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
;
250 /* Area should always be positive here */
251 assert(position
->area
> 0);
254 lp_setup_print_triangle(setup
, v0
, v1
, v2
);
256 if (setup
->scissor_test
) {
263 /* Bounding rectangle (in pixels) */
265 /* Yes this is necessary to accurately calculate bounding boxes
266 * with the two fill-conventions we support. GL (normally) ends
267 * up needing a bottom-left fill convention, which requires
268 * slightly different rounding.
270 int adj
= (setup
->pixel_offset
!= 0) ? 1 : 0;
272 /* Inclusive x0, exclusive x1 */
273 bbox
.x0
= MIN3(position
->x
[0], position
->x
[1], position
->x
[2]) >> FIXED_ORDER
;
274 bbox
.x1
= (MAX3(position
->x
[0], position
->x
[1], position
->x
[2]) - 1) >> FIXED_ORDER
;
276 /* Inclusive / exclusive depending upon adj (bottom-left or top-right) */
277 bbox
.y0
= (MIN3(position
->y
[0], position
->y
[1], position
->y
[2]) + adj
) >> FIXED_ORDER
;
278 bbox
.y1
= (MAX3(position
->y
[0], position
->y
[1], position
->y
[2]) - 1 + adj
) >> FIXED_ORDER
;
281 if (bbox
.x1
< bbox
.x0
||
283 if (0) debug_printf("empty bounding box\n");
284 LP_COUNT(nr_culled_tris
);
288 if (!u_rect_test_intersection(&setup
->draw_region
, &bbox
)) {
289 if (0) debug_printf("offscreen\n");
290 LP_COUNT(nr_culled_tris
);
294 /* Can safely discard negative regions, but need to keep hold of
295 * information about when the triangle extends past screen
296 * boundaries. See trimmed_box in lp_setup_bin_triangle().
298 bbox
.x0
= MAX2(bbox
.x0
, 0);
299 bbox
.y0
= MAX2(bbox
.y0
, 0);
301 tri
= lp_setup_alloc_triangle(scene
,
309 tri
->v
[0][0] = v0
[0][0];
310 tri
->v
[1][0] = v1
[0][0];
311 tri
->v
[2][0] = v2
[0][0];
312 tri
->v
[0][1] = v0
[0][1];
313 tri
->v
[1][1] = v1
[0][1];
314 tri
->v
[2][1] = v2
[0][1];
319 /* Setup parameter interpolants:
321 setup
->setup
.variant
->jit_function( v0
,
325 GET_A0(&tri
->inputs
),
326 GET_DADX(&tri
->inputs
),
327 GET_DADY(&tri
->inputs
) );
329 tri
->inputs
.frontfacing
= frontfacing
;
330 tri
->inputs
.disable
= FALSE
;
331 tri
->inputs
.opaque
= setup
->fs
.current
.variant
->opaque
;
334 lp_dump_setup_coef(&setup
->setup
.variant
->key
,
335 (const float (*)[4])GET_A0(&tri
->inputs
),
336 (const float (*)[4])GET_DADX(&tri
->inputs
),
337 (const float (*)[4])GET_DADY(&tri
->inputs
));
339 plane
= GET_PLANES(tri
);
341 #if defined(PIPE_ARCH_SSE)
343 __m128i vertx
, verty
;
344 __m128i shufx
, shufy
;
345 __m128i dcdx
, dcdy
, c
;
347 __m128i dcdx_neg_mask
;
348 __m128i dcdy_neg_mask
;
349 __m128i dcdx_zero_mask
;
350 __m128i top_left_flag
;
351 __m128i c_inc_mask
, c_inc
;
352 __m128i eo
, p0
, p1
, p2
;
353 __m128i zero
= _mm_setzero_si128();
355 vertx
= _mm_loadu_si128((__m128i
*)position
->x
); /* vertex x coords */
356 verty
= _mm_loadu_si128((__m128i
*)position
->y
); /* vertex y coords */
358 shufx
= _mm_shuffle_epi32(vertx
, _MM_SHUFFLE(3,0,2,1));
359 shufy
= _mm_shuffle_epi32(verty
, _MM_SHUFFLE(3,0,2,1));
361 dcdx
= _mm_sub_epi32(verty
, shufy
