76a8b87a3095168e6d8ada7274e8408bd14b09b3
[profile/ivi/mesa.git] / src / gallium / drivers / llvmpipe / lp_setup.c
1 /**************************************************************************
2  *
3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
4  * All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sub license, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * 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
20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25  *
26  **************************************************************************/
27
28 /**
29  * Tiling engine.
30  *
31  * Builds per-tile display lists and executes them on calls to
32  * lp_setup_flush().
33  */
34
35 #include "pipe/p_defines.h"
36 #include "util/u_inlines.h"
37 #include "util/u_memory.h"
38 #include "util/u_pack_color.h"
39 #include "util/u_surface.h"
40 #include "lp_scene.h"
41 #include "lp_scene_queue.h"
42 #include "lp_buffer.h"
43 #include "lp_texture.h"
44 #include "lp_debug.h"
45 #include "lp_fence.h"
46 #include "lp_rast.h"
47 #include "lp_setup_context.h"
48 #include "lp_screen.h"
49 #include "state_tracker/sw_winsys.h"
50
51 #include "draw/draw_context.h"
52 #include "draw/draw_vbuf.h"
53
54
55 static void set_scene_state( struct lp_setup_context *, unsigned );
56
57
58 struct lp_scene *
59 lp_setup_get_current_scene(struct lp_setup_context *setup)
60 {
61    if (!setup->scene) {
62
63       /* wait for a free/empty scene
64        */
65       setup->scene = lp_scene_dequeue(setup->empty_scenes, TRUE);
66
67       assert(lp_scene_is_empty(setup->scene));
68
69       lp_scene_begin_binning(setup->scene,
70                              &setup->fb );
71    }
72    return setup->scene;
73 }
74
75
76 static void
77 first_triangle( struct lp_setup_context *setup,
78                 const float (*v0)[4],
79                 const float (*v1)[4],
80                 const float (*v2)[4])
81 {
82    set_scene_state( setup, SETUP_ACTIVE );
83    lp_setup_choose_triangle( setup );
84    setup->triangle( setup, v0, v1, v2 );
85 }
86
87 static void
88 first_line( struct lp_setup_context *setup,
89             const float (*v0)[4],
90             const float (*v1)[4])
91 {
92    set_scene_state( setup, SETUP_ACTIVE );
93    lp_setup_choose_line( setup );
94    setup->line( setup, v0, v1 );
95 }
96
97 static void
98 first_point( struct lp_setup_context *setup,
99              const float (*v0)[4])
100 {
101    set_scene_state( setup, SETUP_ACTIVE );
102    lp_setup_choose_point( setup );
103    setup->point( setup, v0 );
104 }
105
106 static void reset_context( struct lp_setup_context *setup )
107 {
108    LP_DBG(DEBUG_SETUP, "%s\n", __FUNCTION__);
109
110    /* Reset derived state */
111    setup->constants.stored_size = 0;
112    setup->constants.stored_data = NULL;
113    setup->fs.stored = NULL;
114    setup->dirty = ~0;
115
116    /* no current bin */
117    setup->scene = NULL;
118
119    /* Reset some state:
120     */
121    setup->clear.flags = 0;
122
123    /* Have an explicit "start-binning" call and get rid of this
124     * pointer twiddling?
125     */
126    setup->line = first_line;
127    setup->point = first_point;
128    setup->triangle = first_triangle;
129 }
130
131
132 /** Rasterize all scene's bins */
133 static void
134 lp_setup_rasterize_scene( struct lp_setup_context *setup,
135                           boolean write_depth )
136 {
137    struct lp_scene *scene = lp_setup_get_current_scene(setup);
138
139    lp_scene_rasterize(scene,
140                       setup->rast,
141                       write_depth);
142
143    reset_context( setup );
144
145    LP_DBG(DEBUG_SETUP, "%s done \n", __FUNCTION__);
146 }
147
148
149
150 static void
151 begin_binning( struct lp_setup_context *setup )
152 {
153    struct lp_scene *scene = lp_setup_get_current_scene(setup);
154
155    LP_DBG(DEBUG_SETUP, "%s color: %s depth: %s\n", __FUNCTION__,
156           (setup->clear.flags & PIPE_CLEAR_COLOR) ? "clear": "load",
157           (setup->clear.flags & PIPE_CLEAR_DEPTHSTENCIL) ? "clear": "load");
158
159    if (setup->fb.nr_cbufs) {
160       if (setup->clear.flags & PIPE_CLEAR_COLOR)
161          lp_scene_bin_everywhere( scene, 
162                                   lp_rast_clear_color, 
163                                   setup->clear.color );
164       else
165          lp_scene_bin_everywhere( scene,
166                                   lp_rast_load_color,
167                                   lp_rast_arg_null() );
168    }
169
170    if (setup->fb.zsbuf) {
171       if (setup->clear.flags & PIPE_CLEAR_DEPTHSTENCIL)
172          lp_scene_bin_everywhere( scene, 
173                                   lp_rast_clear_zstencil, 
174                                   setup->clear.zstencil );
175    }
176
177    LP_DBG(DEBUG_SETUP, "%s done\n", __FUNCTION__);
178 }
179
180
181 /* This basically bins and then flushes any outstanding full-screen
182  * clears.  
