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1 /**************************************************************************
2  *
3  * Copyright 2010, 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 points
30  */
31 
32 #include "util/u_math.h"
33 #include "util/u_memory.h"
34 #include "lp_setup_context.h"
35 #include "lp_perf.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 "tgsi/tgsi_scan.h"
41 #include "draw/draw_context.h"
42 
43 #define NUM_CHANNELS 4
44 
45 struct point_info {
46    /* x,y deltas */
47    int dy01, dy12;
48    int dx01, dx12;
49 
50    const float (*v0)[4];
51 
52    float (*a0)[4];
53    float (*dadx)[4];
54    float (*dady)[4];
55 
56    boolean frontfacing;
57 };
58 
59 
60 /**
61  * Compute a0 for a constant-valued coefficient (GL_FLAT shading).
62  */
63 static void
constant_coef(struct lp_setup_context * setup,struct point_info * info,unsigned slot,const float value,unsigned i)64 constant_coef(struct lp_setup_context *setup,
65               struct point_info *info,
66               unsigned slot,
67               const float value,
68               unsigned i)
69 {
70    info->a0[slot][i] = value;
71    info->dadx[slot][i] = 0.0f;
72    info->dady[slot][i] = 0.0f;
73 }
74 
75 
76 static void
point_persp_coeff(struct lp_setup_context * setup,const struct point_info * info,unsigned slot,unsigned i)77 point_persp_coeff(struct lp_setup_context *setup,
78                   const struct point_info *info,
79                   unsigned slot,
80                   unsigned i)
81 {
82    /*
83     * Fragment shader expects pre-multiplied w for LP_INTERP_PERSPECTIVE. A
84     * better stratergy would be to take the primitive in consideration when
85     * generating the fragment shader key, and therefore avoid the per-fragment
86     * perspective divide.
87     */
88 
89    float w0 = info->v0[0][3];
90 
91    assert(i < 4);
92 
93    info->a0[slot][i] = info->v0[slot][i]*w0;
94    info->dadx[slot][i] = 0.0f;
95    info->dady[slot][i] = 0.0f;
96 }
97 
98 
99 /**
100  * Setup automatic texcoord coefficients (for sprite rendering).
101  * \param slot  the vertex attribute slot to setup
102  * \param i  the attribute channel in [0,3]
103  * \param sprite_coord_origin  one of PIPE_SPRITE_COORD_x
104  * \param perspective  does the shader expects pre-multiplied w, i.e.,
105  *    LP_INTERP_PERSPECTIVE is specified in the shader key
106  */
107 static void
texcoord_coef(struct lp_setup_context * setup,const struct point_info * info,unsigned slot,unsigned i,unsigned sprite_coord_origin,boolean perspective)108 texcoord_coef(struct lp_setup_context *setup,
109               const struct point_info *info,
110               unsigned slot,
111               unsigned i,
112               unsigned sprite_coord_origin,
113               boolean perspective)
114 {
115    float w0 = info->v0[0][3];
116 
117    assert(i < 4);
118 
119    if (i == 0) {
120       float dadx = FIXED_ONE / (float)info->dx12;
121       float dady =  0.0f;
122       float x0 = info->v0[0][0] - setup->pixel_offset;
123       float y0 = info->v0[0][1] - setup->pixel_offset;
124 
125       info->dadx[slot][0] = dadx;
126       info->dady[slot][0] = dady;
127       info->a0[slot][0] = 0.5 - (dadx * x0 + dady * y0);
128 
129       if (perspective) {
130          info->dadx[slot][0] *= w0;
131          info->dady[slot][0] *= w0;
132          info->a0[slot][0] *= w0;
133       }
134    }
135    else if (i == 1) {
136       float dadx = 0.0f;
137       float dady = FIXED_ONE / (float)info->dx12;
138       float x0 = info->v0[0][0] - setup->pixel_offset;
139       float y0 = info->v0[0][1] - setup->pixel_offset;
140 
141       if (sprite_coord_origin == PIPE_SPRITE_COORD_LOWER_LEFT) {
142          dady = -dady;
143       }
144 
145       info->dadx[slot][1] = dadx;
146       info->dady[slot][1] = dady;
147       info->a0[slot][1] = 0.5 - (dadx * x0 + dady * y0);
148 
149       if (perspective) {
150          info->dadx[slot][1] *= w0;
151          info->dady[slot][1] *= w0;
152          info->a0[slot][1] *= w0;
153       }
154    }
155    else if (i == 2) {
156       info->a0[slot][2] = 0.0f;
157       info->dadx[slot][2] = 0.0f;
158       info->dady[slot][2] = 0.0f;
159    }
160    else {
161       info->a0[slot][3] = perspective ? w0 : 1.0f;
162       info->dadx[slot][3] = 0.0f;
163       info->dady[slot][3] = 0.0f;
164    }
165 }
166 
167 
168 /**
169  * Special coefficient setup for gl_FragCoord.
