1 /*
2 * Copyright © 2012 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 * Authors:
24 * Jordan Justen <jordan.l.justen@intel.com>
25 *
26 */
27
28 #include "main/imports.h"
29 #include "main/bufferobj.h"
30 #include "main/varray.h"
31 #include "vbo/vbo.h"
32
33 #include "brw_context.h"
34 #include "brw_defines.h"
35 #include "brw_draw.h"
36
37 #include "intel_batchbuffer.h"
38
39 /**
40 * Check if the hardware's cut index support can handle the primitive
41 * restart index value (pre-Haswell only).
42 */
43 static bool
can_cut_index_handle_restart_index(struct gl_context * ctx,const struct _mesa_index_buffer * ib)44 can_cut_index_handle_restart_index(struct gl_context *ctx,
45 const struct _mesa_index_buffer *ib)
46 {
47 /* The FixedIndex variant means 0xFF, 0xFFFF, or 0xFFFFFFFF based on
48 * the index buffer type, which corresponds exactly to the hardware.
49 */
50 if (ctx->Array.PrimitiveRestartFixedIndex)
51 return true;
52
53 bool cut_index_will_work;
54
55 switch (ib->type) {
56 case GL_UNSIGNED_BYTE:
57 cut_index_will_work = ctx->Array.RestartIndex == 0xff;
58 break;
59 case GL_UNSIGNED_SHORT:
60 cut_index_will_work = ctx->Array.RestartIndex == 0xffff;
61 break;
62 case GL_UNSIGNED_INT:
63 cut_index_will_work = ctx->Array.RestartIndex == 0xffffffff;
64 break;
65 default:
66 unreachable("not reached");
67 }
68
69 return cut_index_will_work;
70 }
71
72 /**
73 * Check if the hardware's cut index support can handle the primitive
74 * restart case.
75 */
76 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)77 can_cut_index_handle_prims(struct gl_context *ctx,
78 const struct _mesa_prim *prim,
79 GLuint nr_prims,
80 const struct _mesa_index_buffer *ib)
81 {
82 struct brw_context *brw = brw_context(ctx);
83
84 /* Otherwise Haswell can do it all. */
85 if (brw->gen >= 8 || brw->is_haswell)
86 return true;
87
88 if (!can_cut_index_handle_restart_index(ctx, ib)) {
89 /* The primitive restart index can't be handled, so take
90 * the software path
91 */
92 return false;
93 }
94
95 for (unsigned i = 0; i < nr_prims; i++) {
96 switch (prim[i].mode) {
97 case GL_POINTS:
98 case GL_LINES:
99 case GL_LINE_STRIP:
100 case GL_TRIANGLES:
101 case GL_TRIANGLE_STRIP:
102 case GL_LINES_ADJACENCY:
103 case GL_LINE_STRIP_ADJACENCY:
104 case GL_TRIANGLES_ADJACENCY:
105 case GL_TRIANGLE_STRIP_ADJACENCY:
106 /* Cut index supports these primitive types */
107 break;
108 default:
109 /* Cut index does not support these primitive types */
110 //case GL_LINE_LOOP:
111 //case GL_TRIANGLE_FAN:
112 //case GL_QUADS:
113 //case GL_QUAD_STRIP:
114 //case GL_POLYGON:
115 return false;
116 }
117 }
118
119 return true;
120 }
121
122 /**
123 * Check if primitive restart is enabled, and if so, handle it properly.
124 *
125 * In some cases the support will be handled in software. When available
126 * hardware will handle primitive restart.
127 */
128 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)129 brw_handle_primitive_restart(struct gl_context *ctx,
130 const struct _mesa_prim *prims,
131 GLuint nr_prims,
132 const struct _mesa_index_buffer *ib,
133 struct gl_buffer_object *indirect)
134 {
135 struct brw_context *brw = brw_context(ctx);
136
137 /* We only need to handle cases where there is an index buffer. */
138 if (ib == NULL) {
139 return GL_FALSE;
140 }
141
142 /* If we have set the in_progress flag, then we are in the middle
143 * of handling the primitive restart draw.
144 */
145 if (brw->prim_restart.in_progress) {
146 return GL_FALSE;
147 }
148
149 /* If PrimitiveRestart is not enabled, then we aren't concerned about
150 * handling this draw.
151 */
152 if (!(ctx->Array._PrimitiveRestart)) {
153 return GL_FALSE;
154 }
155
156 /* Signal that we are in the process of handling the
157 * primitive restart draw
158 */
159 brw->prim_restart.in_progress = true;
160
161 if (can_cut_index_handle_prims(ctx, prims, nr_prims, ib)) {
162 /* Cut index should work for primitive restart, so use it
163 */
164 brw->prim_restart.enable_cut_index = true;
165 brw_draw_prims(ctx, prims, nr_prims, ib, GL_FALSE, -1, -1, NULL, 0,
166 indirect);
167 brw->prim_restart.enable_cut_index = false;
168 } else {
169 /* Not all the primitive draw modes are supported by the cut index,
170 * so take the software path
171 */
172 vbo_sw_primitive_restart(ctx, prims, nr_prims, ib, indirect);
173 }
174
175 brw->prim_restart.in_progress = false;
176
177 /* The primitive restart draw was completed, so return true. */
178 return GL_TRUE;
179 }
180
181 static void
haswell_upload_cut_index(struct brw_context * brw)182 haswell_upload_cut_index(struct brw_context *brw)
183 {
184 struct gl_context *ctx = &brw->ctx;
185
186 /* Don't trigger on Ivybridge */
187 if (brw->gen < 8 && !brw->is_haswell)
188 return;
189
190 const unsigned cut_index_setting =
191 ctx->Array._PrimitiveRestart ? HSW_CUT_INDEX_ENABLE : 0;
192
193 /* BRW_NEW_INDEX_BUFFER */
194 unsigned cut_index;
195 if (brw->ib.ib) {
196 cut_index = _mesa_primitive_restart_index(ctx, brw->ib.type);
197 } else {
198 /* There's no index buffer, but primitive restart may still apply
199 * to glDrawArrays and such. FIXED_INDEX mode only applies to drawing
200 * operations that use an index buffer, so we can ignore it and use
201 * the GL restart index directly.
202 */
203 cut_index = ctx->Array.RestartIndex;
204 }
205
206 BEGIN_BATCH(2);
207 OUT_BATCH(_3DSTATE_VF << 16 | cut_index_setting | (2 - 2));
208 OUT_BATCH(cut_index);
209 ADVANCE_BATCH();
210 }
211
212 const struct brw_tracked_state haswell_cut_index = {
213 .dirty = {
214 .mesa = _NEW_TRANSFORM,
215 .brw = BRW_NEW_BLORP |
216 BRW_NEW_INDEX_BUFFER,
217 },
218 .emit = haswell_upload_cut_index,
219 };
220