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Diffstat (limited to 'src/gallium/docs')
| -rw-r--r-- | src/gallium/docs/source/tgsi.rst | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst index d986e6601e6..49877206fea 100644 --- a/src/gallium/docs/source/tgsi.rst +++ b/src/gallium/docs/source/tgsi.rst @@ -1250,6 +1250,110 @@ This opcode is the inverse of :opcode:`DFRACEXP`. dst.zw = \sqrt{src.zw} +.. _resourceopcodes: + +Resource Access Opcodes +^^^^^^^^^^^^^^^^^^^^^^^^ + +Those opcodes follow very closely semantics of the respective Direct3D +instructions. If in doubt double check Direct3D documentation. + +.. opcode:: LOAD - Simplified alternative to the "SAMPLE" instruction. + Using the provided integer address, LOAD fetches data + from the specified buffer/texture without any filtering. + The source data may come from any resource type other + than CUBE. + LOAD dst, address, resource + e.g. + LOAD TEMP[0], TEMP[1], RES[0] + +.. opcode:: LOAD_MS - Just like LOAD but allows fetch data from + multi-sampled surfaces. + +.. opcode:: SAMPLE - Using provided address, sample data from the + specified texture using the filtering mode identified + by the gven sampler. The source data may come from + any resource type other than buffers. + SAMPLE dst, address, resource, sampler + e.g. + SAMPLE TEMP[0], TEMP[1], RES[0], SAMP[0] + +.. opcode:: SAMPLE_B - Just like the SAMPLE instruction with the + exception that an additiona bias is applied to the + level of detail computed as part of the instruction + execution. + SAMPLE_B dst, address, resource, sampler, lod_bias + e.g. + SAMPLE_B TEMP[0], TEMP[1], RES[0], SAMP[0], TEMP[2].x + +.. opcode:: SAMPLE_C - Similar to the SAMPLE instruction but it + performs a comparison filter. The operands to SAMPLE_C + are identical to SAMPLE, except that tere is an additional + float32 operand, reference value, which must be a register + with single-component, or a scalar literal. + SAMPLE_C makes the hardware use the current samplers + compare_func (in pipe_sampler_state) to compare + reference value against the red component value for the + surce resource at each texel that the currently configured + texture filter covers based on the provided coordinates. + SAMPLE_C dst, address, resource.r, sampler, ref_value + e.g. + SAMPLE_C TEMP[0], TEMP[1], RES[0].r, SAMP[0], TEMP[2].x + +.. opcode:: SAMPLE_C_LZ - Same as SAMPLE_C, but LOD is 0 and derivatives + are ignored. The LZ stands for level-zero. + SAMPLE_C_LZ dst, address, resource.r, sampler, ref_value + e.g. + SAMPLE_C_LZ TEMP[0], TEMP[1], RES[0].r, SAMP[0], TEMP[2].x + + +.. opcode:: SAMPLE_D - SAMPLE_D is identical to the SAMPLE opcode except + that the derivatives for the source address in the x + direction and the y direction are provided by extra + parameters. + SAMPLE_D dst, address, resource, sampler, der_x, der_y + e.g. + SAMPLE_D TEMP[0], TEMP[1], RES[0], SAMP[0], TEMP[2], TEMP[3] + +.. opcode:: SAMPLE_L - SAMPLE_L is identical to the SAMPLE opcode except + that the LOD is provided directly as a scalar value, + representing no anisotropy. Source addresses A channel + is used as the LOD. + SAMPLE_L dst, address, resource, sampler + e.g. + SAMPLE_L TEMP[0], TEMP[1], RES[0], SAMP[0] + + +.. opcode:: GATHER4 - Gathers the four texels to be used in a bi-linear + filtering operation and packs them into a single register. + Only woth with 2D, 2D array, cubemaps, and cubemaps arrays. + For 2D textures, only the addressing modes of the sampler and + the top level of any mip pyramid are used. Set W to zero. + It behaves like the SAMPLE instruction, but a filtered + sample is not generated. The four samples that contribute + to filtering are places into xyzw in cunter-clockwise order, + starting with the (u,v) texture coordinate delta at the + following locations (-, +), (+, +), (+, -), (-, -), where + the magnitude of the deltas are half a texel. + + +.. opcode:: RESINFO - query the dimentions of a given input buffer. + dst receives width, height, depth or array size and + total mip count (also can be slected by writemask). + RESINFO dst, src_mip_level, resource + e.g. + RESINFO TEMP[0], TEMP[1].x, RES[0] + +.. 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. + +.. opcode:: SAMPLE_INFO - dst receives number of components in x. + If the resource is not a multi-sample resource and + not a render target, the result is 0. + + Explanation of symbols used ------------------------------ @@ -1332,6 +1436,8 @@ wrapping when interpolating by the rasteriser. If TGSI_CYLINDRICAL_WRAP_X is set to 1, the X component should be interpolated according to cylindrical wrapping rules. +If file is TGSI_FILE_RESOURCE, a Declaration Resource token follows. + Declaration Semantic ^^^^^^^^^^^^^^^^^^^^^^^^ @@ -1475,6 +1581,23 @@ is a writable stencil reference value. Only the Y component is writable. This allows the fragment shader to change the fragments stencilref value. +Declaration Resource +^^^^^^^^^^^^^^^^^^^^^^^^ + + Follows Declaration token if file is TGSI_FILE_RESOURCE. + + DCL RES[#], resource, type(s) + + Declares a shader input resource and assigns it to a RES[#] + register. + + resource can be one of BUFFER, 1D, 2D, 3D, CUBE, 1DArray and + 2DArray. + + type must be 1 or 4 entries (if specifying on a per-component + level) out of UNORM, SNORM, SINT, UINT and FLOAT. + + Properties ^^^^^^^^^^^^^^^^^^^^^^^^ |