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 "brw_context.h"
26 #include "compiler/nir/nir.h"
27 
28 static char const *get_qual_name(int mode)
29 {
30    switch (mode) {
31       case INTERP_MODE_NONE:          return "none";
32       case INTERP_MODE_FLAT:          return "flat";
33       case INTERP_MODE_SMOOTH:        return "smooth";
34       case INTERP_MODE_NOPERSPECTIVE: return "nopersp";
35       default:                             return "???";
36    }
37 }
38 
39 static void
40 gen4_frag_prog_set_interp_modes(struct brw_wm_prog_data *prog_data,
41                                 struct brw_vue_map *vue_map,
42                                 unsigned location, unsigned slot_count,
43                                 enum glsl_interp_mode interp)
44 {
45    for (unsigned k = 0; k < slot_count; k++) {
46       unsigned slot = vue_map->varying_to_slot[location + k];
47       if (slot != -1 && prog_data->interp_mode[slot] == INTERP_MODE_NONE) {
48          prog_data->interp_mode[slot] = interp;
49 
50          if (prog_data->interp_mode[slot] == INTERP_MODE_FLAT) {
51             prog_data->contains_flat_varying = true;
52          } else if (prog_data->interp_mode[slot] == INTERP_MODE_NOPERSPECTIVE) {
53             prog_data->contains_noperspective_varying = true;
54          }
55       }
56    }
57 }
58 
59 /* Set up interpolation modes for every element in the VUE */
60 void
61 brw_setup_vue_interpolation(struct brw_vue_map *vue_map, nir_shader *nir,
62                             struct brw_wm_prog_data *prog_data,
63                             const struct gen_device_info *devinfo)
64 {
65    /* Initialise interp_mode. INTERP_MODE_NONE == 0 */
66    memset(prog_data->interp_mode, 0, sizeof(prog_data->interp_mode));
67 
68    if (!vue_map)
69       return;
70 
71    /* HPOS always wants noperspective. setting it up here allows
72     * us to not need special handling in the SF program.
73     */
74    unsigned pos_slot = vue_map->varying_to_slot[VARYING_SLOT_POS];
75    if (pos_slot != -1) {;
76       prog_data->interp_mode[pos_slot] = INTERP_MODE_NOPERSPECTIVE;
77       prog_data->contains_noperspective_varying = true;
78    }
79 
80    foreach_list_typed(nir_variable, var, node, &nir->inputs) {
81       unsigned location = var->data.location;
82       unsigned slot_count = glsl_count_attribute_slots(var->type, false);
83 
84       gen4_frag_prog_set_interp_modes(prog_data, vue_map, location, slot_count,
85                                       var->data.interpolation);
86 
87       if (location == VARYING_SLOT_COL0 || location == VARYING_SLOT_COL1) {
88          location = location + VARYING_SLOT_BFC0 - VARYING_SLOT_COL0;
89          gen4_frag_prog_set_interp_modes(prog_data, vue_map, location,
90                                          slot_count, var->data.interpolation);
91       }
92    }
93 
94    bool debug = false;
95    if (debug) {
96       fprintf(stderr, "VUE map:\n");
97       for (int i = 0; i < vue_map->num_slots; i++) {
98          int varying = vue_map->slot_to_varying[i];
99          if (varying == -1) {
100             fprintf(stderr, "%d: --\n", i);
101             continue;
102          }
103 
104          fprintf(stderr, "%d: %d %s ofs %d\n",
105                  i, varying,
106                  get_qual_name(prog_data->interp_mode[i]),
107                  brw_vue_slot_to_offset(i));
108       }
109    }
110 }
111