[virglrenderer-devel] [PATCH] vrend: correct the stride if the client sends it

[Erik Faye-Lund]

On 26. juli 2018 18:57, Gert Wollny wrote:
> If the client sends vrend_transfer_send_readpixels a stride (and vtest does),
> then it is in bytes, but glPixelStorei(GL_PACK_ROW_LENGTH, stride) expects
> the value to be pixels.
>
> Fixes:
>     42e2a4ca7da4604beb377e181aa6b20abf4445e
>     vrend: use the row-stride when directly reading back to an IOV
> Signed-off-by: Gert Wollny <gert.wollny at collabora.com>
> ---
>   src/vrend_renderer.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/vrend_renderer.c b/src/vrend_renderer.c
> index 6536dd8..4bf22ba 100644
> --- a/src/vrend_renderer.c
> +++ b/src/vrend_renderer.c
> @@ -5912,7 +5912,7 @@ static int vrend_transfer_send_readpixels(struct vrend_context *ctx,
>      uint32_t h = u_minify(res->base.height0, info->level);
>      int elsize = util_format_get_blocksize(res->base.format);
>      float depth_scale;
> -   int row_stride = info->stride;
> +   int row_stride = info->stride / elsize;
>

Just dividing rounds down by default unless info->stride is aligned to 
elsize. Is the latter the case? If so, perhaps add

assert(info->stride % elsize == 0);

...to make that assumption clear?