);
362 dcdy
= _mm_sub_epi32(vertx
, shufx
);
364 dcdx_neg_mask
= _mm_srai_epi32(dcdx
, 31);
365 dcdx_zero_mask
= _mm_cmpeq_epi32(dcdx
, zero
);
366 dcdy_neg_mask
= _mm_srai_epi32(dcdy
, 31);
368 top_left_flag
= _mm_set1_epi32((setup
->bottom_edge_rule
== 0) ? ~0 : 0);
370 c_inc_mask
= _mm_or_si128(dcdx_neg_mask
,
371 _mm_and_si128(dcdx_zero_mask
,
372 _mm_xor_si128(dcdy_neg_mask
,
375 c_inc
= _mm_srli_epi32(c_inc_mask
, 31);
377 c
= _mm_sub_epi32(mm_mullo_epi32(dcdx
, vertx
),
378 mm_mullo_epi32(dcdy
, verty
));
380 c
= _mm_add_epi32(c
, c_inc
);
382 /* Scale up to match c:
384 dcdx
= _mm_slli_epi32(dcdx
, FIXED_ORDER
);
385 dcdy
= _mm_slli_epi32(dcdy
, FIXED_ORDER
);
387 /* Calculate trivial reject values:
389 eo
= _mm_sub_epi32(_mm_andnot_si128(dcdy_neg_mask
, dcdy
),
390 _mm_and_si128(dcdx_neg_mask
, dcdx
));
392 /* ei = _mm_sub_epi32(_mm_sub_epi32(dcdy, dcdx), eo); */
394 /* Pointless transpose which gets undone immediately in
397 transpose4_epi32(&c
, &dcdx
, &dcdy
, &eo
,
398 &p0
, &p1
, &p2
, &unused
);
400 _mm_store_si128((__m128i
*)&plane
[0], p0
);
401 _mm_store_si128((__m128i
*)&plane
[1], p1
);
402 _mm_store_si128((__m128i
*)&plane
[2], p2
);
407 plane
[0].dcdy
= position
->dx01
;
408 plane
[1].dcdy
= position
->x
[1] - position
->x
[2];
409 plane
[2].dcdy
= position
->dx20
;
410 plane
[0].dcdx
= position
->dy01
;
411 plane
[1].dcdx
= position
->y
[1] - position
->y
[2];
412 plane
[2].dcdx
= position
->dy20
;
414 for (i
= 0; i
< 3; i
++) {
415 /* half-edge constants, will be interated over the whole render
418 plane
[i
].c
= plane
[i
].dcdx
* position
->x
[i
] - plane
[i
].dcdy
* position
->y
[i
];
420 /* correct for top-left vs. bottom-left fill convention.
422 if (plane
[i
].dcdx
< 0) {
423 /* both fill conventions want this - adjust for left edges */
426 else if (plane
[i
].dcdx
== 0) {
427 if (setup
->bottom_edge_rule
== 0){
428 /* correct for top-left fill convention:
430 if (plane
[i
].dcdy
> 0) plane
[i
].c
++;
433 /* correct for bottom-left fill convention:
435 if (plane
[i
].dcdy
< 0) plane
[i
].c
++;
439 plane
[i
].dcdx
*= FIXED_ONE
;
440 plane
[i
].dcdy
*= FIXED_ONE
;
442 /* find trivial reject offsets for each edge for a single-pixel
443 * sized block. These will be scaled up at each recursive level to
444 * match the active blocksize. Scaling in this way works best if
445 * the blocks are square.
448 if (plane
[i
].dcdx
< 0) plane
[i
].eo
-= plane
[i
].dcdx
;
449 if (plane
[i
].dcdy
> 0) plane
[i
].eo
+= plane
[i
].dcdy
;
455 debug_printf("p0: %08x/%08x/%08x/%08x\n",
461 debug_printf("p1: %08x/%08x/%08x/%08x\n",
467 debug_printf("p0: %08x/%08x/%08x/%08x\n",
476 * When rasterizing scissored tris, use the intersection of the
477 * triangle bounding box and the scissor rect to generate the
480 * This permits us to cut off the triangle "tails" that are present
481 * in the intermediate recursive levels caused when two of the
482 * triangles edges don't diverge quickly enough to trivially reject
483 * exterior blocks from the triangle.
