src/intel/compiler/brw_interpolation_map.c

   1 /*
   2  * Copyright © 2013 Intel Corporation
   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 "brw_compiler.h"
  25 #include "compiler/nir/nir.h"
  26
  27 static char const *get_qual_name(int mode)
  28 {
  29    switch (mode) {
  30       case INTERP_MODE_NONE:          return "none";
  31       case INTERP_MODE_FLAT:          return "flat";
  32       case INTERP_MODE_SMOOTH:        return "smooth";
  33       case INTERP_MODE_NOPERSPECTIVE: return "nopersp";
  34       default:                             return "???";
  35    }
  36 }
  37
  38 static void
  39 gen4_frag_prog_set_interp_modes(struct brw_wm_prog_data *prog_data,
  40                                 struct brw_vue_map *vue_map,
  41                                 unsigned location, unsigned slot_count,
  42                                 enum glsl_interp_mode interp)
  43 {
  44    for (unsigned k = 0; k < slot_count; k++) {
  45       unsigned slot = vue_map->varying_to_slot[location + k];
  46       if (slot != -1 && prog_data->interp_mode[slot] == INTERP_MODE_NONE) {
  47          prog_data->interp_mode[slot] = interp;
  48
  49          if (prog_data->interp_mode[slot] == INTERP_MODE_FLAT) {
  50             prog_data->contains_flat_varying = true;
  51          } else if (prog_data->interp_mode[slot] == INTERP_MODE_NOPERSPECTIVE) {
  52             prog_data->contains_noperspective_varying = true;
  53          }
  54       }
  55    }
  56 }
  57
  58 /* Set up interpolation modes for every element in the VUE */
  59 void
  60 brw_setup_vue_interpolation(struct brw_vue_map *vue_map, nir_shader *nir,
  61                             struct brw_wm_prog_data *prog_data)
  62 {
  63    /* Initialise interp_mode. INTERP_MODE_NONE == 0 */
  64    memset(prog_data->interp_mode, 0, sizeof(prog_data->interp_mode));
  65
  66    if (!vue_map)
  67       return;
  68
  69    /* HPOS always wants noperspective. setting it up here allows
  70     * us to not need special handling in the SF program.
  71     */
  72    unsigned pos_slot = vue_map->varying_to_slot[VARYING_SLOT_POS];
  73    if (pos_slot != -1) {;
  74       prog_data->interp_mode[pos_slot] = INTERP_MODE_NOPERSPECTIVE;
  75       prog_data->contains_noperspective_varying = true;
  76    }
  77
  78    nir_foreach_shader_in_variable(var, nir) {
  79       unsigned location = var->data.location;
  80       unsigned slot_count = glsl_count_attribute_slots(var->type, false);
  81
  82       gen4_frag_prog_set_interp_modes(prog_data, vue_map, location, slot_count,
  83                                       var->data.interpolation);
  84
  85       if (location == VARYING_SLOT_COL0 || location == VARYING_SLOT_COL1) {
  86          location = location + VARYING_SLOT_BFC0 - VARYING_SLOT_COL0;
  87          gen4_frag_prog_set_interp_modes(prog_data, vue_map, location,
  88                                          slot_count, var->data.interpolation);
  89       }
  90    }
  91
  92    const bool debug = false;
  93    if (debug) {
  94       fprintf(stderr, "VUE map:\n");
  95       for (int i = 0; i < vue_map->num_slots; i++) {
  96          int varying = vue_map->slot_to_varying[i];
  97          if (varying == -1) {
  98             fprintf(stderr, "%d: --\n", i);
  99             continue;
 100          }
 101
 102          fprintf(stderr, "%d: %d %s ofs %d\n",
 103                  i, varying,
 104                  get_qual_name(prog_data->interp_mode[i]),
 105                  brw_vue_slot_to_offset(i));
 106       }
 107    }
 108 }