2 * Mesa 3-D graphics library
4 * Copyright (C) 1999-2005 Brian Paul All Rights Reserved.
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:
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
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.
25 * Keith Whitwell <keith@tungstengraphics.com>
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"
37 void vbo_exec_init( struct gl_context
*ctx
)
39 struct vbo_exec_context
*exec
= &vbo_context(ctx
)->exec
;
43 /* Initialize the arrayelt helper
45 if (!ctx
->aelt_context
&&
46 !_ae_create_context( ctx
))
49 vbo_exec_vtx_init( exec
);
51 ctx
->Driver
.NeedFlush
= 0;
52 ctx
->Driver
.CurrentExecPrimitive
= PRIM_OUTSIDE_BEGIN_END
;
53 ctx
->Driver
.BeginVertices
= vbo_exec_BeginVertices
;
54 ctx
->Driver
.FlushVertices
= vbo_exec_FlushVertices
;
56 vbo_exec_invalidate_state( ctx
, ~0 );
60 void vbo_exec_destroy( struct gl_context
*ctx
)
62 struct vbo_exec_context
*exec
= &vbo_context(ctx
)->exec
;
64 if (ctx
->aelt_context
) {
65 _ae_destroy_context( ctx
);
66 ctx
->aelt_context
= NULL
;
69 vbo_exec_vtx_destroy( exec
);
74 * Really want to install these callbacks to a central facility to be
75 * invoked according to the state flags. That will have to wait for a
78 void vbo_exec_invalidate_state( struct gl_context
*ctx
, GLuint new_state
)
80 struct vbo_context
*vbo
= vbo_context(ctx
);
81 struct vbo_exec_context
*exec
= &vbo
->exec
;
83 if (!exec
->validating
&& new_state
& (_NEW_PROGRAM
|_NEW_ARRAY
)) {
84 exec
->array
.recalculate_inputs
= GL_TRUE
;
86 /* If we ended up here because a VAO was deleted, the _DrawArrays
87 * pointer which pointed to the VAO might be invalid now, so set it
88 * to NULL. This prevents crashes in driver functions like Clear
89 * where driver state validation might occur, but the vbo module is
90 * still in an invalid state.
92 * Drivers should skip vertex array state validation if _DrawArrays
93 * is NULL. It also has no effect on performance, because attrib
94 * bindings will be recalculated anyway.
96 if (vbo
->last_draw_method
== DRAW_ARRAYS
) {
97 ctx
->Array
._DrawArrays
= NULL
;
98 vbo
->last_draw_method
= DRAW_NONE
;
102 if (new_state
& _NEW_EVAL
)
103 exec
->eval
.recalculate_maps
= 1;
105 _ae_invalidate_state(ctx
, new_state
);
110 * Figure out the number of transform feedback primitives that will be output
111 * considering the drawing mode, number of vertices, and instance count,
112 * assuming that no geometry shading is done and primitive restart is not
115 * This is used by driver back-ends in implementing the PRIMITIVES_GENERATED
116 * and TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN queries. It is also used to
117 * pre-validate draw calls in GLES3 (where draw calls only succeed if there is
118 * enough room in the transform feedback buffer for the result).
121 vbo_count_tessellated_primitives(GLenum mode
, GLuint count
,
122 GLuint num_instances
)
124 size_t num_primitives
;
127 num_primitives
= count
;
130 num_primitives
= count
>= 2 ? count
- 1 : 0;
133 num_primitives
= count
>= 2 ? count
: 0;
136 num_primitives
= count
/ 2;
138 case GL_TRIANGLE_STRIP
:
139 case GL_TRIANGLE_FAN
:
141 num_primitives
= count
>= 3 ? count
- 2 : 0;
144 num_primitives
= count
/ 3;
147 num_primitives
= count
>= 4 ? ((count
/ 2) - 1) * 2 : 0;
150 num_primitives
= (count
/ 4) * 2;
153 assert(!"Unexpected primitive type in count_tessellated_primitives");
157 return num_primitives
* num_instances
;
163 * In some degenarate cases we can improve our ability to merge
164 * consecutive primitives. For example:
165 * glBegin(GL_LINE_STRIP);
169 * glBegin(GL_LINE_STRIP);
173 * Can be merged as a GL_LINES prim with four vertices.
175 * This function converts 2-vertex line strips/loops into GL_LINES, etc.
178 vbo_try_prim_conversion(struct _mesa_prim
*p
)
180 if (p
->mode
== GL_LINE_STRIP
&& p
->count
== 2) {
181 /* convert 2-vertex line strip to a separate line */
184 else if ((p
->mode
== GL_TRIANGLE_STRIP
|| p
->mode
== GL_TRIANGLE_FAN
)
186 /* convert 3-vertex tri strip or fan to a separate triangle */
187 p
->mode
= GL_TRIANGLES
;
190 /* Note: we can't convert a 4-vertex quad strip to a separate quad
191 * because the vertex ordering is different. We'd have to muck
192 * around in the vertex data to make it work.
198 * Helper function for determining if two subsequent glBegin/glEnd
199 * primitives can be combined. This is only possible for GL_POINTS,
200 * GL_LINES, GL_TRIANGLES and GL_QUADS.
201 * If we return true, it means that we can concatenate p1 onto p0 (and
205 vbo_can_merge_prims(const struct _mesa_prim
*p0
, const struct _mesa_prim
*p1
)
213 /* The prim mode must match (ex: both GL_TRIANGLES) */
214 if (p0
->mode
!= p1
->mode
)
217 /* p1's vertices must come right after p0 */
218 if (p0
->start
+ p0
->count
!= p1
->start
)
221 if (p0
->basevertex
!= p1
->basevertex
||
222 p0
->num_instances
!= p1
->num_instances
||
223 p0
->base_instance
!= p1
->base_instance
)
226 /* can always merge subsequent GL_POINTS primitives */
227 if (p0
->mode
== GL_POINTS
)
230 /* independent lines with no extra vertices */
231 if (p0
->mode
== GL_LINES
&& p0
->count
% 2 == 0 && p1
->count
% 2 == 0)
234 /* independent tris */
235 if (p0
->mode
== GL_TRIANGLES
&& p0
->count
% 3 == 0 && p1
->count
% 3 == 0)
238 /* independent quads */
239 if (p0
->mode
== GL_QUADS
&& p0
->count
% 4 == 0 && p1
->count
% 4 == 0)
247 * If we've determined that p0 and p1 can be merged, this function
248 * concatenates p1 onto p0.
251 vbo_merge_prims(struct _mesa_prim
*p0
, const struct _mesa_prim
*p1
)
253 assert(vbo_can_merge_prims(p0
, p1
));
255 p0
->count
+= p1
->count
;