485 * It's not really clear if it's worth worrying about these tails,
486 * but since we generate the planes for each scissored tri, it's
487 * free to trim them in this case.
489 * Note that otherwise, the scissor planes only vary in 'C' value,
490 * and even then only on state-changes. Could alternatively store
491 * these planes elsewhere.
493 if (nr_planes
== 7) {
494 const struct u_rect
*scissor
= &setup
->scissor
;
498 plane
[3].c
= 1-scissor
->x0
;
503 plane
[4].c
= scissor
->x1
+1;
508 plane
[5].c
= 1-scissor
->y0
;
513 plane
[6].c
= scissor
->y1
+1;
517 return lp_setup_bin_triangle( setup
, tri
, &bbox
, nr_planes
);
521 * Round to nearest less or equal power of two of the input.
523 * Undefined if no bit set exists, so code should check against 0 first.
525 static INLINE
uint32_t
526 floor_pot(uint32_t n
)
528 #if defined(PIPE_CC_GCC) && defined(PIPE_ARCH_X86)
548 lp_setup_bin_triangle( struct lp_setup_context
*setup
,
549 struct lp_rast_triangle
*tri
,
550 const struct u_rect
*bbox
,
553 struct lp_scene
*scene
= setup
->scene
;
554 struct u_rect trimmed_box
= *bbox
;
557 /* What is the largest power-of-two boundary this triangle crosses:
559 int dx
= floor_pot((bbox
->x0
^ bbox
->x1
) |
560 (bbox
->y0
^ bbox
->y1
));
562 /* The largest dimension of the rasterized area of the triangle
563 * (aligned to a 4x4 grid), rounded down to the nearest power of two:
565 int sz
= floor_pot((bbox
->x1
- (bbox
->x0
& ~3)) |
566 (bbox
->y1
- (bbox
->y0
& ~3)));
568 /* Now apply scissor, etc to the bounding box. Could do this
569 * earlier, but it confuses the logic for tri-16 and would force
570 * the rasterizer to also respect scissor, etc, just for the rare
571 * cases where a small triangle extends beyond the scissor.
573 u_rect_find_intersection(&setup
->draw_region
, &trimmed_box
);
575 /* Determine which tile(s) intersect the triangle's bounding box
579 int ix0
= bbox
->x0
/ TILE_SIZE
;
580 int iy0
= bbox
->y0
/ TILE_SIZE
;
581 unsigned px
= bbox
->x0
& 63 & ~3;
582 unsigned py
= bbox
->y0
& 63 & ~3;
584 assert(iy0
== bbox
->y1
/ TILE_SIZE
&&
585 ix0
== bbox
->x1
/ TILE_SIZE
);
587 if (nr_planes
== 3) {
590 /* Triangle is contained in a single 4x4 stamp:
592 assert(px
+ 4 <= TILE_SIZE
);
593 assert(py
+ 4 <= TILE_SIZE
);
594 return lp_scene_bin_cmd_with_state( scene
, ix0
, iy0
,
596 LP_RAST_OP_TRIANGLE_3_4
,
597 lp_rast_arg_triangle_contained(tri
, px
, py
) );
602 /* Triangle is contained in a single 16x16 block:
606 * The 16x16 block is only 4x4 aligned, and can exceed the tile
607 * dimensions if the triangle is 16 pixels in one dimension but 4
608 * in the other. So budge the 16x16 back inside the tile.
