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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          if (shader->info.base.input_semantic_name[slot] == TGSI_SEMANTIC_GENERIC) {
249             unsigned semantic_index = shader->info.base.input_semantic_index[slot];
250             /* Note that sprite_coord enable is a bitfield of
251              * PIPE_MAX_SHADER_OUTPUTS bits.
252              */
253             if (semantic_index < PIPE_MAX_SHADER_OUTPUTS &&
254                 (setup->sprite_coord_enable & (1 << semantic_index))) {
255                for (i = 0; i < NUM_CHANNELS; i++) {
256                   if (usage_mask & (1 << i)) {
257                      texcoord_coef(setup, info, slot + 1, i,
258                                    setup->sprite_coord_origin,
259                                    perspective);
260                   }
261                }
262                break;
263             }
264          }
265          /* fall-through */
266       case LP_INTERP_CONSTANT:
267          for (i = 0; i < NUM_CHANNELS; i++) {
268             if (usage_mask & (1 << i)) {
269                if (perspective) {
270                   point_persp_coeff(setup, info, slot+1, i);
271                }
272                else {
273                   constant_coef(setup, info, slot+1, info->v0[vert_attr][i], i);
274                }
275             }
276          }
277          break;
278 
279       case LP_INTERP_FACING:
280          for (i = 0; i < NUM_CHANNELS; i++)
281             if (usage_mask & (1 << i))
282                constant_coef(setup, info, slot+1,
283                              info->frontfacing ? 1.0f : -1.0f, i);
284          break;
285 
286       default:
287          assert(0);
288          break;
289       }
290    }
291 
292    /* The internal position input is in slot zero:
293     */
294    setup_point_fragcoord_coef(setup, info, 0,
295                               fragcoord_usage_mask);
296 }
297 
298 
299 static inline int
subpixel_snap(float a)300 subpixel_snap(float a)
301 {
302    return util_iround(FIXED_ONE * a);
303 }
304 
305 /**
306  * Print point vertex attribs (for debug).
307  */
308 static void
print_point(struct lp_setup_context * setup,const float (* v0)[4],const float size)309 print_point(struct lp_setup_context *setup,
310             const float (*v0)[4],
311             const float size)
312 {
313    const struct lp_setup_variant_key *key = &setup->setup.variant->key;
314    uint i;
315 
316    debug_printf("llvmpipe point, width %f\n", size);
317    for (i = 0; i < 1 + key->num_inputs; i++) {
318       debug_printf("  v0[%d]:  %f %f %f %f\n", i,
319                    v0[i][0], v0[i][1], v0[i][2], v0[i][3]);
320    }
321 }
322 
323 
324 static boolean
try_setup_point(struct lp_setup_context * setup,const float (* v0)[4])325 try_setup_point( struct lp_setup_context *setup,
326                  const float (*v0)[4] )
327 {
328    struct llvmpipe_context *lp_context = (struct llvmpipe_context *)setup->pipe;
329    /* x/y positions in fixed point */
330    const struct lp_setup_variant_key *key = &setup->setup.variant->key;
331    const int sizeAttr = setup->psize_slot;
332    const float size
333       = (setup->point_size_per_vertex && sizeAttr > 0) ? v0[sizeAttr][0]
334       : setup->point_size;
335 
336    /* Yes this is necessary to accurately calculate bounding boxes
337     * with the two fill-conventions we support.  GL (normally) ends
338     * up needing a bottom-left fill convention, which requires
339     * slightly different rounding.
340     */
341    int adj = (setup->bottom_edge_rule != 0) ? 1 : 0;
342 
343    struct lp_scene *scene = setup->scene;
344    struct lp_rast_triangle *point;
345    unsigned bytes;
346    struct u_rect bbox;
347    unsigned nr_planes = 4;
348    struct point_info info;
349    unsigned viewport_index = 0;
350    unsigned layer = 0;
351    int fixed_width;
352 
353    if (setup->viewport_index_slot > 0) {
354       unsigned *udata = (unsigned*)v0[setup->viewport_index_slot];
355       viewport_index = lp_clamp_viewport_idx(*udata);
356    }
357    if (setup->layer_slot > 0) {
358       layer = *(unsigned*)v0[setup->layer_slot];
359       layer = MIN2(layer, scene->fb_max_layer);
360    }
361 
362    if (0)
363       print_point(setup, v0, size);
364 
365    /* Bounding rectangle (in pixels) */
366    if (!lp_context->rasterizer ||
367        lp_context->rasterizer->point_quad_rasterization) {
368       /*
369        * Rasterize points as quads.
370        */
371       int x0, y0;
372       /* Point size as fixed point integer, remove rounding errors
373        * and gives minimum width for very small points.
374        */
375       fixed_width = MAX2(FIXED_ONE, subpixel_snap(size));
376 
377       x0 = subpixel_snap(v0[0][0] - setup->pixel_offset) - fixed_width/2;
378       y0 = subpixel_snap(v0[0][1] - setup->pixel_offset) - fixed_width/2;
379 
380       bbox.x0 = (x0 + (FIXED_ONE-1)) >> FIXED_ORDER;
381       bbox.x1 = (x0 + fixed_width + (FIXED_ONE-1)) >> FIXED_ORDER;
382       bbox.y0 = (y0 + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
383       bbox.y1 = (y0 + fixed_width + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
384 
385       /* Inclusive coordinates:
386        */
387       bbox.x1--;
388       bbox.y1--;
389    } else {
390       /*
391        * OpenGL legacy rasterization rules for non-sprite points.
