1 /**************************************************************************
3 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
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:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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 TUNGSTEN GRAPHICS 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.
26 **************************************************************************/
29 * Binning code for triangles
32 #include "util/u_math.h"
33 #include "util/u_memory.h"
34 #include "util/u_rect.h"
35 #include "util/u_sse.h"
37 #include "lp_setup_context.h"
39 #include "lp_state_fs.h"
40 #include "lp_state_setup.h"
42 #define NUM_CHANNELS 4
44 #if defined(PIPE_ARCH_SSE)
45 #include <emmintrin.h>
49 subpixel_snap(float a
)
51 return util_iround(FIXED_ONE
* a
);
57 return a
* (1.0f
/ FIXED_ONE
);
61 /* Position and area in fixed point coordinates */
62 struct fixed_position
{
74 * Alloc space for a new triangle plus the input.a0/dadx/dady arrays
75 * immediately after it.
76 * The memory is allocated from the per-scene pool, not per-tile.
77 * \param tri_size returns number of bytes allocated
78 * \param num_inputs number of fragment shader inputs
79 * \return pointer to triangle space
81 struct lp_rast_triangle
*
82 lp_setup_alloc_triangle(struct lp_scene
*scene
,
87 unsigned input_array_sz
= NUM_CHANNELS
* (nr_inputs
+ 1) * sizeof(float);
88 unsigned plane_sz
= nr_planes
* sizeof(struct lp_rast_plane
);
89 struct lp_rast_triangle
*tri
;
91 *tri_size
= (sizeof(struct lp_rast_triangle
) +
95 tri
= lp_scene_alloc_aligned( scene
, *tri_size
, 16 );
99 tri
->inputs
.stride
= input_array_sz
;
102 char *a
= (char *)tri
;
103 char *b
= (char *)&GET_PLANES(tri
)[nr_planes
];
104 assert(b
- a
== *tri_size
);
111 lp_setup_print_vertex(struct lp_setup_context
*setup
,
115 const struct lp_setup_variant_key
*key
= &setup
->setup
.variant
->key
;
118 debug_printf(" wpos (%s[0]) xyzw %f %f %f %f\n",
120 v
[0][0], v
[0][1], v
[0][2], v
[0][3]);
122 for (i
= 0; i
< key
->num_inputs
; i
++) {
123 const float *in
= v
[key
->inputs
[i
].src_index
];
125 debug_printf(" in[%d] (%s[%d]) %s%s%s%s ",
127 name
, key
->inputs
[i
].src_index
,
128 (key
->inputs
[i
].usage_mask
& 0x1) ? "x" : " ",
129 (key
->inputs
[i
].usage_mask
& 0x2) ? "y" : " ",
130 (key
->inputs
[i
].usage_mask
& 0x4) ? "z" : " ",
131 (key
->inputs
[i
].usage_mask
& 0x8) ? "w" : " ");
133 for (j
= 0; j
< 4; j
++)
134 if (key
->inputs
[i
].usage_mask
& (1<<j
))
135 debug_printf("%.5f ", in
[j
]);
143 * Print triangle vertex attribs (for debug).
146 lp_setup_print_triangle(struct lp_setup_context
*setup
,
147 const float (*v0
)[4],
148 const float (*v1
)[4],
149 const float (*v2
)[4])
151 debug_printf("triangle\n");
154 const float ex
= v0
[0][0] - v2
[0][0];
155 const float ey
= v0
[0][1] - v2
[0][1];
156 const float fx
= v1
[0][0] - v2
[0][0];
157 const float fy
= v1
[0][1] - v2
[0][1];
159 /* det = cross(e,f).z */
160 const float det
= ex
* fy
- ey
* fx
;
162 debug_printf(" - ccw\n");
164 debug_printf(" - cw\n");
166 debug_printf(" - zero area\n");
169 lp_setup_print_vertex(setup
, "v0", v0
);
170 lp_setup_print_vertex(setup
, "v1", v1
);
171 lp_setup_print_vertex(setup
, "v2", v2
);
177 lp_rast_tri_tab
[MAX_PLANES
+1] = {
178 0, /* should be impossible */
179 LP_RAST_OP_TRIANGLE_1
,
180 LP_RAST_OP_TRIANGLE_2
,
181 LP_RAST_OP_TRIANGLE_3
,
182 LP_RAST_OP_TRIANGLE_4
,
183 LP_RAST_OP_TRIANGLE_5
,
184 LP_RAST_OP_TRIANGLE_6
,
185 LP_RAST_OP_TRIANGLE_7
,
186 LP_RAST_OP_TRIANGLE_8
192 * The primitive covers the whole tile- shade whole tile.
