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 * Binning code for lines
30 */
31
32#include "util/u_math.h"
33#include "util/u_memory.h"
34#include "lp_perf.h"
35#include "lp_setup_context.h"
36#include "lp_rast.h"
37#include "lp_state_fs.h"
38#include "lp_state_setup.h"
39
40#define NUM_CHANNELS 4
41
42struct lp_line_info {
43
44   float dx;
45   float dy;
46   float oneoverarea;
47
48   const float (*v1)[4];
49   const float (*v2)[4];
50
51   float (*a0)[4];
52   float (*dadx)[4];
53   float (*dady)[4];
54};
55
56
57/**
58 * Compute a0 for a constant-valued coefficient (GL_FLAT shading).
59 */
60static void constant_coef( struct lp_setup_context *setup,
61                           struct lp_line_info *info,
62                           unsigned slot,
63                           const float value,
64                           unsigned i )
65{
66   info->a0[slot][i] = value;
67   info->dadx[slot][i] = 0.0f;
68   info->dady[slot][i] = 0.0f;
69}
70
71
72/**
73 * Compute a0, dadx and dady for a linearly interpolated coefficient,
74 * for a triangle.
75 */
76static void linear_coef( struct lp_setup_context *setup,
77                         struct lp_line_info *info,
78                         unsigned slot,
79                         unsigned vert_attr,
80                         unsigned i)
81{
82   float a1 = info->v1[vert_attr][i];
83   float a2 = info->v2[vert_attr][i];
84
85   float da21 = a1 - a2;
86   float dadx = da21 * info->dx * info->oneoverarea;
87   float dady = da21 * info->dy * info->oneoverarea;
88
89   info->dadx[slot][i] = dadx;
90   info->dady[slot][i] = dady;
91
92   info->a0[slot][i] = (a1 -
93                              (dadx * (info->v1[0][0] - setup->pixel_offset) +
94                               dady * (info->v1[0][1] - setup->pixel_offset)));
95}
96
97
98/**
99 * Compute a0, dadx and dady for a perspective-corrected interpolant,
100 * for a triangle.
101 * We basically multiply the vertex value by 1/w before computing
102 * the plane coefficients (a0, dadx, dady).
103 * Later, when we compute the value at a particular fragment position we'll
104 * divide the interpolated value by the interpolated W at that fragment.
105 */
106static void perspective_coef( struct lp_setup_context *setup,
107                              struct lp_line_info *info,
108                              unsigned slot,
109                              unsigned vert_attr,
110                              unsigned i)
111{
112   /* premultiply by 1/w  (v[0][3] is always 1/w):
113    */
114   float a1 = info->v1[vert_attr][i] * info->v1[0][3];
115   float a2 = info->v2[vert_attr][i] * info->v2[0][3];
116
117   float da21 = a1 - a2;
118   float dadx = da21 * info->dx * info->oneoverarea;
119   float dady = da21 * info->dy * info->oneoverarea;
120
121   info->dadx[slot][i] = dadx;
122   info->dady[slot][i] = dady;
123
124   info->a0[slot][i] = (a1 -
125                        (dadx * (info->v1[0][0] - setup->pixel_offset) +
126                         dady * (info->v1[0][1] - setup->pixel_offset)));
127}
128
129static void
130setup_fragcoord_coef( struct lp_setup_context *setup,
131                      struct lp_line_info *info,
132                      unsigned slot,
133                      unsigned usage_mask)
134{
135   /*X*/
136   if (usage_mask & TGSI_WRITEMASK_X) {
137      info->a0[slot][0] = 0.0;
138      info->dadx[slot][0] = 1.0;
139      info->dady[slot][0] = 0.0;
140   }
141
142   /*Y*/
143   if (usage_mask & TGSI_WRITEMASK_Y) {
144      info->a0[slot][1] = 0.0;
145      info->dadx[slot][1] = 0.0;
146      info->dady[slot][1] = 1.0;
147   }
148
149   /*Z*/
150   if (usage_mask & TGSI_WRITEMASK_Z) {
151      linear_coef(setup, info, slot, 0, 2);
152   }
153
154   /*W*/
155   if (usage_mask & TGSI_WRITEMASK_W) {
156      linear_coef(setup, info, slot, 0, 3);
157   }
158}
159
160/**
161 * Compute the tri->coef[] array dadx, dady, a0 values.
