vl_zscan.c revision 95594bae47d8b3302be188e6f0be2d69c5507bb3
1/**************************************************************************
2 *
3 * Copyright 2011 Christian König
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#include <assert.h>
29
30#include "pipe/p_screen.h"
31#include "pipe/p_context.h"
32
33#include "util/u_draw.h"
34#include "util/u_sampler.h"
35#include "util/u_inlines.h"
36#include "util/u_memory.h"
37
38#include "tgsi/tgsi_ureg.h"
39
40#include "vl_defines.h"
41#include "vl_types.h"
42
43#include "vl_zscan.h"
44#include "vl_vertex_buffers.h"
45
46enum VS_OUTPUT
47{
48   VS_O_VPOS = 0,
49   VS_O_VTEX = 0
50};
51
52const int vl_zscan_linear[] =
53{
54   /* Linear scan pattern */
55    0, 1, 2, 3, 4, 5, 6, 7,
56    8, 9,10,11,12,13,14,15,
57   16,17,18,19,20,21,22,23,
58   24,25,26,27,28,29,30,31,
59   32,33,34,35,36,37,38,39,
60   40,41,42,43,44,45,46,47,
61   48,49,50,51,52,53,54,55,
62   56,57,58,59,60,61,62,63
63};
64
65const int vl_zscan_normal[] =
66{
67   /* Zig-Zag scan pattern */
68    0, 1, 8,16, 9, 2, 3,10,
69   17,24,32,25,18,11, 4, 5,
70   12,19,26,33,40,48,41,34,
71   27,20,13, 6, 7,14,21,28,
72   35,42,49,56,57,50,43,36,
73   29,22,15,23,30,37,44,51,
74   58,59,52,45,38,31,39,46,
75   53,60,61,54,47,55,62,63
76};
77
78const int vl_zscan_alternate[] =
79{
80   /* Alternate scan pattern */
81    0, 8,16,24, 1, 9, 2,10,
82   17,25,32,40,48,56,57,49,
83   41,33,26,18, 3,11, 4,12,
84   19,27,34,42,50,58,35,43,
85   51,59,20,28, 5,13, 6,14,
86   21,29,36,44,52,60,37,45,
87   53,61,22,30, 7,15,23,31,
88   38,46,54,62,39,47,55,63
89};
90
91static void *
92create_vert_shader(struct vl_zscan *zscan)
93{
94   struct ureg_program *shader;
95
96   struct ureg_src scale;
97   struct ureg_src vrect, vpos, block_num;
98
99   struct ureg_dst tmp;
100   struct ureg_dst o_vpos;
101   struct ureg_dst *o_vtex;
102
103   signed i;
104
105   shader = ureg_create(TGSI_PROCESSOR_VERTEX);
106   if (!shader)
107      return NULL;
108
109   o_vtex = MALLOC(zscan->num_channels * sizeof(struct ureg_dst));
110
111   scale = ureg_imm2f(shader,
112      (float)VL_BLOCK_WIDTH / zscan->buffer_width,
113      (float)VL_BLOCK_HEIGHT / zscan->buffer_height);
114
115   vrect = ureg_DECL_vs_input(shader, VS_I_RECT);
116   vpos = ureg_DECL_vs_input(shader, VS_I_VPOS);
117   block_num = ureg_DECL_vs_input(shader, VS_I_BLOCK_NUM);
118
119   tmp = ureg_DECL_temporary(shader);
120
121   o_vpos = ureg_DECL_output(shader, TGSI_SEMANTIC_POSITION, VS_O_VPOS);
122
123   for (i = 0; i < zscan->num_channels; ++i)
124      o_vtex[i] = ureg_DECL_output(shader, TGSI_SEMANTIC_GENERIC, VS_O_VTEX + i);
125
126   /*
127    * o_vpos.xy = (vpos + vrect) * scale
128    * o_vpos.zw = 1.0f
129    *
130    * tmp.xy = InstanceID / blocks_per_line
131    * tmp.x = frac(tmp.x)
132    * tmp.y = floor(tmp.y)
133    *
134    * o_vtex.x = vrect.x / blocks_per_line + tmp.x
135    * o_vtex.y = vrect.y
136    * o_vtex.z = tmp.z * blocks_per_line / blocks_total
137    */
