Reviewed-by: Marek Olšák <marek.ol...@amd.com> Marek
On Sat, Aug 2, 2014 at 4:12 AM, <srol...@vmware.com> wrote: > From: Roland Scheidegger <srol...@vmware.com> > > Add documentation for TEX2/TXL2/TXB2 tgsi opcodes. Also, the texture opcode > documentation wasn't very accurate so fix this up a bit. > --- > src/gallium/docs/source/tgsi.rst | 127 > +++++++++++++++++++++++++++++++-------- > 1 file changed, 102 insertions(+), 25 deletions(-) > > diff --git a/src/gallium/docs/source/tgsi.rst > b/src/gallium/docs/source/tgsi.rst > index 093bf7d..ac0ea54 100644 > --- a/src/gallium/docs/source/tgsi.rst > +++ b/src/gallium/docs/source/tgsi.rst > @@ -584,25 +584,44 @@ This instruction replicates its result. > for array textures src0.y contains the slice for 1D, > and src0.z contain the slice for 2D. > > - for shadow textures with no arrays, src0.z contains > - the reference value. > + for shadow textures with no arrays (and not cube map), > + src0.z contains the reference value. > > for shadow textures with arrays, src0.z contains > the reference value for 1D arrays, and src0.w contains > - the reference value for 2D arrays. > + the reference value for 2D arrays and cube maps. > > - There is no way to pass a bias in the .w value for > - shadow arrays, and GLSL doesn't allow this. > - GLSL does allow cube shadows maps to take a bias value, > - and we have to determine how this will look in TGSI. > + for cube map array shadow textures, the reference value > + cannot be passed in src0.w, and TEX2 must be used instead. > > .. math:: > > coord = src0 > > - bias = 0.0 > + shadow_ref = src0.z or src0.w (optional) > + > + unit = src1 > + > + dst = texture\_sample(unit, coord, shadow_ref) > + > + > +.. opcode:: TEX2 - Texture Lookup (for shadow cube map arrays only) > + > + this is the same as TEX, but uses another reg to encode the > + reference value. > + > +.. math:: > + > + coord = src0 > + > + shadow_ref = src1.x > + > + unit = src2 > + > + dst = texture\_sample(unit, coord, shadow_ref) > + > + > > - dst = texture\_sample(unit, coord, bias) > > .. opcode:: TXD - Texture Lookup with Derivatives > > @@ -614,26 +633,26 @@ This instruction replicates its result. > > ddy = src2 > > - bias = 0.0 > + unit = src3 > > - dst = texture\_sample\_deriv(unit, coord, bias, ddx, ddy) > + dst = texture\_sample\_deriv(unit, coord, ddx, ddy) > > > .. opcode:: TXP - Projective Texture Lookup > > .. math:: > > - coord.x = src0.x / src.w > + coord.x = src0.x / src0.w > > - coord.y = src0.y / src.w > + coord.y = src0.y / src0.w > > - coord.z = src0.z / src.w > + coord.z = src0.z / src0.w > > coord.w = src0.w > > - bias = 0.0 > + unit = src1 > > - dst = texture\_sample(unit, coord, bias) > + dst = texture\_sample(unit, coord) > > > .. opcode:: UP2H - Unpack Two 16-Bit Floats > @@ -763,17 +782,46 @@ This instruction replicates its result. > > .. opcode:: TXB - Texture Lookup With Bias > > + for cube map array textures and shadow cube maps, the bias value > + cannot be passed in src0.w, and TXB2 must be used instead. > + > + if the target is a shadow texture, the reference value is always > + in src.z (this prevents shadow 3d and shadow 2d arrays from > + using this instruction, but this is not needed). > + > .. math:: > > - coord.x = src.x > + coord.x = src0.x > + > + coord.y = src0.y > > - coord.y = src.y > + coord.z = src0.z > > - coord.z = src.z > + coord.w = none > > - coord.w = 1.0 > + bias = src0.w > > - bias = src.z > + unit = src1 > + > + dst = texture\_sample(unit, coord, bias) > + > + > +.. opcode:: TXB2 - Texture Lookup With Bias (some cube maps only) > + > + this is the same as TXB, but uses another reg to encode the > + lod bias value for cube map arrays and shadow cube maps. > + Presumably shadow 2d arrays and shadow 3d targets could use > + this encoding too, but this is not legal. > + > + shadow cube map arrays are neither possible nor required. > + > +.. math:: > + > + coord = src0 > + > + bias = src1.x > + > + unit = src2 > > dst = texture\_sample(unit, coord, bias) > > @@ -815,6 +863,13 @@ This instruction replicates its result. > > .. opcode:: TXL - Texture Lookup With explicit LOD > > + for cube map array textures, the explicit lod value > + cannot be passed in src0.w, and TXL2 must be used instead. > + > + if the target is a shadow texture, the reference value is always > + in src.z (this prevents shadow 3d / 2d array / cube targets from > + using this instruction, but this is not needed). > + > .. math:: > > coord.x = src0.x > @@ -823,10 +878,32 @@ This instruction replicates its result. > > coord.z = src0.z > > - coord.w = 1.0 > + coord.w = none > > lod = src0.w > > + unit = src1 > + > + dst = texture\_sample(unit, coord, lod) > + > + > +.. opcode:: TXL2 - Texture Lookup With explicit LOD (for cube map arrays > only) > + > + this is the same as TXL, but uses another reg to encode the > + explicit lod value. > + Presumably shadow 3d / 2d array / cube targets could use > + this encoding too, but this is not legal. > + > + shadow cube map arrays are neither possible nor required. > + > +.. math:: > + > + coord = src0 > + > + lod = src1.x > + > + unit = src2 > + > dst = texture\_sample(unit, coord, lod) > > > @@ -954,9 +1031,9 @@ XXX doesn't look like most of the opcodes really belong > here. > As per NV_gpu_shader4, extract a single texel from a specified texture > image. The source sampler may not be a CUBE or SHADOW. src 0 is a > four-component signed integer vector used to identify the single texel > - accessed. 3 components + level. src 1 is a 3 component constant signed > - integer vector, with each component only have a range of -8..+8 (hw only > - seems to deal with this range, interface allows for up to unsigned int). > + accessed. 3 components + level. Just like texture instructions, an > optional > + offset vector is provided, which is subject to various driver restrictions > + (regarding range, source of offsets). > TXF(uint_vec coord, int_vec offset). > > > -- > 1.9.1 > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