610 px
= MIN2(px
, TILE_SIZE
- 16);
611 py
= MIN2(py
, TILE_SIZE
- 16);
613 assert(px
+ 16 <= TILE_SIZE
);
614 assert(py
+ 16 <= TILE_SIZE
);
616 return lp_scene_bin_cmd_with_state( scene
, ix0
, iy0
,
618 LP_RAST_OP_TRIANGLE_3_16
,
619 lp_rast_arg_triangle_contained(tri
, px
, py
) );
622 else if (nr_planes
== 4 && sz
< 16)
624 px
= MIN2(px
, TILE_SIZE
- 16);
625 py
= MIN2(py
, TILE_SIZE
- 16);
627 assert(px
+ 16 <= TILE_SIZE
);
628 assert(py
+ 16 <= TILE_SIZE
);
630 return lp_scene_bin_cmd_with_state(scene
, ix0
, iy0
,
632 LP_RAST_OP_TRIANGLE_4_16
,
633 lp_rast_arg_triangle_contained(tri
, px
, py
));
637 /* Triangle is contained in a single tile:
639 return lp_scene_bin_cmd_with_state( scene
, ix0
, iy0
, setup
->fs
.stored
,
640 lp_rast_tri_tab
[nr_planes
],
641 lp_rast_arg_triangle(tri
, (1<<nr_planes
)-1) );
645 struct lp_rast_plane
*plane
= GET_PLANES(tri
);
650 int xstep
[MAX_PLANES
];
651 int ystep
[MAX_PLANES
];
654 int ix0
= trimmed_box
.x0
/ TILE_SIZE
;
655 int iy0
= trimmed_box
.y0
/ TILE_SIZE
;
656 int ix1
= trimmed_box
.x1
/ TILE_SIZE
;
657 int iy1
= trimmed_box
.y1
/ TILE_SIZE
;
659 for (i
= 0; i
< nr_planes
; i
++) {
661 plane
[i
].dcdy
* iy0
* TILE_SIZE
-
662 plane
[i
].dcdx
* ix0
* TILE_SIZE
);
664 ei
[i
] = (plane
[i
].dcdy
-
666 plane
[i
].eo
) << TILE_ORDER
;
668 eo
[i
] = plane
[i
].eo
<< TILE_ORDER
;
669 xstep
[i
] = -(plane
[i
].dcdx
<< TILE_ORDER
);
670 ystep
[i
] = plane
[i
].dcdy
<< TILE_ORDER
;
675 /* Test tile-sized blocks against the triangle.
676 * Discard blocks fully outside the tri. If the block is fully
677 * contained inside the tri, bin an lp_rast_shade_tile command.
678 * Else, bin a lp_rast_triangle command.
680 for (y
= iy0
; y
<= iy1
; y
++)
682 boolean in
= FALSE
; /* are we inside the triangle? */
685 for (i
= 0; i
< nr_planes
; i
++)
688 for (x
= ix0
; x
<= ix1
; x
++)
693 for (i
= 0; i
< nr_planes
; i
++) {
694 int planeout
= cx
[i
] + eo
[i
];
695 int planepartial
= cx
[i
] + ei
[i
] - 1;
696 out
|= (planeout
>> 31);
697 partial
|= (planepartial
>> 31) & (1<<i
);
703 break; /* exiting triangle, all done with this row */
704 LP_COUNT(nr_empty_64
);
707 /* Not trivially accepted by at least one plane -
708 * rasterize/shade partial tile
710 int count
= util_bitcount(partial
);
713 if (!lp_scene_bin_cmd_with_state( scene
, x
, y
,
715 lp_rast_tri_tab
[count
],
716 lp_rast_arg_triangle(tri
, partial
) ))
719 LP_COUNT(nr_partially_covered_64
);
722 /* triangle covers the whole tile- shade whole tile */
723 LP_COUNT(nr_fully_covered_64
);
725 if (!lp_setup_whole_tile(setup
, &tri
->inputs
, x
, y
))
729 /* Iterate cx values across the region:
731 for (i
= 0; i
< nr_planes
; i
++)
735 /* Iterate c values down the region:
737 for (i
= 0; i
< nr_planes
; i
++)
745 /* Need to disable any partially binned triangle. This is easier
746 * than trying to locate all the triangle, shade-tile, etc,
747 * commands which may have been binned.
749 tri
->inputs
.disable
= TRUE
;
755 * Try to draw the triangle, restart the scene on failure.