162 */
163static void setup_line_coefficients( struct lp_setup_context *setup,
164                                     struct lp_line_info *info)
165{
166   const struct lp_setup_variant_key *key = &setup->setup.variant->key;
167   unsigned fragcoord_usage_mask = TGSI_WRITEMASK_XYZ;
168   unsigned slot;
169
170   /* setup interpolation for all the remaining attributes:
171    */
172   for (slot = 0; slot < key->num_inputs; slot++) {
173      unsigned vert_attr = key->inputs[slot].src_index;
174      unsigned usage_mask = key->inputs[slot].usage_mask;
175      unsigned i;
176
177      switch (key->inputs[slot].interp) {
178      case LP_INTERP_CONSTANT:
179         if (key->flatshade_first) {
180            for (i = 0; i < NUM_CHANNELS; i++)
181               if (usage_mask & (1 << i))
182                  constant_coef(setup, info, slot+1, info->v1[vert_attr][i], i);
183         }
184         else {
185            for (i = 0; i < NUM_CHANNELS; i++)
186               if (usage_mask & (1 << i))
187                  constant_coef(setup, info, slot+1, info->v2[vert_attr][i], i);
188         }
189         break;
190
191      case LP_INTERP_LINEAR:
192         for (i = 0; i < NUM_CHANNELS; i++)
193            if (usage_mask & (1 << i))
194               linear_coef(setup, info, slot+1, vert_attr, i);
195         break;
196
197      case LP_INTERP_PERSPECTIVE:
198         for (i = 0; i < NUM_CHANNELS; i++)
199            if (usage_mask & (1 << i))
200               perspective_coef(setup, info, slot+1, vert_attr, i);
201         fragcoord_usage_mask |= TGSI_WRITEMASK_W;
202         break;
203
204      case LP_INTERP_POSITION:
205         /*
206          * The generated pixel interpolators will pick up the coeffs from
207          * slot 0, so all need to ensure that the usage mask is covers all
208          * usages.
209          */
210         fragcoord_usage_mask |= usage_mask;
211         break;
212
213      case LP_INTERP_FACING:
214         for (i = 0; i < NUM_CHANNELS; i++)
215            if (usage_mask & (1 << i))
216               constant_coef(setup, info, slot+1, 1.0, i);
217         break;
218
219      default:
220         assert(0);
221      }
222   }
223
224   /* The internal position input is in slot zero:
225    */
226   setup_fragcoord_coef(setup, info, 0,
227                        fragcoord_usage_mask);
228}
229
230
231
232static INLINE int subpixel_snap( float a )
233{
234   return util_iround(FIXED_ONE * a);
235}
236
237
238/**
239 * Print line vertex attribs (for debug).