183  *
184  * TODO: fast path for fullscreen clears and no triangles.
185  */
186 static void
187 execute_clears( struct lp_setup_context *setup )
188 {
189    LP_DBG(DEBUG_SETUP, "%s\n", __FUNCTION__);
190
191    begin_binning( setup );
192    lp_setup_rasterize_scene( setup, TRUE );
193 }
194
195
196 static void
197 set_scene_state( struct lp_setup_context *setup,
198            unsigned new_state )
199 {
200    unsigned old_state = setup->state;
201
202    if (old_state == new_state)
203       return;
204        
205    LP_DBG(DEBUG_SETUP, "%s old %d new %d\n", __FUNCTION__, old_state, new_state);
206
207    switch (new_state) {
208    case SETUP_ACTIVE:
209       begin_binning( setup );
210       break;
211
212    case SETUP_CLEARED:
213       if (old_state == SETUP_ACTIVE) {
214          assert(0);
215          return;
216       }
217       break;
218       
219    case SETUP_FLUSHED:
220       if (old_state == SETUP_CLEARED)
221          execute_clears( setup );
222       else
223          lp_setup_rasterize_scene( setup, TRUE );
224       break;
225    }
226
227    setup->state = new_state;
228 }
229
230
231 void
232 lp_setup_flush( struct lp_setup_context *setup,
233                 unsigned flags )
234 {
235    LP_DBG(DEBUG_SETUP, "%s\n", __FUNCTION__);
236
237    set_scene_state( setup, SETUP_FLUSHED );
238 }
239
240
241 void
242 lp_setup_bind_framebuffer( struct lp_setup_context *setup,
243                            const struct pipe_framebuffer_state *fb )
244 {
245    LP_DBG(DEBUG_SETUP, "%s\n", __FUNCTION__);
246
247    /* Flush any old scene.
248     */
249    set_scene_state( setup, SETUP_FLUSHED );
250
251    /* Set new state.  This will be picked up later when we next need a
252     * scene.
253     */
254    util_copy_framebuffer_state(&setup->fb, fb);
255 }
256
257
258 void
259 lp_setup_clear( struct lp_setup_context *setup,
260                 const float *color,
261                 double depth,
262                 unsigned stencil,
263                 unsigned flags )
264 {
265    struct lp_scene *scene = lp_setup_get_current_scene(setup);
266    unsigned i;
267
268    LP_DBG(DEBUG_SETUP, "%s state %d\n", __FUNCTION__, setup->state);
269
270
271    if (flags & PIPE_CLEAR_COLOR) {
272       for (i = 0; i < 4; ++i)
273          setup->clear.color.clear_color[i] = float_to_ubyte(color[i]);
274    }
275
276    if (flags & PIPE_CLEAR_DEPTHSTENCIL) {
277       setup->clear.zstencil.clear_zstencil = 
278          util_pack_z_stencil(setup->fb.zsbuf->format, 
279                              depth,
280                              stencil);
281    }
282
283    if (setup->state == SETUP_ACTIVE) {
284       /* Add the clear to existing scene.  In the unusual case where
285        * both color and depth-stencil are being cleared when there's
286        * already been some rendering, we could discard the currently
287        * binned scene and start again, but I don't see that as being
288        * a common usage.
