summaryrefslogtreecommitdiffstats
path: root/src/mesa/state_tracker/st_draw.c
blob: 20af90df7d848d4b37d05a610d7e64bc5f7c6790 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
/**************************************************************************
 * 
 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * 
 **************************************************************************/

 /*
  * Authors:
  *   Keith Whitwell <keith@tungstengraphics.com>
  */

#include "main/imports.h"
#include "main/image.h"

#include "vbo/vbo.h"

#include "st_atom.h"
#include "st_context.h"
#include "st_cb_bufferobjects.h"
#include "st_draw.h"
#include "st_program.h"

#include "pipe/p_context.h"
#include "pipe/p_defines.h"
#include "pipe/p_winsys.h"
#include "pipe/p_inlines.h"

#include "draw/draw_private.h"
#include "draw/draw_context.h"


static GLuint double_types[4] = {
   PIPE_FORMAT_R64_FLOAT,
   PIPE_FORMAT_R64G64_FLOAT,
   PIPE_FORMAT_R64G64B64_FLOAT,
   PIPE_FORMAT_R64G64B64A64_FLOAT
};

static GLuint float_types[4] = {
   PIPE_FORMAT_R32_FLOAT,
   PIPE_FORMAT_R32G32_FLOAT,
   PIPE_FORMAT_R32G32B32_FLOAT,
   PIPE_FORMAT_R32G32B32A32_FLOAT
};

static GLuint uint_types_norm[4] = {
   PIPE_FORMAT_R32_UNORM,
   PIPE_FORMAT_R32G32_UNORM,
   PIPE_FORMAT_R32G32B32_UNORM,
   PIPE_FORMAT_R32G32B32A32_UNORM
};

static GLuint uint_types_scale[4] = {
   PIPE_FORMAT_R32_USCALED,
   PIPE_FORMAT_R32G32_USCALED,
   PIPE_FORMAT_R32G32B32_USCALED,
   PIPE_FORMAT_R32G32B32A32_USCALED
};

static GLuint int_types_norm[4] = {
   PIPE_FORMAT_R32_SNORM,
   PIPE_FORMAT_R32G32_SNORM,
   PIPE_FORMAT_R32G32B32_SNORM,
   PIPE_FORMAT_R32G32B32A32_SNORM
};

static GLuint int_types_scale[4] = {
   PIPE_FORMAT_R32_SSCALED,
   PIPE_FORMAT_R32G32_SSCALED,
   PIPE_FORMAT_R32G32B32_SSCALED,
   PIPE_FORMAT_R32G32B32A32_SSCALED
};

static GLuint ushort_types_norm[4] = {
   PIPE_FORMAT_R16_UNORM,
   PIPE_FORMAT_R16G16_UNORM,
   PIPE_FORMAT_R16G16B16_UNORM,
   PIPE_FORMAT_R16G16B16A16_UNORM
};

static GLuint ushort_types_scale[4] = {
   PIPE_FORMAT_R16_USCALED,
   PIPE_FORMAT_R16G16_USCALED,
   PIPE_FORMAT_R16G16B16_USCALED,
   PIPE_FORMAT_R16G16B16A16_USCALED
};

static GLuint short_types_norm[4] = {
   PIPE_FORMAT_R16_SNORM,
   PIPE_FORMAT_R16G16_SNORM,
   PIPE_FORMAT_R16G16B16_SNORM,
   PIPE_FORMAT_R16G16B16A16_SNORM
};

static GLuint short_types_scale[4] = {
   PIPE_FORMAT_R16_SSCALED,
   PIPE_FORMAT_R16G16_SSCALED,
   PIPE_FORMAT_R16G16B16_SSCALED,
   PIPE_FORMAT_R16G16B16A16_SSCALED
};

static GLuint ubyte_types_norm[4] = {
   PIPE_FORMAT_R8_UNORM,
   PIPE_FORMAT_R8G8_UNORM,
   PIPE_FORMAT_R8G8B8_UNORM,
   PIPE_FORMAT_R8G8B8A8_UNORM
};

static GLuint ubyte_types_scale[4] = {
   PIPE_FORMAT_R8_USCALED,
   PIPE_FORMAT_R8G8_USCALED,
   PIPE_FORMAT_R8G8B8_USCALED,
   PIPE_FORMAT_R8G8B8A8_USCALED
};

static GLuint byte_types_norm[4] = {
   PIPE_FORMAT_R8_SNORM,
   PIPE_FORMAT_R8G8_SNORM,
   PIPE_FORMAT_R8G8B8_SNORM,
   PIPE_FORMAT_R8G8B8A8_SNORM
};

static GLuint byte_types_scale[4] = {
   PIPE_FORMAT_R8_SSCALED,
   PIPE_FORMAT_R8G8_SSCALED,
   PIPE_FORMAT_R8G8B8_SSCALED,
   PIPE_FORMAT_R8G8B8A8_SSCALED
};