240 */
241static void
242print_line(struct lp_setup_context *setup,
243           const float (*v1)[4],
244           const float (*v2)[4])
245{
246   const struct lp_setup_variant_key *key = &setup->setup.variant->key;
247   uint i;
248
249   debug_printf("llvmpipe line\n");
250   for (i = 0; i < 1 + key->num_inputs; i++) {
251      debug_printf("  v1[%d]:  %f %f %f %f\n", i,
252                   v1[i][0], v1[i][1], v1[i][2], v1[i][3]);
253   }
254   for (i = 0; i < 1 + key->num_inputs; i++) {
255      debug_printf("  v2[%d]:  %f %f %f %f\n", i,
256                   v2[i][0], v2[i][1], v2[i][2], v2[i][3]);
257   }
258}
259
260
261static INLINE boolean sign(float x){
262   return x >= 0;
263}
264
265
266/* Used on positive floats only:
267 */
268static INLINE float fracf(float f)
269{
270   return f - floorf(f);
271}
272
273
274
275static boolean
276try_setup_line( struct lp_setup_context *setup,
277               const float (*v1)[4],
278               const float (*v2)[4])
279{
280   struct lp_scene *scene = setup->scene;
281   const struct lp_setup_variant_key *key = &setup->setup.variant->key;
282   struct lp_rast_triangle *line;
283   struct lp_rast_plane *plane;
284   struct lp_line_info info;
285   float width = MAX2(1.0, setup->line_width);
286   struct u_rect bbox;
287   unsigned tri_bytes;
288   int x[4];
289   int y[4];
290   int i;
291   int nr_planes = 4;
292
293   /* linewidth should be interpreted as integer */
294   int fixed_width = util_iround(width) * FIXED_ONE;
295
296   float x_offset=0;
297   float y_offset=0;
298   float x_offset_end=0;
299   float y_offset_end=0;
300
301   float x1diff;
302   float y1diff;
303   float x2diff;
304   float y2diff;
305   float dx, dy;
306   float area;
307
308   boolean draw_start;
309   boolean draw_end;
310   boolean will_draw_start;
311   boolean will_draw_end;
312
313   if (0)
314      print_line(setup, v1, v2);
315
316   if (setup->scissor_test) {
317      nr_planes = 8;
318   }
319   else {
320      nr_planes = 4;
321   }
322
323
324   dx = v1[0][0] - v2[0][0];
325   dy = v1[0][1] - v2[0][1];
326   area = (dx * dx  + dy * dy);
327   if (area == 0) {
328      LP_COUNT(nr_culled_tris);
329      return TRUE;
330   }
331
332   info.oneoverarea = 1.0f / area;
333   info.dx = dx;
334   info.dy = dy;
335   info.v1 = v1;
336   info.v2 = v2;
337
338
339   /* X-MAJOR LINE */
340   if (fabsf(dx) >= fabsf(dy)) {
341      float dydx = dy / dx;
342
343      x1diff = v1[0][0] - (float) floor(v1[0][0]) - 0.5;
344      y1diff = v1[0][1] - (float) floor(v1[0][1]) - 0.5;
345      x2diff = v2[0][0] - (float) floor(v2[0][0]) - 0.5;
346      y2diff = v2[0][1] - (float) floor(v2[0][1]) - 0.5;
347
348      if (y2diff==-0.5 && dy<0){
349         y2diff = 0.5;
350      }
351
352      /*
353       * Diamond exit rule test for starting point
354       */
355      if (fabsf(x1diff) + fabsf(y1diff) < 0.5) {
356         draw_start = TRUE;
357      }
358      else if (sign(x1diff) == sign(-dx)) {
359         draw_start = FALSE;
360      }
361      else if (sign(-y1diff) != sign(dy)) {
362         draw_start = TRUE;
363      }
364      else {
365         /* do intersection test */
366         float yintersect = fracf(v1[0][1]) + x1diff * dydx;
367         draw_start = (yintersect < 1.0 && yintersect > 0.0);
368      }
369
370
371      /*
372       * Diamond exit rule test for ending point
373       */
374      if (fabsf(x2diff) + fabsf(y2diff) < 0.5) {
375         draw_end = FALSE;
376      }
377      else if (sign(x2diff) != sign(-dx)) {
378         draw_end = FALSE;
379      }
380      else if (sign(-y2diff) == sign(dy)) {
381         draw_end = TRUE;
382      }
383      else {
384         /* do intersection test */
385         float yintersect = fracf(v2[0][1]) + x2diff * dydx;
386         draw_end = (yintersect < 1.0 && yintersect > 0.0);
387      }
388
389      /* Are we already drawing start/end?
