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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 
44 struct 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  */
constant_coef(struct lp_setup_context * setup,struct lp_line_info * info,unsigned slot,const float value,unsigned i)63 static 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  */
linear_coef(struct lp_setup_context * setup,struct lp_line_info * info,unsigned slot,unsigned vert_attr,unsigned i)79 static 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  */
perspective_coef(struct lp_setup_context * setup,struct lp_line_info * info,unsigned slot,unsigned vert_attr,unsigned i)109 static 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 
132 static void
setup_fragcoord_coef(struct lp_setup_context * setup,struct lp_line_info * info,unsigned slot,unsigned usage_mask)133 setup_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  */
setup_line_coefficients(struct lp_setup_context * setup,struct lp_line_info * info)166 static 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 
subpixel_snap(float a)236 static 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  */
245 static void
print_line(struct lp_setup_context * setup,const float (* v1)[4],const float (* v2)[4])246 print_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 
sign(float x)265 static inline boolean sign(float x){
266    return x >= 0;
267 }
268 
269 
270 /* Used on positive floats only:
271  */
fracf(float f)272 static inline float fracf(float f)
273 {
274    return f - floorf(f);
275 }
276 
277 
278 
279 static boolean
try_setup_line(struct lp_setup_context * setup,const float (* v1)[4],const float (* v2)[4])280 try_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 
303    float dx, dy;
304    float area;
305    const float (*pv)[4];
306 
307    if (lp_context->active_statistics_queries) {
308       lp_context->pipeline_statistics.c_primitives++;
309    }
310 
311    if (0)
312       print_line(setup, v1, v2);
313 
314    if (setup->flatshade_first) {
315       pv = v1;
316    }
317    else {
318       pv = v2;
319    }
320    if (setup->viewport_index_slot > 0) {
321       unsigned *udata = (unsigned*)pv[setup->viewport_index_slot];
322       viewport_index = lp_clamp_viewport_idx(*udata);
323    }
324    if (setup->layer_slot > 0) {
325       layer = *(unsigned*)pv[setup->layer_slot];
326       layer = MIN2(layer, scene->fb_max_layer);
327    }
328 
329    dx = v1[0][0] - v2[0][0];
330    dy = v1[0][1] - v2[0][1];
331    area = (dx * dx  + dy * dy);
332    if (area == 0) {
333       LP_COUNT(nr_culled_tris);
334       return TRUE;
335    }
336 
337    info.oneoverarea = 1.0f / area;
338    info.dx = dx;
339    info.dy = dy;
340    info.v1 = v1;
341    info.v2 = v2;
342 
343 
344    if (setup->rectangular_lines) {
345       float scale = (setup->line_width * 0.5f) / sqrtf(area);
346       int tx = subpixel_snap(-dy * scale);
347       int ty = subpixel_snap(+dx * scale);
348 
349       x[0] = subpixel_snap(v1[0][0] - pixel_offset) - tx;
350       x[1] = subpixel_snap(v2[0][0] - pixel_offset) - tx;
351       x[2] = subpixel_snap(v2[0][0] - pixel_offset) + tx;
352       x[3] = subpixel_snap(v1[0][0] - pixel_offset) + tx;
353 
354       y[0] = subpixel_snap(v1[0][1] - pixel_offset) - ty;
355       y[1] = subpixel_snap(v2[0][1] - pixel_offset) - ty;
356       y[2] = subpixel_snap(v2[0][1] - pixel_offset) + ty;
357       y[3] = subpixel_snap(v1[0][1] - pixel_offset) + ty;
358    } else {
359       float x_offset = 0, y_offset=0;
360       float x_offset_end = 0, y_offset_end = 0;
361 
362       float x1diff = v1[0][0] - floorf(v1[0][0]) - 0.5f;
363       float y1diff = v1[0][1] - floorf(v1[0][1]) - 0.5f;
364       float x2diff = v2[0][0] - floorf(v2[0][0]) - 0.5f;
365       float y2diff = v2[0][1] - floorf(v2[0][1]) - 0.5f;
366 
367       /* linewidth should be interpreted as integer */
368       int fixed_width = util_iround(width) * FIXED_ONE;
369 
370       bool draw_start;
371       bool draw_end;
372 
373       if (fabsf(dx) >= fabsf(dy)) {
374          float dydx = dy / dx;
375 
376          /* X-MAJOR LINE */
377 
378          if (y2diff == -0.5 && dy < 0) {
379             y2diff = 0.5;
380          }
381 
382          /*
383          * Diamond exit rule test for starting point
384          */
385          if (fabsf(x1diff) + fabsf(y1diff) < 0.5) {
386             draw_start = true;
387          }
388          else if (sign(x1diff) == sign(-dx)) {
389             draw_start = false;
390          }
391          else if (sign(-y1diff) != sign(dy)) {
392             draw_start = true;
393          }
394          else {
395             /* do intersection test */
396             float yintersect = fracf(v1[0][1]) + x1diff * dydx;
397             draw_start = (yintersect < 1.0 && yintersect > 0.0);
398          }
399 
400 
401          /*
402          * Diamond exit rule test for ending point
403          */
404          if (fabsf(x2diff) + fabsf(y2diff) < 0.5) {
405             draw_end = false;
406          }
407          else if (sign(x2diff) != sign(-dx)) {
408             draw_end = false;
409          }
410          else if (sign(-y2diff) == sign(dy)) {
411             draw_end = true;
412          }
413          else {
414             /* do intersection test */
415             float yintersect = fracf(v2[0][1]) + x2diff * dydx;
416             draw_end = (yintersect < 1.0 && yintersect > 0.0);
417          }
418 
419          /* Are we already drawing start/end?