138   ureg_ADD(shader, ureg_writemask(tmp, TGSI_WRITEMASK_XY), vpos, vrect);
139   ureg_MUL(shader, ureg_writemask(o_vpos, TGSI_WRITEMASK_XY), ureg_src(tmp), scale);
140   ureg_MOV(shader, ureg_writemask(o_vpos, TGSI_WRITEMASK_ZW), ureg_imm1f(shader, 1.0f));
141
142   ureg_MUL(shader, ureg_writemask(tmp, TGSI_WRITEMASK_XW), ureg_scalar(block_num, TGSI_SWIZZLE_X),
143            ureg_imm1f(shader, 1.0f / zscan->blocks_per_line));
144
145   ureg_FRC(shader, ureg_writemask(tmp, TGSI_WRITEMASK_Y), ureg_scalar(ureg_src(tmp), TGSI_SWIZZLE_X));
146   ureg_FLR(shader, ureg_writemask(tmp, TGSI_WRITEMASK_W), ureg_src(tmp));
147
148   for (i = 0; i < zscan->num_channels; ++i) {
149      ureg_ADD(shader, ureg_writemask(tmp, TGSI_WRITEMASK_X), ureg_scalar(ureg_src(tmp), TGSI_SWIZZLE_Y),
150               ureg_imm1f(shader, 1.0f / (zscan->blocks_per_line * VL_BLOCK_WIDTH)
151                * (i - (signed)zscan->num_channels / 2)));
152
153      ureg_MAD(shader, ureg_writemask(o_vtex[i], TGSI_WRITEMASK_X), vrect,
154               ureg_imm1f(shader, 1.0f / zscan->blocks_per_line), ureg_src(tmp));
155      ureg_MOV(shader, ureg_writemask(o_vtex[i], TGSI_WRITEMASK_Y), vrect);
156      ureg_MOV(shader, ureg_writemask(o_vtex[i], TGSI_WRITEMASK_Z), vpos);
157      ureg_MUL(shader, ureg_writemask(o_vtex[i], TGSI_WRITEMASK_W), ureg_src(tmp),
158               ureg_imm1f(shader, (float)zscan->blocks_per_line / zscan->blocks_total));
159   }
160
161   ureg_release_temporary(shader, tmp);
162   ureg_END(shader);
163
164   FREE(o_vtex);
165
166   return ureg_create_shader_and_destroy(shader, zscan->pipe);
167}
168
169static void *
170create_frag_shader(struct vl_zscan *zscan)
171{
172   struct ureg_program *shader;
173   struct ureg_src *vtex;
174
175   struct ureg_src samp_src, samp_scan, samp_quant;
176
177   struct ureg_dst *tmp;
178   struct ureg_dst quant, fragment;
179
180   unsigned i;
181
182   shader = ureg_create(TGSI_PROCESSOR_FRAGMENT);
183   if (!shader)
184      return NULL;
185
186   vtex = MALLOC(zscan->num_channels * sizeof(struct ureg_src));
187   tmp = MALLOC(zscan->num_channels * sizeof(struct ureg_dst));
188
189   for (i = 0; i < zscan->num_channels; ++i)
190      vtex[i] = ureg_DECL_fs_input(shader, TGSI_SEMANTIC_GENERIC, VS_O_VTEX + i, TGSI_INTERPOLATE_LINEAR);
191
192   samp_src = ureg_DECL_sampler(shader, 0);
193   samp_scan = ureg_DECL_sampler(shader, 1);
194   samp_quant = ureg_DECL_sampler(shader, 2);
195
196   for (i = 0; i < zscan->num_channels; ++i)
197      tmp[i] = ureg_DECL_temporary(shader);
198   quant = ureg_DECL_temporary(shader);
199
200   fragment = ureg_DECL_output(shader, TGSI_SEMANTIC_COLOR, 0);
201
202   /*
203    * tmp.x = tex(vtex, 1)
204    * tmp.y = vtex.z
205    * fragment = tex(tmp, 0) * quant
206    */
207   for (i = 0; i < zscan->num_channels; ++i)
208      ureg_TEX(shader, ureg_writemask(tmp[i], TGSI_WRITEMASK_X), TGSI_TEXTURE_2D, vtex[i], samp_scan);
209
210   for (i = 0; i < zscan->num_channels; ++i)
211      ureg_MOV(shader, ureg_writemask(tmp[i], TGSI_WRITEMASK_Y), ureg_scalar(vtex[i], TGSI_SWIZZLE_W));
