aboutsummaryrefslogtreecommitdiffstats
path: root/src/mesa/drivers/dri/i965/brw_primitive_restart.c
blob: 2c7a7e8b8dd5483a6806e23e450743a218f995ff (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
/*
 * Copyright © 2012 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.
 *
 * Authors:
 *    Jordan Justen <jordan.l.justen@intel.com>
 *
 */

#include "main/imports.h"
#include "main/bufferobj.h"
#include "main/varray.h"

#include "brw_context.h"
#include "brw_defines.h"
#include "brw_draw.h"

#include "intel_batchbuffer.h"

/**
 * Check if the hardware's cut index support can handle the primitive
 * restart index value (pre-Haswell only).
 */
static bool
can_cut_index_handle_restart_index(struct gl_context *ctx,
                                   const struct _mesa_index_buffer *ib)
{
   /* The FixedIndex variant means 0xFF, 0xFFFF, or 0xFFFFFFFF based on
    * the index buffer type, which corresponds exactly to the hardware.
    */
   if (ctx->Array.PrimitiveRestartFixedIndex)
      return true;

   bool cut_index_will_work;

   switch (ib->type) {
   case GL_UNSIGNED_BYTE:
      cut_index_will_work = ctx->Array.RestartIndex == 0xff;
      break;
   case GL_UNSIGNED_SHORT:
      cut_index_will_work = ctx->Array.RestartIndex == 0xffff;
      break;
   case GL_UNSIGNED_INT:
      cut_index_will_work = ctx->Array.RestartIndex == 0xffffffff;
      break;
   default:
      unreachable("not reached");
   }

   return cut_index_will_work;
}

/**
 * Check if the hardware's cut index support can handle the primitive
 * restart case.
 */
static bool
can_cut_index_handle_prims(struct gl_context *ctx,
                           const struct _mesa_prim *prim,
                           GLuint nr_prims,
                           const struct _mesa_index_buffer *ib)
{
   struct brw_context *brw = brw_context(ctx);

   /* Otherwise Haswell can do it all. */
   if (brw->gen >= 8 || brw->is_haswell)
      return true;

   if (!can_cut_index_handle_restart_index(ctx, ib)) {
      /* The primitive restart index can't be handled, so take
       * the software path
       */
      return false;
   }

   for (int i = 0; i < nr_prims; i++) {
      switch (prim[i].mode) {
      case GL_POINTS:
      case GL_LINES:
      case GL_LINE_STRIP:
      case GL_TRIANGLES:
      case GL_TRIANGLE_STRIP:
      case GL_LINES_ADJACENCY:
      case GL_LINE_STRIP_ADJACENCY:
      case GL_TRIANGLES_ADJACENCY:
      case GL_TRIANGLE_STRIP_ADJACENCY:
         /* Cut index supports these primitive types */
         break;
      default:
         /* Cut index does not support these primitive types */
      //case GL_LINE_LOOP:
      //case GL_TRIANGLE_FAN:
      //case GL_QUADS:
      //case GL_QUAD_STRIP:
      //case GL_POLYGON:
         return false;
      }
   }

   return true;
}

/**
 * Check if primitive restart is enabled, and if so, handle it properly.
 *
 * In some cases the support will be handled in software. When available
 * hardware will handle primitive restart.
 */
GLboolean
brw_handle_primitive_restart(struct gl_context *ctx,
                             const struct _mesa_prim *prims,
                             GLuint nr_prims,
                             const struct _mesa_index_buffer *ib,
                             struct gl_buffer_object *indirect)
{
   struct brw_context *brw = brw_context(ctx);

   /* We only need to handle cases where there is an index buffer. */
   if (ib == NULL) {
      return GL_FALSE;
   }

   /* If we have set the in_progress flag, then we are in the middle
    * of handling the primitive restart draw.
    */
   if (brw->prim_restart.in_progress) {
      return GL_FALSE;
   }

   /* If PrimitiveRestart is not enabled, then we aren't concerned about
    * handling this draw.
    */
   if (!(ctx->Array._PrimitiveRestart)) {
      return GL_FALSE;
   }

   /* Signal that we are in the process of handling the
    * primitive restart draw
    */
   brw->prim_restart.in_progress = true;

   if (can_cut_index_handle_prims(ctx, prims, nr_prims, ib)) {
      /* Cut index should work for primitive restart, so use it
       */
      brw->prim_restart.enable_cut_index = true;
      brw_draw_prims(ctx, prims, nr_prims, ib, GL_FALSE, -1, -1, NULL, indirect);
      brw->prim_restart.enable_cut_index = false;
   } else {
      /* Not all the primitive draw modes are supported by the cut index,
       * so take the software path
       */
      vbo_sw_primitive_restart(ctx, prims, nr_prims, ib, indirect);
   }

   brw->prim_restart.in_progress = false;

   /* The primitive restart draw was completed, so return true. */
   return GL_TRUE;
}

static void
haswell_upload_cut_index(struct brw_context *brw)
{
   struct gl_context *ctx = &brw->ctx;

   /* Don't trigger on Ivybridge */
   if (brw->gen < 8 && !brw->is_haswell)
      return;

   const unsigned cut_index_setting =
      ctx->Array._PrimitiveRestart ? HSW_CUT_INDEX_ENABLE : 0;

   /* BRW_NEW_INDEX_BUFFER */
   unsigned cut_index;
   if (brw->ib.ib) {
      cut_index = _mesa_primitive_restart_index(ctx, brw->ib.type);
   } else {
      /* There's no index buffer, but primitive restart may still apply
       * to glDrawArrays and such.  FIXED_INDEX mode only applies to drawing
       * operations that use an index buffer, so we can ignore it and use
       * the GL restart index directly.
       */
      cut_index = ctx->Array.RestartIndex;
   }

   BEGIN_BATCH(2);
   OUT_BATCH(_3DSTATE_VF << 16 | cut_index_setting | (2 - 2));
   OUT_BATCH(cut_index);
   ADVANCE_BATCH();
}

const struct brw_tracked_state haswell_cut_index = {
   .dirty = {
      .mesa  = _NEW_TRANSFORM,
      .brw   = BRW_NEW_INDEX_BUFFER,
   },
   .emit = haswell_upload_cut_index,
};