1/*
2 Copyright (C) Intel Corp.  2006.  All Rights Reserved.
3 Intel funded Tungsten Graphics to
4 develop this 3D driver.
5
6 Permission is hereby granted, free of charge, to any person obtaining
7 a 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, sublicense, 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
16 portions of the Software.
17
18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21 IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
22 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
23 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
24 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25
26 **********************************************************************/
27 /*
28  * Authors:
29  *   Keith Whitwell <keithw@vmware.com>
30  */
31
32#include "main/macros.h"
33#include "main/enums.h"
34#include "program/program.h"
35
36#include "brw_clip.h"
37
38
39/* This is performed against the original triangles, so no indirection
40 * required:
41BZZZT!
42 */
43static void compute_tri_direction( struct brw_clip_compile *c )
44{
45   struct brw_codegen *p = &c->func;
46   struct brw_reg e = c->reg.tmp0;
47   struct brw_reg f = c->reg.tmp1;
48   GLuint hpos_offset = brw_varying_to_offset(&c->vue_map, VARYING_SLOT_POS);
49   struct brw_reg v0 = byte_offset(c->reg.vertex[0], hpos_offset);
50   struct brw_reg v1 = byte_offset(c->reg.vertex[1], hpos_offset);
51   struct brw_reg v2 = byte_offset(c->reg.vertex[2], hpos_offset);
52
53
54   struct brw_reg v0n = get_tmp(c);
55   struct brw_reg v1n = get_tmp(c);
56   struct brw_reg v2n = get_tmp(c);
57
58   /* Convert to NDC.
59    * NOTE: We can't modify the original vertex coordinates,
60    * as it may impact further operations.
61    * So, we have to keep normalized coordinates in temp registers.
62    *
63    * TBD-KC
64    * Try to optimize unnecessary MOV's.
65    */
66   brw_MOV(p, v0n, v0);
67   brw_MOV(p, v1n, v1);
68   brw_MOV(p, v2n, v2);
69
70   brw_clip_project_position(c, v0n);
71   brw_clip_project_position(c, v1n);
72   brw_clip_project_position(c, v2n);
73
74   /* Calculate the vectors of two edges of the triangle:
75    */
76   brw_ADD(p, e, v0n, negate(v2n));
77   brw_ADD(p, f, v1n, negate(v2n));
78
79   /* Take their crossproduct:
80    */
81   brw_set_default_access_mode(p, BRW_ALIGN_16);
82   brw_MUL(p, vec4(brw_null_reg()), brw_swizzle(e, BRW_SWIZZLE_YZXW),
83           brw_swizzle(f, BRW_SWIZZLE_ZXYW));
84   brw_MAC(p, vec4(e),  negate(brw_swizzle(e, BRW_SWIZZLE_ZXYW)),
85           brw_swizzle(f, BRW_SWIZZLE_YZXW));
86   brw_set_default_access_mode(p, BRW_ALIGN_1);
87
88   brw_MUL(p, c->reg.dir, c->reg.dir, vec4(e));
89}
90
91
92static void cull_direction( struct brw_clip_compile *c )
93{
94   struct brw_codegen *p = &c->func;
95   GLuint conditional;
96
97   assert (!(c->key.fill_ccw == BRW_CLIP_FILL_MODE_CULL &&
98	     c->key.fill_cw == BRW_CLIP_FILL_MODE_CULL));
99
100   if (c->key.fill_ccw == BRW_CLIP_FILL_MODE_CULL)
101      conditional = BRW_CONDITIONAL_GE;
102   else
103      conditional = BRW_CONDITIONAL_L;
104
105   brw_CMP(p,
106	   vec1(brw_null_reg()),
107	   conditional,
108	   get_element(c->reg.dir, 2),
109	   brw_imm_f(0));
110
111   brw_IF(p, BRW_EXECUTE_1);
112   {
113      brw_clip_kill_thread(c);
114   }
115   brw_ENDIF(p);
116}
117
118
119
120static void copy_bfc( struct brw_clip_compile *c )
121{
122   struct brw_codegen *p = &c->func;
123   GLuint conditional;
124
125   /* Do we have any colors to copy?
126    */
127   if (!(brw_clip_have_varying(c, VARYING_SLOT_COL0) &&
128         brw_clip_have_varying(c, VARYING_SLOT_BFC0)) &&
129       !(brw_clip_have_varying(c, VARYING_SLOT_COL1) &&
130         brw_clip_have_varying(c, VARYING_SLOT_BFC1)))
131      return;
132
133   /* In some weird degenerate cases we can end up testing the
134    * direction twice, once for culling and once for bfc copying.  Oh
135    * well, that's what you get for setting weird GL state.