194 * \param tx, ty the tile position in tiles, not pixels
197 lp_setup_whole_tile(struct lp_setup_context
*setup
,
198 const struct lp_rast_shader_inputs
*inputs
,
201 struct lp_scene
*scene
= setup
->scene
;
203 LP_COUNT(nr_fully_covered_64
);
205 /* if variant is opaque and scissor doesn't effect the tile */
206 if (inputs
->opaque
) {
207 if (!scene
->fb
.zsbuf
) {
209 * All previous rendering will be overwritten so reset the bin.
211 lp_scene_bin_reset( scene
, tx
, ty
);
214 LP_COUNT(nr_shade_opaque_64
);
215 return lp_scene_bin_cmd_with_state( scene
, tx
, ty
,
217 LP_RAST_OP_SHADE_TILE_OPAQUE
,
218 lp_rast_arg_inputs(inputs
) );
220 LP_COUNT(nr_shade_64
);
221 return lp_scene_bin_cmd_with_state( scene
, tx
, ty
,
223 LP_RAST_OP_SHADE_TILE
,
224 lp_rast_arg_inputs(inputs
) );
230 * Do basic setup for triangle rasterization and determine which
231 * framebuffer tiles are touched. Put the triangle in the scene's
232 * bins for the tiles which we overlap.
235 do_triangle_ccw(struct lp_setup_context
*setup
,
236 struct fixed_position
* position
,
237 const float (*v0
)[4],
238 const float (*v1
)[4],
239 const float (*v2
)[4],
240 boolean frontfacing
)
242 struct lp_scene
*scene
= setup
->scene
;
243 const struct lp_setup_variant_key
*key
= &setup
->setup
.variant
->key
;
244 struct lp_rast_triangle
*tri
;
245 struct lp_rast_plane
*plane
;
249 unsigned scissor_index
= 0;
251 /* Area should always be positive here */
252 assert(position
->area
> 0);
255 lp_setup_print_triangle(setup
, v0
, v1
, v2
);
257 if (setup
->scissor_test
) {
259 if (setup
->viewport_index_slot
> 0) {
260 unsigned *udata
= (unsigned*)v0
[setup
->viewport_index_slot
];
261 scissor_index
= lp_clamp_scissor_idx(*udata
);
268 /* Bounding rectangle (in pixels) */
270 /* Yes this is necessary to accurately calculate bounding boxes
271 * with the two fill-conventions we support. GL (normally) ends
272 * up needing a bottom-left fill convention, which requires
273 * slightly different rounding.
275 int adj
= (setup
->pixel_offset
!= 0) ? 1 : 0;
277 /* Inclusive x0, exclusive x1 */
278 bbox
.x0
= MIN3(position
->x
[0], position
->x
[1], position
->x
[2]) >> FIXED_ORDER
;
279 bbox
.x1
= (MAX3(position
->x
[0], position
->x
[1], position
->x
[2]) - 1) >> FIXED_ORDER
;
281 /* Inclusive / exclusive depending upon adj (bottom-left or top-right) */
282 bbox
.y0
= (MIN3(position
->y
[0], position
->y
[1], position
->y
[2]) + adj
) >> FIXED_ORDER
;
283 bbox
.y1
= (MAX3(position
->y
[0], position
->y
[1], position
->y
[2]) - 1 + adj
) >> FIXED_ORDER
;
286 if (bbox
.x1
< bbox
.x0
||
288 if (0) debug_printf("empty bounding box\n");
289 LP_COUNT(nr_culled_tris
);
293 if (!u_rect_test_intersection(&setup
->draw_regions
[scissor_index
], &bbox
)) {
294 if (0) debug_printf("offscreen\n");
295 LP_COUNT(nr_culled_tris
);
299 /* Can safely discard negative regions, but need to keep hold of
300 * information about when the triangle extends past screen
301 * boundaries. See trimmed_box in lp_setup_bin_triangle().
