2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2005 Brian Paul All Rights Reserved.
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23 * OTHER DEALINGS IN THE SOFTWARE.
26 * Keith Whitwell <keith@tungstengraphics.com>
30 #include "main/api_arrayelt.h"
31 #include "main/glheader.h"
32 #include "main/mtypes.h"
33 #include "main/vtxfmt.h"
34 #include "vbo_context.h"
38 void vbo_exec_init( struct gl_context
*ctx
)
40 struct vbo_exec_context
*exec
= &vbo_context(ctx
)->exec
;
44 /* Initialize the arrayelt helper
46 if (!ctx
->aelt_context
&&
47 !_ae_create_context( ctx
))
50 vbo_exec_vtx_init( exec
);
52 ctx
->Driver
.NeedFlush
= 0;
53 ctx
->Driver
.CurrentExecPrimitive
= PRIM_OUTSIDE_BEGIN_END
;
54 ctx
->Driver
.BeginVertices
= vbo_exec_BeginVertices
;
55 ctx
->Driver
.FlushVertices
= vbo_exec_FlushVertices
;
57 vbo_exec_invalidate_state( ctx
, ~0 );
61 void vbo_exec_destroy( struct gl_context
*ctx
)
63 struct vbo_exec_context
*exec
= &vbo_context(ctx
)->exec
;
65 if (ctx
->aelt_context
) {
66 _ae_destroy_context( ctx
);
67 ctx
->aelt_context
= NULL
;
70 vbo_exec_vtx_destroy( exec
);
75 * Really want to install these callbacks to a central facility to be
76 * invoked according to the state flags. That will have to wait for a
79 void vbo_exec_invalidate_state( struct gl_context
*ctx
, GLuint new_state
)
81 struct vbo_context
*vbo
= vbo_context(ctx
);
82 struct vbo_exec_context
*exec
= &vbo
->exec
;
84 if (!exec
->validating
&& new_state
& (_NEW_PROGRAM
|_NEW_ARRAY
)) {
85 exec
->array
.recalculate_inputs
= GL_TRUE
;
87 /* If we ended up here because a VAO was deleted, the _DrawArrays
88 * pointer which pointed to the VAO might be invalid now, so set it
89 * to NULL. This prevents crashes in driver functions like Clear
90 * where driver state validation might occur, but the vbo module is
91 * still in an invalid state.
93 * Drivers should skip vertex array state validation if _DrawArrays
94 * is NULL. It also has no effect on performance, because attrib
95 * bindings will be recalculated anyway.
97 if (vbo
->last_draw_method
== DRAW_ARRAYS
) {
98 ctx
->Array
._DrawArrays
= NULL
;
99 vbo
->last_draw_method
= DRAW_NONE
;
103 if (new_state
& _NEW_EVAL
)
104 exec
->eval
.recalculate_maps
= 1;
106 _ae_invalidate_state(ctx
, new_state
);
111 * Figure out the number of transform feedback primitives that will be output
112 * considering the drawing mode, number of vertices, and instance count,
113 * assuming that no geometry shading is done and primitive restart is not
116 * This is used by driver back-ends in implementing the PRIMITIVES_GENERATED
117 * and TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN queries. It is also used to
118 * pre-validate draw calls in GLES3 (where draw calls only succeed if there is
119 * enough room in the transform feedback buffer for the result).
122 vbo_count_tessellated_primitives(GLenum mode
, GLuint count
,
123 GLuint num_instances
)
125 size_t num_primitives
;
128 num_primitives
= count
;
131 num_primitives
= count
>= 2 ? count
- 1 : 0;
134 num_primitives
= count
>= 2 ? count
: 0;
137 num_primitives
= count
/ 2;
139 case GL_TRIANGLE_STRIP
:
140 case GL_TRIANGLE_FAN
:
142 num_primitives
= count
>= 3 ? count
- 2 : 0;
145 num_primitives
= count
/ 3;
148 num_primitives
= count
>= 4 ? ((count
/ 2) - 1) * 2 : 0;
151 num_primitives
= (count
/ 4) * 2;
154 assert(!"Unexpected primitive type in count_tessellated_primitives");
158 return num_primitives
* num_instances
;
164 * In some degenarate cases we can improve our ability to merge
165 * consecutive primitives. For example:
166 * glBegin(GL_LINE_STRIP);
170 * glBegin(GL_LINE_STRIP);
174 * Can be merged as a GL_LINES prim with four vertices.
176 * This function converts 2-vertex line strips/loops into GL_LINES, etc.
179 vbo_try_prim_conversion(struct _mesa_prim
*p
)
181 if (p
->mode
== GL_LINE_STRIP
&& p
->count
== 2) {
182 /* convert 2-vertex line strip to a separate line */
185 else if ((p
->mode
== GL_TRIANGLE_STRIP
|| p
->mode
== GL_TRIANGLE_FAN
)
187 /* convert 3-vertex tri strip or fan to a separate triangle */
188 p
->mode
= GL_TRIANGLES
;
191 /* Note: we can't convert a 4-vertex quad strip to a separate quad
192 * because the vertex ordering is different. We'd have to muck
193 * around in the vertex data to make it work.
199 * Helper function for determining if two subsequent glBegin/glEnd
200 * primitives can be combined. This is only possible for GL_POINTS,
201 * GL_LINES, GL_TRIANGLES and GL_QUADS.
202 * If we return true, it means that we can concatenate p1 onto p0 (and
206 vbo_can_merge_prims(const struct _mesa_prim
*p0
, const struct _mesa_prim
*p1
)
214 /* The prim mode must match (ex: both GL_TRIANGLES) */
215 if (p0
->mode
!= p1
->mode
)
218 /* p1's vertices must come right after p0 */
219 if (p0
->start
+ p0
->count
!= p1
->start
)
222 if (p0
->basevertex
!= p1
->basevertex
||
223 p0
->num_instances
!= p1
->num_instances
||
224 p0
->base_instance
!= p1
->base_instance
)
227 /* can always merge subsequent GL_POINTS primitives */
228 if (p0
->mode
== GL_POINTS
)
231 /* independent lines with no extra vertices */
232 if (p0
->mode
== GL_LINES
&& p0
->count
% 2 == 0 && p1
->count
% 2 == 0)
235 /* independent tris */
236 if (p0
->mode
== GL_TRIANGLES
&& p0
->count
% 3 == 0 && p1
->count
% 3 == 0)
239 /* independent quads */
240 if (p0
->mode
== GL_QUADS
&& p0
->count
% 4 == 0 && p1
->count
% 4 == 0)
248 * If we've determined that p0 and p1 can be merged, this function
249 * concatenates p1 onto p0.
252 vbo_merge_prims(struct _mesa_prim
*p0
, const struct _mesa_prim
*p1
)
254 assert(vbo_can_merge_prims(p0
, p1
));
256 p0
->count
+= p1
->count
;