212
213   for (i = 0; i < zscan->num_channels; ++i) {
214      ureg_TEX(shader, ureg_writemask(tmp[0], TGSI_WRITEMASK_X << i), TGSI_TEXTURE_2D, ureg_src(tmp[i]), samp_src);
215      ureg_TEX(shader, ureg_writemask(quant, TGSI_WRITEMASK_X << i), TGSI_TEXTURE_3D, vtex[i], samp_quant);
216   }
217
218   ureg_MUL(shader, quant, ureg_src(quant), ureg_imm1f(shader, 16.0f));
219   ureg_MUL(shader, fragment, ureg_src(tmp[0]), ureg_src(quant));
220
221   for (i = 0; i < zscan->num_channels; ++i)
222      ureg_release_temporary(shader, tmp[i]);
223   ureg_END(shader);
224
225   FREE(vtex);
226   FREE(tmp);
227
228   return ureg_create_shader_and_destroy(shader, zscan->pipe);
229}
230
231static bool
232init_shaders(struct vl_zscan *zscan)
233{
234   assert(zscan);
235
236   zscan->vs = create_vert_shader(zscan);
237   if (!zscan->vs)
238      goto error_vs;
239
240   zscan->fs = create_frag_shader(zscan);
241   if (!zscan->fs)
242      goto error_fs;
243
244   return true;
245
246error_fs:
247   zscan->pipe->delete_vs_state(zscan->pipe, zscan->vs);
248
249error_vs:
250   return false;
251}
252
253static void
254cleanup_shaders(struct vl_zscan *zscan)
255{
256   assert(zscan);
257
258   zscan->pipe->delete_vs_state(zscan->pipe, zscan->vs);
259   zscan->pipe->delete_fs_state(zscan->pipe, zscan->fs);
260}
261
262static bool
263init_state(struct vl_zscan *zscan)
264{
265   struct pipe_blend_state blend;
266   struct pipe_rasterizer_state rs_state;
267   struct pipe_sampler_state sampler;
268   unsigned i;
269
270   assert(zscan);
271
272   memset(&rs_state, 0, sizeof(rs_state));
273   rs_state.gl_rasterization_rules = true;
274   rs_state.depth_clip = 1;
275   zscan->rs_state = zscan->pipe->create_rasterizer_state(zscan->pipe, &rs_state);
276   if (!zscan->rs_state)
277      goto error_rs_state;
278
279   memset(&blend, 0, sizeof blend);
280
281   blend.independent_blend_enable = 0;
282   blend.rt[0].blend_enable = 0;
283   blend.rt[0].rgb_func = PIPE_BLEND_ADD;
284   blend.rt[0].rgb_src_factor = PIPE_BLENDFACTOR_ONE;
285   blend.rt[0].rgb_dst_factor = PIPE_BLENDFACTOR_ONE;
286   blend.rt[0].alpha_func = PIPE_BLEND_ADD;
287   blend.rt[0].alpha_src_factor = PIPE_BLENDFACTOR_ONE;
288   blend.rt[0].alpha_dst_factor = PIPE_BLENDFACTOR_ONE;
289   blend.logicop_enable = 0;
290   blend.logicop_func = PIPE_LOGICOP_CLEAR;
291   /* Needed to allow color writes to FB, even if blending disabled */
292   blend.rt[0].colormask = PIPE_MASK_RGBA;
293   blend.dither = 0;
294   zscan->blend = zscan->pipe->create_blend_state(zscan->pipe, &blend);
295   if (!zscan->blend)
296      goto error_blend;
297
298   for (i = 0; i < 3; ++i) {
299      memset(&sampler, 0, sizeof(sampler));
300      sampler.wrap_s = PIPE_TEX_WRAP_REPEAT;
301      sampler.wrap_t = PIPE_TEX_WRAP_REPEAT;
302      sampler.wrap_r = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
303      sampler.min_img_filter = PIPE_TEX_FILTER_NEAREST;
304      sampler.min_mip_filter = PIPE_TEX_MIPFILTER_NONE;