289        */
290       if (flags & PIPE_CLEAR_COLOR)
291          lp_scene_bin_everywhere( scene, 
292                                   lp_rast_clear_color,
293                                   setup->clear.color );
294
295       if (setup->clear.flags & PIPE_CLEAR_DEPTHSTENCIL)
296          lp_scene_bin_everywhere( scene, 
297                                   lp_rast_clear_zstencil,
298                                   setup->clear.zstencil );
299    }
300    else {
301       /* Put ourselves into the 'pre-clear' state, specifically to try
302        * and accumulate multiple clears to color and depth_stencil
303        * buffers which the app or state-tracker might issue
304        * separately.
305        */
306       set_scene_state( setup, SETUP_CLEARED );
307
308       setup->clear.flags |= flags;
309    }
310 }
311
312
313 /**
314  * Emit a fence.
315  */
316 struct pipe_fence_handle *
317 lp_setup_fence( struct lp_setup_context *setup )
318 {
319    struct lp_scene *scene = lp_setup_get_current_scene(setup);
320    const unsigned rank = lp_scene_get_num_bins( scene ); /* xxx */
321    struct lp_fence *fence = lp_fence_create(rank);
322
323    LP_DBG(DEBUG_SETUP, "%s rank %u\n", __FUNCTION__, rank);
324
325    set_scene_state( setup, SETUP_ACTIVE );
326
327    /* insert the fence into all command bins */
328    lp_scene_bin_everywhere( scene,
329                             lp_rast_fence,
330                             lp_rast_arg_fence(fence) );
331
332    return (struct pipe_fence_handle *) fence;
333 }
334
335
336 void 
337 lp_setup_set_triangle_state( struct lp_setup_context *setup,
338                              unsigned cull_mode,
339                              boolean ccw_is_frontface,
340                              boolean scissor,
341                              boolean gl_rasterization_rules)
342 {
343    LP_DBG(DEBUG_SETUP, "%s\n", __FUNCTION__);
344
345    setup->ccw_is_frontface = ccw_is_frontface;
346    setup->cullmode = cull_mode;
347    setup->triangle = first_triangle;
348    setup->scissor_test = scissor;
349    setup->pixel_offset = gl_rasterization_rules ? 0.5f : 0.0f;
350 }
351
352
353
354 void
355 lp_setup_set_fs_inputs( struct lp_setup_context *setup,
356                         const struct lp_shader_input *input,
357                         unsigned nr )
358 {
359    LP_DBG(DEBUG_SETUP, "%s %p %u\n", __FUNCTION__, (void *) input, nr);
360
361    memcpy( setup->fs.input, input, nr * sizeof input[0] );
362    setup->fs.nr_inputs = nr;
363 }
364
365 void
366 lp_setup_set_fs_functions( struct lp_setup_context *setup,
367                            lp_jit_frag_func jit_function0,
368                            lp_jit_frag_func jit_function1,
369                            boolean opaque )
370 {
371    LP_DBG(DEBUG_SETUP, "%s %p\n", __FUNCTION__, (void *) jit_function0);
372    /* FIXME: reference count */
373
374    setup->fs.current.jit_function[0] = jit_function0;
375    setup->fs.current.jit_function[1] = jit_function1;
376    setup->fs.current.opaque = opaque;
377    setup->dirty |= LP_SETUP_NEW_FS;
378 }
379
380 void
381 lp_setup_set_fs_constants(struct lp_setup_context *setup,
382                           struct pipe_buffer *buffer)
383 {
384    LP_DBG(DEBUG_SETUP, "%s %p\n", __FUNCTION__, (void *) buffer);
385
386    pipe_buffer_reference(&setup->constants.current, buffer);
387
388    setup->dirty |= LP_SETUP_NEW_CONSTANTS;
389 }
390
391
392 void
393 lp_setup_set_alpha_ref_value( struct lp_setup_context *setup,
394                               float alpha_ref_value )
395 {
396    LP_DBG(DEBUG_SETUP, "%s %f\n", __FUNCTION__, alpha_ref_value);
397
398    if(setup->fs.current.jit_context.alpha_ref_value != alpha_ref_value) {
399       setup->fs.current.jit_context.alpha_ref_value = alpha_ref_value;
400       setup->dirty |= LP_SETUP_NEW_FS;
401    }
402 }
403
404 void
405 lp_setup_set_stencil_ref_values( struct lp_setup_context *setup,
406                                  const ubyte refs[2] )
407 {
408    LP_DBG(DEBUG_SETUP, "%s %d %d\n", __FUNCTION__, refs[0], refs[1]);