/**
 * Return a PIPE_FORMAT_x for the given GL datatype and size.
 */
static GLuint
pipe_vertex_format(GLenum type, GLuint size, GLboolean normalized)
{
   assert(type >= GL_BYTE);
   assert(type <= GL_DOUBLE);
   assert(size >= 1);
   assert(size <= 4);

   if (normalized) {
      switch (type) {
      case GL_DOUBLE: return double_types[size-1];
      case GL_FLOAT: return float_types[size-1];
      case GL_INT: return int_types_norm[size-1];
      case GL_SHORT: return short_types_norm[size-1];
      case GL_BYTE: return byte_types_norm[size-1];
      case GL_UNSIGNED_INT: return uint_types_norm[size-1];
      case GL_UNSIGNED_SHORT: return ushort_types_norm[size-1];
      case GL_UNSIGNED_BYTE: return ubyte_types_norm[size-1];
      default: assert(0); return 0;
      }      
   }
   else {
      switch (type) {
      case GL_DOUBLE: return double_types[size-1];
      case GL_FLOAT: return float_types[size-1];
      case GL_INT: return int_types_scale[size-1];
      case GL_SHORT: return short_types_scale[size-1];
      case GL_BYTE: return byte_types_scale[size-1];
      case GL_UNSIGNED_INT: return uint_types_scale[size-1];
      case GL_UNSIGNED_SHORT: return ushort_types_scale[size-1];
      case GL_UNSIGNED_BYTE: return ubyte_types_scale[size-1];
      default: assert(0); return 0;
      }      
   }
   return 0; /* silence compiler warning */
}


/**
 * This function gets plugged into the VBO module and is called when
 * we have something to render.
 * Basically, translate the information into the format expected by pipe.
 */
void
st_draw_vbo(GLcontext *ctx,
            const struct gl_client_array **arrays,
            const struct _mesa_prim *prims,
            GLuint nr_prims,
            const struct _mesa_index_buffer *ib,
            GLuint min_index,
            GLuint max_index)
{
   struct pipe_context *pipe = ctx->st->pipe;
   struct pipe_winsys *winsys = pipe->winsys;
   const struct st_vertex_program *vp;
   const struct pipe_shader_state *vs;
   struct pipe_vertex_buffer vbuffer[PIPE_MAX_SHADER_INPUTS];
   GLuint attr;

   /* sanity check for pointer arithmetic below */
   assert(sizeof(arrays[0]->Ptr[0]) == 1);

   st_validate_state(ctx->st);

   /* must get these after state validation! */
   vp = ctx->st->vp;
   vs = &ctx->st->vp->state;

   /* loop over TGSI shader inputs to determine vertex buffer
    * and attribute info
    */
   for (attr = 0; attr < vp->num_inputs; attr++) {
      const GLuint mesaAttr = vp->index_to_input[attr];
      struct gl_buffer_object *bufobj = arrays[mesaAttr]->BufferObj;
      struct pipe_vertex_element velement;

      if (bufobj && bufobj->Name) {
         /* Attribute data is in a VBO.
          * Recall that for VBOs, the gl_client_array->Ptr field is
          * really an offset from the start of the VBO, not a pointer.
          */
         struct st_buffer_object *stobj = st_buffer_object(bufobj);
         assert(stobj->buffer);

         vbuffer[attr].buffer = NULL;
         pipe_buffer_reference(winsys, &vbuffer[attr].buffer, stobj->buffer);
         vbuffer[attr].buffer_offset = (unsigned) arrays[0]->Ptr;/* in bytes */
         velement.src_offset = arrays[mesaAttr]->Ptr - arrays[0]->Ptr;
         assert(velement.src_offset <= 2048); /* 11-bit field */
      }
      else {
         /* attribute data is in user-space memory, not a VBO */
         uint bytes;
	
         if (!arrays[mesaAttr]->StrideB) {
            bytes = arrays[mesaAttr]->Size
                    * _mesa_sizeof_type(arrays[mesaAttr]->Type);
         } else {
            bytes = arrays[mesaAttr]->StrideB * (max_index + 1);
         }

