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 
get_qual_name(int mode)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
gfx4_frag_prog_set_interp_modes(struct brw_wm_prog_data * prog_data,const struct brw_vue_map * vue_map,unsigned location,unsigned slot_count,enum glsl_interp_mode interp)39 gfx4_frag_prog_set_interp_modes(struct brw_wm_prog_data *prog_data,
40                                 const 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
brw_setup_vue_interpolation(const struct brw_vue_map * vue_map,nir_shader * nir,struct brw_wm_prog_data * prog_data)60 brw_setup_vue_interpolation(const 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       gfx4_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          gfx4_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 }
109