409
410    if (setup->fs.current.jit_context.stencil_ref_front != refs[0] ||
411        setup->fs.current.jit_context.stencil_ref_back != refs[1]) {
412       setup->fs.current.jit_context.stencil_ref_front = refs[0];
413       setup->fs.current.jit_context.stencil_ref_back = refs[1];
414       setup->dirty |= LP_SETUP_NEW_FS;
415    }
416 }
417
418 void
419 lp_setup_set_blend_color( struct lp_setup_context *setup,
420                           const struct pipe_blend_color *blend_color )
421 {
422    LP_DBG(DEBUG_SETUP, "%s\n", __FUNCTION__);
423
424    assert(blend_color);
425
426    if(memcmp(&setup->blend_color.current, blend_color, sizeof *blend_color) != 0) {
427       memcpy(&setup->blend_color.current, blend_color, sizeof *blend_color);
428       setup->dirty |= LP_SETUP_NEW_BLEND_COLOR;
429    }
430 }
431
432
433 void
434 lp_setup_set_scissor( struct lp_setup_context *setup,
435                       const struct pipe_scissor_state *scissor )
436 {
437    LP_DBG(DEBUG_SETUP, "%s\n", __FUNCTION__);
438
439    assert(scissor);
440
441    if (memcmp(&setup->scissor.current, scissor, sizeof(*scissor)) != 0) {
442       setup->scissor.current = *scissor; /* struct copy */
443       setup->dirty |= LP_SETUP_NEW_SCISSOR;
444    }
445 }
446
447
448 void 
449 lp_setup_set_flatshade_first( struct lp_setup_context *setup,
450                               boolean flatshade_first )
451 {
452    setup->flatshade_first = flatshade_first;
453 }
454
455
456 void 
457 lp_setup_set_vertex_info( struct lp_setup_context *setup,
458                           struct vertex_info *vertex_info )
459 {
460    /* XXX: just silently holding onto the pointer:
461     */
462    setup->vertex_info = vertex_info;
463 }
464
465
466 /**
467  * Called during state validation when LP_NEW_SAMPLER_VIEW is set.
468  */
469 void
470 lp_setup_set_fragment_sampler_views(struct lp_setup_context *setup,
471                                     unsigned num,
472                                     struct pipe_sampler_view **views)
473 {
474    unsigned i;
475
476    LP_DBG(DEBUG_SETUP, "%s\n", __FUNCTION__);
477
478    assert(num <= PIPE_MAX_SAMPLERS);
479
480    for (i = 0; i < PIPE_MAX_SAMPLERS; i++) {
481       struct pipe_sampler_view *view = i < num ? views[i] : NULL;
482
483       if(view) {
484          struct pipe_texture *tex = view->texture;
485          struct llvmpipe_texture *lp_tex = llvmpipe_texture(tex);
486          struct lp_jit_texture *jit_tex;
487          jit_tex = &setup->fs.current.jit_context.textures[i];
488          jit_tex->width = tex->width0;
489          jit_tex->height = tex->height0;
490          jit_tex->depth = tex->depth0;
491          jit_tex->last_level = tex->last_level;
492
493          /* We're referencing the texture's internal data, so save a
494           * reference to it.
495           */
496          pipe_texture_reference(&setup->fs.current_tex[i], tex);
497
498          if (!lp_tex->dt) {
499             /* regular texture - setup array of mipmap level pointers */
500             int j;
501             for (j = 0; j <= tex->last_level; j++) {
502                jit_tex->data[j] =
503                   (ubyte *) lp_tex->data + lp_tex->level_offset[j];
504                jit_tex->row_stride[j] = lp_tex->stride[j];
505             }
506          }
507          else {
508             /* display target texture/surface */
509             /*
510              * XXX: Where should this be unmapped?
511              */
512
513             struct llvmpipe_screen *screen = llvmpipe_screen(tex->screen);
514             struct sw_winsys *winsys = screen->winsys;
515             jit_tex->data[0] = winsys->displaytarget_map(winsys, lp_tex->dt,
516                                                       PIPE_BUFFER_USAGE_CPU_READ);
517             jit_tex->row_stride[0] = lp_tex->stride[0];
518             assert(jit_tex->data[0]);
519          }
520       }
521    }
522
523    setup->dirty |= LP_SETUP_NEW_FS;
524 }
525
526
527 /**
528  * Is the given texture referenced by any scene?
