| /* |
| * Copyright (C) 2019 Andreas Baierl |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| */ |
| |
| #include "nir.h" |
| #include "nir_builder.h" |
| |
| /* Lower gl_FragCoord and transform the w component |
| * according to the following pseudocode: |
| * |
| * gl_FragCoord.xyz = gl_FragCoord_orig.xyz |
| * gl_FragCoord.w = 1.0 / gl_FragCoord_orig.w |
| * |
| * To trigger the transformation, gl_FragCoord currently has to be treated |
| * as a system value with PIPE_CAP_TGSI_FS_POSITION_IS_SYSVAL enabled. |
| */ |
| |
| static void |
| lower_fragcoord_wtrans(nir_builder *b, nir_intrinsic_instr *intr) |
| { |
| assert(intr->dest.is_ssa); |
| |
| b->cursor = nir_before_instr(&intr->instr); |
| |
| nir_ssa_def *fragcoord_in = nir_load_frag_coord(b); |
| nir_ssa_def *w_rcp = nir_frcp(b, nir_channel(b, fragcoord_in, 3)); |
| nir_ssa_def *fragcoord_wtrans = nir_vec4(b, |
| nir_channel(b, fragcoord_in, 0), |
| nir_channel(b, fragcoord_in, 1), |
| nir_channel(b, fragcoord_in, 2), |
| w_rcp); |
| nir_ssa_def_rewrite_uses(&intr->dest.ssa, |
| nir_src_for_ssa(fragcoord_wtrans)); |
| } |
| |
| void |
| nir_lower_fragcoord_wtrans(nir_shader *shader) |
| { |
| assert(shader->info.stage == MESA_SHADER_FRAGMENT); |
| |
| nir_foreach_function(func, shader) { |
| if (!func->impl) |
| continue; |
| |
| nir_builder b; |
| nir_builder_init(&b, func->impl); |
| nir_foreach_block(block, func->impl) { |
| nir_foreach_instr_safe(instr, block) { |
| if (instr->type != nir_instr_type_intrinsic) |
| continue; |
| |
| nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); |
| if (intr->intrinsic != nir_intrinsic_load_frag_coord) |
| continue; |
| |
| lower_fragcoord_wtrans(&b, intr); |
| } |
| } |
| nir_metadata_preserve(func->impl, nir_metadata_block_index | |
| nir_metadata_dominance); |
| } |
| } |