392        *
393        * Per OpenGL 2.1 spec, section 3.3.1, "Basic Point Rasterization".
394        *
395        * This type of point rasterization is only available in pre 3.0 contexts
396        * (or compatibilility contexts which we don't support) anyway.
397        */
398 
399       const int x0 = subpixel_snap(v0[0][0]);
400       const int y0 = subpixel_snap(v0[0][1]) - adj;
401 
402       int int_width;
403       /* Point size as fixed point integer. For GL legacy points
404        * the point size is always a whole integer.
405        */
406       fixed_width = MAX2(FIXED_ONE,
407                          (subpixel_snap(size) + FIXED_ONE/2 - 1) & ~(FIXED_ONE-1));
408       int_width = fixed_width >> FIXED_ORDER;
409 
410       assert(setup->pixel_offset != 0);
411 
412       if (int_width == 1) {
413          bbox.x0 = x0 >> FIXED_ORDER;
414          bbox.y0 = y0 >> FIXED_ORDER;
415          bbox.x1 = bbox.x0;
416          bbox.y1 = bbox.y0;
417       } else {
418          if (int_width & 1) {
419             /* Odd width */
420             bbox.x0 = (x0 >> FIXED_ORDER) - (int_width - 1)/2;
421             bbox.y0 = (y0 >> FIXED_ORDER) - (int_width - 1)/2;
422          } else {
423             /* Even width */
424             bbox.x0 = ((x0 + FIXED_ONE/2) >> FIXED_ORDER) - int_width/2;
425             bbox.y0 = ((y0 + FIXED_ONE/2) >> FIXED_ORDER) - int_width/2;
426          }
427 
428          bbox.x1 = bbox.x0 + int_width - 1;
429          bbox.y1 = bbox.y0 + int_width - 1;
430       }
431    }
432 
433    if (0) {
434       debug_printf("  bbox: (%i, %i) - (%i, %i)\n",
435                    bbox.x0, bbox.y0,
436                    bbox.x1, bbox.y1);
437    }
438 
439    if (!u_rect_test_intersection(&setup->draw_regions[viewport_index], &bbox)) {
440       if (0) debug_printf("offscreen\n");
441       LP_COUNT(nr_culled_tris);
442       return TRUE;
443    }
444 
445    u_rect_find_intersection(&setup->draw_regions[viewport_index], &bbox);
446 
447    point = lp_setup_alloc_triangle(scene,
448                                    key->num_inputs,
449                                    nr_planes,
450                                    &bytes);
451    if (!point)
452       return FALSE;
453 
454 #ifdef DEBUG
455    point->v[0][0] = v0[0][0];
456    point->v[0][1] = v0[0][1];
457 #endif
458 
459    LP_COUNT(nr_tris);
460 
461    if (lp_context->active_statistics_queries &&
462        !llvmpipe_rasterization_disabled(lp_context)) {
463       lp_context->pipeline_statistics.c_primitives++;
464    }
465 
466    if (draw_will_inject_frontface(lp_context->draw) &&
467        setup->face_slot > 0) {
468       point->inputs.frontfacing = v0[setup->face_slot][0];
469    } else {
470       point->inputs.frontfacing = TRUE;
471    }
472 
473    info.v0 = v0;
474    info.dx01 = 0;
475    info.dx12 = fixed_width;
476    info.dy01 = fixed_width;
477    info.dy12 = 0;
478    info.a0 = GET_A0(&point->inputs);
479    info.dadx = GET_DADX(&point->inputs);
480    info.dady = GET_DADY(&point->inputs);
481    info.frontfacing = point->inputs.frontfacing;
482 
483    /* Setup parameter interpolants:
484     */
485    setup_point_coefficients(setup, &info);
486 
487    point->inputs.disable = FALSE;
488    point->inputs.opaque = FALSE;
489    point->inputs.layer = layer;
490    point->inputs.viewport_index = viewport_index;
491 
492    {
493       struct lp_rast_plane *plane = GET_PLANES(point);
494 
495       plane[0].dcdx = -1 << 8;
496       plane[0].dcdy = 0;
497       plane[0].c = (1-bbox.x0) << 8;
498       plane[0].eo = 1 << 8;
499 
500       plane[1].dcdx = 1 << 8;
501       plane[1].dcdy = 0;
502       plane[1].c = (bbox.x1+1) << 8;
503       plane[1].eo = 0;
504 
505       plane[2].dcdx = 0;
506       plane[2].dcdy = 1 << 8;
507       plane[2].c = (1-bbox.y0) << 8;
508       plane[2].eo = 1 << 8;
509 
510       plane[3].dcdx = 0;
511       plane[3].dcdy = -1 << 8;
512       plane[3].c = (bbox.y1+1) << 8;
513       plane[3].eo = 0;
514    }
515 
516    return lp_setup_bin_triangle(setup, point, &bbox, nr_planes, viewport_index);
517 }
518 
519 
520 static void
lp_setup_point(struct lp_setup_context * setup,const float (* v0)[4])521 lp_setup_point(struct lp_setup_context *setup,
522                const float (*v0)[4])
523 {
524    if (!try_setup_point( setup, v0 ))
525    {
526       if (!lp_setup_flush_and_restart(setup))
527          return;
528 
529       if (!try_setup_point( setup, v0 ))
530          return;
531    }
532 }
533 
534 
535 void
lp_setup_choose_point(struct lp_setup_context * setup)536 lp_setup_choose_point( struct lp_setup_context *setup )
537 {
538    setup->point = lp_setup_point;
539 }
540 
541 
542