420          */
421          bool will_draw_start = sign(-x1diff) != sign(dx);
422          bool will_draw_end = (sign(x2diff) == sign(-dx)) || x2diff==0;
423 
424          /* interpolate using the preferred wide-lines formula */
425          info.dx *= 1 + dydx * dydx;
426          info.dy = 0;
427 
428          if (dx < 0) {
429             /* if v2 is to the right of v1, swap pointers */
430             const float (*temp)[4] = v1;
431             v1 = v2;
432             v2 = temp;
433             dx = -dx;
434             dy = -dy;
435             /* Otherwise shift planes appropriately */
436             if (will_draw_start != draw_start) {
437                x_offset_end = -x1diff - 0.5;
438                y_offset_end = x_offset_end * dydx;
439 
440             }
441             if (will_draw_end != draw_end) {
442                x_offset = -x2diff - 0.5;
443                y_offset = x_offset * dydx;
444             }
445 
446          }
447          else {
448             /* Otherwise shift planes appropriately */
449             if (will_draw_start != draw_start) {
450                x_offset = -x1diff + 0.5;
451                y_offset = x_offset * dydx;
452             }
453             if (will_draw_end != draw_end) {
454                x_offset_end = -x2diff + 0.5;
455                y_offset_end = x_offset_end * dydx;
456             }
457          }
458 
459          /* x/y positions in fixed point */
460          x[0] = subpixel_snap(v1[0][0] + x_offset     - pixel_offset);
461          x[1] = subpixel_snap(v2[0][0] + x_offset_end - pixel_offset);
462          x[2] = subpixel_snap(v2[0][0] + x_offset_end - pixel_offset);
463          x[3] = subpixel_snap(v1[0][0] + x_offset     - pixel_offset);
464 
465          y[0] = subpixel_snap(v1[0][1] + y_offset     - pixel_offset) - fixed_width/2;
466          y[1] = subpixel_snap(v2[0][1] + y_offset_end - pixel_offset) - fixed_width/2;
467          y[2] = subpixel_snap(v2[0][1] + y_offset_end - pixel_offset) + fixed_width/2;
468          y[3] = subpixel_snap(v1[0][1] + y_offset     - pixel_offset) + fixed_width/2;
469       }
470       else {
471          const float dxdy = dx / dy;
472 
473          /* Y-MAJOR LINE */
474          x1diff = v1[0][0] - floorf(v1[0][0]) - 0.5f;
475          y1diff = v1[0][1] - floorf(v1[0][1]) - 0.5f;
476          x2diff = v2[0][0] - floorf(v2[0][0]) - 0.5f;
477          y2diff = v2[0][1] - floorf(v2[0][1]) - 0.5f;
478 
479          if (x2diff == -0.5 && dx < 0) {
480             x2diff = 0.5;
481          }
482 
483          /*
484          * Diamond exit rule test for starting point
485          */
486          if (fabsf(x1diff) + fabsf(y1diff) < 0.5) {
487             draw_start = true;
488          }
489          else if (sign(-y1diff) == sign(dy)) {
490             draw_start = false;
491          }
492          else if (sign(x1diff) != sign(-dx)) {
493             draw_start = true;
494          }
495          else {
496             /* do intersection test */
497             float xintersect = fracf(v1[0][0]) + y1diff * dxdy;
498             draw_start = (xintersect < 1.0 && xintersect > 0.0);
499          }
500 
501          /*
502          * Diamond exit rule test for ending point
503          */
504          if (fabsf(x2diff) + fabsf(y2diff) < 0.5) {
505             draw_end = false;
506          }
507          else if (sign(-y2diff) != sign(dy) ) {
508             draw_end = false;
509          }
510          else if (sign(x2diff) == sign(-dx) ) {
511             draw_end = true;
512          }
513          else {
514             /* do intersection test */
515             float xintersect = fracf(v2[0][0]) + y2diff * dxdy;
516             draw_end = (xintersect < 1.0 && xintersect >= 0.0);
517          }
518 
519          /* Are we already drawing start/end?