170  * X and Y are trivial
171  * Z and W are copied from position_coef which should have already been computed.
172  * We could do a bit less work if we'd examine gl_FragCoord's swizzle mask.
173  */
174 static void
setup_point_fragcoord_coef(struct lp_setup_context * setup,struct point_info * info,unsigned slot,unsigned usage_mask)175 setup_point_fragcoord_coef(struct lp_setup_context *setup,
176                            struct point_info *info,
177                            unsigned slot,
178                            unsigned usage_mask)
179 {
180    /*X*/
181    if (usage_mask & TGSI_WRITEMASK_X) {
182       info->a0[slot][0] = 0.0;
183       info->dadx[slot][0] = 1.0;
184       info->dady[slot][0] = 0.0;
185    }
186 
187    /*Y*/
188    if (usage_mask & TGSI_WRITEMASK_Y) {
189       info->a0[slot][1] = 0.0;
190       info->dadx[slot][1] = 0.0;
191       info->dady[slot][1] = 1.0;
192    }
193 
194    /*Z*/
195    if (usage_mask & TGSI_WRITEMASK_Z) {
196       constant_coef(setup, info, slot, info->v0[0][2], 2);
197    }
198 
199    /*W*/
200    if (usage_mask & TGSI_WRITEMASK_W) {
201       constant_coef(setup, info, slot, info->v0[0][3], 3);
202    }
203 }
204 
205 
206 /**
207  * Compute the point->coef[] array dadx, dady, a0 values.
208  */
209 static void
setup_point_coefficients(struct lp_setup_context * setup,struct point_info * info)210 setup_point_coefficients( struct lp_setup_context *setup,
211                           struct point_info *info)
212 {
213    const struct lp_setup_variant_key *key = &setup->setup.variant->key;
214    const struct lp_fragment_shader *shader = setup->fs.current.variant->shader;
215    unsigned fragcoord_usage_mask = TGSI_WRITEMASK_XYZ;
216    unsigned slot;
217 
218    /* setup interpolation for all the remaining attributes:
219     */
220    for (slot = 0; slot < key->num_inputs; slot++) {
221       unsigned vert_attr = key->inputs[slot].src_index;
222       unsigned usage_mask = key->inputs[slot].usage_mask;
223       enum lp_interp interp = key->inputs[slot].interp;
224       boolean perspective = !!(interp == LP_INTERP_PERSPECTIVE);
225       unsigned i;
226 
227       if (perspective && usage_mask) {
228          fragcoord_usage_mask |= TGSI_WRITEMASK_W;
229       }
230 
231       switch (interp) {
232       case LP_INTERP_POSITION:
233          /*
234           * The generated pixel interpolators will pick up the coeffs from
235           * slot 0, so all need to ensure that the usage mask is covers all
236           * usages.
237           */
238          fragcoord_usage_mask |= usage_mask;
239          break;
240 
241       case LP_INTERP_LINEAR:
242          /* Sprite tex coords may use linear interpolation someday */
243          /* fall-through */
244       case LP_INTERP_PERSPECTIVE: {
245          /* check if the sprite coord flag is set for this attribute.
