[Mesa-dev] [PATCH] mesa: fix an issue with texture border and array textures

[Brian Paul]

On 02/16/2012 11:38 AM, Anuj Phogat wrote:
> As suggested by Brian, for a 1D texture array, the border only applies to
> the width.  For a 2D texture array the border applies to the width and
> height but not the depth.  This was not handled correctly in
> _mesa_init_teximage_fields().
>
> Note: This is a candidate for stable branches
>
> Signed-off-by: Anuj Phogat<anuj.phogat at gmail.com>
> ---
> updated patch as per Brian's comments
>
>   src/mesa/main/teximage.c |   14 ++++++++++++--
>   1 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/src/mesa/main/teximage.c b/src/mesa/main/teximage.c
> index e4eb7f6..6a24e9d 100644
> --- a/src/mesa/main/teximage.c
> +++ b/src/mesa/main/teximage.c
> @@ -1083,11 +1083,13 @@ _mesa_init_teximage_fields(struct gl_context *ctx,
>                              GLint border, GLenum internalFormat,
>                              gl_format format)
>   {
> +   GLenum target;
>      ASSERT(img);
>      ASSERT(width>= 0);
>      ASSERT(height>= 0);
>      ASSERT(depth>= 0);
>
> +   target = img->TexObject->Target;
>      img->_BaseFormat = _mesa_base_tex_format( ctx, internalFormat );
>      ASSERT(img->_BaseFormat>  0);
>      img->InternalFormat = internalFormat;
> @@ -1099,19 +1101,27 @@ _mesa_init_teximage_fields(struct gl_context *ctx,
>      img->Width2 = width - 2 * border;   /* == 1<<  img->WidthLog2; */
>      img->WidthLog2 = _mesa_logbase2(img->Width2);
>
> -   if (height == 1) { /* 1-D texture */
> +   if (target ==  GL_TEXTURE_1D) {

or target == GL_TEXTURE_BUFFER

>         img->Height2 = 1;
>         img->HeightLog2 = 0;
>      }
> +   else if(target ==  GL_TEXTURE_1D_ARRAY) {
> +      img->Height2 = height; /* no border */
> +      img->HeightLog2 = 0; /* not used */
> +   }
>      else {
>         img->Height2 = height - 2 * border; /* == 1<<  img->HeightLog2; */
>         img->HeightLog2 = _mesa_logbase2(img->Height2);
>      }
>
> -   if (depth == 1) {  /* 2-D texture */
> +   if (target == GL_TEXTURE_2D) {
>         img->Depth2 = 1;
>         img->DepthLog2 = 0;
>      }
> +   else if (target == GL_TEXTURE_2D_ARRAY) {
> +      img->Depth2 = depth; /* no border */
> +      img->DepthLog2 = 0; /* not used */
> +   }
>      else {
>         img->Depth2 = depth - 2 * border;   /* == 1<<  img->DepthLog2; */
>         img->DepthLog2 = _mesa_logbase2(img->Depth2);

This will set Depth2, etc incorrectly if the texture target is 1D, 
1D_ARRAY, CUBE, etc.

I think you need to carefully consider all the possible texture 
targets and how width/height/depth will be computed for each type.

It might wind up being cleanest to have a switch(target) which sets 
both the width and height values for each possible texture type.

Or maybe just leave the "if (height==1)" and "if (depth==1)" tests 
as-is.  I'd have to take a few minutes to think that through.

-Brian