520          */
521          bool will_draw_start = sign(y1diff) == sign(dy);
522          bool will_draw_end = (sign(-y2diff) == sign(dy)) || y2diff==0;
523 
524          /* interpolate using the preferred wide-lines formula */
525          info.dx = 0;
526          info.dy *= 1 + dxdy * dxdy;
527 
528          if (dy > 0) {
529             /* if v2 is on top of v1, swap pointers */
530             const float (*temp)[4] = v1;
531             v1 = v2;
532             v2 = temp;
533             dx = -dx;
534             dy = -dy;
535 
536             /* Otherwise shift planes appropriately */
537             if (will_draw_start != draw_start) {
538                y_offset_end = -y1diff + 0.5;
539                x_offset_end = y_offset_end * dxdy;
540             }
541             if (will_draw_end != draw_end) {
542                y_offset = -y2diff + 0.5;
543                x_offset = y_offset * dxdy;
544             }
545          }
546          else {
547             /* Otherwise shift planes appropriately */
548             if (will_draw_start != draw_start) {
549                y_offset = -y1diff - 0.5;
550                x_offset = y_offset * dxdy;
551             }
552             if (will_draw_end != draw_end) {
553                y_offset_end = -y2diff - 0.5;
554                x_offset_end = y_offset_end * dxdy;
555             }
556          }
557 
558          /* x/y positions in fixed point */
559          x[0] = subpixel_snap(v1[0][0] + x_offset     - pixel_offset) - fixed_width/2;
560          x[1] = subpixel_snap(v2[0][0] + x_offset_end - pixel_offset) - fixed_width/2;
561          x[2] = subpixel_snap(v2[0][0] + x_offset_end - pixel_offset) + fixed_width/2;
562          x[3] = subpixel_snap(v1[0][0] + x_offset     - pixel_offset) + fixed_width/2;
563 
564          y[0] = subpixel_snap(v1[0][1] + y_offset     - pixel_offset);
565          y[1] = subpixel_snap(v2[0][1] + y_offset_end - pixel_offset);
566          y[2] = subpixel_snap(v2[0][1] + y_offset_end - pixel_offset);
567          y[3] = subpixel_snap(v1[0][1] + y_offset     - pixel_offset);
568       }
569    }
570 
571    /* Bounding rectangle (in pixels) */
572    {
573       /* Yes this is necessary to accurately calculate bounding boxes
574        * with the two fill-conventions we support.  GL (normally) ends
575        * up needing a bottom-left fill convention, which requires
576        * slightly different rounding.
577        */
578       int adj = (setup->bottom_edge_rule != 0) ? 1 : 0;
579 
580       bbox.x0 = (MIN4(x[0], x[1], x[2], x[3]) + (FIXED_ONE-1)) >> FIXED_ORDER;
581       bbox.x1 = (MAX4(x[0], x[1], x[2], x[3]) + (FIXED_ONE-1)) >> FIXED_ORDER;
582       bbox.y0 = (MIN4(y[0], y[1], y[2], y[3]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
583       bbox.y1 = (MAX4(y[0], y[1], y[2], y[3]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
584 
585       /* Inclusive coordinates:
586        */
587       bbox.x1--;
588       bbox.y1--;
589    }
590 
591    if (!u_rect_test_intersection(&setup->draw_regions[viewport_index], &bbox)) {
592       if (0) debug_printf("no intersection\n");
593       LP_COUNT(nr_culled_tris);
594       return TRUE;
595    }
596 
597    int max_szorig = ((bbox.x1 - (bbox.x0 & ~3)) |
598                      (bbox.y1 - (bbox.y0 & ~3)));
599    boolean use_32bits = max_szorig <= MAX_FIXED_LENGTH32;
600    bboxpos = bbox;
601 
602    /* Can safely discard negative regions:
603     */
604    bboxpos.x0 = MAX2(bboxpos.x0, 0);
605    bboxpos.y0 = MAX2(bboxpos.y0, 0);
606 
607    nr_planes = 4;
608    /*
609     * Determine how many scissor planes we need, that is drop scissor
610     * edges if the bounding box of the tri is fully inside that edge.