246           * If so, set it up so it up so x and y vary from 0 to 1.
247           */
248          bool do_texcoord_coef = false;
249          if (shader->info.base.input_semantic_name[slot] == TGSI_SEMANTIC_PCOORD) {
250             do_texcoord_coef = true;
251          }
252          else if (shader->info.base.input_semantic_name[slot] == TGSI_SEMANTIC_TEXCOORD) {
253             unsigned semantic_index = shader->info.base.input_semantic_index[slot];
254             /* Note that sprite_coord enable is a bitfield of
255              * PIPE_MAX_SHADER_OUTPUTS bits.
256              */
257             if (semantic_index < PIPE_MAX_SHADER_OUTPUTS &&
258                 (setup->sprite_coord_enable & (1u << semantic_index))) {
259                do_texcoord_coef = true;
260             }
261          }
262          if (do_texcoord_coef) {
263             for (i = 0; i < NUM_CHANNELS; i++) {
264                if (usage_mask & (1 << i)) {
265                   texcoord_coef(setup, info, slot + 1, i,
266                                 setup->sprite_coord_origin,
267                                 perspective);
268                }
269             }
270             break;
271          }
272       }
273          /* fall-through */
274       case LP_INTERP_CONSTANT:
275          for (i = 0; i < NUM_CHANNELS; i++) {
276             if (usage_mask & (1 << i)) {
277                if (perspective) {
278                   point_persp_coeff(setup, info, slot+1, i);
279                }
280                else {
281                   constant_coef(setup, info, slot+1, info->v0[vert_attr][i], i);
282                }
283             }
284          }
285          break;
286 
287       case LP_INTERP_FACING:
288          for (i = 0; i < NUM_CHANNELS; i++)
289             if (usage_mask & (1 << i))
290                constant_coef(setup, info, slot+1,
291                              info->frontfacing ? 1.0f : -1.0f, i);
292          break;
293 
294       default:
295          assert(0);
296          break;
297       }
298    }
299 
300    /* The internal position input is in slot zero:
301     */
302    setup_point_fragcoord_coef(setup, info, 0,
303                               fragcoord_usage_mask);
304 }
305 
306 
307 static inline int
subpixel_snap(float a)308 subpixel_snap(float a)
309 {
310    return util_iround(FIXED_ONE * a);
311 }
312 
313 /**
314  * Print point vertex attribs (for debug).
315  */
316 static void
print_point(struct lp_setup_context * setup,const float (* v0)[4],const float size)317 print_point(struct lp_setup_context *setup,
318             const float (*v0)[4],
319             const float size)
320 {
321    const struct lp_setup_variant_key *key = &setup->setup.variant->key;
322    uint i;
323 
324    debug_printf("llvmpipe point, width %f\n", size);
325    for (i = 0; i < 1 + key->num_inputs; i++) {
326       debug_printf("  v0[%d]:  %f %f %f %f\n", i,
327                    v0[i][0], v0[i][1], v0[i][2], v0[i][3]);
328    }
329 }
330 
331 
332 static boolean
try_setup_point(struct lp_setup_context * setup,const float (* v0)[4])333 try_setup_point( struct lp_setup_context *setup,
334                  const float (*v0)[4] )
335 {
336    struct llvmpipe_context *lp_context = (struct llvmpipe_context *)setup->pipe;
337    /* x/y positions in fixed point */
338    const struct lp_setup_variant_key *key = &setup->setup.variant->key;
339    const int sizeAttr = setup->psize_slot;
340    float size
341       = (setup->point_size_per_vertex && sizeAttr > 0) ? v0[sizeAttr][0]
342       : setup->point_size;
343 
344    if (size > LP_MAX_POINT_WIDTH)
345       size = LP_MAX_POINT_WIDTH;
346 
347    /* Yes this is necessary to accurately calculate bounding boxes
348     * with the two fill-conventions we support.  GL (normally) ends
349     * up needing a bottom-left fill convention, which requires
350     * slightly different rounding.
