1/**************************************************************************
2 *
3 * Copyright 2007 VMware, Inc.
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 VMWARE 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#include "lp_context.h"
40#include "draw/draw_context.h"
41
42#define NUM_CHANNELS 4
43
44struct lp_line_info {
45
46   float dx;
47   float dy;
48   float oneoverarea;
49   boolean frontfacing;
50
51   const float (*v1)[4];
52   const float (*v2)[4];
53
54   float (*a0)[4];
55   float (*dadx)[4];
56   float (*dady)[4];
57};
58
59
60/**
61 * Compute a0 for a constant-valued coefficient (GL_FLAT shading).
62 */
63static void constant_coef( struct lp_setup_context *setup,
64                           struct lp_line_info *info,
65                           unsigned slot,
66                           const float value,
67                           unsigned i )
68{
69   info->a0[slot][i] = value;
70   info->dadx[slot][i] = 0.0f;
71   info->dady[slot][i] = 0.0f;
72}
73
74
75/**
76 * Compute a0, dadx and dady for a linearly interpolated coefficient,
77 * for a triangle.
78 */
79static void linear_coef( struct lp_setup_context *setup,
80                         struct lp_line_info *info,
81                         unsigned slot,
82                         unsigned vert_attr,
83                         unsigned i)
84{
85   float a1 = info->v1[vert_attr][i];
86   float a2 = info->v2[vert_attr][i];
87
88   float da21 = a1 - a2;
89   float dadx = da21 * info->dx * info->oneoverarea;
90   float dady = da21 * info->dy * info->oneoverarea;
91
92   info->dadx[slot][i] = dadx;
93   info->dady[slot][i] = dady;
94
95   info->a0[slot][i] = (a1 -
96                              (dadx * (info->v1[0][0] - setup->pixel_offset) +
97                               dady * (info->v1[0][1] - setup->pixel_offset)));
98}
99
100
101/**
102 * Compute a0, dadx and dady for a perspective-corrected interpolant,
103 * for a triangle.
104 * We basically multiply the vertex value by 1/w before computing
105 * the plane coefficients (a0, dadx, dady).
106 * Later, when we compute the value at a particular fragment position we'll
107 * divide the interpolated value by the interpolated W at that fragment.
108 */
109static void perspective_coef( struct lp_setup_context *setup,
110                              struct lp_line_info *info,
111                              unsigned slot,
112                              unsigned vert_attr,
113                              unsigned i)
114{
115   /* premultiply by 1/w  (v[0][3] is always 1/w):
116    */
117   float a1 = info->v1[vert_attr][i] * info->v1[0][3];
118   float a2 = info->v2[vert_attr][i] * info->v2[0][3];
119
120   float da21 = a1 - a2;
121   float dadx = da21 * info->dx * info->oneoverarea;
122   float dady = da21 * info->dy * info->oneoverarea;
123
124   info->dadx[slot][i] = dadx;
125   info->dady[slot][i] = dady;
126
127   info->a0[slot][i] = (a1 -
128                        (dadx * (info->v1[0][0] - setup->pixel_offset) +
129                         dady * (info->v1[0][1] - setup->pixel_offset)));
130}
131
132static void
133setup_fragcoord_coef( struct lp_setup_context *setup,
134                      struct lp_line_info *info,
135                      unsigned slot,
136                      unsigned usage_mask)
137{
138   /*X*/
139   if (usage_mask & TGSI_WRITEMASK_X) {
140      info->a0[slot][0] = 0.0;
141      info->dadx[slot][0] = 1.0;
142      info->dady[slot][0] = 0.0;
143   }
144
145   /*Y*/
146   if (usage_mask & TGSI_WRITEMASK_Y) {
147      info->a0[slot][1] = 0.0;
148      info->dadx[slot][1] = 0.0;
149      info->dady[slot][1] = 1.0;
150   }
151
152   /*Z*/
153   if (usage_mask & TGSI_WRITEMASK_Z) {
154      linear_coef(setup, info, slot, 0, 2);
155   }
156
157   /*W*/
158   if (usage_mask & TGSI_WRITEMASK_W) {
159      linear_coef(setup, info, slot, 0, 3);
160   }
161}
162
163/**
164 * Compute the tri->coef[] array dadx, dady, a0 values.
