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 * \brief Primitive rasterization/rendering (points, lines, triangles)
31 * \author Keith Whitwell <keith@tungstengraphics.com>
35 #include "lp_context.h"
36 #include "lp_prim_setup.h"
40 #include "draw/draw_context.h"
41 #include "draw/draw_private.h"
42 #include "draw/draw_vertex.h"
43 #include "pipe/p_shader_tokens.h"
44 #include "pipe/p_thread.h"
45 #include "util/u_math.h"
46 #include "util/u_memory.h"
47 #include "lp_bld_debug.h"
48 #include "lp_tile_cache.h"
49 #include "lp_tile_soa.h"
59 float dx
; /**< X(v1) - X(v0), used only during setup */
60 float dy
; /**< Y(v1) - Y(v0), used only during setup */
61 float dxdy
; /**< dx/dy */
62 float sx
, sy
; /**< first sample point coord */
63 int lines
; /**< number of lines on this edge */
71 * Triangle setup info (derived from draw_stage).
72 * Also used for line drawing (taking some liberties).
74 struct setup_context
{
75 struct llvmpipe_context
*llvmpipe
;
77 /* Vertices are just an array of floats making up each attribute in
78 * turn. Currently fixed at 4 floats, but should change in time.
79 * Codegen will help cope with this.
81 const float (*vmax
)[4];
82 const float (*vmid
)[4];
83 const float (*vmin
)[4];
84 const float (*vprovoke
)[4];
93 struct quad_header quad
[MAX_QUADS
];
94 struct quad_header
*quad_ptrs
[MAX_QUADS
];
97 struct quad_interp_coef coef
;
100 int left
[2]; /**< [0] = row0, [1] = row1 */
106 uint numFragsEmitted
; /**< per primitive */
107 uint numFragsWritten
; /**< per primitive */
110 unsigned winding
; /* which winding to cull */
116 * Execute fragment shader for the four fragments in the quad.
120 shade_quads(struct llvmpipe_context
*llvmpipe
,
121 struct quad_header
*quads
[],
124 struct lp_fragment_shader
*fs
= llvmpipe
->fs
;
125 struct quad_header
*quad
= quads
[0];
126 const unsigned x
= quad
->input
.x0
;
127 const unsigned y
= quad
->input
.y0
;
131 uint32_t ALIGN16_ATTRIB mask
[4][NUM_CHANNELS
];
140 assert(nr
* QUAD_SIZE
== TILE_VECTOR_HEIGHT
* TILE_VECTOR_WIDTH
);
141 assert(x
% TILE_VECTOR_WIDTH
== 0);
142 assert(y
% TILE_VECTOR_HEIGHT
== 0);
143 for (q
= 0; q
< nr
; ++q
) {
144 assert(quads
[q
]->input
.x0
== x
+ q
*2);
145 assert(quads
[q
]->input
.y0
== y
);
149 for (q
= 0; q
< 4; ++q
)
150 for (chan_index
= 0; chan_index
< NUM_CHANNELS
; ++chan_index
)
151 mask
[q
][chan_index
] = quads
[q
]->inout
.mask
& (1 << chan_index
) ? ~0 : 0;
154 if(llvmpipe
->framebuffer
.nr_cbufs
>= 1 &&
155 llvmpipe
->framebuffer
.cbufs
[0]) {
156 tile
= lp_get_cached_tile(llvmpipe
->cbuf_cache
[0], x
, y
);
157 color
= &TILE_PIXEL(tile
, x
& (TILE_SIZE
-1), y
& (TILE_SIZE
-1), 0);
163 if(llvmpipe
->zsbuf_map
) {
164 assert((x
% 2) == 0);
165 assert((y
% 2) == 0);
166 depth
= llvmpipe
->zsbuf_map
+
167 y
*llvmpipe
->zsbuf_transfer
->stride
+
168 2*x
*llvmpipe
->zsbuf_transfer
->block
.size
;
173 /* XXX: This will most likely fail on 32bit x86 without -mstackrealign */
174 assert(lp_check_alignment(mask
, 16));
176 assert(lp_check_alignment(depth
, 16));
177 assert(lp_check_alignment(color
, 16));
178 assert(lp_check_alignment(llvmpipe
->jit_context
.blend_color
, 16));
181 fs
->current
->jit_function( &llvmpipe
->jit_context
,
195 * Do triangle cull test using tri determinant (sign indicates orientation)
196 * \return true if triangle is to be culled.