         /* wrap user data */
         vbuffer[attr].buffer
            = winsys->user_buffer_create(winsys,
                                         (void *) arrays[mesaAttr]->Ptr,
                                         bytes);
         vbuffer[attr].buffer_offset = 0;
         velement.src_offset = 0;
      }

      /* common-case setup */
      vbuffer[attr].pitch = arrays[mesaAttr]->StrideB; /* in bytes */
      vbuffer[attr].max_index = max_index;
      velement.vertex_buffer_index = attr;
      velement.nr_components = arrays[mesaAttr]->Size;
      velement.src_format = pipe_vertex_format(arrays[mesaAttr]->Type,
                                               arrays[mesaAttr]->Size,
                                               arrays[mesaAttr]->Normalized);
      assert(velement.src_format);

      /* tell pipe about this attribute */
      pipe->set_vertex_buffer(pipe, attr, &vbuffer[attr]);
      pipe->set_vertex_element(pipe, attr, &velement);
   }


   /* do actual drawing */
   if (ib) {
      /* indexed primitive */
      struct gl_buffer_object *bufobj = ib->obj;
      struct pipe_buffer *indexBuf = NULL;
      unsigned indexSize, indexOffset, i;

      switch (ib->type) {
      case GL_UNSIGNED_INT:
         indexSize = 4;
         break;
      case GL_UNSIGNED_SHORT:
         indexSize = 2;
         break;
      case GL_UNSIGNED_BYTE:
         indexSize = 1;
         break;
      default:
         assert(0);
	 return;
      }

      /* get/create the index buffer object */
      if (bufobj && bufobj->Name) {
         /* elements/indexes are in a real VBO */
         struct st_buffer_object *stobj = st_buffer_object(bufobj);
         pipe_buffer_reference(winsys, &indexBuf, stobj->buffer);
         indexOffset = (unsigned) ib->ptr / indexSize;
      }
      else {
         /* element/indicies are in user space memory */
         indexBuf = winsys->user_buffer_create(winsys,
                                               (void *) ib->ptr,
                                               ib->count * indexSize);
         indexOffset = 0;
      }

      /* draw */
      for (i = 0; i < nr_prims; i++) {
         pipe->draw_elements(pipe, indexBuf, indexSize,
                             prims[i].mode,
                             prims[i].start + indexOffset, prims[i].count);
      }

      pipe_buffer_reference(winsys, &indexBuf, NULL);
   }
   else {
      /* non-indexed */
      GLuint i;
      for (i = 0; i < nr_prims; i++) {
         pipe->draw_arrays(pipe, prims[i].mode, prims[i].start, prims[i].count);
      }
   }

   /* unreference buffers (frees wrapped user-space buffer objects) */
   for (attr = 0; attr < vp->num_inputs; attr++) {
      pipe_buffer_reference(winsys, &vbuffer[attr].buffer, NULL);
      assert(!vbuffer[attr].buffer);
      pipe->set_vertex_buffer(pipe, attr, &vbuffer[attr]);
   }
}



/**
 * Utility function for drawing simple primitives (such as quads for
 * glClear and glDrawPixels).  Coordinates are in screen space.
 * \param mode  one of PIPE_PRIM_x
 * \param numVertex  number of vertices
 * \param verts  vertex data (all attributes are float[4])
 * \param numAttribs  number of attributes per vertex
 */
void 
st_draw_vertices(GLcontext *ctx, unsigned prim,
                 unsigned numVertex, float *verts,
                 unsigned numAttribs,
                 GLboolean inClipCoords)
{
   const float width = ctx->DrawBuffer->Width;
   const float height = ctx->DrawBuffer->Height;
   const unsigned vertex_bytes = numVertex * numAttribs * 4 * sizeof(float);
   struct pipe_context *pipe = ctx->st->pipe;
   struct pipe_buffer *vbuf;
   struct pipe_vertex_buffer vbuffer;
   struct pipe_vertex_element velement;
   unsigned i;

   assert(numAttribs > 0);

   if (!inClipCoords) {
      /* convert to clip coords */
      for (i = 0; i < numVertex; i++) {
         float x = verts[i * numAttribs * 4 + 0];
         float y = verts[i * numAttribs * 4 + 1];
         x = x / width * 2.0 - 1.0;
         y = y / height * 2.0 - 1.0;
         verts[i * numAttribs * 4 + 0] = x;
         verts[i * numAttribs * 4 + 1] = y;
      }
   }

