[Mesa-dev] [PATCH] mesa: Correctly handle GL_BGRA_EXT in ES3 format_and_type checks

[Jason Ekstrand]

On Wed, Oct 7, 2015 at 4:18 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> On Wed, Oct 7, 2015 at 6:58 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
>> The EXT_texture_format_BGRA8888 extension (which mesa supports
>> unconditionally) adds a new format and internal format called GL_BGRA_EXT.
>> Previously, this was not really handled at all in
>> _mesa_ex3_error_check_format_and_type.  When the checks were tightened in
>> commit f15a7f3c, we accidentally tightened things too far and GL_BGRA_EXT
>> would always cause an error to be thrown.
>>
>> There were two primary issues here.  First, is that
>> _mesa_es3_effective_internal_format_for_format_and_type didn't handle the
>> GL_BGRA_EXT format.  Second is that it blindly uses _mesa_base_tex_format
>> which returns GL_RGBA for GL_BGRA_EXT.  This commit fixes both of these
>> issues as well as adds explicit checks that GL_BGRA_EXT is only ever used
>> with GL_BGRA_EXT and GL_UNSIGNED_BYTE.
>>
>> Signed-off-by: Jason Ekstrand <jason.ekstrand at intel.com>
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92265
>> Cc: Eduardo Lima Mitev <elima at igalia.com>
>
> Does this also need a
>
> Cc: "11.0" <mesa-stable at lists.freedesktop.org>
>
> since the original change was cherry-picked into the release branch?

Yes.  I realized that right after I sent the e-mail and added it
locally.  It'll get tagged when I push.
--Jason

>> ---
>>  src/mesa/main/glformats.c | 21 +++++++++++++++++++--
>>  1 file changed, 19 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/mesa/main/glformats.c b/src/mesa/main/glformats.c
>> index 7dab33c..843ec02 100644
>> --- a/src/mesa/main/glformats.c
>> +++ b/src/mesa/main/glformats.c
>> @@ -2678,6 +2678,7 @@ _mesa_es3_effective_internal_format_for_format_and_type(GLenum format,
>>         * internal formats, they do not correspond to GL constants, so the base
>>         * format is returned instead.
>>         */
>> +      case GL_BGRA_EXT:
>>        case GL_LUMINANCE_ALPHA:
>>        case GL_LUMINANCE:
>>        case GL_ALPHA:
>> @@ -2797,8 +2798,19 @@ _mesa_es3_error_check_format_and_type(const struct gl_context *ctx,
>>        if (effectiveInternalFormat == GL_NONE)
>>           return GL_INVALID_OPERATION;
>>
>> -      GLenum baseInternalFormat =
>> -         _mesa_base_tex_format(ctx, effectiveInternalFormat);
>> +      GLenum baseInternalFormat;
>> +      if (internalFormat == GL_BGRA_EXT) {
>> +         /* Unfortunately, _mesa_base_tex_format returns a base format of
>> +          * GL_RGBA for GL_BGRA_EXT.  This makes perfect sense if you're
>> +          * asking the question, "what channels doe this format have?"
>> +          * However, if we're trying to determine if two internal formats
>> +          * match in the ES3 sense, we actually want GL_BGRA.
>> +          */
>> +         baseInternalFormat = GL_BGRA_EXT;
>> +      } else {
>> +         baseInternalFormat =
>> +            _mesa_base_tex_format(ctx, effectiveInternalFormat);
>> +      }
>>
>>        if (internalFormat != baseInternalFormat)
>>           return GL_INVALID_OPERATION;
>> @@ -2807,6 +2819,11 @@ _mesa_es3_error_check_format_and_type(const struct gl_context *ctx,
>>     }
>>
>>     switch (format) {
>> +   case GL_BGRA_EXT:
>> +      if (type != GL_UNSIGNED_BYTE || internalFormat != GL_BGRA)
>> +         return GL_INVALID_OPERATION;
>> +      break;
>> +
>>     case GL_RGBA:
>>        switch (type) {
>>        case GL_UNSIGNED_BYTE:
>> --
>> 2.5.0.400.gff86faf
>>
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