303 bbox
.x0
= MAX2(bbox
.x0
, 0);
304 bbox
.y0
= MAX2(bbox
.y0
, 0);
306 tri
= lp_setup_alloc_triangle(scene
,
314 tri
->v
[0][0] = v0
[0][0];
315 tri
->v
[1][0] = v1
[0][0];
316 tri
->v
[2][0] = v2
[0][0];
317 tri
->v
[0][1] = v0
[0][1];
318 tri
->v
[1][1] = v1
[0][1];
319 tri
->v
[2][1] = v2
[0][1];
324 /* Setup parameter interpolants:
326 setup
->setup
.variant
->jit_function( v0
,
330 GET_A0(&tri
->inputs
),
331 GET_DADX(&tri
->inputs
),
332 GET_DADY(&tri
->inputs
) );
334 tri
->inputs
.frontfacing
= frontfacing
;
335 tri
->inputs
.disable
= FALSE
;
336 tri
->inputs
.opaque
= setup
->fs
.current
.variant
->opaque
;
339 lp_dump_setup_coef(&setup
->setup
.variant
->key
,
340 (const float (*)[4])GET_A0(&tri
->inputs
),
341 (const float (*)[4])GET_DADX(&tri
->inputs
),
342 (const float (*)[4])GET_DADY(&tri
->inputs
));
344 plane
= GET_PLANES(tri
);
346 #if defined(PIPE_ARCH_SSE)
348 __m128i vertx
, verty
;
349 __m128i shufx
, shufy
;
350 __m128i dcdx
, dcdy
, c
;
352 __m128i dcdx_neg_mask
;
353 __m128i dcdy_neg_mask
;
354 __m128i dcdx_zero_mask
;
355 __m128i top_left_flag
;
356 __m128i c_inc_mask
, c_inc
;
357 __m128i eo
, p0
, p1
, p2
;
358 __m128i zero
= _mm_setzero_si128();
360 vertx
= _mm_loadu_si128((__m128i
*)position
->x
); /* vertex x coords */
361 verty
= _mm_loadu_si128((__m128i
*)position
->y
); /* vertex y coords */
363 shufx
= _mm_shuffle_epi32(vertx
, _MM_SHUFFLE(3,0,2,1));
364 shufy
= _mm_shuffle_epi32(verty
, _MM_SHUFFLE(3,0,2,1));
366 dcdx
= _mm_sub_epi32(verty
, shufy
);
367 dcdy
= _mm_sub_epi32(vertx
, shufx
);
369 dcdx_neg_mask
= _mm_srai_epi32(dcdx
, 31);
370 dcdx_zero_mask
= _mm_cmpeq_epi32(dcdx
, zero
);
371 dcdy_neg_mask
= _mm_srai_epi32(dcdy
, 31);
373 top_left_flag
= _mm_set1_epi32((setup
->bottom_edge_rule
== 0) ? ~0 : 0);
375 c_inc_mask
= _mm_or_si128(dcdx_neg_mask
,
376 _mm_and_si128(dcdx_zero_mask
,
377 _mm_xor_si128(dcdy_neg_mask
,
380 c_inc
= _mm_srli_epi32(c_inc_mask
, 31);
382 c
= _mm_sub_epi32(mm_mullo_epi32(dcdx
, vertx
),
383 mm_mullo_epi32(dcdy
, verty
));
385 c
= _mm_add_epi32(c
, c_inc
);
387 /* Scale up to match c:
389 dcdx
= _mm_slli_epi32(dcdx
, FIXED_ORDER
);
390 dcdy
= _mm_slli_epi32(dcdy
, FIXED_ORDER
);
392 /* Calculate trivial reject values:
394 eo
= _mm_sub_epi32(_mm_andnot_si128(dcdy_neg_mask
, dcdy
),
395 _mm_and_si128(dcdx_neg_mask
, dcdx
));
397 /* ei = _mm_sub_epi32(_mm_sub_epi32(dcdy, dcdx), eo); */
399 /* Pointless transpose which gets undone immediately in
402 transpose4_epi32(&c
, &dcdx
, &dcdy
, &eo
,
403 &p0
, &p1
, &p2
, &unused
);
405 _mm_store_si128((__m128i
*)&plane
[0], p0
);
406 _mm_store_si128((__m128i
*)&plane
[1], p1
);
407 _mm_store_si128((__m128i
*)&plane
[2], p2
);
412 plane
[0].dcdy
= position
->dx01
;
413 plane
[1].dcdy
= position
->x
[1] - position
->x
[2];
414 plane
[2].dcdy
= position
->dx20
;
415 plane
[0].dcdx
= position
->dy01
;
416 plane
[1].dcdx
= position
->y
[1] - position
->y
[2];
417 plane
[2].dcdx
= position
->dy20
;
419 for (i
= 0; i
< 3; i
++) {
420 /* half-edge constants, will be interated over the whole render
423 plane
[i
].c
= plane
[i
].dcdx
* position
->x
[i
] - plane
[i
].dcdy
* position
->y
[i
];
425 /* correct for top-left vs. bottom-left fill convention.
