++) {
> +			for (j = 0; j < vis_width; j++) {
>   				write_pix8(fb, bpix, eformat, palette, bmap);
>   				bmap++;
>   				fb += bpix / 8;
> @@ -343,7 +342,7 @@ int video_bmp_display(struct udevice *dev, ulong bmp_image, int x, int y,
>   		if (IS_ENABLED(CONFIG_BMP_16BPP)) {
>   			for (i = 0; i < height; ++i) {
>   				WATCHDOG_RESET();
> -				for (j = 0; j < width; j++) {
> +				for (j = 0; j < vis_width; j++) {
>   					*fb++ = *bmap++;
>   					*fb++ = *bmap++;
>   				}
> @@ -355,7 +354,7 @@ int video_bmp_display(struct udevice *dev, ulong bmp_image, int x, int y,
>   	case 24:
>   		if (IS_ENABLED(CONFIG_BMP_24BPP)) {
>   			for (i = 0; i < height; ++i) {
> -				for (j = 0; j < width; j++) {
> +				for (j = 0; j < vis_width; j++) {
>   					if (bpix == 16) {
>   						/* 16bit 565RGB format */
>   						*(u16 *)fb = ((bmap[2] >> 3)
> @@ -389,7 +388,7 @@ int video_bmp_display(struct udevice *dev, ulong bmp_image, int x, int y,
>   	case 32:
>   		if (IS_ENABLED(CONFIG_BMP_32BPP)) {
>   			for (i = 0; i < height; ++i) {
> -				for (j = 0; j < width; j++) {
> +				for (j = 0; j < vis_width; j++) {
>   					if (eformat == VIDEO_X2R10G10B10) {
>   						u32 pix;
>