529  * Note: we have to check all scenes including any scenes currently
530  * being rendered and the current scene being built.
531  */
532 unsigned
533 lp_setup_is_texture_referenced( const struct lp_setup_context *setup,
534                                 const struct pipe_texture *texture )
535 {
536    unsigned i;
537
538    /* check the render targets */
539    for (i = 0; i < setup->fb.nr_cbufs; i++) {
540       if (setup->fb.cbufs[i]->texture == texture)
541          return PIPE_REFERENCED_FOR_READ | PIPE_REFERENCED_FOR_WRITE;
542    }
543    if (setup->fb.zsbuf && setup->fb.zsbuf->texture == texture) {
544       return PIPE_REFERENCED_FOR_READ | PIPE_REFERENCED_FOR_WRITE;
545    }
546
547    /* check textures referenced by the scene */
548    for (i = 0; i < Elements(setup->scenes); i++) {
549       if (lp_scene_is_texture_referenced(setup->scenes[i], texture)) {
550          return PIPE_REFERENCED_FOR_READ;
551       }
552    }
553
554    return PIPE_UNREFERENCED;
555 }
556
557
558 /**
559  * Called by vbuf code when we're about to draw something.
560  */
561 void
562 lp_setup_update_state( struct lp_setup_context *setup )
563 {
564    struct lp_scene *scene = lp_setup_get_current_scene(setup);
565
566    LP_DBG(DEBUG_SETUP, "%s\n", __FUNCTION__);
567
568    assert(setup->fs.current.jit_function);
569
570    if(setup->dirty & LP_SETUP_NEW_BLEND_COLOR) {
571       uint8_t *stored;
572       unsigned i, j;
573
574       stored = lp_scene_alloc_aligned(scene, 4 * 16, 16);
575
576       /* smear each blend color component across 16 ubyte elements */
577       for (i = 0; i < 4; ++i) {
578          uint8_t c = float_to_ubyte(setup->blend_color.current.color[i]);
579          for (j = 0; j < 16; ++j)
580             stored[i*16 + j] = c;
581       }
582
583       setup->blend_color.stored = stored;
584
585       setup->fs.current.jit_context.blend_color = setup->blend_color.stored;
586       setup->dirty |= LP_SETUP_NEW_FS;
587    }
588
589    if (setup->dirty & LP_SETUP_NEW_SCISSOR) {
590       float *stored;
591
592       stored = lp_scene_alloc_aligned(scene, 4 * sizeof(int32_t), 16);
593
594       stored[0] = (float) setup->scissor.current.minx;
595       stored[1] = (float) setup->scissor.current.miny;
596       stored[2] = (float) setup->scissor.current.maxx;
597       stored[3] = (float) setup->scissor.current.maxy;
598
599       setup->scissor.stored = stored;
600
601       setup->fs.current.jit_context.scissor_xmin = stored[0];
602       setup->fs.current.jit_context.scissor_ymin = stored[1];
603       setup->fs.current.jit_context.scissor_xmax = stored[2];
604       setup->fs.current.jit_context.scissor_ymax = stored[3];
605
606       setup->dirty |= LP_SETUP_NEW_FS;
607    }
608
609    if(setup->dirty & LP_SETUP_NEW_CONSTANTS) {
610       struct pipe_buffer *buffer = setup->constants.current;
611
612       if(buffer) {
613          unsigned current_size = buffer->size;
614          const void *current_data = llvmpipe_buffer(buffer)->data;
615
616          /* TODO: copy only the actually used constants? */
617
618          if(setup->constants.stored_size != current_size ||
619             !setup->constants.stored_data ||
620             memcmp(setup->constants.stored_data,
621                    current_data,
622                    current_size) != 0) {
623             void *stored;
624
625             stored = lp_scene_alloc(scene, current_size);
626             if(stored) {
627                memcpy(stored,
628                       current_data,
629                       current_size);
630                setup->constants.stored_size = current_size;
631                setup->constants.stored_data = stored;
632             }
633          }
634       }
635       else {
636          setup->constants.stored_size = 0;
637          setup->constants.stored_data = NULL;
638       }
639
640       setup->fs.current.jit_context.constants = setup->constants.stored_data;
641       setup->dirty |= LP_SETUP_NEW_FS;
642    }
643
644
645    if(setup->dirty & LP_SETUP_NEW_FS) {
646       if(!setup->fs.stored ||
647          memcmp(setup->fs.stored,
648                 &setup->fs.current,
649                 sizeof setup->fs.current) != 0) {
650          /* The fs state that's been stored in the scene is different from
651           * the new, current state.  So allocate a new lp_rast_state object
652           * and append it to the bin's setup data buffer.