427 if (plane
[i
].dcdx
< 0) {
428 /* both fill conventions want this - adjust for left edges */
431 else if (plane
[i
].dcdx
== 0) {
432 if (setup
->bottom_edge_rule
== 0){
433 /* correct for top-left fill convention:
435 if (plane
[i
].dcdy
> 0) plane
[i
].c
++;
438 /* correct for bottom-left fill convention:
440 if (plane
[i
].dcdy
< 0) plane
[i
].c
++;
444 plane
[i
].dcdx
*= FIXED_ONE
;
445 plane
[i
].dcdy
*= FIXED_ONE
;
447 /* find trivial reject offsets for each edge for a single-pixel
448 * sized block. These will be scaled up at each recursive level to
449 * match the active blocksize. Scaling in this way works best if
450 * the blocks are square.
453 if (plane
[i
].dcdx
< 0) plane
[i
].eo
-= plane
[i
].dcdx
;
454 if (plane
[i
].dcdy
> 0) plane
[i
].eo
+= plane
[i
].dcdy
;
460 debug_printf("p0: %08x/%08x/%08x/%08x\n",
466 debug_printf("p1: %08x/%08x/%08x/%08x\n",
472 debug_printf("p0: %08x/%08x/%08x/%08x\n",
481 * When rasterizing scissored tris, use the intersection of the
482 * triangle bounding box and the scissor rect to generate the
485 * This permits us to cut off the triangle "tails" that are present
486 * in the intermediate recursive levels caused when two of the
487 * triangles edges don't diverge quickly enough to trivially reject
488 * exterior blocks from the triangle.
490 * It's not really clear if it's worth worrying about these tails,
491 * but since we generate the planes for each scissored tri, it's
492 * free to trim them in this case.
494 * Note that otherwise, the scissor planes only vary in 'C' value,
495 * and even then only on state-changes. Could alternatively store
496 * these planes elsewhere.
498 if (nr_planes
== 7) {
499 const struct u_rect
*scissor
= &setup
->scissors
[scissor_index
];
503 plane
[3].c
= 1-scissor
->x0
;
508 plane
[4].c
= scissor
->x1
+1;
513 plane
[5].c
= 1-scissor
->y0
;
518 plane
[6].c
= scissor
->y1
+1;
522 return lp_setup_bin_triangle( setup
, tri
, &bbox
, nr_planes
, scissor_index
);
526 * Round to nearest less or equal power of two of the input.
528 * Undefined if no bit set exists, so code should check against 0 first.
530 static INLINE
uint32_t
531 floor_pot(uint32_t n
)
533 #if defined(PIPE_CC_GCC) && defined(PIPE_ARCH_X86)
553 lp_setup_bin_triangle( struct lp_setup_context
*setup
,
554 struct lp_rast_triangle
*tri
,
555 const struct u_rect
*bbox
,
557 unsigned scissor_index
)
559 struct lp_scene
*scene
= setup
->scene
;
560 struct u_rect trimmed_box
= *bbox
;
563 /* What is the largest power-of-two boundary this triangle crosses:
565 int dx
= floor_pot((bbox
->x0
^ bbox
->x1
) |
566 (bbox
->y0
^ bbox
->y1
));
568 /* The largest dimension of the rasterized area of the triangle
569 * (aligned to a 4x4 grid), rounded down to the nearest power of two:
571 int sz
= floor_pot((bbox
->x1
- (bbox
->x0
& ~3)) |
572 (bbox
->y1
- (bbox
->y0
& ~3)));
574 /* Now apply scissor, etc to the bounding box. Could do this
575 * earlier, but it confuses the logic for tri-16 and would force
576 * the rasterizer to also respect scissor, etc, just for the rare
577 * cases where a small triangle extends beyond the scissor.