390       */
391      will_draw_start = sign(-x1diff) != sign(dx);
392      will_draw_end = (sign(x2diff) == sign(-dx)) || x2diff==0;
393
394      if (dx < 0) {
395         /* if v2 is to the right of v1, swap pointers */
396         const float (*temp)[4] = v1;
397         v1 = v2;
398         v2 = temp;
399         dx = -dx;
400         dy = -dy;
401         /* Otherwise shift planes appropriately */
402         if (will_draw_start != draw_start) {
403            x_offset_end = - x1diff - 0.5;
404            y_offset_end = x_offset_end * dydx;
405
406         }
407         if (will_draw_end != draw_end) {
408            x_offset = - x2diff - 0.5;
409            y_offset = x_offset * dydx;
410         }
411
412      }
413      else{
414         /* Otherwise shift planes appropriately */
415         if (will_draw_start != draw_start) {
416            x_offset = - x1diff + 0.5;
417            y_offset = x_offset * dydx;
418         }
419         if (will_draw_end != draw_end) {
420            x_offset_end = - x2diff + 0.5;
421            y_offset_end = x_offset_end * dydx;
422         }
423      }
424
425      /* x/y positions in fixed point */
426      x[0] = subpixel_snap(v1[0][0] + x_offset     - setup->pixel_offset);
427      x[1] = subpixel_snap(v2[0][0] + x_offset_end - setup->pixel_offset);
428      x[2] = subpixel_snap(v2[0][0] + x_offset_end - setup->pixel_offset);
429      x[3] = subpixel_snap(v1[0][0] + x_offset     - setup->pixel_offset);
430
431      y[0] = subpixel_snap(v1[0][1] + y_offset     - setup->pixel_offset) - fixed_width/2;
432      y[1] = subpixel_snap(v2[0][1] + y_offset_end - setup->pixel_offset) - fixed_width/2;
433      y[2] = subpixel_snap(v2[0][1] + y_offset_end - setup->pixel_offset) + fixed_width/2;
434      y[3] = subpixel_snap(v1[0][1] + y_offset     - setup->pixel_offset) + fixed_width/2;
435
436   }
437   else {
438      const float dxdy = dx / dy;
439
440      /* Y-MAJOR LINE */
441      x1diff = v1[0][0] - (float) floor(v1[0][0]) - 0.5;
442      y1diff = v1[0][1] - (float) floor(v1[0][1]) - 0.5;
443      x2diff = v2[0][0] - (float) floor(v2[0][0]) - 0.5;
444      y2diff = v2[0][1] - (float) floor(v2[0][1]) - 0.5;
445
446      if (x2diff==-0.5 && dx<0) {
447         x2diff = 0.5;
448      }
449
450      /*
451       * Diamond exit rule test for starting point
452       */
453      if (fabsf(x1diff) + fabsf(y1diff) < 0.5) {
454         draw_start = TRUE;
455      }
456      else if (sign(-y1diff) == sign(dy)) {
457         draw_start = FALSE;
458      }
459      else if (sign(x1diff) != sign(-dx)) {
460         draw_start = TRUE;
461      }
462      else {
463         /* do intersection test */
464         float xintersect = fracf(v1[0][0]) + y1diff * dxdy;
465         draw_start = (xintersect < 1.0 && xintersect > 0.0);
466      }
467
468      /*
469       * Diamond exit rule test for ending point
470       */
471      if (fabsf(x2diff) + fabsf(y2diff) < 0.5) {
472         draw_end = FALSE;
473      }
474      else if (sign(-y2diff) != sign(dy) ) {
475         draw_end = FALSE;
476      }
477      else if (sign(x2diff) == sign(-dx) ) {
478         draw_end = TRUE;
479      }
480      else {
481         /* do intersection test */
482         float xintersect = fracf(v2[0][0]) + y2diff * dxdy;
483         draw_end = (xintersect < 1.0 && xintersect >= 0.0);
484      }
485
486      /* Are we already drawing start/end?