165 */
166static void setup_line_coefficients( struct lp_setup_context *setup,
167                                     struct lp_line_info *info)
168{
169   const struct lp_setup_variant_key *key = &setup->setup.variant->key;
170   unsigned fragcoord_usage_mask = TGSI_WRITEMASK_XYZ;
171   unsigned slot;
172
173   /* setup interpolation for all the remaining attributes:
174    */
175   for (slot = 0; slot < key->num_inputs; slot++) {
176      unsigned vert_attr = key->inputs[slot].src_index;
177      unsigned usage_mask = key->inputs[slot].usage_mask;
178      unsigned i;
179
180      switch (key->inputs[slot].interp) {
181      case LP_INTERP_CONSTANT:
182         if (key->flatshade_first) {
183            for (i = 0; i < NUM_CHANNELS; i++)
184               if (usage_mask & (1 << i))
185                  constant_coef(setup, info, slot+1, info->v1[vert_attr][i], i);
186         }
187         else {
188            for (i = 0; i < NUM_CHANNELS; i++)
189               if (usage_mask & (1 << i))
190                  constant_coef(setup, info, slot+1, info->v2[vert_attr][i], i);
191         }
192         break;
193
194      case LP_INTERP_LINEAR:
195         for (i = 0; i < NUM_CHANNELS; i++)
196            if (usage_mask & (1 << i))
197               linear_coef(setup, info, slot+1, vert_attr, i);
198         break;
199
200      case LP_INTERP_PERSPECTIVE:
201         for (i = 0; i < NUM_CHANNELS; i++)
202            if (usage_mask & (1 << i))
203               perspective_coef(setup, info, slot+1, vert_attr, i);
204         fragcoord_usage_mask |= TGSI_WRITEMASK_W;
205         break;
206
207      case LP_INTERP_POSITION:
208         /*
209          * The generated pixel interpolators will pick up the coeffs from
210          * slot 0, so all need to ensure that the usage mask is covers all
211          * usages.
212          */
213         fragcoord_usage_mask |= usage_mask;
214         break;
215
216      case LP_INTERP_FACING:
217         for (i = 0; i < NUM_CHANNELS; i++)
218            if (usage_mask & (1 << i))
219               constant_coef(setup, info, slot+1,
220                             info->frontfacing ? 1.0f : -1.0f, i);
221         break;
222
223      default:
224         assert(0);
225      }
226   }
227
228   /* The internal position input is in slot zero:
229    */
230   setup_fragcoord_coef(setup, info, 0,
231                        fragcoord_usage_mask);
232}
233
234
235
236static inline int subpixel_snap( float a )
237{
238   return util_iround(FIXED_ONE * a);
239}
240
241
242/**
243 * Print line vertex attribs (for debug).
244 */
245static void
246print_line(struct lp_setup_context *setup,
247           const float (*v1)[4],
248           const float (*v2)[4])
249{
250   const struct lp_setup_variant_key *key = &setup->setup.variant->key;
251   uint i;
252
253   debug_printf("llvmpipe line\n");
254   for (i = 0; i < 1 + key->num_inputs; i++) {
255      debug_printf("  v1[%d]:  %f %f %f %f\n", i,
256                   v1[i][0], v1[i][1], v1[i][2], v1[i][3]);
257   }
258   for (i = 0; i < 1 + key->num_inputs; i++) {
259      debug_printf("  v2[%d]:  %f %f %f %f\n", i,
260                   v2[i][0], v2[i][1], v2[i][2], v2[i][3]);
261   }
262}
263
264
265static inline boolean sign(float x){
266   return x >= 0;
267}
268
269
270/* Used on positive floats only:
271 */
272static inline float fracf(float f)
273{
274   return f - floorf(f);
275}
276
277
278
279static boolean
280try_setup_line( struct lp_setup_context *setup,
281               const float (*v1)[4],
282               const float (*v2)[4])
283{
284   struct llvmpipe_context *lp_context = (struct llvmpipe_context *)setup->pipe;
285   struct lp_scene *scene = setup->scene;
286   const struct lp_setup_variant_key *key = &setup->setup.variant->key;
287   struct lp_rast_triangle *line;
288   struct lp_rast_plane *plane;
289   struct lp_line_info info;
290   float width = MAX2(1.0, setup->line_width);