   /* XXX create one-time */
   vbuf = pipe->winsys->buffer_create(pipe->winsys, 32,
                                      PIPE_BUFFER_USAGE_VERTEX, vertex_bytes);
   assert(vbuf);

   memcpy(pipe->winsys->buffer_map(pipe->winsys, vbuf,
                                   PIPE_BUFFER_USAGE_CPU_WRITE),
          verts, vertex_bytes);
   pipe->winsys->buffer_unmap(pipe->winsys, vbuf);

   /* tell pipe about the vertex buffer */
   vbuffer.buffer = vbuf;
   vbuffer.pitch = numAttribs * 4 * sizeof(float);  /* vertex size */
   vbuffer.buffer_offset = 0;
   pipe->set_vertex_buffer(pipe, 0, &vbuffer);

   /* tell pipe about the vertex attributes */
   for (i = 0; i < numAttribs; i++) {
      velement.src_offset = i * 4 * sizeof(GLfloat);
      velement.vertex_buffer_index = 0;
      velement.src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
      velement.nr_components = 4;
      pipe->set_vertex_element(pipe, i, &velement);
   }

   /* draw */
   pipe->draw_arrays(pipe, prim, 0, numVertex);

   /* XXX: do one-time */
   pipe_buffer_reference(pipe->winsys, &vbuf, NULL);
}


/**
 * Set the (private) draw module's post-transformed vertex format when in
 * GL_SELECT or GL_FEEDBACK mode or for glRasterPos.
 */
static void
set_feedback_vertex_format(GLcontext *ctx)
{
#if 0
   struct st_context *st = ctx->st;
   struct vertex_info vinfo;
   GLuint i;

   memset(&vinfo, 0, sizeof(vinfo));

   if (ctx->RenderMode == GL_SELECT) {
      assert(ctx->RenderMode == GL_SELECT);
      vinfo.num_attribs = 1;
      vinfo.format[0] = FORMAT_4F;
      vinfo.interp_mode[0] = INTERP_LINEAR;
   }
   else {
      /* GL_FEEDBACK, or glRasterPos */
      /* emit all attribs (pos, color, texcoord) as GLfloat[4] */
      vinfo.num_attribs = st->state.vs->cso->state.num_outputs;
      for (i = 0; i < vinfo.num_attribs; i++) {
         vinfo.format[i] = FORMAT_4F;
         vinfo.interp_mode[i] = INTERP_LINEAR;
      }
   }

   draw_set_vertex_info(st->draw, &vinfo);
#endif
}


/**
 * Called by VBO to draw arrays when in selection or feedback mode and
 * to implement glRasterPos.
 * This is very much like the normal draw_vbo() function above.
 * Look at code refactoring some day.
 * Might move this into the failover module some day.
 */
void
st_feedback_draw_vbo(GLcontext *ctx,
                     const struct gl_client_array **arrays,
                     const struct _mesa_prim *prims,
                     GLuint nr_prims,
                     const struct _mesa_index_buffer *ib,
                     GLuint min_index,
                     GLuint max_index)
{
   struct st_context *st = ctx->st;
   struct pipe_context *pipe = st->pipe;
   struct draw_context *draw = st->draw;
   struct pipe_winsys *winsys = pipe->winsys;
   const struct st_vertex_program *vp;
   const struct pipe_shader_state *vs;
   struct pipe_buffer *index_buffer_handle = 0;
   struct pipe_vertex_buffer vbuffer[PIPE_MAX_SHADER_INPUTS];
   GLuint attr, i;
   ubyte *mapped_constants;

   assert(draw);

   st_validate_state(ctx->st);

   /* must get these after state validation! */
   vp = ctx->st->vp;
   vs = &st->vp->state;

   if (!st->vp->draw_shader) {
      st->vp->draw_shader = draw_create_vertex_shader(draw, vs);
   }

   /*
    * Set up the draw module's state.
    *
    * We'd like to do this less frequently, but the normal state-update
    * code sends state updates to the pipe, not to our private draw module.
    */
   assert(draw);
   draw_set_viewport_state(draw, &st->state.viewport);
   draw_set_clip_state(draw, &st->state.clip);
   draw_set_rasterizer_state(draw, &st->state.rasterizer);
   draw_bind_vertex_shader(draw, st->vp->draw_shader);
   set_feedback_vertex_format(ctx);