757 static void retry_triangle_ccw( struct lp_setup_context
*setup
,
758 struct fixed_position
* position
,
759 const float (*v0
)[4],
760 const float (*v1
)[4],
761 const float (*v2
)[4],
764 if (!do_triangle_ccw( setup
, position
, v0
, v1
, v2
, front
))
766 if (!lp_setup_flush_and_restart(setup
))
769 if (!do_triangle_ccw( setup
, position
, v0
, v1
, v2
, front
))
776 * Calculate fixed position data for a triangle
779 calc_fixed_position( struct lp_setup_context
*setup
,
780 struct fixed_position
* position
,
781 const float (*v0
)[4],
782 const float (*v1
)[4],
783 const float (*v2
)[4])
785 position
->x
[0] = subpixel_snap(v0
[0][0] - setup
->pixel_offset
);
786 position
->x
[1] = subpixel_snap(v1
[0][0] - setup
->pixel_offset
);
787 position
->x
[2] = subpixel_snap(v2
[0][0] - setup
->pixel_offset
);
790 position
->y
[0] = subpixel_snap(v0
[0][1] - setup
->pixel_offset
);
791 position
->y
[1] = subpixel_snap(v1
[0][1] - setup
->pixel_offset
);
792 position
->y
[2] = subpixel_snap(v2
[0][1] - setup
->pixel_offset
);
795 position
->dx01
= position
->x
[0] - position
->x
[1];
796 position
->dy01
= position
->y
[0] - position
->y
[1];
798 position
->dx20
= position
->x
[2] - position
->x
[0];
799 position
->dy20
= position
->y
[2] - position
->y
[0];
801 position
->area
= position
->dx01
* position
->dy20
- position
->dx20
* position
->dy01
;
806 * Rotate a triangle, flipping its clockwise direction,
807 * Swaps values for xy[0] and xy[1]
810 rotate_fixed_position_01( struct fixed_position
* position
)
816 position
->x
[1] = position
->x
[0];
817 position
->y
[1] = position
->y
[0];
821 position
->dx01
= -position
->dx01
;
822 position
->dy01
= -position
->dy01
;
823 position
->dx20
= position
->x
[2] - position
->x
[0];
824 position
->dy20
= position
->y
[2] - position
->y
[0];
826 position
->area
= -position
->area
;
831 * Rotate a triangle, flipping its clockwise direction,
832 * Swaps values for xy[1] and xy[2]
835 rotate_fixed_position_12( struct fixed_position
* position
)
841 position
->x
[2] = position
->x
[1];
842 position
->y
[2] = position
->y
[1];
848 position
->dx01
= -position
->dx20
;
849 position
->dy01
= -position
->dy20
;
853 position
->area
= -position
->area
;
857 typedef void (*triangle_func_t
)(struct lp_setup_context
*setup
,
858 const float (*v0
)[4],
859 const float (*v1
)[4],
860 const float (*v2
)[4]);
864 * Subdivide this triangle by bisecting edge (v0, v1).
865 * \param pv the provoking vertex (must = v0 or v1 or v2)
868 subdiv_tri(struct lp_setup_context
*setup
,
869 const float (*v0
)[4],
870 const float (*v1
)[4],
871 const float (*v2
)[4],
872 const float (*pv
)[4],
875 unsigned n
= setup
->fs
.current
.variant
->shader
->info
.base
.num_inputs
+ 1;
876 const struct lp_shader_input
*inputs
=
877 setup
->fs
.current
.variant
->shader
->inputs
;
878 float vmid
[PIPE_MAX_ATTRIBS
][4];
879 const float (*vm
)[4] = (const float (*)[4]) vmid
;
882 boolean flatshade
= setup
->fs
.current
.variant
->key
.flatshade
;
884 /* find position midpoint (attrib[0] = position) */
885 vmid
[0][0] = 0.5f
* (v1
[0][0] + v0
[0][0]);
886 vmid
[0][1] = 0.5f
* (v1
[0][1] + v0
[0][1]);
887 vmid
[0][2] = 0.5f
