diff options
| -rw-r--r-- | src/compiler/Makefile.sources | 1 | ||||
| -rw-r--r-- | src/compiler/nir/nir.h | 1 | ||||
| -rw-r--r-- | src/compiler/nir/nir_lower_wpos_center.c | 107 |
3 files changed, 109 insertions, 0 deletions
diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources index 97f9eb4f1f3..b8f2b4950b4 100644 --- a/src/compiler/Makefile.sources +++ b/src/compiler/Makefile.sources @@ -212,6 +212,7 @@ NIR_FILES = \ nir/nir_lower_vars_to_ssa.c \ nir/nir_lower_var_copies.c \ nir/nir_lower_vec_to_movs.c \ + nir/nir_lower_wpos_center.c \ nir/nir_lower_wpos_ytransform.c \ nir/nir_metadata.c \ nir/nir_move_vec_src_uses_to_dest.c \ diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index a21a7bdc6fa..78913d30deb 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -2407,6 +2407,7 @@ typedef struct nir_lower_wpos_ytransform_options { bool nir_lower_wpos_ytransform(nir_shader *shader, const nir_lower_wpos_ytransform_options *options); +bool nir_lower_wpos_center(nir_shader *shader); typedef struct nir_lower_drawpixels_options { int texcoord_state_tokens[5]; diff --git a/src/compiler/nir/nir_lower_wpos_center.c b/src/compiler/nir/nir_lower_wpos_center.c new file mode 100644 index 00000000000..0de750365d1 --- /dev/null +++ b/src/compiler/nir/nir_lower_wpos_center.c @@ -0,0 +1,107 @@ +/* + * Copyright © 2015 Red Hat + * Copyright © 2016 Intel Corporation + * + * 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" +#include "program/prog_instruction.h" + +/** + * This pass adds <0.5, 0.5> to all uses of gl_FragCoord. + * + * Run before nir_lower_io(). + * + * For a more full featured pass, consider using nir_lower_wpos_ytransform(), + * which can handle pixel center integer / half integer, and origin lower + * left / upper left transformations. + * + * This simple pass is primarily intended for use by Vulkan drivers on + * hardware which provides an integer pixel center. Vulkan mandates that + * the pixel center must be half-integer, and also that the coordinate + * system's origin must be upper left. This means that there's no need + * for a uniform - we can always just add a constant. + */ + +static void +add_half_to_fragcoord(nir_builder *b, nir_intrinsic_instr *intr) +{ + nir_ssa_def *wpos = &intr->dest.ssa; + + assert(intr->dest.is_ssa); + + b->cursor = nir_after_instr(&intr->instr); + + wpos = nir_fadd(b, wpos, nir_imm_vec4(b, 0.5f, 0.5f, 0.0f, 0.0f)); + + nir_ssa_def_rewrite_uses_after(&intr->dest.ssa, nir_src_for_ssa(wpos), + &intr->instr); +} + +static bool +lower_wpos_center_block(nir_builder *b, nir_block *block) +{ + bool progress = false; + + nir_foreach_instr(instr, block) { + if (instr->type == nir_instr_type_intrinsic) { + nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); + if (intr->intrinsic == nir_intrinsic_load_var) { + nir_deref_var *dvar = intr->variables[0]; + nir_variable *var = dvar->var; + + if (var->data.mode == nir_var_shader_in && + var->data.location == VARYING_SLOT_POS) { + /* gl_FragCoord should not have array/struct deref's: */ + assert(dvar->deref.child == NULL); + add_half_to_fragcoord(b, intr); + progress = true; + } + } + } + } + + return progress; +} + +bool +nir_lower_wpos_center(nir_shader *shader) +{ + bool progress = false; + nir_builder b; + + assert(shader->stage == MESA_SHADER_FRAGMENT); + + nir_foreach_function(function, shader) { + if (function->impl) { + nir_builder_init(&b, function->impl); + + nir_foreach_block(block, function->impl) { + progress = lower_wpos_center_block(&b, block) || progress; + } + nir_metadata_preserve(function->impl, nir_metadata_block_index | + nir_metadata_dominance); + } + } + + return progress; +} |