136    */
137   if (c->key.copy_bfc_ccw)
138      conditional = BRW_CONDITIONAL_GE;
139   else
140      conditional = BRW_CONDITIONAL_L;
141
142   brw_CMP(p,
143	   vec1(brw_null_reg()),
144	   conditional,
145	   get_element(c->reg.dir, 2),
146	   brw_imm_f(0));
147
148   brw_IF(p, BRW_EXECUTE_1);
149   {
150      GLuint i;
151
152      for (i = 0; i < 3; i++) {
153	 if (brw_clip_have_varying(c, VARYING_SLOT_COL0) &&
154             brw_clip_have_varying(c, VARYING_SLOT_BFC0))
155	    brw_MOV(p,
156		    byte_offset(c->reg.vertex[i],
157                                brw_varying_to_offset(&c->vue_map,
158                                                      VARYING_SLOT_COL0)),
159		    byte_offset(c->reg.vertex[i],
160                                brw_varying_to_offset(&c->vue_map,
161                                                      VARYING_SLOT_BFC0)));
162
163	 if (brw_clip_have_varying(c, VARYING_SLOT_COL1) &&
164             brw_clip_have_varying(c, VARYING_SLOT_BFC1))
165	    brw_MOV(p,
166		    byte_offset(c->reg.vertex[i],
167                                brw_varying_to_offset(&c->vue_map,
168                                                      VARYING_SLOT_COL1)),
169		    byte_offset(c->reg.vertex[i],
170                                brw_varying_to_offset(&c->vue_map,
171                                                      VARYING_SLOT_BFC1)));
172      }
173   }
174   brw_ENDIF(p);
175}
176
177
178
179
180/*
181  GLfloat iz	= 1.0 / dir.z;
182  GLfloat ac	= dir.x * iz;
183  GLfloat bc	= dir.y * iz;
184  offset = ctx->Polygon.OffsetUnits * DEPTH_SCALE;
185  offset += MAX2( abs(ac), abs(bc) ) * ctx->Polygon.OffsetFactor;
186  if (ctx->Polygon.OffsetClamp && isfinite(ctx->Polygon.OffsetClamp)) {
187    if (ctx->Polygon.OffsetClamp < 0)
188      offset = MAX2( offset, ctx->Polygon.OffsetClamp );
189    else
190      offset = MIN2( offset, ctx->Polygon.OffsetClamp );
191  }
192  offset *= MRD;
193*/
194static void compute_offset( struct brw_clip_compile *c )
195{
196   struct brw_codegen *p = &c->func;
197   struct brw_reg off = c->reg.offset;
198   struct brw_reg dir = c->reg.dir;
199
200   brw_math_invert(p, get_element(off, 2), get_element(dir, 2));
201   brw_MUL(p, vec2(off), vec2(dir), get_element(off, 2));
202
203   brw_CMP(p,
204	   vec1(brw_null_reg()),
205	   BRW_CONDITIONAL_GE,
206	   brw_abs(get_element(off, 0)),
207	   brw_abs(get_element(off, 1)));
208
209   brw_SEL(p, vec1(off),
210           brw_abs(get_element(off, 0)), brw_abs(get_element(off, 1)));
211   brw_inst_set_pred_control(p->devinfo, brw_last_inst, BRW_PREDICATE_NORMAL);
212
213   brw_MUL(p, vec1(off), vec1(off), brw_imm_f(c->key.offset_factor));
214   brw_ADD(p, vec1(off), vec1(off), brw_imm_f(c->key.offset_units));
215   if (c->key.offset_clamp && isfinite(c->key.offset_clamp)) {
216      brw_CMP(p,
217              vec1(brw_null_reg()),
218              c->key.offset_clamp < 0 ? BRW_CONDITIONAL_GE : BRW_CONDITIONAL_L,
219              vec1(off),
220              brw_imm_f(c->key.offset_clamp));
221      brw_SEL(p, vec1(off), vec1(off), brw_imm_f(c->key.offset_clamp));
222   }
223}
224
225
226static void merge_edgeflags( struct brw_clip_compile *c )
227{
228   struct brw_codegen *p = &c->func;
229   struct brw_reg tmp0 = get_element_ud(c->reg.tmp0, 0);
230
231   brw_AND(p, tmp0, get_element_ud(c->reg.R0, 2), brw_imm_ud(PRIM_MASK));
232   brw_CMP(p,