* (v1
[0][2] + v0
[0][2]);
888 vmid
[0][3] = 0.5f
* (v1
[0][3] + v0
[0][3]);
894 /* interpolate other attributes */
895 for (i
= 1; i
< n
; i
++) {
896 if ((inputs
[i
- 1].interp
== LP_INTERP_COLOR
&& flatshade
) ||
897 inputs
[i
- 1].interp
== LP_INTERP_CONSTANT
) {
898 /* copy the provoking vertex's attribute */
899 vmid
[i
][0] = pv
[i
][0];
900 vmid
[i
][1] = pv
[i
][1];
901 vmid
[i
][2] = pv
[i
][2];
902 vmid
[i
][3] = pv
[i
][3];
905 /* interpolate with perspective correction (for linear too) */
906 vmid
[i
][0] = 0.5f
* (v1
[i
][0] * w1
+ v0
[i
][0] * w0
) / wm
;
907 vmid
[i
][1] = 0.5f
* (v1
[i
][1] * w1
+ v0
[i
][1] * w0
) / wm
;
908 vmid
[i
][2] = 0.5f
* (v1
[i
][2] * w1
+ v0
[i
][2] * w0
) / wm
;
909 vmid
[i
][3] = 0.5f
* (v1
[i
][3] * w1
+ v0
[i
][3] * w0
) / wm
;
913 /* handling flat shading and first vs. last provoking vertex is a
917 if (setup
->flatshade_first
) {
918 /* first vertex must be v0 or vm */
919 tri(setup
, v0
, vm
, v2
);
920 tri(setup
, vm
, v1
, v2
);
923 /* last vertex must be v0 or vm */
924 tri(setup
, vm
, v2
, v0
);
925 tri(setup
, v1
, v2
, vm
);
929 if (setup
->flatshade_first
) {
930 tri(setup
, vm
, v2
, v0
);
931 tri(setup
, v1
, v2
, vm
);
934 tri(setup
, v2
, v0
, vm
);
935 tri(setup
, v2
, vm
, v1
);
939 if (setup
->flatshade_first
) {
940 tri(setup
, v2
, v0
, vm
);
941 tri(setup
, v2
, vm
, v1
);
944 tri(setup
, v0
, vm
, v2
);
945 tri(setup
, vm
, v1
, v2
);
952 * Check the lengths of the edges of the triangle. If any edge is too
953 * long, subdivide the longest edge and draw two sub-triangles.
954 * Note: this may be called recursively.
955 * \return TRUE if triangle was subdivided, FALSE otherwise
958 check_subdivide_triangle(struct lp_setup_context
*setup
,
959 const float (*v0
)[4],
960 const float (*v1
)[4],
961 const float (*v2
)[4],
964 const float maxLen
= 2048.0f
; /* longest permissible edge, in pixels */
965 float dx10
, dy10
, len10
;
966 float dx21
, dy21
, len21
;
967 float dx02
, dy02
, len02
;
968 const float (*pv
)[4] = setup
->flatshade_first
? v0
: v2
;
970 /* compute lengths of triangle edges, squared */
971 dx10
= v1
[0][0] - v0
[0][0];
972 dy10
= v1
[0][1] - v0
[0][1];
973 len10
= dx10
* dx10
+ dy10
* dy10
;
975 dx21
= v2
[0][0] - v1
[0][0];
976 dy21
= v2
[0][1] - v1
[0][1];
977 len21
= dx21
* dx21
+ dy21
* dy21
;
979 dx02
= v0
[0][0] - v2
[0][0];
980 dy02
= v0
[0][1] - v2
[0][1];
981 len02
= dx02
* dx02
+ dy02
* dy02
;
983 /* Look for longest the edge that's longer than maxLen. If we find
984 * such an edge, split the triangle using the midpoint of that edge.
985 * Note: it's important to split the longest edge, not just any edge
986 * that's longer than maxLen. Otherwise, we can get into a degenerate
987 * situation and recurse indefinitely.
989 if (len10
> maxLen
* maxLen
&&
992 /* subdivide v0, v1 edge */
993 subdiv_tri(setup
, v0
, v1
, v2
, pv
, tri
);
997 if (len21
> maxLen
* maxLen
&&
1000 /* subdivide v1, v2 edge */
1001 subdiv_tri(setup
, v1
, v2
, v0
, pv
, tri
);
1005 if (len02
> maxLen
* maxLen
&&
1008 /* subdivide v2, v0 edge */
1009 subdiv_tri(setup
, v2
, v0
, v1
, pv
, tri
);
1018 * Draw triangle if it's CW, cull otherwise.