198 static INLINE boolean
199 cull_tri(const struct setup_context
*setup
, float det
)
202 /* if (det < 0 then Z points toward camera and triangle is
203 * counter-clockwise winding.
205 unsigned winding
= (det
< 0) ? PIPE_WINDING_CCW
: PIPE_WINDING_CW
;
207 if ((winding
& setup
->winding
) == 0)
219 * Clip setup->quad against the scissor/surface bounds.
222 quad_clip( struct setup_context
*setup
, struct quad_header
*quad
)
224 const struct pipe_scissor_state
*cliprect
= &setup
->llvmpipe
->cliprect
;
225 const int minx
= (int) cliprect
->minx
;
226 const int maxx
= (int) cliprect
->maxx
;
227 const int miny
= (int) cliprect
->miny
;
228 const int maxy
= (int) cliprect
->maxy
;
230 if (quad
->input
.x0
>= maxx
||
231 quad
->input
.y0
>= maxy
||
232 quad
->input
.x0
+ 1 < minx
||
233 quad
->input
.y0
+ 1 < miny
) {
234 /* totally clipped */
235 quad
->inout
.mask
= 0x0;
238 if (quad
->input
.x0
< minx
)
239 quad
->inout
.mask
&= (MASK_BOTTOM_RIGHT
| MASK_TOP_RIGHT
);
240 if (quad
->input
.y0
< miny
)
241 quad
->inout
.mask
&= (MASK_BOTTOM_LEFT
| MASK_BOTTOM_RIGHT
);
242 if (quad
->input
.x0
== maxx
- 1)
243 quad
->inout
.mask
&= (MASK_BOTTOM_LEFT
| MASK_TOP_LEFT
);
244 if (quad
->input
.y0
== maxy
- 1)
245 quad
->inout
.mask
&= (MASK_TOP_LEFT
| MASK_TOP_RIGHT
);
251 * Given an X or Y coordinate, return the block/quad coordinate that it
254 static INLINE
int block( int x
)
259 static INLINE
int block_x( int x
)
261 return x
& ~(TILE_VECTOR_WIDTH
- 1);
266 * Emit a quad (pass to next stage) with clipping.
269 clip_emit_quad( struct setup_context
*setup
, struct quad_header
*quad
)
271 quad_clip( setup
, quad
);
273 if (quad
->inout
.mask
) {
274 struct llvmpipe_context
*lp
= setup
->llvmpipe
;
277 /* XXX: The blender expects 4 quads. This is far from efficient, but
278 * until we codegenerate single-quad variants of the fragment pipeline
279 * we need this hack. */
280 const unsigned nr_quads
= TILE_VECTOR_HEIGHT
*TILE_VECTOR_WIDTH
/QUAD_SIZE
;
281 struct quad_header quads
[nr_quads
];
282 struct quad_header
*quad_ptrs
[nr_quads
];
283 int x0
= block_x(quad
->input
.x0
);
286 for(i
= 0; i
< nr_quads
; ++i
) {
288 if(x
== quad
->input
.x0
)
289 memcpy(&quads
[i
], quad
, sizeof quads
[i
]);
291 memset(&quads
[i
], 0, sizeof quads
[i
]);
292 quads
[i
].input
.x0
= x
;
293 quads
[i
].input
.y0
= quad
->input
.y0
;
294 quads
[i
].coef
= quad
->coef
;
296 quad_ptrs
[i
] = &quads
[i
];
299 shade_quads( lp
, quad_ptrs
, nr_quads
);
301 shade_quads( lp
, &quad
, 1 );
308 * Render a horizontal span of quads
310 static void flush_spans( struct setup_context
*setup
)
312 const int step
= TILE_VECTOR_WIDTH
;
313 const int xleft0
= setup
->span
.left
[0];
314 const int xleft1
= setup
->span
.left
[1];
315 const int xright0
= setup
->span
.right
[0];
316 const int xright1
= setup
->span
.right
[1];
319 int minleft
= block_x(MIN2(xleft0
, xleft1
));
320 int maxright
= MAX2(xright0
, xright1
);
323 for (x
= minleft
; x
< maxright
; x
+= step
) {
324 unsigned skip_left0
= CLAMP(xleft0
- x
, 0, step
);
325 unsigned skip_left1
= CLAMP(xleft1
- x
, 0, step
);
326 unsigned skip_right0
= CLAMP(x
+ step
- xright0
, 0, step
);
327 unsigned skip_right1
= CLAMP(x
+ step
- xright1
, 0, step
);
329 const unsigned nr_quads
= TILE_VECTOR_HEIGHT
*TILE_VECTOR_WIDTH
/QUAD_SIZE
;
332 unsigned skipmask_left0
= (1U << skip_left0
) - 1U;
333 unsigned skipmask_left1
= (1U << skip_left1
) - 1U;
335 /* These calculations fail when step == 32 and skip_right == 0.