579 u_rect_find_intersection(&setup
->draw_regions
[scissor_index
],
582 /* Determine which tile(s) intersect the triangle's bounding box
586 int ix0
= bbox
->x0
/ TILE_SIZE
;
587 int iy0
= bbox
->y0
/ TILE_SIZE
;
588 unsigned px
= bbox
->x0
& 63 & ~3;
589 unsigned py
= bbox
->y0
& 63 & ~3;
591 assert(iy0
== bbox
->y1
/ TILE_SIZE
&&
592 ix0
== bbox
->x1
/ TILE_SIZE
);
594 if (nr_planes
== 3) {
597 /* Triangle is contained in a single 4x4 stamp:
599 assert(px
+ 4 <= TILE_SIZE
);
600 assert(py
+ 4 <= TILE_SIZE
);
601 return lp_scene_bin_cmd_with_state( scene
, ix0
, iy0
,
603 LP_RAST_OP_TRIANGLE_3_4
,
604 lp_rast_arg_triangle_contained(tri
, px
, py
) );
609 /* Triangle is contained in a single 16x16 block:
613 * The 16x16 block is only 4x4 aligned, and can exceed the tile
614 * dimensions if the triangle is 16 pixels in one dimension but 4
615 * in the other. So budge the 16x16 back inside the tile.
617 px
= MIN2(px
, TILE_SIZE
- 16);
618 py
= MIN2(py
, TILE_SIZE
- 16);
620 assert(px
+ 16 <= TILE_SIZE
);
621 assert(py
+ 16 <= TILE_SIZE
);
623 return lp_scene_bin_cmd_with_state( scene
, ix0
, iy0
,
625 LP_RAST_OP_TRIANGLE_3_16
,
626 lp_rast_arg_triangle_contained(tri
, px
, py
) );
629 else if (nr_planes
== 4 && sz
< 16)
631 px
= MIN2(px
, TILE_SIZE
- 16);
632 py
= MIN2(py
, TILE_SIZE
- 16);
634 assert(px
+ 16 <= TILE_SIZE
);
635 assert(py
+ 16 <= TILE_SIZE
);
637 return lp_scene_bin_cmd_with_state(scene
, ix0
, iy0
,
639 LP_RAST_OP_TRIANGLE_4_16
,
640 lp_rast_arg_triangle_contained(tri
, px
, py
));
644 /* Triangle is contained in a single tile:
646 return lp_scene_bin_cmd_with_state( scene
, ix0
, iy0
, setup
->fs
.stored
,
647 lp_rast_tri_tab
[nr_planes
],
648 lp_rast_arg_triangle(tri
, (1<<nr_planes
)-1) );
652 struct lp_rast_plane
*plane
= GET_PLANES(tri
);
657 int xstep
[MAX_PLANES
];
658 int ystep
[MAX_PLANES
];
661 int ix0
= trimmed_box
.x0
/ TILE_SIZE
;
662 int iy0
= trimmed_box
.y0
/ TILE_SIZE
;
663 int ix1
= trimmed_box
.x1
/ TILE_SIZE
;
664 int iy1
= trimmed_box
.y1
/ TILE_SIZE
;
666 for (i
= 0; i
< nr_planes
; i
++) {
668 plane
[i
].dcdy
* iy0
* TILE_SIZE
-
669 plane
[i
].dcdx
* ix0
* TILE_SIZE
);
671 ei
[i
] = (plane
[i
].dcdy
-
673 plane
[i
].eo
) << TILE_ORDER
;
675 eo
[i
] = plane
[i
].eo
<< TILE_ORDER
;
676 xstep
[i
] = -(plane
[i
].dcdx
<< TILE_ORDER
);
677 ystep
[i
] = plane
[i
].dcdy
<< TILE_ORDER
;
682 /* Test tile-sized blocks against the triangle.
683 * Discard blocks fully outside the tri. If the block is fully
684 * contained inside the tri, bin an lp_rast_shade_tile command.
685 * Else, bin a lp_rast_triangle command.
687 for (y
= iy0
; y
<= iy1
; y
++)
689 boolean in
= FALSE
; /* are we inside the triangle? */
692 for (i
= 0; i
< nr_planes
; i
++)
695 for (x
= ix0
; x
<= ix1
; x
++)
700 for (i
= 0; i
< nr_planes
; i
++) {
701 int planeout
= cx
[i
] + eo
[i
];
702 int planepartial
= cx
[i
] + ei
[i
] - 1;
703 out
|= (planeout
>> 31);
704 partial
|= (planepartial
>> 31) & (1<<i
);
710 break; /* exiting triangle, all done with this row */
711 LP_COUNT(nr_empty_64
);
714 /* Not trivially accepted by at least one plane -
715 * rasterize/shade partial tile
717 int count
= util_bitcount(partial
);
720 if (!lp_scene_bin_cmd_with_state( scene
, x
, y
,
722 lp_rast_tri_tab
[count
],
723 lp_rast_arg_triangle(tri
, partial
) ))
726 LP_COUNT(nr_partially_covered_64
);
729 /* triangle covers the whole tile- shade whole tile */
730 LP_COUNT(nr_fully_covered_64
);
732 if (!lp_setup_whole_tile(setup
, &tri
->inputs
, x
, y
))
736 /* Iterate cx values across the region:
738 for (i
= 0; i
< nr_planes
; i
++)
742 /* Iterate c values down the region:
744 for (i
= 0; i
< nr_planes
; i
++)
752 /* Need to disable any partially binned triangle. This is easier
753 * than trying to locate all the triangle, shade-tile, etc,
754 * commands which may have been binned.
