src/mesa/vbo/vbo_split_inplace.c

   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
  30 #include "main/mtypes.h"
  31 #include "main/macros.h"
  32 #include "main/enums.h"
  33 #include "main/image.h"
  34 #include "vbo_split.h"
  35
  36
  37 #define MAX_PRIM 32
  38
  39 /* Used for splitting without copying. No attempt is made to handle
  40  * too large indexed vertex buffers: In general you need to copy to do
  41  * that.
  42  */
  43 struct split_context {
  44    struct gl_context *ctx;
  45    const struct gl_client_array **array;
  46    const struct _mesa_prim *prim;
  47    GLuint nr_prims;
  48    const struct _mesa_index_buffer *ib;
  49    GLuint min_index;
  50    GLuint max_index;
  51    vbo_draw_func draw;
  52
  53    const struct split_limits *limits;
  54    GLuint limit;
  55
  56    struct _mesa_prim dstprim[MAX_PRIM];
  57    GLuint dstprim_nr;
  58 };
  59
  60
  61
  62
  63 static void flush_vertex( struct split_context *split )
  64 {
  65    struct _mesa_index_buffer ib;
  66    GLuint i;
  67
  68    if (!split->dstprim_nr)
  69       return;
  70
  71    if (split->ib) {
  72       ib = *split->ib;
  73
  74       ib.count = split->max_index - split->min_index + 1;
  75       ib.ptr = (const void *)((const char *)ib.ptr +
  76                               split->min_index * _mesa_sizeof_type(ib.type));
  77
  78       /* Rebase the primitives to save index buffer entries. */
  79       for (i = 0; i < split->dstprim_nr; i++)
  80          split->dstprim[i].start -= split->min_index;
  81    }
  82
  83    assert(split->max_index >= split->min_index);
  84
  85    split->draw(split->ctx,
  86                split->array,
  87                split->dstprim,
  88                split->dstprim_nr,
  89                split->ib ? &ib : NULL,
  90                !split->ib,
  91                split->min_index,
  92                split->max_index,
  93                NULL);
  94
  95    split->dstprim_nr = 0;
  96    split->min_index = ~0;
  97    split->max_index = 0;
  98 }
  99
 100
 101 static struct _mesa_prim *next_outprim( struct split_context *split )
 102 {
 103    if (split->dstprim_nr == MAX_PRIM-1) {
 104       flush_vertex(split);
 105    }
 106
 107    {
 108       struct _mesa_prim *prim = &split->dstprim[split->dstprim_nr++];
 109       memset(prim, 0, sizeof(*prim));
 110       return prim;
 111    }
 112 }
 113
 114 static void update_index_bounds(struct split_context *split,
 115                                 const struct _mesa_prim *prim)
 116 {
 117    split->min_index = MIN2(split->min_index, prim->start);
 118    split->max_index = MAX2(split->max_index, prim->start + prim->count - 1);
 119 }
 120
 121 /* Return the maximum amount of vertices that can be emitted for a
 122  * primitive starting at 'prim->start', depending on the previous
 123  * index bounds.
 124  */
 125 static GLuint get_max_vertices(struct split_context *split,
 126                                const struct _mesa_prim *prim)
 127 {
 128    if ((prim->start > split->min_index &&
 129         prim->start - split->min_index >= split->limit) ||
 130        (prim->start < split->max_index &&
 131         split->max_index - prim->start >= split->limit))
 132       /* "prim" starts too far away from the old range. */
 133       return 0;
 134
 135    return MIN2(split->min_index, prim->start) + split->limit - prim->start;
 136 }
 137
 138 /* Break large primitives into smaller ones.  If not possible, convert
 139  * the primitive to indexed and pass to split_elts().