305      sampler.mag_img_filter = PIPE_TEX_FILTER_NEAREST;
306      sampler.compare_mode = PIPE_TEX_COMPARE_NONE;
307      sampler.compare_func = PIPE_FUNC_ALWAYS;
308      sampler.normalized_coords = 1;
309      zscan->samplers[i] = zscan->pipe->create_sampler_state(zscan->pipe, &sampler);
310      if (!zscan->samplers[i])
311         goto error_samplers;
312   }
313
314   return true;
315
316error_samplers:
317   for (i = 0; i < 2; ++i)
318      if (zscan->samplers[i])
319         zscan->pipe->delete_sampler_state(zscan->pipe, zscan->samplers[i]);
320
321   zscan->pipe->delete_rasterizer_state(zscan->pipe, zscan->rs_state);
322
323error_blend:
324   zscan->pipe->delete_blend_state(zscan->pipe, zscan->blend);
325
326error_rs_state:
327   return false;
328}
329
330static void
331cleanup_state(struct vl_zscan *zscan)
332{
333   unsigned i;
334
335   assert(zscan);
336
337   for (i = 0; i < 3; ++i)
338      zscan->pipe->delete_sampler_state(zscan->pipe, zscan->samplers[i]);
339
340   zscan->pipe->delete_rasterizer_state(zscan->pipe, zscan->rs_state);
341   zscan->pipe->delete_blend_state(zscan->pipe, zscan->blend);
342}
343
344struct pipe_sampler_view *
345vl_zscan_layout(struct pipe_context *pipe, const int layout[64], unsigned blocks_per_line)
346{
347   const unsigned total_size = blocks_per_line * VL_BLOCK_WIDTH * VL_BLOCK_HEIGHT;
348
349   int patched_layout[64];
350
351   struct pipe_resource res_tmpl, *res;
352   struct pipe_sampler_view sv_tmpl, *sv;
353   struct pipe_transfer *buf_transfer;
354   unsigned x, y, i, pitch;
355   float *f;
356
357   struct pipe_box rect =
358   {
359      0, 0, 0,
360      VL_BLOCK_WIDTH * blocks_per_line,
361      VL_BLOCK_HEIGHT,
362      1
363   };
364
365   assert(pipe && layout && blocks_per_line);
366
367   for (i = 0; i < 64; ++i)
368      patched_layout[layout[i]] = i;
369
370   memset(&res_tmpl, 0, sizeof(res_tmpl));
371   res_tmpl.target = PIPE_TEXTURE_2D;
372   res_tmpl.format = PIPE_FORMAT_R32_FLOAT;
373   res_tmpl.width0 = VL_BLOCK_WIDTH * blocks_per_line;
374   res_tmpl.height0 = VL_BLOCK_HEIGHT;
375   res_tmpl.depth0 = 1;
376   res_tmpl.array_size = 1;
377   res_tmpl.usage = PIPE_USAGE_IMMUTABLE;
378   res_tmpl.bind = PIPE_BIND_SAMPLER_VIEW;
379
380   res = pipe->screen->resource_create(pipe->screen, &res_tmpl);
381   if (!res)
382      goto error_resource;
383
384   buf_transfer = pipe->get_transfer
385   (
386      pipe, res,
387      0, PIPE_TRANSFER_WRITE | PIPE_TRANSFER_DISCARD_RANGE,
388      &rect
389   );
390   if (!buf_transfer)
391      goto error_transfer;
392
393   pitch = buf_transfer->stride / sizeof(float);
394
395   f = pipe->transfer_map(pipe, buf_transfer);
396   if (!f)
397      goto error_map;
398
399   for (i = 0; i < blocks_per_line; ++i)
400      for (y = 0; y < VL_BLOCK_HEIGHT; ++y)
401         for (x = 0; x < VL_BLOCK_WIDTH; ++x) {
402            float addr = patched_layout[x + y * VL_BLOCK_WIDTH] +
403               i * VL_BLOCK_WIDTH * VL_BLOCK_HEIGHT;
404
405            addr /= total_size;
406
