On Fri, Nov 16, 2012 at 4:15 PM, Brian Paul <bri...@vmware.com> wrote: > On 11/16/2012 05:06 PM, Anuj Phogat wrote: >> >> On Fri, Nov 16, 2012 at 3:28 PM, Ian Romanick<i...@freedesktop.org> wrote: >>> >>> On 11/16/2012 01:21 PM, Anuj Phogat wrote: >>>> >>>> >>>> We need to rebase colors (ex: set G=B=0) when getting GL_LUMINANCE >>>> textures in following cases: >>>> 1. If the luminance texture is actually stored as rgba >>>> 2. If getting a luminance texture, but returning rgba >>>> 3. If getting an rgba texture, but returning luminance >>>> >>>> A similar fix was pushed by Brian Paul for uncompressed textures >>>> in commit: f5d0ced. >>>> >>>> Fixes intel oglconform pxconv-gettex test: >>>> https://bugs.freedesktop.org/show_bug.cgi?id=47220 >>>> >>>> Observed no failures in piglit and ogles2conform due to this fix. >>>> This patch will cause failures in intel oglconform pxstore-gettex >>>> and pxtrans-gettex test cases. The cause of a failures is a bug >>>> in test cases. Expected luminance value is calculted incorrectly: >>> >>> >>> calculated >>> >>>> L = R+G+B. >>> >>> >>> >>> This seems weird. We fail pxconv-gettex because we convert the luminance >>> texture supplied by the application to RGB by replicating the L value to >>> each of R, G, and B. In this case, and this case only, we need to read >>> back >>> luminance by just returning R. If the application actually specified an >>> RGB >>> texture, we need to read back luminance by R+G+B. Right? >>> >> If a texture is stored in RGB/RGBA internal format and we later read it >> back >> using glGetTexImage. There is no way to find out the format of initial >> texture >> data supplied by application later in the driver. > > > Mmm, you should be able to look at gl_texture_image::InternalFormat to see > what the user requested. And then check for luminance with > _mesa_base_tex_format(texImage->InternalFormat)==GL_LUMINANCE. > Brian, this is what I was trying to say: Case1 glTexImage2D(internalformat=GL_RGBA, format=GL_RGBA); glGetTexImage(GL_LUMINANCE);
Case2: glTexImage2D(internalformat=GL_RGBA, format=GL_LUMINANCE); glGetTexImage(GL_LUMINANCE); In both cases glGetTexImage() will be able to see the requested texture information as: texImage->InternalFormat= GL_RGBA texImage->_BaseFormat = GL_RGBA. texImage->texFormat = MESA_FORMAT_RGBA8888 Here, I don't see a way to query the format of texture data initially uploaded by application in glTexImage2D. i.e GL_RGBA in case 1 and GL_LUMINANCE in case 2. I said this to explain why we always return L = Tex(R) while getting a RGBA texture but returning LUMINANCE irrespective of texture data format initially uploaded by glTexImage2D. Ian, there is a piglit test case test_rgba() in getteximage-luminance.c which tests the exact case you described for uncompressed textures. It expects L = tex(R). > >> For glGetTexImage we >> return L = Tex(R). This is what we do in mesa for uncompressed textures. >> it's different from glReadPixels which returns L=R+G+B. >> >>> Does this match what pxconv-gettex and pxconv-trans expect? >>> >>> This L vs. RGB crap confuses me every time... >>> >> Yeah this is confusing. pxstore-gettex and pxtrans-gettex expects >> L=R+G+B when getting an rgba texture, but returning luminance. >> Sometime back I submitted a fix to change the expected values >> in pxconv-gettex to L = tex(R). Similar fix is required for failing two >> test cases. > > > -Brian _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
