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;