233	   vec1(brw_null_reg()),
234	   BRW_CONDITIONAL_EQ,
235	   tmp0,
236	   brw_imm_ud(_3DPRIM_POLYGON));
237
238   /* Get away with using reg.vertex because we know that this is not
239    * a _3DPRIM_TRISTRIP_REVERSE:
240    */
241   brw_IF(p, BRW_EXECUTE_1);
242   {
243      brw_AND(p, vec1(brw_null_reg()), get_element_ud(c->reg.R0, 2), brw_imm_ud(1<<8));
244      brw_inst_set_cond_modifier(p->devinfo, brw_last_inst, BRW_CONDITIONAL_EQ);
245      brw_MOV(p, byte_offset(c->reg.vertex[0],
246                             brw_varying_to_offset(&c->vue_map,
247                                                   VARYING_SLOT_EDGE)),
248              brw_imm_f(0));
249      brw_inst_set_pred_control(p->devinfo, brw_last_inst, BRW_PREDICATE_NORMAL);
250
251      brw_AND(p, vec1(brw_null_reg()), get_element_ud(c->reg.R0, 2), brw_imm_ud(1<<9));
252      brw_inst_set_cond_modifier(p->devinfo, brw_last_inst, BRW_CONDITIONAL_EQ);
253      brw_MOV(p, byte_offset(c->reg.vertex[2],
254                             brw_varying_to_offset(&c->vue_map,
255                                                   VARYING_SLOT_EDGE)),
256              brw_imm_f(0));
257      brw_inst_set_pred_control(p->devinfo, brw_last_inst, BRW_PREDICATE_NORMAL);
258   }
259   brw_ENDIF(p);
260}
261
262
263
264static void apply_one_offset( struct brw_clip_compile *c,
265			  struct brw_indirect vert )
266{
267   struct brw_codegen *p = &c->func;
268   GLuint ndc_offset = brw_varying_to_offset(&c->vue_map,
269                                             BRW_VARYING_SLOT_NDC);
270   struct brw_reg z = deref_1f(vert, ndc_offset +
271			       2 * type_sz(BRW_REGISTER_TYPE_F));
272
273   brw_ADD(p, z, z, vec1(c->reg.offset));
274}
275
276
277
278/***********************************************************************
279 * Output clipped polygon as an unfilled primitive:
280 */
281static void emit_lines(struct brw_clip_compile *c,
282		       bool do_offset)
283{
284   struct brw_codegen *p = &c->func;
285   struct brw_indirect v0 = brw_indirect(0, 0);
286   struct brw_indirect v1 = brw_indirect(1, 0);
287   struct brw_indirect v0ptr = brw_indirect(2, 0);
288   struct brw_indirect v1ptr = brw_indirect(3, 0);
289
290   /* Need a separate loop for offset:
291    */
292   if (do_offset) {
293      brw_MOV(p, c->reg.loopcount, c->reg.nr_verts);
294      brw_MOV(p, get_addr_reg(v0ptr), brw_address(c->reg.inlist));
295
296      brw_DO(p, BRW_EXECUTE_1);
297      {
298	 brw_MOV(p, get_addr_reg(v0), deref_1uw(v0ptr, 0));
299	 brw_ADD(p, get_addr_reg(v0ptr), get_addr_reg(v0ptr), brw_imm_uw(2));
300
301	 apply_one_offset(c, v0);
302
303	 brw_ADD(p, c->reg.loopcount, c->reg.loopcount, brw_imm_d(-1));
304         brw_inst_set_cond_modifier(p->devinfo, brw_last_inst, BRW_CONDITIONAL_G);
305      }
306      brw_WHILE(p);
307      brw_inst_set_pred_control(p->devinfo, brw_last_inst, BRW_PREDICATE_NORMAL);
308   }
309
310   /* v1ptr = &inlist[nr_verts]
311    * *v1ptr = v0
312    */
313   brw_MOV(p, c->reg.loopcount, c->reg.nr_verts);
314   brw_MOV(p, get_addr_reg(v0ptr), brw_address(c->reg.inlist));
315   brw_ADD(p, get_addr_reg(v1ptr), get_addr_reg(v0ptr), retype(c->reg.nr_verts, BRW_REGISTER_TYPE_UW));
316   brw_ADD(p, get_addr_reg(v1ptr), get_addr_reg(v1ptr), retype(c->reg.nr_verts, BRW_REGISTER_TYPE_UW));
317   brw_MOV(p, deref_1uw(v1ptr, 0), deref_1uw(v0ptr, 0));
318
319   brw_DO(p, BRW_EXECUTE_1);