756 tri
->inputs
.disable
= TRUE
;
762 * Try to draw the triangle, restart the scene on failure.
764 static void retry_triangle_ccw( struct lp_setup_context
*setup
,
765 struct fixed_position
* position
,
766 const float (*v0
)[4],
767 const float (*v1
)[4],
768 const float (*v2
)[4],
771 if (!do_triangle_ccw( setup
, position
, v0
, v1
, v2
, front
))
773 if (!lp_setup_flush_and_restart(setup
))
776 if (!do_triangle_ccw( setup
, position
, v0
, v1
, v2
, front
))
783 * Calculate fixed position data for a triangle
786 calc_fixed_position( struct lp_setup_context
*setup
,
787 struct fixed_position
* position
,
788 const float (*v0
)[4],
789 const float (*v1
)[4],
790 const float (*v2
)[4])
792 position
->x
[0] = subpixel_snap(v0
[0][0] - setup
->pixel_offset
);
793 position
->x
[1] = subpixel_snap(v1
[0][0] - setup
->pixel_offset
);
794 position
->x
[2] = subpixel_snap(v2
[0][0] - setup
->pixel_offset
);
797 position
->y
[0] = subpixel_snap(v0
[0][1] - setup
->pixel_offset
);
798 position
->y
[1] = subpixel_snap(v1
[0][1] - setup
->pixel_offset
);
799 position
->y
[2] = subpixel_snap(v2
[0][1] - setup
->pixel_offset
);
802 position
->dx01
= position
->x
[0] - position
->x
[1];
803 position
->dy01
= position
->y
[0] - position
->y
[1];
805 position
->dx20
= position
->x
[2] - position
->x
[0];
806 position
->dy20
= position
->y
[2] - position
->y
[0];
808 position
->area
= position
->dx01
* position
->dy20
- position
->dx20
* position
->dy01
;
813 * Rotate a triangle, flipping its clockwise direction,
814 * Swaps values for xy[0] and xy[1]
817 rotate_fixed_position_01( struct fixed_position
* position
)
823 position
->x
[1] = position
->x
[0];
824 position
->y
[1] = position
->y
[0];
828 position
->dx01
= -position
->dx01
;
829 position
->dy01
= -position
->dy01
;
830 position
->dx20
= position
->x
[2] - position
->x
[0];
831 position
->dy20
= position
->y
[2] - position
->y
[0];
833 position
->area
= -position
->area
;
838 * Rotate a triangle, flipping its clockwise direction,
839 * Swaps values for xy[1] and xy[2]
842 rotate_fixed_position_12( struct fixed_position
* position
)
848 position
->x
[2] = position
->x
[1];
849 position
->y
[2] = position
->y
[1];
855 position
->dx01
= -position
->dx20
;
856 position
->dy01
= -position
->dy20
;
860 position
->area
= -position
->area
;
864 typedef void (*triangle_func_t
)(struct lp_setup_context
*setup
,
865 const float (*v0
)[4],
866 const float (*v1
)[4],
867 const float (*v2
)[4]);
871 * Subdivide this triangle by bisecting edge (v0, v1).