487       */
488      will_draw_start = sign(y1diff) == sign(dy);
489      will_draw_end = (sign(-y2diff) == sign(dy)) || y2diff==0;
490
491      if (dy > 0) {
492         /* if v2 is on top of v1, swap pointers */
493         const float (*temp)[4] = v1;
494         v1 = v2;
495         v2 = temp;
496         dx = -dx;
497         dy = -dy;
498
499         /* Otherwise shift planes appropriately */
500         if (will_draw_start != draw_start) {
501            y_offset_end = - y1diff + 0.5;
502            x_offset_end = y_offset_end * dxdy;
503         }
504         if (will_draw_end != draw_end) {
505            y_offset = - y2diff + 0.5;
506            x_offset = y_offset * dxdy;
507         }
508      }
509      else {
510         /* Otherwise shift planes appropriately */
511         if (will_draw_start != draw_start) {
512            y_offset = - y1diff - 0.5;
513            x_offset = y_offset * dxdy;
514
515         }
516         if (will_draw_end != draw_end) {
517            y_offset_end = - y2diff - 0.5;
518            x_offset_end = y_offset_end * dxdy;
519         }
520      }
521
522      /* x/y positions in fixed point */
523      x[0] = subpixel_snap(v1[0][0] + x_offset     - setup->pixel_offset) - fixed_width/2;
524      x[1] = subpixel_snap(v2[0][0] + x_offset_end - setup->pixel_offset) - fixed_width/2;
525      x[2] = subpixel_snap(v2[0][0] + x_offset_end - setup->pixel_offset) + fixed_width/2;
526      x[3] = subpixel_snap(v1[0][0] + x_offset     - setup->pixel_offset) + fixed_width/2;
527
528      y[0] = subpixel_snap(v1[0][1] + y_offset     - setup->pixel_offset);
529      y[1] = subpixel_snap(v2[0][1] + y_offset_end - setup->pixel_offset);
530      y[2] = subpixel_snap(v2[0][1] + y_offset_end - setup->pixel_offset);
531      y[3] = subpixel_snap(v1[0][1] + y_offset     - setup->pixel_offset);
532   }
533
534
535
536   LP_COUNT(nr_tris);
537
538
539   /* Bounding rectangle (in pixels) */
540   {
541      /* Yes this is necessary to accurately calculate bounding boxes
542       * with the two fill-conventions we support.  GL (normally) ends
543       * up needing a bottom-left fill convention, which requires
544       * slightly different rounding.
545       */
546      int adj = (setup->pixel_offset != 0) ? 1 : 0;
547
548      bbox.x0 = (MIN4(x[0], x[1], x[2], x[3]) + (FIXED_ONE-1)) >> FIXED_ORDER;
549      bbox.x1 = (MAX4(x[0], x[1], x[2], x[3]) + (FIXED_ONE-1)) >> FIXED_ORDER;
550      bbox.y0 = (MIN4(y[0], y[1], y[2], y[3]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
551      bbox.y1 = (MAX4(y[0], y[1], y[2], y[3]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
552
553      /* Inclusive coordinates:
554       */
555      bbox.x1--;
556      bbox.y1--;
557   }
558
559   if (bbox.x1 < bbox.x0 ||
560       bbox.y1 < bbox.y0) {
561      if (0) debug_printf("empty bounding box\n");
562      LP_COUNT(nr_culled_tris);
563      return TRUE;
564   }
565
566   if (!u_rect_test_intersection(&setup->draw_region, &bbox)) {
567      if (0) debug_printf("offscreen\n");
568      LP_COUNT(nr_culled_tris);
569      return TRUE;
570   }
571
572   /* Can safely discard negative regions:
573    */
574   bbox.x0 = MAX2(bbox.x0, 0);
575   bbox.y0 = MAX2(bbox.y0, 0);
576
577   line = lp_setup_alloc_triangle(scene,
578                                  key->num_inputs,
579                                  nr_planes,
580                                  &tri_bytes);
581   if (!line)
582      return FALSE;
583
584#ifdef DEBUG
585   line->v[0][0] = v1[0][0];
586   line->v[1][0] = v2[0][0];
587   line->v[0][1] = v1[0][1];
588   line->v[1][1] = v2[0][1];
589#endif
590
591   /* calculate the deltas */
592   plane = GET_PLANES(line);
593   plane[0].dcdy = x[0] - x[1];
594   plane[1].dcdy = x[1] - x[2];
595   plane[2].dcdy = x[2] - x[3];
596   plane[3].dcdy = x[3] - x[0];
597
598   plane[0].dcdx = y[0] - y[1];
599   plane[1].dcdx = y[1] - y[2];
600   plane[2].dcdx = y[2] - y[3];
601   plane[3].dcdx = y[3] - y[0];
602
603
604   /* Setup parameter interpolants:
605    */
606   info.a0 = GET_A0(&line->inputs);
607   info.dadx = GET_DADX(&line->inputs);
608   info.dady = GET_DADY(&line->inputs);
609   setup_line_coefficients(setup, &info);
610
611   line->inputs.frontfacing = TRUE;
612   line->inputs.disable = FALSE;
613   line->inputs.opaque = FALSE;
614
615   for (i = 0; i < 4; i++) {
616
617      /* half-edge constants, will be interated over the whole render
618       * target.