1020 static void triangle_cw( struct lp_setup_context
*setup
,
1021 const float (*v0
)[4],
1022 const float (*v1
)[4],
1023 const float (*v2
)[4] )
1025 struct fixed_position position
;
1027 if (setup
->subdivide_large_triangles
&&
1028 check_subdivide_triangle(setup
, v0
, v1
, v2
, triangle_cw
))
1031 calc_fixed_position(setup
, &position
, v0
, v1
, v2
);
1033 if (position
.area
< 0) {
1034 if (setup
->flatshade_first
) {
1035 rotate_fixed_position_12(&position
);
1036 retry_triangle_ccw(setup
, &position
, v0
, v2
, v1
, !setup
->ccw_is_frontface
);
1038 rotate_fixed_position_01(&position
);
1039 retry_triangle_ccw(setup
, &position
, v1
, v0
, v2
, !setup
->ccw_is_frontface
);
1045 static void triangle_ccw( struct lp_setup_context
*setup
,
1046 const float (*v0
)[4],
1047 const float (*v1
)[4],
1048 const float (*v2
)[4])
1050 struct fixed_position position
;
1052 if (setup
->subdivide_large_triangles
&&
1053 check_subdivide_triangle(setup
, v0
, v1
, v2
, triangle_ccw
))
1056 calc_fixed_position(setup
, &position
, v0
, v1
, v2
);
1058 if (position
.area
> 0)
1059 retry_triangle_ccw(setup
, &position
, v0
, v1
, v2
, setup
->ccw_is_frontface
);
1063 * Draw triangle whether it's CW or CCW.
1065 static void triangle_both( struct lp_setup_context
*setup
,
1066 const float (*v0
)[4],
1067 const float (*v1
)[4],
1068 const float (*v2
)[4] )
1070 struct fixed_position position
;
1072 if (setup
->subdivide_large_triangles
&&
1073 check_subdivide_triangle(setup
, v0
, v1
, v2
, triangle_both
))
1076 calc_fixed_position(setup
, &position
, v0
, v1
, v2
);
1079 assert(!util_is_inf_or_nan(v0
[0][0]));
1080 assert(!util_is_inf_or_nan(v0
[0][1]));
1081 assert(!util_is_inf_or_nan(v1
[0][0]));
1082 assert(!util_is_inf_or_nan(v1
[0][1]));
1083 assert(!util_is_inf_or_nan(v2
[0][0]));
1084 assert(!util_is_inf_or_nan(v2
[0][1]));
1087 if (position
.area
> 0)
1088 retry_triangle_ccw( setup
, &position
, v0
, v1
, v2
, setup
->ccw_is_frontface
);
1089 else if (position
.area
< 0) {
1090 if (setup
->flatshade_first
) {
1091 rotate_fixed_position_12( &position
);
1092 retry_triangle_ccw( setup
, &position
, v0
, v2
, v1
, !setup
->ccw_is_frontface
);
1094 rotate_fixed_position_01( &position
);
1095 retry_triangle_ccw( setup
, &position
, v1
, v0
, v2
, !setup
->ccw_is_frontface
);
1101 static void triangle_nop( struct lp_setup_context
*setup
,
1102 const float (*v0
)[4],
1103 const float (*v1
)[4],
1104 const float (*v2
)[4] )
1110 lp_setup_choose_triangle( struct lp_setup_context
*setup
)
1112 switch (setup
->cullmode
) {
1113 case PIPE_FACE_NONE
:
1114 setup
->triangle
= triangle_both
;
1116 case PIPE_FACE_BACK
:
1117 setup
->triangle
= setup
->ccw_is_frontface
? triangle_ccw
: triangle_cw
;
1119 case PIPE_FACE_FRONT
:
1120 setup
->triangle
= setup
->ccw_is_frontface
? triangle_cw
: triangle_ccw
;
1123 setup
->triangle
= triangle_nop
;