1 /*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2005 Brian Paul All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors:
25 * Keith Whitwell <keithw@vmware.com>
26 */
27
28
29 #include "main/api_arrayelt.h"
30 #include "main/glheader.h"
31 #include "main/mtypes.h"
32 #include "main/vtxfmt.h"
33 #include "vbo_context.h"
34
35
36
vbo_exec_init(struct gl_context * ctx)37 void vbo_exec_init( struct gl_context *ctx )
38 {
39 struct vbo_exec_context *exec = &vbo_context(ctx)->exec;
40
41 exec->ctx = ctx;
42
43 /* Initialize the arrayelt helper
44 */
45 if (!ctx->aelt_context &&
46 !_ae_create_context( ctx ))
47 return;
48
49 vbo_exec_vtx_init( exec );
50
51 ctx->Driver.NeedFlush = 0;
52 ctx->Driver.CurrentExecPrimitive = PRIM_OUTSIDE_BEGIN_END;
53
54 vbo_exec_invalidate_state( ctx, ~0 );
55 }
56
57
vbo_exec_destroy(struct gl_context * ctx)58 void vbo_exec_destroy( struct gl_context *ctx )
59 {
60 struct vbo_exec_context *exec = &vbo_context(ctx)->exec;
61
62 if (ctx->aelt_context) {
63 _ae_destroy_context( ctx );
64 ctx->aelt_context = NULL;
65 }
66
67 vbo_exec_vtx_destroy( exec );
68 }
69
70
71 /**
72 * Really want to install these callbacks to a central facility to be
73 * invoked according to the state flags. That will have to wait for a
74 * mesa rework:
75 */
vbo_exec_invalidate_state(struct gl_context * ctx,GLbitfield new_state)76 void vbo_exec_invalidate_state( struct gl_context *ctx, GLbitfield new_state )
77 {
78 struct vbo_context *vbo = vbo_context(ctx);
79 struct vbo_exec_context *exec = &vbo->exec;
80
81 if (!exec->validating && new_state & (_NEW_PROGRAM|_NEW_ARRAY)) {
82 exec->array.recalculate_inputs = GL_TRUE;
83 }
84
85 if (new_state & _NEW_EVAL)
86 exec->eval.recalculate_maps = GL_TRUE;
87
88 _ae_invalidate_state(ctx, new_state);
89 }
90
91
92 /**
93 * Figure out the number of transform feedback primitives that will be output
94 * considering the drawing mode, number of vertices, and instance count,
95 * assuming that no geometry shading is done and primitive restart is not
96 * used.
97 *
98 * This is used by driver back-ends in implementing the PRIMITIVES_GENERATED
99 * and TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN queries. It is also used to
100 * pre-validate draw calls in GLES3 (where draw calls only succeed if there is
101 * enough room in the transform feedback buffer for the result).
102 */
103 size_t
vbo_count_tessellated_primitives(GLenum mode,GLuint count,GLuint num_instances)104 vbo_count_tessellated_primitives(GLenum mode, GLuint count,
105 GLuint num_instances)
106 {
107 size_t num_primitives;
108 switch (mode) {
109 case GL_POINTS:
110 num_primitives = count;
111 break;
112 case GL_LINE_STRIP:
113 num_primitives = count >= 2 ? count - 1 : 0;
114 break;
115 case GL_LINE_LOOP:
116 num_primitives = count >= 2 ? count : 0;
117 break;
118 case GL_LINES:
119 num_primitives = count / 2;
120 break;
121 case GL_TRIANGLE_STRIP:
122 case GL_TRIANGLE_FAN:
123 case GL_POLYGON:
124 num_primitives = count >= 3 ? count - 2 : 0;
125 break;
126 case GL_TRIANGLES:
127 num_primitives = count / 3;
128 break;
129 case GL_QUAD_STRIP:
130 num_primitives = count >= 4 ? ((count / 2) - 1) * 2 : 0;
131 break;
132 case GL_QUADS:
133 num_primitives = (count / 4) * 2;
134 break;
135 case GL_LINES_ADJACENCY:
136 num_primitives = count / 4;
137 break;
138 case GL_LINE_STRIP_ADJACENCY:
139 num_primitives = count >= 4 ? count - 3 : 0;
140 break;
141 case GL_TRIANGLES_ADJACENCY:
142 num_primitives = count / 6;
143 break;
144 case GL_TRIANGLE_STRIP_ADJACENCY:
145 num_primitives = count >= 6 ? (count - 4) / 2 : 0;
146 break;
147 default:
148 assert(!"Unexpected primitive type in count_tessellated_primitives");
149 num_primitives = 0;
150 break;
151 }
152 return num_primitives * num_instances;
153 }
154
155
156
157 /**
158 * In some degenarate cases we can improve our ability to merge
159 * consecutive primitives. For example:
160 * glBegin(GL_LINE_STRIP);
161 * glVertex(1);
162 * glVertex(1);
163 * glEnd();
164 * glBegin(GL_LINE_STRIP);
165 * glVertex(1);
166 * glVertex(1);
167 * glEnd();
168 * Can be merged as a GL_LINES prim with four vertices.