351     */
352    int adj = (setup->bottom_edge_rule != 0) ? 1 : 0;
353    float pixel_offset = setup->multisample ? 0.0 : setup->pixel_offset;
354    struct lp_scene *scene = setup->scene;
355    struct lp_rast_triangle *point;
356    unsigned bytes;
357    struct u_rect bbox;
358    unsigned nr_planes = 4;
359    struct point_info info;
360    unsigned viewport_index = 0;
361    unsigned layer = 0;
362    int fixed_width;
363 
364    if (setup->viewport_index_slot > 0) {
365       unsigned *udata = (unsigned*)v0[setup->viewport_index_slot];
366       viewport_index = lp_clamp_viewport_idx(*udata);
367    }
368    if (setup->layer_slot > 0) {
369       layer = *(unsigned*)v0[setup->layer_slot];
370       layer = MIN2(layer, scene->fb_max_layer);
371    }
372 
373    if (0)
374       print_point(setup, v0, size);
375 
376    /* Bounding rectangle (in pixels) */
377    if (!lp_context->rasterizer ||
378        lp_context->rasterizer->point_quad_rasterization) {
379       /*
380        * Rasterize points as quads.
381        */
382       int x0, y0;
383       /* Point size as fixed point integer, remove rounding errors
384        * and gives minimum width for very small points.
385        */
386       fixed_width = MAX2(FIXED_ONE, subpixel_snap(size));
387 
388       x0 = subpixel_snap(v0[0][0] - pixel_offset) - fixed_width/2;
389       y0 = subpixel_snap(v0[0][1] - pixel_offset) - fixed_width/2;
390 
391       bbox.x0 = (x0 + (FIXED_ONE-1)) >> FIXED_ORDER;
392       bbox.x1 = (x0 + fixed_width + (FIXED_ONE-1)) >> FIXED_ORDER;
393       bbox.y0 = (y0 + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
394       bbox.y1 = (y0 + fixed_width + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
395 
396       /* Inclusive coordinates:
397        */
398       bbox.x1--;
399       bbox.y1--;
400    } else {
401       /*
402        * OpenGL legacy rasterization rules for non-sprite points.
403        *
404        * Per OpenGL 2.1 spec, section 3.3.1, "Basic Point Rasterization".
405        *
406        * This type of point rasterization is only available in pre 3.0 contexts
407        * (or compatibilility contexts which we don't support) anyway.
408        */
409 
410       const int x0 = subpixel_snap(v0[0][0]);
411       const int y0 = subpixel_snap(v0[0][1]) - adj;
412 
413       int int_width;
414       /* Point size as fixed point integer. For GL legacy points
415        * the point size is always a whole integer.
416        */
417       fixed_width = MAX2(FIXED_ONE,
418                          (subpixel_snap(size) + FIXED_ONE/2 - 1) & ~(FIXED_ONE-1));
419       int_width = fixed_width >> FIXED_ORDER;
420 
421       assert(setup->pixel_offset != 0);
422 
423       if (int_width == 1) {
424          bbox.x0 = x0 >> FIXED_ORDER;
425          bbox.y0 = y0 >> FIXED_ORDER;
426          bbox.x1 = bbox.x0;
427          bbox.y1 = bbox.y0;
428       } else {
429          if (int_width & 1) {
430             /* Odd width */
431             bbox.x0 = (x0 >> FIXED_ORDER) - (int_width - 1)/2;
432             bbox.y0 = (y0 >> FIXED_ORDER) - (int_width - 1)/2;
433          } else {
434             /* Even width */
435             bbox.x0 = ((x0 + FIXED_ONE/2) >> FIXED_ORDER) - int_width/2;
436             bbox.y0 = ((y0 + FIXED_ONE/2) >> FIXED_ORDER) - int_width/2;
437          }
438 
439          bbox.x1 = bbox.x0 + int_width - 1;
440          bbox.y1 = bbox.y0 + int_width - 1;
441       }
442    }