407            f[i * VL_BLOCK_WIDTH + y * pitch + x] = addr;
408         }
409
410   pipe->transfer_unmap(pipe, buf_transfer);
411   pipe->transfer_destroy(pipe, buf_transfer);
412
413   memset(&sv_tmpl, 0, sizeof(sv_tmpl));
414   u_sampler_view_default_template(&sv_tmpl, res, res->format);
415   sv = pipe->create_sampler_view(pipe, res, &sv_tmpl);
416   pipe_resource_reference(&res, NULL);
417   if (!sv)
418      goto error_map;
419
420   return sv;
421
422error_map:
423   pipe->transfer_destroy(pipe, buf_transfer);
424
425error_transfer:
426   pipe_resource_reference(&res, NULL);
427
428error_resource:
429   return NULL;
430}
431
432bool
433vl_zscan_init(struct vl_zscan *zscan, struct pipe_context *pipe,
434              unsigned buffer_width, unsigned buffer_height,
435              unsigned blocks_per_line, unsigned blocks_total,
436              unsigned num_channels)
437{
438   assert(zscan && pipe);
439
440   zscan->pipe = pipe;
441   zscan->buffer_width = buffer_width;
442   zscan->buffer_height = buffer_height;
443   zscan->num_channels = num_channels;
444   zscan->blocks_per_line = blocks_per_line;
445   zscan->blocks_total = blocks_total;
446
447   if(!init_shaders(zscan))
448      return false;
449
450   if(!init_state(zscan)) {
451      cleanup_shaders(zscan);
452      return false;
453   }
454
455   return true;
456}
457
458void
459vl_zscan_cleanup(struct vl_zscan *zscan)
460{
461   assert(zscan);
462
463   cleanup_shaders(zscan);
464   cleanup_state(zscan);
465}
466
467bool
468vl_zscan_init_buffer(struct vl_zscan *zscan, struct vl_zscan_buffer *buffer,
469                     struct pipe_sampler_view *src, struct pipe_surface *dst)
470{
471   struct pipe_resource res_tmpl, *res;
472   struct pipe_sampler_view sv_tmpl;
473
474   assert(zscan && buffer);
475
476   memset(buffer, 0, sizeof(struct vl_zscan_buffer));
477
478   pipe_sampler_view_reference(&buffer->src, src);
479
480   buffer->viewport.scale[0] = dst->width;
481   buffer->viewport.scale[1] = dst->height;
482   buffer->viewport.scale[2] = 1;
483   buffer->viewport.scale[3] = 1;
484   buffer->viewport.translate[0] = 0;
485   buffer->viewport.translate[1] = 0;
486   buffer->viewport.translate[2] = 0;
487   buffer->viewport.translate[3] = 0;
488
489   buffer->fb_state.width = dst->width;
490   buffer->fb_state.height = dst->height;
491   buffer->fb_state.nr_cbufs = 1;
492   pipe_surface_reference(&buffer->fb_state.cbufs[0], dst);
493
494   memset(&res_tmpl, 0, sizeof(res_tmpl));
495   res_tmpl.target = PIPE_TEXTURE_3D;
496   res_tmpl.format = PIPE_FORMAT_R8_UNORM;
497   res_tmpl.width0 = VL_BLOCK_WIDTH * zscan->blocks_per_line;
498   res_tmpl.height0 = VL_BLOCK_HEIGHT;
499   res_tmpl.depth0 = 2;
500   res_tmpl.array_size = 1;
501   res_tmpl.usage = PIPE_USAGE_IMMUTABLE;
502   res_tmpl.bind = PIPE_BIND_SAMPLER_VIEW;
503
504   res = zscan->pipe->screen->resource_create(zscan->pipe->screen, &res_tmpl);
505   if (!res)
506      return false;
507
508   memset(&sv_tmpl, 0, sizeof(sv_tmpl));