872 * \param pv the provoking vertex (must = v0 or v1 or v2)
875 subdiv_tri(struct lp_setup_context
*setup
,
876 const float (*v0
)[4],
877 const float (*v1
)[4],
878 const float (*v2
)[4],
879 const float (*pv
)[4],
882 unsigned n
= setup
->fs
.current
.variant
->shader
->info
.base
.num_inputs
+ 1;
883 const struct lp_shader_input
*inputs
=
884 setup
->fs
.current
.variant
->shader
->inputs
;
885 float vmid
[PIPE_MAX_ATTRIBS
][4];
886 const float (*vm
)[4] = (const float (*)[4]) vmid
;
889 boolean flatshade
= setup
->fs
.current
.variant
->key
.flatshade
;
891 /* find position midpoint (attrib[0] = position) */
892 vmid
[0][0] = 0.5f
* (v1
[0][0] + v0
[0][0]);
893 vmid
[0][1] = 0.5f
* (v1
[0][1] + v0
[0][1]);
894 vmid
[0][2] = 0.5f
* (v1
[0][2] + v0
[0][2]);
895 vmid
[0][3] = 0.5f
* (v1
[0][3] + v0
[0][3]);
901 /* interpolate other attributes */
902 for (i
= 1; i
< n
; i
++) {
903 if ((inputs
[i
- 1].interp
== LP_INTERP_COLOR
&& flatshade
) ||
904 inputs
[i
- 1].interp
== LP_INTERP_CONSTANT
) {
905 /* copy the provoking vertex's attribute */
906 vmid
[i
][0] = pv
[i
][0];
907 vmid
[i
][1] = pv
[i
][1];
908 vmid
[i
][2] = pv
[i
][2];
909 vmid
[i
][3] = pv
[i
][3];
912 /* interpolate with perspective correction (for linear too) */
913 vmid
[i
][0] = 0.5f
* (v1
[i
][0] * w1
+ v0
[i
][0] * w0
) / wm
;
914 vmid
[i
][1] = 0.5f
* (v1
[i
][1] * w1
+ v0
[i
][1] * w0
) / wm
;
915 vmid
[i
][2] = 0.5f
* (v1
[i
][2] * w1
+ v0
[i
][2] * w0
) / wm
;
916 vmid
[i
][3] = 0.5f
* (v1
[i
][3] * w1
+ v0
[i
][3] * w0
) / wm
;
920 /* handling flat shading and first vs. last provoking vertex is a
924 if (setup
->flatshade_first
) {
925 /* first vertex must be v0 or vm */
926 tri(setup
, v0
, vm
, v2
);
927 tri(setup
, vm
, v1
, v2
);
930 /* last vertex must be v0 or vm */
931 tri(setup
, vm
, v2
, v0
);
932 tri(setup
, v1
, v2
, vm
);
936 if (setup
->flatshade_first
) {
937 tri(setup
, vm
, v2
, v0
);
938 tri(setup
, v1
, v2
, vm
);
941 tri(setup
, v2
, v0
, vm
);
942 tri(setup
, v2
, vm
, v1
);
946 if (setup
->flatshade_first
) {
947 tri(setup
, v2
, v0
, vm
);
948 tri(setup
, v2
, vm
, v1
);
951 tri(setup
, v0
, vm
, v2
);
952 tri(setup
, vm
, v1
, v2
);
959 * Check the lengths of the edges of the triangle. If any edge is too
960 * long, subdivide the longest edge and draw two sub-triangles.
961 * Note: this may be called recursively.
962 * \return TRUE if triangle was subdivided, FALSE otherwise
965 check_subdivide_triangle(struct lp_setup_context
*setup
,
966 const float (*v0
)[4],
967 const float (*v1
)[4],
968 const float (*v2
)[4],
971 const float maxLen
= 2048.0f
; /* longest permissible edge, in pixels */
972 float dx10
, dy10
, len10
;
973 float dx21
, dy21
, len21
;
974 float dx02
, dy02
, len02
;
975 const float (*pv
)[4] = setup
->flatshade_first
? v0
: v2
;
977 /* compute lengths of triangle edges, squared */
978 dx10
= v1
[0][0] - v0
[0][0];
979 dy10
= v1
[0][1] - v0
[0][1];
980 len10
= dx10
* dx10
+ dy10
* dy10
;
982 dx21
= v2
[0][0] - v1
[0][0];
983 dy21
= v2
[0][1] - v1
[0][1];
984 len21
= dx21
* dx21
+ dy21
* dy21
;
986 dx02
= v0
[0][0] - v2
[0][0];
987 dy02
= v0
[0][1] - v2
[0][1];
988 len02
= dx02
* dx02
+ dy02
* dy02
;
990 /* Look for longest the edge that's longer than maxLen. If we find
991 * such an edge, split the triangle using the midpoint of that edge.
992 * Note: it's important to split the longest edge, not just any edge
993 * that's longer than maxLen. Otherwise, we can get into a degenerate
994 * situation and recurse indefinitely.