443 
444    if (0) {
445       debug_printf("  bbox: (%i, %i) - (%i, %i)\n",
446                    bbox.x0, bbox.y0,
447                    bbox.x1, bbox.y1);
448    }
449 
450    if (lp_context->active_statistics_queries) {
451       lp_context->pipeline_statistics.c_primitives++;
452    }
453 
454    if (!u_rect_test_intersection(&setup->draw_regions[viewport_index], &bbox)) {
455       if (0) debug_printf("offscreen\n");
456       LP_COUNT(nr_culled_tris);
457       return TRUE;
458    }
459 
460    u_rect_find_intersection(&setup->draw_regions[viewport_index], &bbox);
461 
462    point = lp_setup_alloc_triangle(scene,
463                                    key->num_inputs,
464                                    nr_planes,
465                                    &bytes);
466    if (!point)
467       return FALSE;
468 
469 #ifdef DEBUG
470    point->v[0][0] = v0[0][0];
471    point->v[0][1] = v0[0][1];
472 #endif
473 
474    LP_COUNT(nr_tris);
475 
476    if (draw_will_inject_frontface(lp_context->draw) &&
477        setup->face_slot > 0) {
478       point->inputs.frontfacing = v0[setup->face_slot][0];
479    } else {
480       point->inputs.frontfacing = TRUE;
481    }
482 
483    info.v0 = v0;
484    info.dx01 = 0;
485    info.dx12 = fixed_width;
486    info.dy01 = fixed_width;
487    info.dy12 = 0;
488    info.a0 = GET_A0(&point->inputs);
489    info.dadx = GET_DADX(&point->inputs);
490    info.dady = GET_DADY(&point->inputs);
491    info.frontfacing = point->inputs.frontfacing;
492 
493    /* Setup parameter interpolants:
494     */
495    setup_point_coefficients(setup, &info);
496 
497    point->inputs.disable = FALSE;
498    point->inputs.opaque = FALSE;
499    point->inputs.layer = layer;
500    point->inputs.viewport_index = viewport_index;
501 
502    {
503       struct lp_rast_plane *plane = GET_PLANES(point);
504 
505       plane[0].dcdx = ~0U << 8;
506       plane[0].dcdy = 0;
507       plane[0].c = (1-bbox.x0) << 8;
508       plane[0].eo = 1 << 8;
509 
510       plane[1].dcdx = 1 << 8;
511       plane[1].dcdy = 0;
512       plane[1].c = (bbox.x1+1) << 8;
513       plane[1].eo = 0;
514 
515       plane[2].dcdx = 0;
516       plane[2].dcdy = 1 << 8;
517       plane[2].c = (1-bbox.y0) << 8;
518       plane[2].eo = 1 << 8;
519 
520       plane[3].dcdx = 0;
521       plane[3].dcdy = ~0U << 8;
522       plane[3].c = (bbox.y1+1) << 8;
523       plane[3].eo = 0;
524    }
525 
526    return lp_setup_bin_triangle(setup, point, &bbox, &bbox, nr_planes, viewport_index);
527 }
528 
529 
530 static void
lp_setup_point_discard(struct lp_setup_context * setup,const float (* v0)[4])531 lp_setup_point_discard(struct lp_setup_context *setup,
532                        const float (*v0)[4])
533 {
534 }
535 
536 static void
lp_setup_point(struct lp_setup_context * setup,const float (* v0)[4])537 lp_setup_point(struct lp_setup_context *setup,
538                const float (*v0)[4])
539 {
540    if (!try_setup_point(setup, v0)) {
541       if (!lp_setup_flush_and_restart(setup))
542          return;
543 
544       if (!try_setup_point(setup, v0))
545          return;
546    }
547 }
548 
549 
550 void
lp_setup_choose_point(struct lp_setup_context * setup)551 lp_setup_choose_point(struct lp_setup_context *setup)
552 {
553    if (setup->rasterizer_discard) {
554       setup->point = lp_setup_point_discard;
555    } else {
556       setup->point = lp_setup_point;
557    }
558 }
559 
560 
561