3 * Mesa 3-D graphics library
6 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
15 * The above copyright notice and this permission notice shall be included
16 * in all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
22 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
23 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 * Keith Whitwell <keith@tungstengraphics.com>
29 /* Helper for drivers which find themselves rendering a range of
30 * indices starting somewhere above zero. Typically the application
31 * is issuing multiple DrawArrays() or DrawElements() to draw
32 * successive primitives layed out linearly in the vertex arrays.
33 * Unless the vertex arrays are all in a VBO, the OpenGL semantics
34 * imply that we need to re-upload the vertex data on each draw call.
35 * In that case, we want to avoid starting the upload at zero, as it
36 * will mean every draw call uploads an increasing amount of not-used
37 * vertex data. Worse - in the software tnl module, all those
38 * vertices will be transformed and lit.
40 * If we just upload the new data, however, the indices will be
41 * incorrect as we tend to upload each set of vertex data to a new
44 * This file provides a helper to adjust the arrays, primitives and
45 * indices of a draw call so that it can be re-issued with a min_index
49 #include "main/glheader.h"
50 #include "main/imports.h"
51 #include "main/mtypes.h"
56 #define REBASE(TYPE) \
57 static void *rebase_##TYPE( const void *ptr, \
61 const TYPE *in = (TYPE *)ptr; \
62 TYPE *tmp_indices = malloc(count * sizeof(TYPE)); \
65 for (i = 0; i < count; i++) \
66 tmp_indices[i] = in[i] - min_index; \
68 return (void *)tmp_indices; \
76 GLboolean vbo_all_varyings_in_vbos( const struct gl_client_array *arrays[] )
80 for (i = 0; i < VERT_ATTRIB_MAX; i++)
81 if (arrays[i]->BufferObj->Name == 0)
87 GLboolean vbo_any_varyings_in_vbos( const struct gl_client_array *arrays[] )
91 for (i = 0; i < VERT_ATTRIB_MAX; i++)
92 if (arrays[i]->BufferObj->Name != 0)
98 /* Adjust primitives, indices and vertex definitions so that min_index
99 * becomes zero. There are lots of reasons for wanting to do this, eg:
102 * - any time min_index != 0, otherwise unused vertices lower than
103 * min_index will be transformed.
106 * - if ib != NULL and min_index != 0, otherwise vertices lower than
107 * min_index will be uploaded. Requires adjusting index values.
109 * - if ib == NULL and min_index != 0, just for convenience so this doesn't
110 * have to be handled within the driver.
112 * Hardware tnl with VBO support:
113 * - as above, but only when vertices are not (all?) in VBO's.
114 * - can't save time by trying to upload half a vbo - typically it is
117 void vbo_rebase_prims( struct gl_context *ctx,
118 const struct gl_client_array *arrays[],
119 const struct _mesa_prim *prim,
121 const struct _mesa_index_buffer *ib,
126 struct gl_client_array tmp_arrays[VERT_ATTRIB_MAX];
127 const struct gl_client_array *tmp_array_pointers[VERT_ATTRIB_MAX];
129 struct _mesa_index_buffer tmp_ib;
130 struct _mesa_prim *tmp_prims = NULL;
131 void *tmp_indices = NULL;
134 assert(min_index != 0);
137 printf("%s %d..%d\n", __FUNCTION__, min_index, max_index);
140 /* XXX this path is disabled for now.
141 * There's rendering corruption in some apps when it's enabled.
143 if (0 && ib && ctx->Extensions.ARB_draw_elements_base_vertex) {
144 /* If we can just tell the hardware or the TNL to interpret our
145 * indices with a different base, do so.
147 tmp_prims = (struct _mesa_prim *)malloc(sizeof(*prim) * nr_prims);
149 for (i = 0; i < nr_prims; i++) {
150 tmp_prims[i] = prim[i];
151 tmp_prims[i].basevertex -= min_index;
156 /* Unfortunately need to adjust each index individually.
158 GLboolean map_ib = ib->obj->Name && !ib->obj->Pointer;
162 ctx->Driver.MapBuffer(ctx,
163 GL_ELEMENT_ARRAY_BUFFER,
168 ptr = ADD_POINTERS(ib->obj->Pointer, ib->ptr);
170 /* Some users might prefer it if we translated elements to
171 * GLuints here. Others wouldn't...
174 case GL_UNSIGNED_INT:
175 tmp_indices = rebase_GLuint( ptr, ib->count, min_index );
177 case GL_UNSIGNED_SHORT:
178 tmp_indices = rebase_GLushort( ptr, ib->count, min_index );
180 case GL_UNSIGNED_BYTE:
181 tmp_indices = rebase_GLubyte( ptr, ib->count, min_index );
186 ctx->Driver.UnmapBuffer(ctx,
187 GL_ELEMENT_ARRAY_BUFFER,
190 tmp_ib.obj = ctx->Shared->NullBufferObj;
191 tmp_ib.ptr = tmp_indices;
192 tmp_ib.count = ib->count;
193 tmp_ib.type = ib->type;
198 /* Otherwise the primitives need adjustment.
200 tmp_prims = (struct _mesa_prim *)malloc(sizeof(*prim) * nr_prims);
202 for (i = 0; i < nr_prims; i++) {
203 /* If this fails, it could indicate an application error:
205 assert(prim[i].start >= min_index);
207 tmp_prims[i] = prim[i];
208 tmp_prims[i].start -= min_index;
214 /* Just need to adjust the pointer values on each incoming array.
215 * This works for VBO and non-vbo rendering and shouldn't pesimize
216 * VBO-based upload schemes. However this may still not be a fast
217 * path for hardware tnl for VBO based rendering as most machines
218 * will be happier if you just specify a starting vertex value in
221 * For drivers with hardware tnl, you only want to do this if you
222 * are forced to, eg non-VBO indexed rendering with start != 0.
224 for (i = 0; i < VERT_ATTRIB_MAX; i++) {
225 tmp_arrays[i] = *arrays[i];
226 tmp_arrays[i].Ptr += min_index * tmp_arrays[i].StrideB;
227 tmp_array_pointers[i] = &tmp_arrays[i];
230 /* Re-issue the draw call.
239 max_index - min_index );