"Fossies" - the Fresh Open Source Software Archive

Member "mesa-20.1.8/src/compiler/nir/nir_lower_fragcoord_wtrans.c" (16 Sep 2020, 3056 Bytes) of package /linux/misc/mesa-20.1.8.tar.xz:


As a special service "Fossies" has tried to format the requested source page into HTML format using (guessed) C and C++ source code syntax highlighting (style: standard) with prefixed line numbers and code folding option. Alternatively you can here view or download the uninterpreted source code file. For more information about "nir_lower_fragcoord_wtrans.c" see the Fossies "Dox" file reference documentation.

    1 /*
    2  * Copyright (C) 2019 Andreas Baierl
    3  *
    4  * Permission is hereby granted, free of charge, to any person obtaining a
    5  * copy of this software and associated documentation files (the "Software"),
    6  * to deal in the Software without restriction, including without limitation
    7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
    8  * and/or sell copies of the Software, and to permit persons to whom the
    9  * Software is furnished to do so, subject to the following conditions:
   10  *
   11  * The above copyright notice and this permission notice (including the next
   12  * paragraph) shall be included in all copies or substantial portions of the
   13  * Software.
   14  *
   15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
   21  * IN THE SOFTWARE.
   22  */
   23 
   24 #include "nir.h"
   25 #include "nir_builder.h"
   26 
   27 /* Lower gl_FragCoord and transform the w component
   28  * according to the following pseudocode:
   29  *
   30  *    gl_FragCoord.xyz = gl_FragCoord_orig.xyz
   31  *    gl_FragCoord.w = 1.0 / gl_FragCoord_orig.w
   32  *
   33  * To trigger the transformation, gl_FragCoord currently has to be treated
   34  * as a system value with PIPE_CAP_TGSI_FS_POSITION_IS_SYSVAL enabled.
   35  */
   36 
   37 static void
   38 lower_fragcoord_wtrans(nir_builder *b, nir_intrinsic_instr *intr)
   39 {
   40    assert(intr->dest.is_ssa);
   41 
   42    b->cursor = nir_before_instr(&intr->instr);
   43 
   44    nir_ssa_def *fragcoord_in = nir_load_frag_coord(b);
   45    nir_ssa_def *w_rcp = nir_frcp(b, nir_channel(b, fragcoord_in, 3));
   46    nir_ssa_def *fragcoord_wtrans = nir_vec4(b,
   47                                             nir_channel(b, fragcoord_in, 0),
   48                                             nir_channel(b, fragcoord_in, 1),
   49                                             nir_channel(b, fragcoord_in, 2),
   50                                             w_rcp);
   51    nir_ssa_def_rewrite_uses(&intr->dest.ssa,
   52                             nir_src_for_ssa(fragcoord_wtrans));
   53 }
   54 
   55 void
   56 nir_lower_fragcoord_wtrans(nir_shader *shader)
   57 {
   58    assert(shader->info.stage == MESA_SHADER_FRAGMENT);
   59 
   60    nir_foreach_function(func, shader) {
   61       if (!func->impl)
   62          continue;
   63 
   64       nir_builder b;
   65       nir_builder_init(&b, func->impl);
   66       nir_foreach_block(block, func->impl) {
   67          nir_foreach_instr_safe(instr, block) {
   68             if (instr->type != nir_instr_type_intrinsic)
   69                continue;
   70 
   71             nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
   72             if (intr->intrinsic != nir_intrinsic_load_frag_coord)
   73                continue;
   74 
   75             lower_fragcoord_wtrans(&b, intr);
   76          }
   77       }
   78       nir_metadata_preserve(func->impl, nir_metadata_block_index |
   79                             nir_metadata_dominance);
   80    }
   81 }