320   {
321      brw_MOV(p, get_addr_reg(v0), deref_1uw(v0ptr, 0));
322      brw_MOV(p, get_addr_reg(v1), deref_1uw(v0ptr, 2));
323      brw_ADD(p, get_addr_reg(v0ptr), get_addr_reg(v0ptr), brw_imm_uw(2));
324
325      /* draw edge if edgeflag != 0 */
326      brw_CMP(p,
327	      vec1(brw_null_reg()), BRW_CONDITIONAL_NZ,
328	      deref_1f(v0, brw_varying_to_offset(&c->vue_map,
329                                                 VARYING_SLOT_EDGE)),
330	      brw_imm_f(0));
331      brw_IF(p, BRW_EXECUTE_1);
332      {
333	 brw_clip_emit_vue(c, v0, BRW_URB_WRITE_ALLOCATE_COMPLETE,
334                           (_3DPRIM_LINESTRIP << URB_WRITE_PRIM_TYPE_SHIFT)
335                           | URB_WRITE_PRIM_START);
336	 brw_clip_emit_vue(c, v1, BRW_URB_WRITE_ALLOCATE_COMPLETE,
337                           (_3DPRIM_LINESTRIP << URB_WRITE_PRIM_TYPE_SHIFT)
338                           | URB_WRITE_PRIM_END);
339      }
340      brw_ENDIF(p);
341
342      brw_ADD(p, c->reg.loopcount, c->reg.loopcount, brw_imm_d(-1));
343      brw_inst_set_cond_modifier(p->devinfo, brw_last_inst, BRW_CONDITIONAL_NZ);
344   }
345   brw_WHILE(p);
346   brw_inst_set_pred_control(p->devinfo, brw_last_inst, BRW_PREDICATE_NORMAL);
347}
348
349
350
351static void emit_points(struct brw_clip_compile *c,
352			bool do_offset )
353{
354   struct brw_codegen *p = &c->func;
355
356   struct brw_indirect v0 = brw_indirect(0, 0);
357   struct brw_indirect v0ptr = brw_indirect(2, 0);
358
359   brw_MOV(p, c->reg.loopcount, c->reg.nr_verts);
360   brw_MOV(p, get_addr_reg(v0ptr), brw_address(c->reg.inlist));
361
362   brw_DO(p, BRW_EXECUTE_1);
363   {
364      brw_MOV(p, get_addr_reg(v0), deref_1uw(v0ptr, 0));
365      brw_ADD(p, get_addr_reg(v0ptr), get_addr_reg(v0ptr), brw_imm_uw(2));
366
367      /* draw if edgeflag != 0
368       */
369      brw_CMP(p,
370	      vec1(brw_null_reg()), BRW_CONDITIONAL_NZ,
371	      deref_1f(v0, brw_varying_to_offset(&c->vue_map,
372                                                 VARYING_SLOT_EDGE)),
373	      brw_imm_f(0));
374      brw_IF(p, BRW_EXECUTE_1);
375      {
376	 if (do_offset)
377	    apply_one_offset(c, v0);
378
379	 brw_clip_emit_vue(c, v0, BRW_URB_WRITE_ALLOCATE_COMPLETE,
380                           (_3DPRIM_POINTLIST << URB_WRITE_PRIM_TYPE_SHIFT)
381                           | URB_WRITE_PRIM_START | URB_WRITE_PRIM_END);
382      }
383      brw_ENDIF(p);
384
385      brw_ADD(p, c->reg.loopcount, c->reg.loopcount, brw_imm_d(-1));
386      brw_inst_set_cond_modifier(p->devinfo, brw_last_inst, BRW_CONDITIONAL_NZ);
387   }
388   brw_WHILE(p);
389   brw_inst_set_pred_control(p->devinfo, brw_last_inst, BRW_PREDICATE_NORMAL);
390}
391
392
393
394
395
396
397
398static void emit_primitives( struct brw_clip_compile *c,
399			     GLuint mode,
400			     bool do_offset )
401{
402   switch (mode) {
403   case BRW_CLIP_FILL_MODE_FILL:
404      brw_clip_tri_emit_polygon(c);
405      break;
406
407   case BRW_CLIP_FILL_MODE_LINE:
408      emit_lines(c, do_offset);
409      break;
410
411   case BRW_CLIP_FILL_MODE_POINT:
412      emit_points(c, do_offset);
413      break;
414
415   case BRW_CLIP_FILL_MODE_CULL:
416      unreachable("not reached");
417   }
418}
419
420
421
422static void emit_unfilled_primitives( struct brw_clip_compile *c )
423{
424   struct brw_codegen *p = &c->func;
425
426   /* Direction culling has already been done.
