[Mesa-dev] [PATCH 2/2] mesa: rearrange texture error checking order

[Brian Paul]

On 07/23/2015 04:24 PM, Ilia Mirkin wrote:
> On Wed, Jul 22, 2015 at 1:44 PM, Brian Paul <brianp at vmware.com> wrote:
>> On 07/22/2015 11:29 AM, Ilia Mirkin wrote:
>>>
>>> On Wed, Jul 22, 2015 at 1:20 PM, Brian Paul <brianp at vmware.com> wrote:
>>>>
>>>> On 07/22/2015 11:02 AM, Ilia Mirkin wrote:
>>>>>
>>>>>
>>>>> This moves the width/height/depth == 0 check to the front and avoids
>>>>> doing any other checking when that is the case.
>>>>>
>>>>> Also moves the dimensions check after the format/type checks so that we
>>>>> don't bail out with success on a width/height/depth == 0 request when
>>>>> the format/type don't match.
>>>>>
>>>>> Bugzilla:
>>>>>
>>>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__bugs.freedesktop.org_show-5Fbug.cgi-3Fid-3D91425&d=BQIBAg&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=T0t4QG7chq2ZwJo6wilkFznRSFy-8uDKartPGbomVj8&m=Y1TotaJmX1E7sCopvmMJc8PQKFXlHu6QxfcYOydKuII&s=L0lmmuk31G6M4hZEiwnX-IC4CPhW7rsrSCgEYtDgXjw&e=
>>>>> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
>>>>
>>>>
>>>>
>>>> I suspect this isn't really needed in light of my patch to
>>>> getteximage-invalid-format-for-packed-type.c
>>>>
>>>> I believe the test was in error, or at least sloppy, in that it was
>>>> calling
>>>> glGetTexImage to test format/type validation when there wasn't even a
>>>> texture image to return.  The OpenGL spec doesn't specify an order for
>>>> error
>>>> checking multiple things, so if there's multiple errors, you can't be
>>>> sure
>>>> which one will be reported first.  My patch to the test removes that
>>>> ambiguity.
>>>
>>>
>>> Well, irrespective of the piglit test, the current code is a little
>>> suspect -- it does the width/height/depth == 0 checks after it ensures
>>> that height == 1 for 1d and depth == 1 for 2d. Any thoughts on that?
>>
>>
>> Yeah, that makes sense.  I guess we don't have any tests that exercise
>> getting a 0 x 0 texture image.
>>
>> Reviewed-by: Brian Paul <brianp at vmware.com>
>
> Ugh, so Dylan points out that this breaks
>
> bin/arb_direct_state_access-get-textures
>
> (which I didn't notice, because I guess it got recently enabled on mesa)
>
> It has this check:
>
>          /* No Storage
>           *
>           * The spec doesn't say what should happen in this case.  This is
>           * addressed by Khronos Bug 13223.
>           */
>          glCreateTextures(GL_TEXTURE_CUBE_MAP, 1, &name);
>          glGetTextureImage(name, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0, data);
>          pass &= piglit_check_gl_error(GL_INVALID_OPERATION);
>          glDeleteTextures(1, &name);
>
> But my width == 0 || ... check at the top of dimensions_error_check
> short-circuits all that.
>
> Brian, what situation is the "width == 0 || height == 0 || depth == 0"
> supposed to account for?

After error checking, it just lets up skip all the 
ctx->Driver.GetTexSubImage() calls and associated stuff (mapping PBOs, etc).

-Brian