509   u_sampler_view_default_template(&sv_tmpl, res, res->format);
510   sv_tmpl.swizzle_r = sv_tmpl.swizzle_g = sv_tmpl.swizzle_b = sv_tmpl.swizzle_a = TGSI_SWIZZLE_X;
511   buffer->quant = zscan->pipe->create_sampler_view(zscan->pipe, res, &sv_tmpl);
512   pipe_resource_reference(&res, NULL);
513   if (!buffer->quant)
514      return false;
515
516   return true;
517}
518
519void
520vl_zscan_cleanup_buffer(struct vl_zscan_buffer *buffer)
521{
522   assert(buffer);
523
524   pipe_sampler_view_reference(&buffer->src, NULL);
525   pipe_sampler_view_reference(&buffer->layout, NULL);
526   pipe_sampler_view_reference(&buffer->quant, NULL);
527   pipe_surface_reference(&buffer->fb_state.cbufs[0], NULL);
528}
529
530void
531vl_zscan_set_layout(struct vl_zscan_buffer *buffer, struct pipe_sampler_view *layout)
532{
533   assert(buffer);
534   assert(layout);
535
536   pipe_sampler_view_reference(&buffer->layout, layout);
537}
538
539void
540vl_zscan_upload_quant(struct vl_zscan *zscan, struct vl_zscan_buffer *buffer,
541                      const uint8_t matrix[64], bool intra)
542{
543   struct pipe_context *pipe;
544   struct pipe_transfer *buf_transfer;
545   unsigned x, y, i, pitch;
546   uint8_t *data;
547
548   struct pipe_box rect =
549   {
550      0, 0, intra ? 1 : 0,
551      VL_BLOCK_WIDTH,
552      VL_BLOCK_HEIGHT,
553      1
554   };
555
556   assert(buffer);
557   assert(matrix);
558
559   pipe = zscan->pipe;
560
561   rect.width *= zscan->blocks_per_line;
562
563   buf_transfer = pipe->get_transfer
564   (
565      pipe, buffer->quant->texture,
566      0, PIPE_TRANSFER_WRITE | PIPE_TRANSFER_DISCARD_RANGE,
567      &rect
568   );
569   if (!buf_transfer)
570      goto error_transfer;
571
572   pitch = buf_transfer->stride;
573
574   data = pipe->transfer_map(pipe, buf_transfer);
575   if (!data)
576      goto error_map;
577
578   for (i = 0; i < zscan->blocks_per_line; ++i)
579      for (y = 0; y < VL_BLOCK_HEIGHT; ++y)
580         for (x = 0; x < VL_BLOCK_WIDTH; ++x)
581            data[i * VL_BLOCK_WIDTH + y * pitch + x] = matrix[x + y * VL_BLOCK_WIDTH];
582
583   pipe->transfer_unmap(pipe, buf_transfer);
584
585error_map:
586   pipe->transfer_destroy(pipe, buf_transfer);
587
588error_transfer:
589   return;
590}
591
592void
593vl_zscan_render(struct vl_zscan *zscan, struct vl_zscan_buffer *buffer, unsigned num_instances)
594{
595   assert(buffer);
596
597   zscan->pipe->bind_rasterizer_state(zscan->pipe, zscan->rs_state);
598   zscan->pipe->bind_blend_state(zscan->pipe, zscan->blend);
599   zscan->pipe->bind_fragment_sampler_states(zscan->pipe, 3, zscan->samplers);
600   zscan->pipe->set_framebuffer_state(zscan->pipe, &buffer->fb_state);
601   zscan->pipe->set_viewport_state(zscan->pipe, &buffer->viewport);
602   zscan->pipe->set_fragment_sampler_views(zscan->pipe, 3, &buffer->src);
603   zscan->pipe->bind_vs_state(zscan->pipe, zscan->vs);
604   zscan->pipe->bind_fs_state(zscan->pipe, zscan->fs);
605   util_draw_arrays_instanced(zscan->pipe, PIPE_PRIM_QUADS, 0, 4, 0, num_instances);
606}
607