[Mesa-stable] [Mesa-dev] [PATCH] mesa: Accept GL_BACK in get_fb0_attachment with ARB_ES3_1_compatibility.

[Tapani Pälli]

Reviewed-by: Tapani Pälli <tapani.palli at intel.com>

On 10/26/2017 11:26 PM, Kenneth Graunke wrote:
> According to the ARB_ES3_1_compatibility specification,
> glGetFramebufferAttachmentParameteriv is supposed to accept BACK,
> and it behaves exactly like BACK_LEFT.
> 
> Fixes a GL error in GFXBench 5 Aztec Ruins.
> 
> Cc: mesa-stable at lists.freedesktop.org
> ---
>   src/mesa/main/fbobject.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
> 
> diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
> index 71e91f9301f..9a2c7ebbcf7 100644
> --- a/src/mesa/main/fbobject.c
> +++ b/src/mesa/main/fbobject.c
> @@ -330,6 +330,15 @@ get_fb0_attachment(struct gl_context *ctx, struct gl_framebuffer *fb,
>         return &fb->Attachment[BUFFER_BACK_LEFT];
>      case GL_BACK_RIGHT:
>         return &fb->Attachment[BUFFER_BACK_RIGHT];
> +   case GL_BACK:
> +      /* The ARB_ES3_1_compatibility spec says:
> +       *
> +       *    "Since this command can only query a single framebuffer
> +       *     attachment, BACK is equivalent to BACK_LEFT."
> +       */
> +      if (ctx->Extensions.ARB_ES3_1_compatibility)
> +         return &fb->Attachment[BUFFER_BACK_LEFT];
> +      return NULL;
>      case GL_AUX0:
>         if (fb->Visual.numAuxBuffers == 1) {
>            return &fb->Attachment[BUFFER_AUX0];
>