653           */
654          uint i;
655          struct lp_rast_state *stored =
656             (struct lp_rast_state *) lp_scene_alloc(scene, sizeof *stored);
657          if(stored) {
658             memcpy(stored,
659                    &setup->fs.current,
660                    sizeof setup->fs.current);
661             setup->fs.stored = stored;
662
663             /* put the state-set command into all bins */
664             lp_scene_bin_state_command( scene,
665                                         lp_rast_set_state, 
666                                         lp_rast_arg_state(setup->fs.stored) );
667          }
668
669          /* The scene now references the textures in the rasterization
670           * state record.  Note that now.
671           */
672          for (i = 0; i < Elements(setup->fs.current_tex); i++) {
673             if (setup->fs.current_tex[i])
674                lp_scene_texture_reference(scene, setup->fs.current_tex[i]);
675          }
676       }
677    }
678
679    setup->dirty = 0;
680
681    assert(setup->fs.stored);
682 }
683
684
685
686 /* Only caller is lp_setup_vbuf_destroy()
687  */
688 void 
689 lp_setup_destroy( struct lp_setup_context *setup )
690 {
691    uint i;
692
693    reset_context( setup );
694
695    for (i = 0; i < Elements(setup->fs.current_tex); i++) {
696       pipe_texture_reference(&setup->fs.current_tex[i], NULL);
697    }
698
699    pipe_buffer_reference(&setup->constants.current, NULL);
700
701    /* free the scenes in the 'empty' queue */
702    while (1) {
703       struct lp_scene *scene = lp_scene_dequeue(setup->empty_scenes, FALSE);
704       if (!scene)
705          break;
706       lp_scene_destroy(scene);
707    }
708
709    lp_rast_destroy( setup->rast );
710
711    FREE( setup );
712 }
713
714
715 /**
716  * Create a new primitive tiling engine.  Plug it into the backend of
717  * the draw module.  Currently also creates a rasterizer to use with
718  * it.
719  */
720 struct lp_setup_context *
721 lp_setup_create( struct pipe_context *pipe,
722                  struct draw_context *draw )
723 {
724    unsigned i;
725    struct lp_setup_context *setup = CALLOC_STRUCT(lp_setup_context);
726
727    if (!setup)
728       return NULL;
729
730    lp_setup_init_vbuf(setup);
731
732    setup->empty_scenes = lp_scene_queue_create();
733    if (!setup->empty_scenes)
734       goto fail;
735
736    /* XXX: move this to the screen and share between contexts:
737     */
738    setup->rast = lp_rast_create();
739    if (!setup->rast) 
740       goto fail;
741
742    setup->vbuf = draw_vbuf_stage(draw, &setup->base);
743    if (!setup->vbuf)
744       goto fail;
745
746    draw_set_rasterize_stage(draw, setup->vbuf);
747    draw_set_render(draw, &setup->base);
748
749    /* create some empty scenes */
750    for (i = 0; i < MAX_SCENES; i++) {
751       setup->scenes[i] = lp_scene_create( pipe, setup->empty_scenes );
752
753       lp_scene_enqueue(setup->empty_scenes, setup->scenes[i]);
754    }
755
756    setup->triangle = first_triangle;
757    setup->line     = first_line;
758    setup->point    = first_point;
759    
760    setup->dirty = ~0;
761
762    return setup;
763
764 fail:
765    if (setup->rast)
766       lp_rast_destroy( setup->rast );
767    
768    if (setup->vbuf)
769       ;
770
771    if (setup->empty_scenes)
772       lp_scene_queue_destroy(setup->empty_scenes);
773
774    FREE(setup);
775    return NULL;
776 }
777