337 unsigned skipmask_right0
= ~0U << (unsigned)(step
- skip_right0
);
338 unsigned skipmask_right1
= ~0U << (unsigned)(step
- skip_right1
);
340 unsigned mask0
= ~skipmask_left0
& ~skipmask_right0
;
341 unsigned mask1
= ~skipmask_left1
& ~skipmask_right1
;
344 for(q
= 0; q
< nr_quads
; ++q
) {
345 unsigned quadmask
= (mask0
& 3) | ((mask1
& 3) << 2);
346 setup
->quad
[q
].input
.x0
= lx
;
347 setup
->quad
[q
].input
.y0
= setup
->span
.y
;
348 setup
->quad
[q
].inout
.mask
= quadmask
;
349 setup
->quad_ptrs
[q
] = &setup
->quad
[q
];
354 assert(!(mask0
| mask1
));
356 shade_quads(setup
->llvmpipe
, setup
->quad_ptrs
, nr_quads
);
362 setup
->span
.right
[0] = 0;
363 setup
->span
.right
[1] = 0;
364 setup
->span
.left
[0] = 1000000; /* greater than right[0] */
365 setup
->span
.left
[1] = 1000000; /* greater than right[1] */
370 static void print_vertex(const struct setup_context
*setup
,
374 debug_printf(" Vertex: (%p)\n", v
);
375 for (i
= 0; i
< setup
->quad
[0].nr_attrs
; i
++) {
376 debug_printf(" %d: %f %f %f %f\n", i
,
377 v
[i
][0], v
[i
][1], v
[i
][2], v
[i
][3]);
378 if (util_is_inf_or_nan(v
[i
][0])) {
379 debug_printf(" NaN!\n");
386 * Sort the vertices from top to bottom order, setting up the triangle
387 * edge fields (ebot, emaj, etop).
388 * \return FALSE if coords are inf/nan (cull the tri), TRUE otherwise
390 static boolean
setup_sort_vertices( struct setup_context
*setup
,
392 const float (*v0
)[4],
393 const float (*v1
)[4],
394 const float (*v2
)[4] )
396 setup
->vprovoke
= v2
;
398 /* determine bottom to top order of vertices */
445 setup
->ebot
.dx
= setup
->vmid
[0][0] - setup
->vmin
[0][0];
446 setup
->ebot
.dy
= setup
->vmid
[0][1] - setup
->vmin
[0][1];
447 setup
->emaj
.dx
= setup
->vmax
[0][0] - setup
->vmin
[0][0];
448 setup
->emaj
.dy
= setup
->vmax
[0][1] - setup
->vmin
[0][1];
449 setup
->etop
.dx
= setup
->vmax
[0][0] - setup
->vmid
[0][0];
450 setup
->etop
.dy
= setup
->vmax
[0][1] - setup
->vmid
[0][1];
453 * Compute triangle's area. Use 1/area to compute partial
454 * derivatives of attributes later.
456 * The area will be the same as prim->det, but the sign may be
457 * different depending on how the vertices get sorted above.
459 * To determine whether the primitive is front or back facing we
460 * use the prim->det value because its sign is correct.