291   const struct u_rect *scissor;
292   struct u_rect bbox, bboxpos;
293   boolean s_planes[4];
294   unsigned tri_bytes;
295   int x[4];
296   int y[4];
297   int i;
298   int nr_planes = 4;
299   unsigned viewport_index = 0;
300   unsigned layer = 0;
301   float pixel_offset = setup->multisample ? 0.0 : setup->pixel_offset;
302   /* linewidth should be interpreted as integer */
303   int fixed_width = util_iround(width) * FIXED_ONE;
304
305   float x_offset=0;
306   float y_offset=0;
307   float x_offset_end=0;
308   float y_offset_end=0;
309
310   float x1diff;
311   float y1diff;
312   float x2diff;
313   float y2diff;
314   float dx, dy;
315   float area;
316   const float (*pv)[4];
317
318   boolean draw_start;
319   boolean draw_end;
320   boolean will_draw_start;
321   boolean will_draw_end;
322
323   if (lp_context->active_statistics_queries) {
324      lp_context->pipeline_statistics.c_primitives++;
325   }
326
327   if (0)
328      print_line(setup, v1, v2);
329
330   if (setup->flatshade_first) {
331      pv = v1;
332   }
333   else {
334      pv = v2;
335   }
336   if (setup->viewport_index_slot > 0) {
337      unsigned *udata = (unsigned*)pv[setup->viewport_index_slot];
338      viewport_index = lp_clamp_viewport_idx(*udata);
339   }
340   if (setup->layer_slot > 0) {
341      layer = *(unsigned*)pv[setup->layer_slot];
342      layer = MIN2(layer, scene->fb_max_layer);
343   }
344
345   dx = v1[0][0] - v2[0][0];
346   dy = v1[0][1] - v2[0][1];
347   area = (dx * dx  + dy * dy);
348   if (area == 0) {
349      LP_COUNT(nr_culled_tris);
350      return TRUE;
351   }
352
353   info.oneoverarea = 1.0f / area;
354   info.dx = dx;
355   info.dy = dy;
356   info.v1 = v1;
357   info.v2 = v2;
358
359
360   if (setup->rectangular_lines) {
361      float scale = (setup->line_width * 0.5f) / sqrtf(area);
362      int tx = subpixel_snap(-dy * scale);
363      int ty = subpixel_snap(+dx * scale);
364
365      x[0] = subpixel_snap(v1[0][0] - pixel_offset) - tx;
366      x[1] = subpixel_snap(v2[0][0] - pixel_offset) - tx;
367      x[2] = subpixel_snap(v2[0][0] - pixel_offset) + tx;
368      x[3] = subpixel_snap(v1[0][0] - pixel_offset) + tx;
369
370      y[0] = subpixel_snap(v1[0][1] - pixel_offset) - ty;
371      y[1] = subpixel_snap(v2[0][1] - pixel_offset) - ty;
372      y[2] = subpixel_snap(v2[0][1] - pixel_offset) + ty;
373      y[3] = subpixel_snap(v1[0][1] - pixel_offset) + ty;
374   } else if (fabsf(dx) >= fabsf(dy)) {
375      float dydx = dy / dx;
376
377      /* X-MAJOR LINE */
378      x1diff = v1[0][0] - floorf(v1[0][0]) - 0.5f;
379      y1diff = v1[0][1] - floorf(v1[0][1]) - 0.5f;
380      x2diff = v2[0][0] - floorf(v2[0][0]) - 0.5f;
381      y2diff = v2[0][1] - floorf(v2[0][1]) - 0.5f;
382
383      if (y2diff==-0.5 && dy<0){
384         y2diff = 0.5;
385      }
386
387      /*
388       * Diamond exit rule test for starting point
389       */
390      if (fabsf(x1diff) + fabsf(y1diff) < 0.5) {
391         draw_start = TRUE;
392      }
393      else if (sign(x1diff) == sign(-dx)) {
394         draw_start = FALSE;
395      }
396      else if (sign(-y1diff) != sign(dy)) {
397         draw_start = TRUE;
398      }
399      else {
400         /* do intersection test */
401         float yintersect = fracf(v1[0][1]) + x1diff * dydx;
402         draw_start = (yintersect < 1.0 && yintersect > 0.0);
403      }
404
405
406      /*
407       * Diamond exit rule test for ending point
408       */
409      if (fabsf(x2diff) + fabsf(y2diff) < 0.5) {
410         draw_end = FALSE;
411      }
412      else if (sign(x2diff) != sign(-dx)) {
413         draw_end = FALSE;
414      }
415      else if (sign(-y2diff) == sign(dy)) {
416         draw_end = TRUE;
417      }
418      else {
419         /* do intersection test */
420         float yintersect = fracf(v2[0][1]) + x2diff * dydx;
421         draw_end = (yintersect < 1.0 && yintersect > 0.0);
422      }
423
424      /* Are we already drawing start/end?