619       */
620      plane[i].c = plane[i].dcdx * x[i] - plane[i].dcdy * y[i];
621
622
623      /* correct for top-left vs. bottom-left fill convention.
624       *
625       * note that we're overloading gl_rasterization_rules to mean
626       * both (0.5,0.5) pixel centers *and* bottom-left filling
627       * convention.
628       *
629       * GL actually has a top-left filling convention, but GL's
630       * notion of "top" differs from gallium's...
631       *
632       * Also, sometimes (in FBO cases) GL will render upside down
633       * to its usual method, in which case it will probably want
634       * to use the opposite, top-left convention.
635       */
636      if (plane[i].dcdx < 0) {
637         /* both fill conventions want this - adjust for left edges */
638         plane[i].c++;
639      }
640      else if (plane[i].dcdx == 0) {
641         if (setup->pixel_offset == 0) {
642            /* correct for top-left fill convention:
643             */
644            if (plane[i].dcdy > 0) plane[i].c++;
645         }
646         else {
647            /* correct for bottom-left fill convention:
648             */
649            if (plane[i].dcdy < 0) plane[i].c++;
650         }
651      }
652
653      plane[i].dcdx *= FIXED_ONE;
654      plane[i].dcdy *= FIXED_ONE;
655
656      /* find trivial reject offsets for each edge for a single-pixel
657       * sized block.  These will be scaled up at each recursive level to
658       * match the active blocksize.  Scaling in this way works best if
659       * the blocks are square.
660       */
661      plane[i].eo = 0;
662      if (plane[i].dcdx < 0) plane[i].eo -= plane[i].dcdx;
663      if (plane[i].dcdy > 0) plane[i].eo += plane[i].dcdy;
664   }
665
666
667   /*
668    * When rasterizing scissored tris, use the intersection of the
669    * triangle bounding box and the scissor rect to generate the
670    * scissor planes.
671    *
672    * This permits us to cut off the triangle "tails" that are present
673    * in the intermediate recursive levels caused when two of the
674    * triangles edges don't diverge quickly enough to trivially reject
675    * exterior blocks from the triangle.
676    *
677    * It's not really clear if it's worth worrying about these tails,
678    * but since we generate the planes for each scissored tri, it's
679    * free to trim them in this case.
680    *
681    * Note that otherwise, the scissor planes only vary in 'C' value,
682    * and even then only on state-changes.  Could alternatively store
683    * these planes elsewhere.
684    */
685   if (nr_planes == 8) {
686      const struct u_rect *scissor = &setup->scissor;
687
688      plane[4].dcdx = -1;
689      plane[4].dcdy = 0;
690      plane[4].c = 1-scissor->x0;
691      plane[4].eo = 1;
692
693      plane[5].dcdx = 1;
694      plane[5].dcdy = 0;
695      plane[5].c = scissor->x1+1;
696      plane[5].eo = 0;
697
698      plane[6].dcdx = 0;
699      plane[6].dcdy = 1;
700      plane[6].c = 1-scissor->y0;
701      plane[6].eo = 1;
702
703      plane[7].dcdx = 0;
704      plane[7].dcdy = -1;
705      plane[7].c = scissor->y1+1;
706      plane[7].eo = 0;
707   }
708
709   return lp_setup_bin_triangle(setup, line, &bbox, nr_planes);
710}
711
712
713static void lp_setup_line( struct lp_setup_context *setup,
714                           const float (*v0)[4],
715                           const float (*v1)[4] )
716{
717   if (!try_setup_line( setup, v0, v1 ))
718   {
719      if (!lp_setup_flush_and_restart(setup))
720         return;
721
722      if (!try_setup_line( setup, v0, v1 ))
723         return;
724   }
725}
726
727
728void lp_setup_choose_line( struct lp_setup_context *setup )
729{
730   setup->line = lp_setup_line;
731}
732
733
734