611     */
612    scissor = &setup->draw_regions[viewport_index];
613    scissor_planes_needed(s_planes, &bboxpos, scissor);
614    nr_planes += s_planes[0] + s_planes[1] + s_planes[2] + s_planes[3];
615 
616    line = lp_setup_alloc_triangle(scene,
617                                   key->num_inputs,
618                                   nr_planes,
619                                   &tri_bytes);
620    if (!line)
621       return FALSE;
622 
623 #ifdef DEBUG
624    line->v[0][0] = v1[0][0];
625    line->v[1][0] = v2[0][0];
626    line->v[0][1] = v1[0][1];
627    line->v[1][1] = v2[0][1];
628 #endif
629 
630    LP_COUNT(nr_tris);
631 
632    /* calculate the deltas */
633    plane = GET_PLANES(line);
634    plane[0].dcdy = x[0] - x[1];
635    plane[1].dcdy = x[1] - x[2];
636    plane[2].dcdy = x[2] - x[3];
637    plane[3].dcdy = x[3] - x[0];
638 
639    plane[0].dcdx = y[0] - y[1];
640    plane[1].dcdx = y[1] - y[2];
641    plane[2].dcdx = y[2] - y[3];
642    plane[3].dcdx = y[3] - y[0];
643 
644    if (draw_will_inject_frontface(lp_context->draw) &&
645        setup->face_slot > 0) {
646       line->inputs.frontfacing = v1[setup->face_slot][0];
647    } else {
648       line->inputs.frontfacing = TRUE;
649    }
650 
651    /* Setup parameter interpolants:
652     */
653    info.a0 = GET_A0(&line->inputs);
654    info.dadx = GET_DADX(&line->inputs);
655    info.dady = GET_DADY(&line->inputs);
656    info.frontfacing = line->inputs.frontfacing;
657    setup_line_coefficients(setup, &info);
658 
659    line->inputs.disable = FALSE;
660    line->inputs.layer = layer;
661    line->inputs.viewport_index = viewport_index;
662    line->inputs.view_index = setup->view_index;
663 
664    /*
665     * XXX: this code is mostly identical to the one in lp_setup_tri, except it
666     * uses 4 planes instead of 3. Could share the code (including the sse
667     * assembly, in fact we'd get the 4th plane for free).
668     * The only difference apart from storing the 4th plane would be some
669     * different shuffle for calculating dcdx/dcdy.
670     */
671    for (i = 0; i < 4; i++) {
672 
673       /* half-edge constants, will be iterated over the whole render
674        * target.
675        */
676       plane[i].c = IMUL64(plane[i].dcdx, x[i]) - IMUL64(plane[i].dcdy, y[i]);
677 
678       /* correct for top-left vs. bottom-left fill convention.
679        */
680       if (plane[i].dcdx < 0) {
681          /* both fill conventions want this - adjust for left edges */
682          plane[i].c++;
683       }
684       else if (plane[i].dcdx == 0) {
685          if (setup->bottom_edge_rule == 0) {
686             /* correct for top-left fill convention:
687              */
688             if (plane[i].dcdy > 0) plane[i].c++;
689          }
690          else {
691             /* correct for bottom-left fill convention:
692              */
693             if (plane[i].dcdy < 0) plane[i].c++;
694          }
695       }
696 
697       plane[i].dcdx *= FIXED_ONE;
698       plane[i].dcdy *= FIXED_ONE;
699 
700       /* find trivial reject offsets for each edge for a single-pixel
701        * sized block.  These will be scaled up at each recursive level to
702        * match the active blocksize.  Scaling in this way works best if
703        * the blocks are square.
704        */
705       plane[i].eo = 0;
706       if (plane[i].dcdx < 0) plane[i].eo -= plane[i].dcdx;
707       if (plane[i].dcdy > 0) plane[i].eo += plane[i].dcdy;
708    }
709 
710    if (nr_planes > 4) {
711       lp_setup_add_scissor_planes(scissor, &plane[4], s_planes, setup->multisample);
712    }
713 
714    return lp_setup_bin_triangle(setup, line, use_32bits, false, &bboxpos, nr_planes, viewport_index);
715 }
716 
717 
lp_setup_line_discard(struct lp_setup_context * setup,const float (* v0)[4],const float (* v1)[4])718 static void lp_setup_line_discard(struct lp_setup_context *setup,
719                                   const float (*v0)[4],
720                                   const float (*v1)[4])
721 {
722 }
723 
lp_setup_line(struct lp_setup_context * setup,const float (* v0)[4],const float (* v1)[4])724 static void lp_setup_line(struct lp_setup_context *setup,
725                           const float (*v0)[4],
726                           const float (*v1)[4])
727 {
728    if (!try_setup_line(setup, v0, v1)) {
729       if (!lp_setup_flush_and_restart(setup))
730          return;
731 
732       if (!try_setup_line(setup, v0, v1))
733          return;
734    }
735 }
736 
737 
lp_setup_choose_line(struct lp_setup_context * setup)738 void lp_setup_choose_line(struct lp_setup_context *setup)
739 {
740    if (setup->rasterizer_discard) {
741       setup->line = lp_setup_line_discard;
742    } else {
743       setup->line = lp_setup_line;
744    }
745 }
746 
747 
748