1 /* 2 * Copyright 2007 VMware, Inc. 3 * All Rights Reserved. 4 * 5 * Copyright 2012 Intel Corporation 6 * 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: 13 * 14 * The above copyright notice and this permission notice (including the next 15 * paragraph) shall be included in all copies or substantial portions of the 16 * Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 24 * IN THE SOFTWARE. 25 * 26 * Authors: 27 * Jordan Justen <jordan.l.justen (at) intel.com> 28 * 29 */ 30 31 #include "main/imports.h" 32 #include "main/bufferobj.h" 33 #include "main/macros.h" 34 #include "main/varray.h" 35 36 #include "vbo.h" 37 #include "vbo_context.h" 38 39 #define UPDATE_MIN2(a, b) (a) = MIN2((a), (b)) 40 #define UPDATE_MAX2(a, b) (a) = MAX2((a), (b)) 41 42 /* 43 * Notes on primitive restart: 44 * The code below is used when the driver does not fully support primitive 45 * restart (for example, if it only does restart index of ~0). 46 * 47 * We map the index buffer, find the restart indexes, unmap 48 * the index buffer then draw the sub-primitives delineated by the restarts. 49 * 50 * A couple possible optimizations: 51 * 1. Save the list of sub-primitive (start, count) values in a list attached 52 * to the index buffer for re-use in subsequent draws. The list would be 53 * invalidated when the contents of the buffer changed. 54 * 2. If drawing triangle strips or quad strips, create a new index buffer 55 * that uses duplicated vertices to render the disjoint strips as one 56 * long strip. We'd have to be careful to avoid using too much memory 57 * for this. 58 * 59 * Finally, some apps might perform better if they don't use primitive restart 60 * at all rather than this fallback path. Set MESA_EXTENSION_OVERRIDE to 61 * "-GL_NV_primitive_restart" to test that. 62 */ 63 64 65 struct sub_primitive 66 { 67 GLuint start; 68 GLuint count; 69 GLuint min_index; 70 GLuint max_index; 71 }; 72 73 74 /** 75 * Scan the elements array to find restart indexes. Return an array 76 * of struct sub_primitive to indicate how to draw the sub-primitives 77 * are delineated by the restart index. 78 */ 79 static struct sub_primitive * 80 find_sub_primitives(const void *elements, unsigned element_size, 81 unsigned start, unsigned end, unsigned restart_index, 82 unsigned *num_sub_prims) 83 { 84 const unsigned max_prims = end - start; 85 struct sub_primitive *sub_prims; 86 unsigned i, cur_start, cur_count; 87 GLuint scan_index; 88 unsigned scan_num; 89 90 sub_prims = 91 malloc(max_prims * sizeof(struct sub_primitive)); 92 93 if (!sub_prims) { 94 *num_sub_prims = 0; 95 return NULL; 96 } 97 98 cur_start = start; 99 cur_count = 0; 100 scan_num = 0; 101 102 #define IB_INDEX_READ(TYPE, INDEX) (((const GL##TYPE *) elements)[INDEX]) 103 104 #define SCAN_ELEMENTS(TYPE) \ 105 sub_prims[scan_num].min_index = (GL##TYPE) 0xffffffff; \ 106 sub_prims[scan_num].max_index = 0; \ 107 for (i = start; i < end; i++) { \ 108 scan_index = IB_INDEX_READ(TYPE, i); \ 109 if (scan_index == restart_index) { \ 110 if (cur_count > 0) { \ 111 assert(scan_num < max_prims); \ 112 sub_prims[scan_num].start = cur_start; \ 113 sub_prims[scan_num].count = cur_count; \ 114 scan_num++; \ 115 sub_prims[scan_num].min_index = (GL##TYPE) 0xffffffff; \ 116 sub_prims[scan_num].max_index = 0; \ 117 } \ 118 cur_start = i + 1; \ 119 cur_count = 0; \ 120 } \ 121 else { \ 122 UPDATE_MIN2(sub_prims[scan_num].min_index, scan_index); \ 123 UPDATE_MAX2(sub_prims[scan_num].max_index, scan_index); \ 124 cur_count++; \ 125 } \ 126 } \ 127 if (cur_count > 0) { \ 128 assert(scan_num < max_prims); \ 129 sub_prims[scan_num].start = cur_start; \ 130 sub_prims[scan_num].count = cur_count; \ 131 scan_num++; \ 132 } 133 134 switch (element_size) { 135 case 1: 136 SCAN_ELEMENTS(ubyte); 137 break; 138 case 2: 139 SCAN_ELEMENTS(ushort); 140 break; 141 case 4: 142 SCAN_ELEMENTS(uint); 143 break; 144 default: 145 assert(0 && "bad index_size in find_sub_primitives()"); 146 } 147 148 #undef SCAN_ELEMENTS 149 150 *num_sub_prims = scan_num; 151 152 return sub_prims; 153 } 154 155 156 /** 157 * Handle primitive restart in software. 