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/bufferobj.h"
29 #include "main/varray.h"
30 #include "vbo/vbo.h"
31
32 #include "brw_context.h"
33 #include "brw_defines.h"
34 #include "brw_draw.h"
35
36 #include "intel_batchbuffer.h"
37
38 /**
39 * Check if the hardware's cut index support can handle the primitive
40 * restart index value (pre-Haswell only).
41 */
42 static bool
can_cut_index_handle_restart_index(struct gl_context * ctx,const struct _mesa_index_buffer * ib)43 can_cut_index_handle_restart_index(struct gl_context *ctx,
44 const struct _mesa_index_buffer *ib)
45 {
46 /* The FixedIndex variant means 0xFF, 0xFFFF, or 0xFFFFFFFF based on
47 * the index buffer type, which corresponds exactly to the hardware.
48 */
49 if (ctx->Array.PrimitiveRestartFixedIndex)
50 return true;
51
52 bool cut_index_will_work;
53
54 switch (ib->index_size_shift) {
55 case 0:
56 cut_index_will_work = ctx->Array.RestartIndex == 0xff;
57 break;
58 case 1:
59 cut_index_will_work = ctx->Array.RestartIndex == 0xffff;
60 break;
61 case 2:
62 cut_index_will_work = ctx->Array.RestartIndex == 0xffffffff;
63 break;
64 default:
65 unreachable("not reached");
66 }
67
68 return cut_index_will_work;
69 }
70
71 /**
72 * Check if the hardware's cut index support can handle the primitive
73 * restart case.
74 */
75 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)76 can_cut_index_handle_prims(struct gl_context *ctx,
77 const struct _mesa_prim *prim,
78 GLuint nr_prims,
79 const struct _mesa_index_buffer *ib)
80 {
81 struct brw_context *brw = brw_context(ctx);
82 const struct gen_device_info *devinfo = &brw->screen->devinfo;
83
84 /* Otherwise Haswell can do it all. */
85 if (devinfo->gen >= 8 || devinfo->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,GLuint num_instances,GLuint base_instance)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 GLuint num_instances, GLuint base_instance)
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,
166 num_instances, base_instance, NULL, 0);
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 struct gl_buffer_object *indirect_data = brw->draw.draw_indirect_data;
173
174 /* Clear this to make the draw direct. */
175 brw->draw.draw_indirect_data = NULL;
176
177 vbo_sw_primitive_restart(ctx, prims, nr_prims, ib, num_instances,
178 base_instance, indirect_data,
179 brw->draw.draw_indirect_offset);
180 }
181
182 brw->prim_restart.in_progress = false;
183
184 /* The primitive restart draw was completed, so return true. */
185 return GL_TRUE;
186 }
187