Am 15.06.2017 um 22:14 schrieb Brian Paul: > For the SAMPLE_POS and SAMPLE_INFO opcodes, clarify resource vs. render > target queries, range of postion values, swizzling, etc. We basically > follow the DX10.1 conventions. > > For the TXQS opcode and TGSI_SEMANTIC_SAMPLEID, clarify return value > and type. > > For the TGSI_SEMANTIC_SAMPLEPOS system value, clarify the range of > positions returned. > > v2: use 'undef' for unused vector components. Use (0.5, 0.5, undef, undef) > for sample pos when MSAA not applicable. > > v3: Add note that OPCODE_SAMPLE_INFO, OPCODE_SAMPLE_POS are not used yet > and the information is subject to change. > > Reviewed-by: Nicolai Hähnle <nicolai.haeh...@amd.com>
Reviewed-by: Roland Scheidegger <srol...@vmware.com> > --- > src/gallium/docs/source/tgsi.rst | 58 > ++++++++++++++++++++++++++++++++-------- > 1 file changed, 47 insertions(+), 11 deletions(-) > > diff --git a/src/gallium/docs/source/tgsi.rst > b/src/gallium/docs/source/tgsi.rst > index c65d721..fab0012 100644 > --- a/src/gallium/docs/source/tgsi.rst > +++ b/src/gallium/docs/source/tgsi.rst > @@ -982,7 +982,9 @@ XXX doesn't look like most of the opcodes really belong > here. > .. opcode:: TXQS - Texture Samples Query > > This retrieves the number of samples in the texture, and stores it > - into the x component. The other components are undefined. > + into the x component as an unsigned integer. The other components are > + undefined. If the texture is not multisampled, this function returns > + (1, undef, undef, undef). > > .. math:: > > @@ -2538,15 +2540,46 @@ after lookup. > > .. opcode:: SAMPLE_POS > > - Query the position of a given sample. dst receives float4 (x, y, 0, 0) > - indicated where the sample is located. If the resource is not a > multi-sample > - resource and not a render target, the result is 0. > + Query the position of a sample in the given resource or render target > + when per-sample fragment shading is in effect. > + > + Syntax: ``SAMPLE_POS dst, source, sample_index`` > + > + dst receives float4 (x, y, undef, undef) indicated where the sample is > + located. Sample locations are in the range [0, 1] where 0.5 is the center > + of the fragment. > + > + source is either a sampler view (to indicate a shader resource) or temp > + register (to indicate the render target). The source register may have > + an optional swizzle to apply to the returned result > + > + sample_index is an integer scalar indicating which sample position is to > + be queried. > + > + If per-sample shading is not in effect or the source resource or render > + target is not multisampled, the result is (0.5, 0.5, undef, undef). > + > + NOTE: no driver has implemented this opcode yet (and no state tracker > + emits it). This information is subject to change. > > .. opcode:: SAMPLE_INFO > > - dst receives number of samples in x. If the resource is not a multi-sample > - resource and not a render target, the result is 0. > + Query the number of samples in a multisampled resource or render target. > > + Syntax: ``SAMPLE_INFO dst, source`` > + > + dst receives int4 (n, 0, 0, 0) where n is the number of samples in a > + resource or the render target. > + > + source is either a sampler view (to indicate a shader resource) or temp > + register (to indicate the render target). The source register may have > + an optional swizzle to apply to the returned result > + > + If per-sample shading is not in effect or the source resource or render > + target is not multisampled, the result is (1, 0, 0, 0). > + > + NOTE: no driver has implemented this opcode yet (and no state tracker > + emits it). This information is subject to change. > > .. _resourceopcodes: > > @@ -3284,15 +3317,18 @@ TGSI_SEMANTIC_SAMPLEID > """""""""""""""""""""" > > For fragment shaders, this semantic label indicates that a system value > -contains the current sample id (i.e. gl_SampleID). > -This is an integer value, and only the X component is used. > +contains the current sample id (i.e. gl_SampleID) as an unsigned int. > +Only the X component is used. If per-sample shading is not enabled, > +the result is (0, undef, undef, undef). > > TGSI_SEMANTIC_SAMPLEPOS > """"""""""""""""""""""" > > -For fragment shaders, this semantic label indicates that a system value > -contains the current sample's position (i.e. gl_SamplePosition). Only the X > -and Y values are used. > +For fragment shaders, this semantic label indicates that a system > +value contains the current sample's position as float4(x, y, undef, undef) > +in the render target (i.e. gl_SamplePosition) when per-fragment shading > +is in effect. Position values are in the range [0, 1] where 0.5 is > +the center of the fragment. > > TGSI_SEMANTIC_SAMPLEMASK > """""""""""""""""""""""" > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
