[Mesa-dev] [PATCH 2/4] mesa: Don't call driver RenderTexture for really broken textures

[Ian Romanick]

On 07/28/2013 03:24 PM, Jordan Justen wrote:
> On Sun, Jul 28, 2013 at 12:56 PM, Ian Romanick <idr at freedesktop.org> wrote:
>> From: Ian Romanick <ian.d.romanick at intel.com>
>>
>> This fixes the segfault in the '0x0 texture' subtest of piglit's
>> fbo-incomplete test.
>>
>> Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
>> Cc: mesa-stable at lists.freedesktop.org
>> ---
>>   src/mesa/main/fbobject.c | 22 ++++++++++++++++++++--
>>   1 file changed, 20 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
>> index a55b56c..f10af41 100644
>> --- a/src/mesa/main/fbobject.c
>> +++ b/src/mesa/main/fbobject.c
>> @@ -343,6 +343,22 @@ _mesa_remove_attachment(struct gl_context *ctx,
>>   }
>>
>>   /**
>> + * Verify a couple error conditions that will lead to an incomplete FBO and
>> + * may cause problems for the driver's RenderTexture path.
>> + */
>> +static bool
>> +driver_RenderTexture_is_safe(const struct gl_renderbuffer_attachment *att)
>> +{
>> +   const struct gl_texture_image *const texImage =
>> +      att->Texture->Image[att->CubeMapFace][att->TextureLevel];
>> +
>> +   if (texImage->Width == 0 || texImage->Height == 0 || texImage->Depth == 0)
>> +      return false;
>> +
>> +   return true;
>> +}
>> +
>> +/**
>>    * Create a renderbuffer which will be set up by the driver to wrap the
>>    * texture image slice.
>>    *
>> @@ -391,7 +407,8 @@ _mesa_update_texture_renderbuffer(struct gl_context *ctx,
>>      rb->NumSamples = texImage->NumSamples;
>>      rb->TexImage = texImage;
>>
>> -   ctx->Driver.RenderTexture(ctx, fb, att);
>> +   if (driver_RenderTexture_is_safe(att))
>> +      ctx->Driver.RenderTexture(ctx, fb, att);
>
> Should !driver_RenderTexture_is_safe generate an error?
>
> Or will not having called ctx->Driver.RenderTexture lead to the error
> at a later point?

It should lead to a failure in the framebuffer completeness check later. 
  I could augment the test to make sure that there isn't a crash if the 
application doesn't explicitly call glCheckFramebufferStatus.

> -Jordan
>
>>   }
>>
>>   /**
>> @@ -1891,7 +1908,8 @@ check_begin_texture_render(struct gl_context *ctx, struct gl_framebuffer *fb)
>>
>>      for (i = 0; i < BUFFER_COUNT; i++) {
>>         struct gl_renderbuffer_attachment *att = fb->Attachment + i;
>> -      if (att->Texture && att->Renderbuffer->TexImage) {
>> +      if (att->Texture && att->Renderbuffer->TexImage
>> +          && driver_RenderTexture_is_safe(att)) {
>>            ctx->Driver.RenderTexture(ctx, fb, att);
>>         }
>>      }
>> --
>> 1.8.1.4
>>
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