| /* |
| * Copyright © 2020 Mike Blumenkrantz |
| * |
| * 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. |
| * |
| * Authors: |
| * Mike Blumenkrantz <michael.blumenkrantz@gmail.com> |
| */ |
| |
| #include "nir.h" |
| #include "nir_builder.h" |
| |
| /** |
| * This pass splits gl_FragColor into gl_FragData[0-7] for drivers which handle |
| * the former but not the latter, e.g., zink. |
| */ |
| |
| /* |
| If a fragment shader writes to "gl_FragColor", DrawBuffersIndexedEXT |
| specifies a set of draw buffers into which the color written to |
| "gl_FragColor" is written. If a fragment shader writes to |
| gl_FragData, DrawBuffersIndexedEXT specifies a set of draw buffers |
| into which each of the multiple output colors defined by these |
| variables are separately written. If a fragment shader writes to |
| neither gl_FragColor nor gl_FragData, the values of the fragment |
| colors following shader execution are undefined, and may differ |
| for each fragment color. |
| |
| - EXT_multiview_draw_buffers |
| |
| */ |
| |
| static bool |
| lower_fragcolor_instr(nir_builder *b, nir_instr *intr, void *data) |
| { |
| if (intr->type != nir_instr_type_intrinsic) |
| return false; |
| |
| nir_intrinsic_instr *instr = nir_instr_as_intrinsic(intr); |
| unsigned *max_draw_buffers = data; |
| |
| nir_variable *out; |
| if (instr->intrinsic != nir_intrinsic_store_deref) |
| return false; |
| |
| out = nir_deref_instr_get_variable(nir_src_as_deref(instr->src[0])); |
| if (out->data.location != FRAG_RESULT_COLOR || out->data.mode != nir_var_shader_out) |
| return false; |
| b->cursor = nir_after_instr(&instr->instr); |
| |
| assert(instr->src[1].is_ssa); |
| nir_ssa_def *frag_color = instr->src[1].ssa; |
| ralloc_free(out->name); |
| |
| const char *name = out->data.index == 0 ? "gl_FragData[0]" : |
| "gl_SecondaryFragDataEXT[0]"; |
| const char *name_tmpl = out->data.index == 0 ? "gl_FragData[%u]" : |
| "gl_SecondaryFragDataEXT[%u]"; |
| |
| out->name = ralloc_strdup(out, name); |
| |
| /* translate gl_FragColor -> gl_FragData since this is already handled */ |
| out->data.location = FRAG_RESULT_DATA0; |
| nir_component_mask_t writemask = nir_intrinsic_write_mask(instr); |
| b->shader->info.outputs_written &= ~BITFIELD64_BIT(FRAG_RESULT_COLOR); |
| b->shader->info.outputs_written |= BITFIELD64_BIT(FRAG_RESULT_DATA0); |
| |
| for (unsigned i = 1; i < *max_draw_buffers; i++) { |
| char name[28]; |
| snprintf(name, sizeof(name), name_tmpl, i); |
| nir_variable *out_color = nir_variable_create(b->shader, nir_var_shader_out, |
| out->type, name); |
| out_color->data.location = FRAG_RESULT_DATA0 + i; |
| out_color->data.driver_location = b->shader->num_outputs++; |
| out_color->data.index = out->data.index; |
| nir_store_var(b, out_color, frag_color, writemask); |
| b->shader->info.outputs_written |= BITFIELD64_BIT(FRAG_RESULT_DATA0 + i); |
| } |
| return true; |
| } |
| |
| bool |
| nir_lower_fragcolor(nir_shader *shader, unsigned max_draw_buffers) |
| { |
| if (shader->info.stage != MESA_SHADER_FRAGMENT) |
| return false; |
| |
| return nir_shader_instructions_pass(shader, lower_fragcolor_instr, |
| nir_metadata_block_index | nir_metadata_dominance, &max_draw_buffers); |
| } |