158 * 159 * This function breaks up calls into the driver so primitive restart 160 * support is not required in the driver. 161 */ 162 void 163 vbo_sw_primitive_restart(struct gl_context *ctx, 164 const struct _mesa_prim *prims, 165 GLuint nr_prims, 166 const struct _mesa_index_buffer *ib, 167 struct gl_buffer_object *indirect) 168 { 169 GLuint prim_num; 170 struct _mesa_prim new_prim; 171 struct _mesa_index_buffer new_ib; 172 struct sub_primitive *sub_prims; 173 struct sub_primitive *sub_prim; 174 GLuint num_sub_prims; 175 GLuint sub_prim_num; 176 GLuint end_index; 177 GLuint sub_end_index; 178 GLuint restart_index = _mesa_primitive_restart_index(ctx, ib->index_size); 179 struct _mesa_prim temp_prim; 180 struct vbo_context *vbo = vbo_context(ctx); 181 vbo_draw_func draw_prims_func = vbo->draw_prims; 182 GLboolean map_ib = ib->obj->Name && !ib->obj->Mappings[MAP_INTERNAL].Pointer; 183 void *ptr; 184 185 /* If there is an indirect buffer, map it and extract the draw params */ 186 if (indirect && prims[0].is_indirect) { 187 const uint32_t *indirect_params; 188 if (!ctx->Driver.MapBufferRange(ctx, 0, indirect->Size, GL_MAP_READ_BIT, 189 indirect, MAP_INTERNAL)) { 190 191 /* something went wrong with mapping, give up */ 192 _mesa_error(ctx, GL_OUT_OF_MEMORY, 193 "failed to map indirect buffer for sw primitive restart"); 194 return; 195 } 196 197 assert(nr_prims == 1); 198 new_prim = prims[0]; 199 indirect_params = (const uint32_t *) 200 ADD_POINTERS(indirect->Mappings[MAP_INTERNAL].Pointer, 201 new_prim.indirect_offset); 202 203 new_prim.is_indirect = 0; 204 new_prim.count = indirect_params[0]; 205 new_prim.num_instances = indirect_params[1]; 206 new_prim.start = indirect_params[2]; 207 new_prim.basevertex = indirect_params[3]; 208 new_prim.base_instance = indirect_params[4]; 209 210 new_ib = *ib; 211 new_ib.count = new_prim.count; 212 213 prims = &new_prim; 214 ib = &new_ib; 215 216 ctx->Driver.UnmapBuffer(ctx, indirect, MAP_INTERNAL); 217 } 218 219 /* Find the sub-primitives. These are regions in the index buffer which 220 * are split based on the primitive restart index value. 221 */ 222 if (map_ib) { 223 ctx->Driver.MapBufferRange(ctx, 0, ib->obj->Size, GL_MAP_READ_BIT, 224 ib->obj, MAP_INTERNAL); 225 } 226 227 ptr = ADD_POINTERS(ib->obj->Mappings[MAP_INTERNAL].Pointer, ib->ptr); 228 229 sub_prims = find_sub_primitives(ptr, ib->index_size, 230 0, ib->count, restart_index, 231 &num_sub_prims); 232 233 if (map_ib) { 234 ctx->Driver.UnmapBuffer(ctx, ib->obj, MAP_INTERNAL); 235 } 236 237 /* Loop over the primitives, and use the located sub-primitives to draw 238 * each primitive with a break to implement each primitive restart. 239 */ 240 for (prim_num = 0; prim_num < nr_prims; prim_num++) { 241 end_index = prims[prim_num].start + prims[prim_num].count; 242 memcpy(&temp_prim, &prims[prim_num], sizeof (temp_prim)); 243 /* Loop over the sub-primitives drawing sub-ranges of the primitive. */ 244 for (sub_prim_num = 0; sub_prim_num < num_sub_prims; sub_prim_num++) { 245 sub_prim = &sub_prims[sub_prim_num]; 246 sub_end_index = sub_prim->start + sub_prim->count; 247 if (prims[prim_num].start <= sub_prim->start) { 248 temp_prim.start = MAX2(prims[prim_num].start, sub_prim->start); 249 temp_prim.count = MIN2(sub_end_index, end_index) - temp_prim.start; 250 if ((temp_prim.start == sub_prim->start) && 251 (temp_prim.count == sub_prim->count)) { 252 draw_prims_func(ctx, &temp_prim, 1, ib, 253 GL_TRUE, sub_prim->min_index, sub_prim->max_index, 254 NULL, 0, NULL); 255 } else { 256 draw_prims_func(ctx, &temp_prim, 1, ib, 257 GL_FALSE, -1, -1, 258 NULL, 0, NULL); 259 } 260 } 261 if (sub_end_index >= end_index) { 262 break; 263 } 264 } 265 } 266 267 free(sub_prims); 268 } 269 270