996 if (len10
> maxLen
* maxLen
&&
999 /* subdivide v0, v1 edge */
1000 subdiv_tri(setup
, v0
, v1
, v2
, pv
, tri
);
1004 if (len21
> maxLen
* maxLen
&&
1007 /* subdivide v1, v2 edge */
1008 subdiv_tri(setup
, v1
, v2
, v0
, pv
, tri
);
1012 if (len02
> maxLen
* maxLen
&&
1015 /* subdivide v2, v0 edge */
1016 subdiv_tri(setup
, v2
, v0
, v1
, pv
, tri
);
1025 * Draw triangle if it's CW, cull otherwise.
1027 static void triangle_cw( struct lp_setup_context
*setup
,
1028 const float (*v0
)[4],
1029 const float (*v1
)[4],
1030 const float (*v2
)[4] )
1032 struct fixed_position position
;
1034 if (setup
->subdivide_large_triangles
&&
1035 check_subdivide_triangle(setup
, v0
, v1
, v2
, triangle_cw
))
1038 calc_fixed_position(setup
, &position
, v0
, v1
, v2
);
1040 if (position
.area
< 0) {
1041 if (setup
->flatshade_first
) {
1042 rotate_fixed_position_12(&position
);
1043 retry_triangle_ccw(setup
, &position
, v0
, v2
, v1
, !setup
->ccw_is_frontface
);
1045 rotate_fixed_position_01(&position
);
1046 retry_triangle_ccw(setup
, &position
, v1
, v0
, v2
, !setup
->ccw_is_frontface
);
1052 static void triangle_ccw( struct lp_setup_context
*setup
,
1053 const float (*v0
)[4],
1054 const float (*v1
)[4],
1055 const float (*v2
)[4])
1057 struct fixed_position position
;
1059 if (setup
->subdivide_large_triangles
&&
1060 check_subdivide_triangle(setup
, v0
, v1
, v2
, triangle_ccw
))
1063 calc_fixed_position(setup
, &position
, v0
, v1
, v2
);
1065 if (position
.area
> 0)
1066 retry_triangle_ccw(setup
, &position
, v0
, v1
, v2
, setup
->ccw_is_frontface
);
1070 * Draw triangle whether it's CW or CCW.
1072 static void triangle_both( struct lp_setup_context
*setup
,
1073 const float (*v0
)[4],
1074 const float (*v1
)[4],
1075 const float (*v2
)[4] )
1077 struct fixed_position position
;
1079 if (setup
->subdivide_large_triangles
&&
1080 check_subdivide_triangle(setup
, v0
, v1
, v2
, triangle_both
))
1083 calc_fixed_position(setup
, &position
, v0
, v1
, v2
);
1086 assert(!util_is_inf_or_nan(v0
[0][0]));
1087 assert(!util_is_inf_or_nan(v0
[0][1]));
1088 assert(!util_is_inf_or_nan(v1
[0][0]));
1089 assert(!util_is_inf_or_nan(v1
[0][1]));
1090 assert(!util_is_inf_or_nan(v2
[0][0]));
1091 assert(!util_is_inf_or_nan(v2
[0][1]));
1094 if (position
.area
> 0)
1095 retry_triangle_ccw( setup
, &position
, v0
, v1
, v2
, setup
->ccw_is_frontface
);
1096 else if (position
.area
< 0) {
1097 if (setup
->flatshade_first
) {
1098 rotate_fixed_position_12( &position
);
1099 retry_triangle_ccw( setup
, &position
, v0
, v2
, v1
, !setup
->ccw_is_frontface
);
1101 rotate_fixed_position_01( &position
);
1102 retry_triangle_ccw( setup
, &position
, v1
, v0
, v2
, !setup
->ccw_is_frontface
);
1108 static void triangle_nop( struct lp_setup_context
*setup
,
1109 const float (*v0
)[4],
1110 const float (*v1
)[4],
1111 const float (*v2
)[4] )
1117 lp_setup_choose_triangle( struct lp_setup_context
*setup
)
1119 switch (setup
->cullmode
) {
1120 case PIPE_FACE_NONE
:
1121 setup
->triangle
= triangle_both
;
1123 case PIPE_FACE_BACK
:
1124 setup
->triangle
= setup
->ccw_is_frontface
? triangle_ccw
: triangle_cw
;
1126 case PIPE_FACE_FRONT
:
1127 setup
->triangle
= setup
->ccw_is_frontface
? triangle_cw
: triangle_ccw
;
1130 setup
->triangle
= triangle_nop
;