169 *
170 * This function converts 2-vertex line strips/loops into GL_LINES, etc.
171 */
172 void
vbo_try_prim_conversion(struct _mesa_prim * p)173 vbo_try_prim_conversion(struct _mesa_prim *p)
174 {
175 if (p->mode == GL_LINE_STRIP && p->count == 2) {
176 /* convert 2-vertex line strip to a separate line */
177 p->mode = GL_LINES;
178 }
179 else if ((p->mode == GL_TRIANGLE_STRIP || p->mode == GL_TRIANGLE_FAN)
180 && p->count == 3) {
181 /* convert 3-vertex tri strip or fan to a separate triangle */
182 p->mode = GL_TRIANGLES;
183 }
184
185 /* Note: we can't convert a 4-vertex quad strip to a separate quad
186 * because the vertex ordering is different. We'd have to muck
187 * around in the vertex data to make it work.
188 */
189 }
190
191
192 /**
193 * Helper function for determining if two subsequent glBegin/glEnd
194 * primitives can be combined. This is only possible for GL_POINTS,
195 * GL_LINES, GL_TRIANGLES and GL_QUADS.
196 * If we return true, it means that we can concatenate p1 onto p0 (and
197 * discard p1).
198 */
199 bool
vbo_can_merge_prims(const struct _mesa_prim * p0,const struct _mesa_prim * p1)200 vbo_can_merge_prims(const struct _mesa_prim *p0, const struct _mesa_prim *p1)
201 {
202 if (!p0->begin ||
203 !p1->begin ||
204 !p0->end ||
205 !p1->end)
206 return false;
207
208 /* The prim mode must match (ex: both GL_TRIANGLES) */
209 if (p0->mode != p1->mode)
210 return false;
211
212 /* p1's vertices must come right after p0 */
213 if (p0->start + p0->count != p1->start)
214 return false;
215
216 if (p0->basevertex != p1->basevertex ||
217 p0->num_instances != p1->num_instances ||
218 p0->base_instance != p1->base_instance)
219 return false;
220
221 /* can always merge subsequent GL_POINTS primitives */
222 if (p0->mode == GL_POINTS)
223 return true;
224
225 /* independent lines with no extra vertices */
226 if (p0->mode == GL_LINES && p0->count % 2 == 0 && p1->count % 2 == 0)
227 return true;
228
229 /* independent tris */
230 if (p0->mode == GL_TRIANGLES && p0->count % 3 == 0 && p1->count % 3 == 0)
231 return true;
232
233 /* independent quads */
234 if (p0->mode == GL_QUADS && p0->count % 4 == 0 && p1->count % 4 == 0)
235 return true;
236
237 return false;
238 }
239
240
241 /**
242 * If we've determined that p0 and p1 can be merged, this function
243 * concatenates p1 onto p0.
244 */
245 void
vbo_merge_prims(struct _mesa_prim * p0,const struct _mesa_prim * p1)246 vbo_merge_prims(struct _mesa_prim *p0, const struct _mesa_prim *p1)
247 {
248 assert(vbo_can_merge_prims(p0, p1));
249
250 p0->count += p1->count;
251 p0->end = p1->end;
252 }
253