425       */
426      will_draw_start = sign(-x1diff) != sign(dx);
427      will_draw_end = (sign(x2diff) == sign(-dx)) || x2diff==0;
428
429      /* interpolate using the preferred wide-lines formula */
430      info.dx *= 1 + dydx * dydx;
431      info.dy = 0;
432
433      if (dx < 0) {
434         /* if v2 is to the right of v1, swap pointers */
435         const float (*temp)[4] = v1;
436         v1 = v2;
437         v2 = temp;
438         dx = -dx;
439         dy = -dy;
440         /* Otherwise shift planes appropriately */
441         if (will_draw_start != draw_start) {
442            x_offset_end = - x1diff - 0.5;
443            y_offset_end = x_offset_end * dydx;
444
445         }
446         if (will_draw_end != draw_end) {
447            x_offset = - x2diff - 0.5;
448            y_offset = x_offset * dydx;
449         }
450
451      }
452      else{
453         /* Otherwise shift planes appropriately */
454         if (will_draw_start != draw_start) {
455            x_offset = - x1diff + 0.5;
456            y_offset = x_offset * dydx;
457         }
458         if (will_draw_end != draw_end) {
459            x_offset_end = - x2diff + 0.5;
460            y_offset_end = x_offset_end * dydx;
461         }
462      }
463
464      /* x/y positions in fixed point */
465      x[0] = subpixel_snap(v1[0][0] + x_offset     - pixel_offset);
466      x[1] = subpixel_snap(v2[0][0] + x_offset_end - pixel_offset);
467      x[2] = subpixel_snap(v2[0][0] + x_offset_end - pixel_offset);
468      x[3] = subpixel_snap(v1[0][0] + x_offset     - pixel_offset);
469
470      y[0] = subpixel_snap(v1[0][1] + y_offset     - pixel_offset) - fixed_width/2;
471      y[1] = subpixel_snap(v2[0][1] + y_offset_end - pixel_offset) - fixed_width/2;
472      y[2] = subpixel_snap(v2[0][1] + y_offset_end - pixel_offset) + fixed_width/2;
473      y[3] = subpixel_snap(v1[0][1] + y_offset     - pixel_offset) + fixed_width/2;
474
475   }
476   else {
477      const float dxdy = dx / dy;
478
479      /* Y-MAJOR LINE */
480      x1diff = v1[0][0] - floorf(v1[0][0]) - 0.5f;
481      y1diff = v1[0][1] - floorf(v1[0][1]) - 0.5f;
482      x2diff = v2[0][0] - floorf(v2[0][0]) - 0.5f;
483      y2diff = v2[0][1] - floorf(v2[0][1]) - 0.5f;
484
485      if (x2diff==-0.5 && dx<0) {
486         x2diff = 0.5;
487      }
488
489      /*
490       * Diamond exit rule test for starting point
491       */
492      if (fabsf(x1diff) + fabsf(y1diff) < 0.5) {
493         draw_start = TRUE;
494      }
495      else if (sign(-y1diff) == sign(dy)) {
496         draw_start = FALSE;
497      }
498      else if (sign(x1diff) != sign(-dx)) {
499         draw_start = TRUE;
500      }
501      else {
502         /* do intersection test */
503         float xintersect = fracf(v1[0][0]) + y1diff * dxdy;
504         draw_start = (xintersect < 1.0 && xintersect > 0.0);
505      }
506
507      /*
508       * Diamond exit rule test for ending point
509       */
510      if (fabsf(x2diff) + fabsf(y2diff) < 0.5) {
511         draw_end = FALSE;
512      }
513      else if (sign(-y2diff) != sign(dy) ) {
514         draw_end = FALSE;
515      }
516      else if (sign(x2diff) == sign(-dx) ) {
517         draw_end = TRUE;
518      }
519      else {
520         /* do intersection test */
521         float xintersect = fracf(v2[0][0]) + y2diff * dxdy;
522         draw_end = (xintersect < 1.0 && xintersect >= 0.0);
523      }
524
525      /* Are we already drawing start/end?