427    */
428   if (c->key.fill_ccw != c->key.fill_cw &&
429       c->key.fill_ccw != BRW_CLIP_FILL_MODE_CULL &&
430       c->key.fill_cw != BRW_CLIP_FILL_MODE_CULL)
431   {
432      brw_CMP(p,
433	      vec1(brw_null_reg()),
434	      BRW_CONDITIONAL_GE,
435	      get_element(c->reg.dir, 2),
436	      brw_imm_f(0));
437
438      brw_IF(p, BRW_EXECUTE_1);
439      {
440	 emit_primitives(c, c->key.fill_ccw, c->key.offset_ccw);
441      }
442      brw_ELSE(p);
443      {
444	 emit_primitives(c, c->key.fill_cw, c->key.offset_cw);
445      }
446      brw_ENDIF(p);
447   }
448   else if (c->key.fill_cw != BRW_CLIP_FILL_MODE_CULL) {
449      emit_primitives(c, c->key.fill_cw, c->key.offset_cw);
450   }
451   else if (c->key.fill_ccw != BRW_CLIP_FILL_MODE_CULL) {
452      emit_primitives(c, c->key.fill_ccw, c->key.offset_ccw);
453   }
454}
455
456
457
458
459static void check_nr_verts( struct brw_clip_compile *c )
460{
461   struct brw_codegen *p = &c->func;
462
463   brw_CMP(p, vec1(brw_null_reg()), BRW_CONDITIONAL_L, c->reg.nr_verts, brw_imm_d(3));
464   brw_IF(p, BRW_EXECUTE_1);
465   {
466      brw_clip_kill_thread(c);
467   }
468   brw_ENDIF(p);
469}
470
471
472void brw_emit_unfilled_clip( struct brw_clip_compile *c )
473{
474   struct brw_codegen *p = &c->func;
475
476   c->need_direction = ((c->key.offset_ccw || c->key.offset_cw) ||
477			(c->key.fill_ccw != c->key.fill_cw) ||
478			c->key.fill_ccw == BRW_CLIP_FILL_MODE_CULL ||
479			c->key.fill_cw == BRW_CLIP_FILL_MODE_CULL ||
480			c->key.copy_bfc_cw ||
481			c->key.copy_bfc_ccw);
482
483   brw_clip_tri_alloc_regs(c, 3 + c->key.nr_userclip + 6);
484   brw_clip_tri_init_vertices(c);
485   brw_clip_init_ff_sync(c);
486
487   assert(brw_clip_have_varying(c, VARYING_SLOT_EDGE));
488
489   if (c->key.fill_ccw == BRW_CLIP_FILL_MODE_CULL &&
490       c->key.fill_cw == BRW_CLIP_FILL_MODE_CULL) {
491      brw_clip_kill_thread(c);
492      return;
493   }
494
495   merge_edgeflags(c);
496
497   /* Need to use the inlist indirection here:
498    */
499   if (c->need_direction)
500      compute_tri_direction(c);
501
502   if (c->key.fill_ccw == BRW_CLIP_FILL_MODE_CULL ||
503       c->key.fill_cw == BRW_CLIP_FILL_MODE_CULL)
504      cull_direction(c);
505
506   if (c->key.offset_ccw ||
507       c->key.offset_cw)
508      compute_offset(c);
509
510   if (c->key.copy_bfc_ccw ||
511       c->key.copy_bfc_cw)
512      copy_bfc(c);
513
514   /* Need to do this whether we clip or not:
515    */
516   if (c->key.contains_flat_varying)
517      brw_clip_tri_flat_shade(c);
518
519   brw_clip_init_clipmask(c);
520   brw_CMP(p, vec1(brw_null_reg()), BRW_CONDITIONAL_NZ, c->reg.planemask, brw_imm_ud(0));
521   brw_IF(p, BRW_EXECUTE_1);
522   {
523      brw_clip_init_planes(c);
524      brw_clip_tri(c);
525      check_nr_verts(c);
526   }
527   brw_ENDIF(p);
528
529   emit_unfilled_primitives(c);
530   brw_clip_kill_thread(c);
531}
532