463 const float area
= (setup
->emaj
.dx
* setup
->ebot
.dy
-
464 setup
->ebot
.dx
* setup
->emaj
.dy
);
466 setup
->oneoverarea
= 1.0f
/ area
;
469 debug_printf("%s one-over-area %f area %f det %f\n",
470 __FUNCTION__, setup->oneoverarea, area, det );
472 if (util_is_inf_or_nan(setup
->oneoverarea
))
476 /* We need to know if this is a front or back-facing triangle for:
477 * - the GLSL gl_FrontFacing fragment attribute (bool)
478 * - two-sided stencil test
482 (setup
->llvmpipe
->rasterizer
->front_winding
== PIPE_WINDING_CW
));
489 * Compute a0, dadx and dady for a linearly interpolated coefficient,
492 static void tri_pos_coeff( struct setup_context
*setup
,
493 uint vertSlot
, unsigned i
)
495 float botda
= setup
->vmid
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
496 float majda
= setup
->vmax
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
497 float a
= setup
->ebot
.dy
* majda
- botda
* setup
->emaj
.dy
;
498 float b
= setup
->emaj
.dx
* botda
- majda
* setup
->ebot
.dx
;
499 float dadx
= a
* setup
->oneoverarea
;
500 float dady
= b
* setup
->oneoverarea
;
504 setup
->coef
.dadx
[0][i
] = dadx
;
505 setup
->coef
.dady
[0][i
] = dady
;
507 /* calculate a0 as the value which would be sampled for the
508 * fragment at (0,0), taking into account that we want to sample at
509 * pixel centers, in other words (0.5, 0.5).
511 * this is neat but unfortunately not a good way to do things for
512 * triangles with very large values of dadx or dady as it will
513 * result in the subtraction and re-addition from a0 of a very
514 * large number, which means we'll end up loosing a lot of the
515 * fractional bits and precision from a0. the way to fix this is
516 * to define a0 as the sample at a pixel center somewhere near vmin
517 * instead - i'll switch to this later.
519 setup
->coef
.a0
[0][i
] = (setup
->vmin
[vertSlot
][i
] -
520 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
521 dady
* (setup
->vmin
[0][1] - 0.5f
)));
524 debug_printf("attr[%d].%c: %f dx:%f dy:%f\n",
526 setup->coef[slot].a0[i],
527 setup->coef[slot].dadx[i],
528 setup->coef[slot].dady[i]);
534 * Compute a0 for a constant-valued coefficient (GL_FLAT shading).
535 * The value value comes from vertex[slot][i].
536 * The result will be put into setup->coef[slot].a0[i].
537 * \param slot which attribute slot
538 * \param i which component of the slot (0..3)
540 static void const_pos_coeff( struct setup_context
*setup
,
541 uint vertSlot
, unsigned i
)
543 setup
->coef
.dadx
[0][i
] = 0;
544 setup
->coef
.dady
[0][i
] = 0;
546 /* need provoking vertex info!
548 setup
->coef
.a0
[0][i
] = setup
->vprovoke
[vertSlot
][i
];
553 * Compute a0 for a constant-valued coefficient (GL_FLAT shading).
554 * The value value comes from vertex[slot][i].
555 * The result will be put into setup->coef[slot].a0[i].
556 * \param slot which attribute slot
557 * \param i which component of the slot (0..3)
559 static void const_coeff( struct setup_context
*setup
,
564 for (i
= 0; i
< NUM_CHANNELS
; ++i
) {
565 setup
->coef
.dadx
[1 + attrib
][i
] = 0;
566 setup
->coef
.dady
[1 + attrib
][i
] = 0;
568 /* need provoking vertex info!
570 setup
->coef
.a0
[1 + attrib
][i
] = setup
->vprovoke
[vertSlot
][i
];
576 * Compute a0, dadx and dady for a linearly interpolated coefficient,
579 static void tri_linear_coeff( struct setup_context
*setup
,
584 for (i
= 0; i
< NUM_CHANNELS
; ++i
) {
585 float botda
= setup
->vmid
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
586 float majda
= setup
->vmax
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
587 float a
= setup
->ebot
.dy
* majda
- botda
* setup
->emaj
.dy
;
588 float b
= setup
->emaj
.dx
* botda
- majda
* setup
->ebot
.dx
;
589 float dadx
= a
* setup
->oneoverarea
;
590 float dady
= b
* setup
->oneoverarea
;
594 setup
->coef
.dadx
[1 + attrib
][i
] = dadx
;
595 setup
->coef
.dady
[1 + attrib
][i
] = dady
;
597 /* calculate a0 as the value which would be sampled for the
598 * fragment at (0,0), taking into account that we want to sample at
599 * pixel centers, in other words (0.5, 0.5).