   /* loop over TGSI shader inputs to determine vertex buffer
    * and attribute info
    */
   for (attr = 0; attr < vp->num_inputs; attr++) {
      const GLuint mesaAttr = vp->index_to_input[attr];
      struct gl_buffer_object *bufobj = arrays[mesaAttr]->BufferObj;
      struct pipe_vertex_element velement;
      void *map;

      if (bufobj && bufobj->Name) {
         /* Attribute data is in a VBO.
          * Recall that for VBOs, the gl_client_array->Ptr field is
          * really an offset from the start of the VBO, not a pointer.
          */
         struct st_buffer_object *stobj = st_buffer_object(bufobj);
         assert(stobj->buffer);

         vbuffer[attr].buffer = NULL;
         pipe_buffer_reference(winsys, &vbuffer[attr].buffer, stobj->buffer);
         vbuffer[attr].buffer_offset = (unsigned) arrays[0]->Ptr;/* in bytes */
         velement.src_offset = arrays[mesaAttr]->Ptr - arrays[0]->Ptr;
      }
      else {
         /* attribute data is in user-space memory, not a VBO */
         uint bytes = (arrays[mesaAttr]->Size
                       * _mesa_sizeof_type(arrays[mesaAttr]->Type)
                       * (max_index + 1));

         /* wrap user data */
         vbuffer[attr].buffer
            = winsys->user_buffer_create(winsys,
                                         (void *) arrays[mesaAttr]->Ptr,
                                         bytes);
         vbuffer[attr].buffer_offset = 0;
         velement.src_offset = 0;
      }

      /* common-case setup */
      vbuffer[attr].pitch = arrays[mesaAttr]->StrideB; /* in bytes */
      vbuffer[attr].max_index = max_index;
      velement.vertex_buffer_index = attr;
      velement.nr_components = arrays[mesaAttr]->Size;
      velement.src_format = pipe_vertex_format(arrays[mesaAttr]->Type,
                                               arrays[mesaAttr]->Size,
                                               arrays[mesaAttr]->Normalized);
      assert(velement.src_format);

      /* tell draw about this attribute */
      draw_set_vertex_buffer(draw, attr, &vbuffer[attr]);
      draw_set_vertex_element(draw, attr, &velement);

      /* map the attrib buffer */
      map = pipe->winsys->buffer_map(pipe->winsys,
                                     vbuffer[attr].buffer,
                                     PIPE_BUFFER_USAGE_CPU_READ);
      draw_set_mapped_vertex_buffer(draw, attr, map);
   }

   if (ib) {
      unsigned indexSize;
      struct gl_buffer_object *bufobj = ib->obj;
      struct st_buffer_object *stobj = st_buffer_object(bufobj);
      index_buffer_handle = stobj->buffer;
      void *map;

      switch (ib->type) {
      case GL_UNSIGNED_INT:
         indexSize = 4;
         break;
      case GL_UNSIGNED_SHORT:
         indexSize = 2;
         break;
      default:
         assert(0);
	 return;
      }

      map = pipe->winsys->buffer_map(pipe->winsys,
                                     index_buffer_handle,
                                     PIPE_BUFFER_USAGE_CPU_READ);
      draw_set_mapped_element_buffer(draw, indexSize, map);
   }
   else {
      /* no index/element buffer */
      draw_set_mapped_element_buffer(draw, 0, NULL);
   }


   /* map constant buffers */
   mapped_constants = winsys->buffer_map(winsys,
                               st->state.constants[PIPE_SHADER_VERTEX].buffer,
                               PIPE_BUFFER_USAGE_CPU_READ);
   draw_set_mapped_constant_buffer(st->draw, mapped_constants);


   /* draw here */
   for (i = 0; i < nr_prims; i++) {
      draw_arrays(draw, prims[i].mode, prims[i].start, prims[i].count);
   }


   /* unmap constant buffers */
   winsys->buffer_unmap(winsys, st->state.constants[PIPE_SHADER_VERTEX].buffer);

   /*
    * unmap vertex/index buffers
    */
   for (i = 0; i < PIPE_ATTRIB_MAX; i++) {
      if (draw->vertex_buffer[i].buffer) {
         pipe->winsys->buffer_unmap(pipe->winsys,
                                    draw->vertex_buffer[i].buffer);
         pipe_buffer_reference(winsys, &draw->vertex_buffer[i].buffer, NULL);
         draw_set_mapped_vertex_buffer(draw, i, NULL);
      }
   }
   if (ib) {
      pipe->winsys->buffer_unmap(pipe->winsys, index_buffer_handle);
      draw_set_mapped_element_buffer(draw, 0, NULL);
   }
}



void st_init_draw( struct st_context *st )
{
   GLcontext *ctx = st->ctx;

   vbo_set_draw_func(ctx, st_draw_vbo);
}


void st_destroy_draw( struct st_context *st )
{
}