526       */
527      will_draw_start = sign(y1diff) == sign(dy);
528      will_draw_end = (sign(-y2diff) == sign(dy)) || y2diff==0;
529
530      /* interpolate using the preferred wide-lines formula */
531      info.dx = 0;
532      info.dy *= 1 + dxdy * dxdy;
533
534      if (dy > 0) {
535         /* if v2 is on top of v1, swap pointers */
536         const float (*temp)[4] = v1;
537         v1 = v2;
538         v2 = temp;
539         dx = -dx;
540         dy = -dy;
541
542         /* Otherwise shift planes appropriately */
543         if (will_draw_start != draw_start) {
544            y_offset_end = - y1diff + 0.5;
545            x_offset_end = y_offset_end * dxdy;
546         }
547         if (will_draw_end != draw_end) {
548            y_offset = - y2diff + 0.5;
549            x_offset = y_offset * dxdy;
550         }
551      }
552      else {
553         /* Otherwise shift planes appropriately */
554         if (will_draw_start != draw_start) {
555            y_offset = - y1diff - 0.5;
556            x_offset = y_offset * dxdy;
557
558         }
559         if (will_draw_end != draw_end) {
560            y_offset_end = - y2diff - 0.5;
561            x_offset_end = y_offset_end * dxdy;
562         }
563      }
564
565      /* x/y positions in fixed point */
566      x[0] = subpixel_snap(v1[0][0] + x_offset     - pixel_offset) - fixed_width/2;
567      x[1] = subpixel_snap(v2[0][0] + x_offset_end - pixel_offset) - fixed_width/2;
568      x[2] = subpixel_snap(v2[0][0] + x_offset_end - pixel_offset) + fixed_width/2;
569      x[3] = subpixel_snap(v1[0][0] + x_offset     - pixel_offset) + fixed_width/2;
570
571      y[0] = subpixel_snap(v1[0][1] + y_offset     - pixel_offset);
572      y[1] = subpixel_snap(v2[0][1] + y_offset_end - pixel_offset);
573      y[2] = subpixel_snap(v2[0][1] + y_offset_end - pixel_offset);
574      y[3] = subpixel_snap(v1[0][1] + y_offset     - pixel_offset);
575   }
576
577   /* Bounding rectangle (in pixels) */
578   {
579      /* Yes this is necessary to accurately calculate bounding boxes
580       * with the two fill-conventions we support.  GL (normally) ends
581       * up needing a bottom-left fill convention, which requires
582       * slightly different rounding.
583       */
584      int adj = (setup->bottom_edge_rule != 0) ? 1 : 0;
585
586      bbox.x0 = (MIN4(x[0], x[1], x[2], x[3]) + (FIXED_ONE-1)) >> FIXED_ORDER;
587      bbox.x1 = (MAX4(x[0], x[1], x[2], x[3]) + (FIXED_ONE-1)) >> FIXED_ORDER;
588      bbox.y0 = (MIN4(y[0], y[1], y[2], y[3]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
589      bbox.y1 = (MAX4(y[0], y[1], y[2], y[3]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
590
591      /* Inclusive coordinates:
592       */
593      bbox.x1--;
594      bbox.y1--;
595   }
596
597   if (!u_rect_test_intersection(&setup->draw_regions[viewport_index], &bbox)) {
598      if (0) debug_printf("no intersection\n");
599      LP_COUNT(nr_culled_tris);
600      return TRUE;
601   }
602
603   bboxpos = bbox;
604
605   /* Can safely discard negative regions:
606    */
607   bboxpos.x0 = MAX2(bboxpos.x0, 0);
608   bboxpos.y0 = MAX2(bboxpos.y0, 0);
609
610   nr_planes = 4;
611   /*
612    * Determine how many scissor planes we need, that is drop scissor
613    * edges if the bounding box of the tri is fully inside that edge.