 140  */
 141 static void split_prims( struct split_context *split)
 142 {
 143    GLuint i;
 144
 145    for (i = 0; i < split->nr_prims; i++) {
 146       const struct _mesa_prim *prim = &split->prim[i];
 147       GLuint first, incr;
 148       GLboolean split_inplace = split_prim_inplace(prim->mode, &first, &incr);
 149       GLuint available = get_max_vertices(split, prim);
 150       GLuint count = prim->count - (prim->count - first) % incr;
 151
 152       if (prim->count < first)
 153          continue;
 154
 155       if ((available < count && !split_inplace) ||
 156           (available < first && split_inplace)) {
 157          flush_vertex(split);
 158          available = get_max_vertices(split, prim);
 159       }
 160
 161       if (available >= count) {
 162          struct _mesa_prim *outprim = next_outprim(split);
 163
 164          *outprim = *prim;
 165          update_index_bounds(split, outprim);
 166       }
 167       else if (split_inplace) {
 168          GLuint j, nr;
 169
 170          for (j = 0 ; j < count ; ) {
 171             GLuint remaining = count - j;
 172             struct _mesa_prim *outprim = next_outprim(split);
 173
 174             nr = MIN2( available, remaining );
 175             nr -= (nr - first) % incr;
 176
 177             outprim->mode = prim->mode;
 178             outprim->begin = (j == 0 && prim->begin);
 179             outprim->end = (nr == remaining && prim->end);
 180             outprim->start = prim->start + j;
 181             outprim->count = nr;
 182             outprim->num_instances = prim->num_instances;
 183
 184             update_index_bounds(split, outprim);
 185
 186             if (nr == remaining) {
 187                /* Finished.
 188                 */
 189                j += nr;
 190             }
 191             else {
 192                /* Wrapped the primitive:
 193                 */
 194                j += nr - (first - incr);
 195                flush_vertex(split);
 196                available = get_max_vertices(split, prim);
 197             }
 198          }
 199       }
 200       else if (split->ib == NULL) {
 201          /* XXX: could at least send the first max_verts off from the
 202           * inplace buffers.
 203           */
 204
 205          /* else convert to indexed primitive and pass to split_elts,
 206           * which will do the necessary copying and turn it back into a
 207           * vertex primitive for rendering...
 208           */
 209          struct _mesa_index_buffer ib;
 210          struct _mesa_prim tmpprim;
 211          GLuint *elts = malloc(count * sizeof(GLuint));
 212          GLuint j;
 213
 214          for (j = 0; j < count; j++)
 215             elts[j] = prim->start + j;
 216
 217          ib.count = count;
 218          ib.type = GL_UNSIGNED_INT;
 219          ib.obj = split->ctx->Shared->NullBufferObj;
 220          ib.ptr = elts;
 221
 222          tmpprim = *prim;
 223          tmpprim.indexed = 1;
 224          tmpprim.start = 0;
 225          tmpprim.count = count;
 226          tmpprim.num_instances = 1;
 227
 228          flush_vertex(split);
 229
 230          vbo_split_copy(split->ctx,
 231                         split->array,
 232                         &tmpprim, 1,
 233                         &ib,
 234                         split->draw,
 235                         split->limits);
 236
 237          free(elts);
 238       }
 239       else {
 240          flush_vertex(split);
 241
 242          vbo_split_copy(split->ctx,
 243                         split->array,
 244                         prim, 1,
 245                         split->ib,
 246                         split->draw,
 247                         split->limits);
 248       }
 249    }
 250
 251    flush_vertex(split);
 252 }
 253
 254
 255 void vbo_split_inplace( struct gl_context *ctx,
 256                         const struct gl_client_array *arrays[],
 257                         const struct _mesa_prim *prim,
 258                         GLuint nr_prims,
 259                         const struct _mesa_index_buffer *ib,
 260                         GLuint min_index,
 261                         GLuint max_index,
 262                         vbo_draw_func draw,
 263                         const struct split_limits *limits )
 264 {
 265    struct split_context split;
 266
 267    memset(&split, 0, sizeof(split));
 268
 269    split.ctx = ctx;
 270    split.array = arrays;
 271    split.prim = prim;
 272    split.nr_prims = nr_prims;
 273    split.ib = ib;
 274
 275    /* Empty interval, makes calculations simpler. */
 276    split.min_index = ~0;
 277    split.max_index = 0;
 278
 279    split.draw = draw;
 280    split.limits = limits;
 281    split.limit = ib ? limits->max_indices : limits->max_verts;
 282
 283    split_prims( &split );
 284 }
 285
 286