vbo_rebase.c revision 43873b53c4d15f10f0321c770b1b8bd537cc226d
1 2/* 3 * Mesa 3-D graphics library 4 * Version: 6.5 5 * 6 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved. 7 * 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: 14 * 15 * The above copyright notice and this permission notice shall be included 16 * in all copies or substantial portions of the Software. 17 * 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. 24 * 25 * Authors: 26 * Keith Whitwell <keith@tungstengraphics.com> 27 */ 28 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. 39 * 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 42 * region. 43 * 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 46 * of zero. 47 */ 48 49#include "main/glheader.h" 50#include "main/imports.h" 51#include "main/mtypes.h" 52 53#include "vbo.h" 54 55 56#define REBASE(TYPE) \ 57static void *rebase_##TYPE( const void *ptr, \ 58 GLuint count, \ 59 TYPE min_index ) \ 60{ \ 61 const TYPE *in = (TYPE *)ptr; \ 62 TYPE *tmp_indices = malloc(count * sizeof(TYPE)); \ 63 GLuint i; \ 64 \ 65 for (i = 0; i < count; i++) \ 66 tmp_indices[i] = in[i] - min_index; \ 67 \ 68 return (void *)tmp_indices; \ 69} 70 71 72REBASE(GLuint) 73REBASE(GLushort) 74REBASE(GLubyte) 75 76GLboolean vbo_all_varyings_in_vbos( const struct gl_client_array *arrays[] ) 77{ 78 GLuint i; 79 80 for (i = 0; i < VERT_ATTRIB_MAX; i++) 81 if (arrays[i]->StrideB && 82 arrays[i]->BufferObj->Name == 0) 83 return GL_FALSE; 84 85 return GL_TRUE; 86} 87 88GLboolean vbo_any_varyings_in_vbos( const struct gl_client_array *arrays[] ) 89{ 90 GLuint i; 91 92 for (i = 0; i < VERT_ATTRIB_MAX; i++) 93 if (arrays[i]->StrideB && 94 arrays[i]->BufferObj->Name != 0) 95 return GL_TRUE; 96 97 return GL_FALSE; 98} 99 100/* Adjust primitives, indices and vertex definitions so that min_index 101 * becomes zero. There are lots of reasons for wanting to do this, eg: 102 * 103 * Software tnl: 104 * - any time min_index != 0, otherwise unused vertices lower than 105 * min_index will be transformed. 106 * 107 * Hardware tnl: 108 * - if ib != NULL and min_index != 0, otherwise vertices lower than 109 * min_index will be uploaded. Requires adjusting index values. 110 * 111 * - if ib == NULL and min_index != 0, just for convenience so this doesn't 112 * have to be handled within the driver. 113 * 114 * Hardware tnl with VBO support: 115 * - as above, but only when vertices are not (all?) in VBO's. 116 * - can't save time by trying to upload half a vbo - typically it is 117 * all or nothing. 118 */ 119void vbo_rebase_prims( GLcontext *ctx, 120 const struct gl_client_array *arrays[], 121 const struct _mesa_prim *prim, 122 GLuint nr_prims, 123 const struct _mesa_index_buffer *ib, 124 GLuint min_index, 125 GLuint max_index, 126 vbo_draw_func draw ) 127{ 128 struct gl_client_array tmp_arrays[VERT_ATTRIB_MAX]; 129 const struct gl_client_array *tmp_array_pointers[VERT_ATTRIB_MAX]; 130 131 struct _mesa_index_buffer tmp_ib; 132 struct _mesa_prim *tmp_prims = NULL; 133 void *tmp_indices = NULL; 134 GLuint i; 135 136 assert(min_index != 0); 137 138 if (0) 139 printf("%s %d..%d\n", __FUNCTION__, min_index, max_index); 140 141 142 /* XXX this path is disabled for now. 143 * There's rendering corruption in some apps when it's enabled. 144 */ 145 if (0 && ib && ctx->Extensions.ARB_draw_elements_base_vertex) { 146 /* If we can just tell the hardware or the TNL to interpret our 147 * indices with a different base, do so. 148 */ 149 tmp_prims = (struct _mesa_prim *)malloc(sizeof(*prim) * nr_prims); 150 151 for (i = 0; i < nr_prims; i++) { 152 tmp_prims[i] = prim[i]; 153 tmp_prims[i].basevertex -= min_index; 154 } 155 156 prim = tmp_prims; 157 } else if (ib) { 158 /* Unfortunately need to adjust each index individually. 159 */ 160 GLboolean map_ib = ib->obj->Name && !ib->obj->Pointer; 161 void *ptr; 162 163 if (map_ib) 164 ctx->Driver.MapBuffer(ctx, 165 GL_ELEMENT_ARRAY_BUFFER, 166 GL_READ_ONLY_ARB, 167 ib->obj); 168 169 170 ptr = ADD_POINTERS(ib->obj->Pointer, ib->ptr); 171 172 /* Some users might prefer it if we translated elements to 173 * GLuints here. Others wouldn't... 174 */ 175 switch (ib->type) { 176 case GL_UNSIGNED_INT: 177 tmp_indices = rebase_GLuint( ptr, ib->count, min_index ); 178 break; 179 case GL_UNSIGNED_SHORT: 180 tmp_indices = rebase_GLushort( ptr, ib->count, min_index ); 181 break; 182 case GL_UNSIGNED_BYTE: 183 tmp_indices = rebase_GLubyte( ptr, ib->count, min_index ); 184 break; 185 } 186 187 if (map_ib) 188 ctx->Driver.UnmapBuffer(ctx, 189 GL_ELEMENT_ARRAY_BUFFER, 190 ib->obj); 191 192 tmp_ib.obj = ctx->Shared->NullBufferObj; 193 tmp_ib.ptr = tmp_indices; 194 tmp_ib.count = ib->count; 195 tmp_ib.type = ib->type; 196 197 ib = &tmp_ib; 198 } 199 else { 200 /* Otherwise the primitives need adjustment. 201 */ 202 tmp_prims = (struct _mesa_prim *)malloc(sizeof(*prim) * nr_prims); 203 204 for (i = 0; i < nr_prims; i++) { 205 /* If this fails, it could indicate an application error: 206 */ 207 assert(prim[i].start >= min_index); 208 209 tmp_prims[i] = prim[i]; 210 tmp_prims[i].start -= min_index; 211 } 212 213 prim = tmp_prims; 214 } 215 216 /* Just need to adjust the pointer values on each incoming array. 217 * This works for VBO and non-vbo rendering and shouldn't pesimize 218 * VBO-based upload schemes. However this may still not be a fast 219 * path for hardware tnl for VBO based rendering as most machines 220 * will be happier if you just specify a starting vertex value in 221 * each primitive. 222 * 223 * For drivers with hardware tnl, you only want to do this if you 224 * are forced to, eg non-VBO indexed rendering with start != 0. 225 */ 226 for (i = 0; i < VERT_ATTRIB_MAX; i++) { 227 tmp_arrays[i] = *arrays[i]; 228 tmp_arrays[i].Ptr += min_index * tmp_arrays[i].StrideB; 229 tmp_array_pointers[i] = &tmp_arrays[i]; 230 } 231 232 /* Re-issue the draw call. 233 */ 234 draw( ctx, 235 tmp_array_pointers, 236 prim, 237 nr_prims, 238 ib, 239 GL_TRUE, 240 0, 241 max_index - min_index ); 242 243 if (tmp_indices) 244 free(tmp_indices); 245 246 if (tmp_prims) 247 free(tmp_prims); 248} 249 250 251 252