[Mesa-dev] [Mesa-stable] [PATCH] mesa: Add GL_BGRA_EXT to the list of GenerateMipmap internal formats.

[Ian Romanick]

On 07/21/2016 05:44 PM, Kenneth Graunke wrote:
> The GL_EXT_texture_format_BGRA8888 extension specification defines a
> GL_BGRA_EXT unsized internal format (which is a little odd - usually
> BGRA is a pixel transfer format).  The extension is written against
> the ES 1.0 specification, so it's a little hard to map, but I believe
> it's effectively adding it to the table used here, so we should allow
> it here as well.

OpenGL ES 1.x and 2.0 only have unsized internal formats, so this is
"correct."  The internal format is inferred from the format and type...
and the driver isn't supposed to (have to) do any conversions.

> Note that GL_EXT_texture_format_BGRA8888 is always enabled (dummy_true),
> so we don't need to check if it's enabled here.
> 
> This fixes mipmap generation in Skia and ChromeOS.
> 
> Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
> References: https://bugs.chromium.org/p/chromium/issues/detail?id=630371
> Cc: Stéphane Marchesin <marcheu at chromium.org>
> Cc: mesa-stable at lists.freedesktop.org

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

> ---
>  src/mesa/main/genmipmap.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/src/mesa/main/genmipmap.c b/src/mesa/main/genmipmap.c
> index 5e780c9..c952c4f 100644
> --- a/src/mesa/main/genmipmap.c
> +++ b/src/mesa/main/genmipmap.c
> @@ -85,10 +85,15 @@ _mesa_is_valid_generate_texture_mipmap_internalformat(struct gl_context *ctx,
>         *  not specified with an unsized internal format from table 8.3 or a
>         *  sized internal format that is both color-renderable and
>         *  texture-filterable according to table 8.10."
> +       *
> +       * GL_EXT_texture_format_BGRA8888 adds a GL_BGRA_EXT unsized internal
> +       * format, and includes it in a very similar looking table.  So we
> +       * include it here as well.
>         */
>        return internalformat == GL_RGBA || internalformat == GL_RGB ||
>               internalformat == GL_LUMINANCE_ALPHA ||
>               internalformat == GL_LUMINANCE || internalformat == GL_ALPHA ||
> +             internalformat == GL_BGRA_EXT ||
>               (_mesa_is_es3_color_renderable(internalformat) &&
>                _mesa_is_es3_texture_filterable(ctx, internalformat));
>     }