614    */
615   scissor = &setup->draw_regions[viewport_index];
616   scissor_planes_needed(s_planes, &bboxpos, scissor);
617   nr_planes += s_planes[0] + s_planes[1] + s_planes[2] + s_planes[3];
618
619   line = lp_setup_alloc_triangle(scene,
620                                  key->num_inputs,
621                                  nr_planes,
622                                  &tri_bytes);
623   if (!line)
624      return FALSE;
625
626#ifdef DEBUG
627   line->v[0][0] = v1[0][0];
628   line->v[1][0] = v2[0][0];
629   line->v[0][1] = v1[0][1];
630   line->v[1][1] = v2[0][1];
631#endif
632
633   LP_COUNT(nr_tris);
634
635   /* calculate the deltas */
636   plane = GET_PLANES(line);
637   plane[0].dcdy = x[0] - x[1];
638   plane[1].dcdy = x[1] - x[2];
639   plane[2].dcdy = x[2] - x[3];
640   plane[3].dcdy = x[3] - x[0];
641
642   plane[0].dcdx = y[0] - y[1];
643   plane[1].dcdx = y[1] - y[2];
644   plane[2].dcdx = y[2] - y[3];
645   plane[3].dcdx = y[3] - y[0];
646
647   if (draw_will_inject_frontface(lp_context->draw) &&
648       setup->face_slot > 0) {
649      line->inputs.frontfacing = v1[setup->face_slot][0];
650   } else {
651      line->inputs.frontfacing = TRUE;
652   }
653
654   /* Setup parameter interpolants:
655    */
656   info.a0 = GET_A0(&line->inputs);
657   info.dadx = GET_DADX(&line->inputs);
658   info.dady = GET_DADY(&line->inputs);
659   info.frontfacing = line->inputs.frontfacing;
660   setup_line_coefficients(setup, &info);
661
662   line->inputs.disable = FALSE;
663   line->inputs.opaque = FALSE;
664   line->inputs.layer = layer;
665   line->inputs.viewport_index = viewport_index;
666   line->inputs.view_index = setup->view_index;
667
668   /*
669    * XXX: this code is mostly identical to the one in lp_setup_tri, except it
670    * uses 4 planes instead of 3. Could share the code (including the sse
671    * assembly, in fact we'd get the 4th plane for free).
672    * The only difference apart from storing the 4th plane would be some
673    * different shuffle for calculating dcdx/dcdy.
674    */
675   for (i = 0; i < 4; i++) {
676
677      /* half-edge constants, will be iterated over the whole render
678       * target.
679       */
680      plane[i].c = IMUL64(plane[i].dcdx, x[i]) - IMUL64(plane[i].dcdy, y[i]);
681
682      /* correct for top-left vs. bottom-left fill convention.
683       */
684      if (plane[i].dcdx < 0) {
685         /* both fill conventions want this - adjust for left edges */
686         plane[i].c++;
687      }
688      else if (plane[i].dcdx == 0) {
689         if (setup->bottom_edge_rule == 0) {
690            /* correct for top-left fill convention:
691             */
692            if (plane[i].dcdy > 0) plane[i].c++;
693         }
694         else {
695            /* correct for bottom-left fill convention:
696             */
697            if (plane[i].dcdy < 0) plane[i].c++;
698         }
699      }
700
701      plane[i].dcdx *= FIXED_ONE;
702      plane[i].dcdy *= FIXED_ONE;
703
704      /* find trivial reject offsets for each edge for a single-pixel
705       * sized block.  These will be scaled up at each recursive level to
706       * match the active blocksize.  Scaling in this way works best if
707       * the blocks are square.
708       */
709      plane[i].eo = 0;
710      if (plane[i].dcdx < 0) plane[i].eo -= plane[i].dcdx;
711      if (plane[i].dcdy > 0) plane[i].eo += plane[i].dcdy;
712   }
713
714   if (nr_planes > 4) {
715      lp_setup_add_scissor_planes(scissor, &plane[4], s_planes, setup->multisample);
716   }
717
718   return lp_setup_bin_triangle(setup, line, &bbox, &bboxpos, nr_planes, viewport_index);
719}
720
721
722static void lp_setup_line_discard(struct lp_setup_context *setup,
723                                  const float (*v0)[4],
724                                  const float (*v1)[4])
725{
726}
727
728static void lp_setup_line(struct lp_setup_context *setup,
729                          const float (*v0)[4],
730                          const float (*v1)[4])
731{
732   if (!try_setup_line(setup, v0, v1)) {
733      if (!lp_setup_flush_and_restart(setup))
734         return;
735
736      if (!try_setup_line(setup, v0, v1))
737         return;
738   }
739}
740
741
742void lp_setup_choose_line(struct lp_setup_context *setup)
743{
744   if (setup->rasterizer_discard) {
745      setup->line = lp_setup_line_discard;
746   } else {
747      setup->line = lp_setup_line;
748   }
749}
750
751
752