601 * this is neat but unfortunately not a good way to do things for
602 * triangles with very large values of dadx or dady as it will
603 * result in the subtraction and re-addition from a0 of a very
604 * large number, which means we'll end up loosing a lot of the
605 * fractional bits and precision from a0. the way to fix this is
606 * to define a0 as the sample at a pixel center somewhere near vmin
607 * instead - i'll switch to this later.
609 setup
->coef
.a0
[1 + attrib
][i
] = (setup
->vmin
[vertSlot
][i
] -
610 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
611 dady
* (setup
->vmin
[0][1] - 0.5f
)));
614 debug_printf("attr[%d].%c: %f dx:%f dy:%f\n",
616 setup->coef[slot].a0[i],
617 setup->coef[slot].dadx[i],
618 setup->coef[slot].dady[i]);
625 * Compute a0, dadx and dady for a perspective-corrected interpolant,
627 * We basically multiply the vertex value by 1/w before computing
628 * the plane coefficients (a0, dadx, dady).
629 * Later, when we compute the value at a particular fragment position we'll
630 * divide the interpolated value by the interpolated W at that fragment.
632 static void tri_persp_coeff( struct setup_context
*setup
,
637 for (i
= 0; i
< NUM_CHANNELS
; ++i
) {
638 /* premultiply by 1/w (v[0][3] is always W):
640 float mina
= setup
->vmin
[vertSlot
][i
] * setup
->vmin
[0][3];
641 float mida
= setup
->vmid
[vertSlot
][i
] * setup
->vmid
[0][3];
642 float maxa
= setup
->vmax
[vertSlot
][i
] * setup
->vmax
[0][3];
643 float botda
= mida
- mina
;
644 float majda
= maxa
- mina
;
645 float a
= setup
->ebot
.dy
* majda
- botda
* setup
->emaj
.dy
;
646 float b
= setup
->emaj
.dx
* botda
- majda
* setup
->ebot
.dx
;
647 float dadx
= a
* setup
->oneoverarea
;
648 float dady
= b
* setup
->oneoverarea
;
651 debug_printf("tri persp %d,%d: %f %f %f\n", vertSlot, i,
652 setup->vmin[vertSlot][i],
653 setup->vmid[vertSlot][i],
654 setup->vmax[vertSlot][i]
659 setup
->coef
.dadx
[1 + attrib
][i
] = dadx
;
660 setup
->coef
.dady
[1 + attrib
][i
] = dady
;
661 setup
->coef
.a0
[1 + attrib
][i
] = (mina
-
662 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
663 dady
* (setup
->vmin
[0][1] - 0.5f
)));
669 * Special coefficient setup for gl_FragCoord.
670 * X and Y are trivial, though Y has to be inverted for OpenGL.
671 * Z and W are copied from posCoef which should have already been computed.
672 * We could do a bit less work if we'd examine gl_FragCoord's swizzle mask.
675 setup_fragcoord_coeff(struct setup_context
*setup
, uint slot
)
678 setup
->coef
.a0
[1 + slot
][0] = 0;
679 setup
->coef
.dadx
[1 + slot
][0] = 1.0;
680 setup
->coef
.dady
[1 + slot
][0] = 0.0;
682 setup
->coef
.a0
[1 + slot
][1] = 0.0;
683 setup
->coef
.dadx
[1 + slot
][1] = 0.0;
684 setup
->coef
.dady
[1 + slot
][1] = 1.0;
686 setup
->coef
.a0
[1 + slot
][2] = setup
->coef
.a0
[0][2];
687 setup
->coef
.dadx
[1 + slot
][2] = setup
->coef
.dadx
[0][2];
688 setup
->coef
.dady
[1 + slot
][2] = setup
->coef
.dady
[0][2];
690 setup
->coef
.a0
[1 + slot
][3] = setup
->coef
.a0
[0][3];
691 setup
->coef
.dadx
[1 + slot
][3] = setup
->coef
.dadx
[0][3];
692 setup
->coef
.dady
[1 + slot
][3] = setup
->coef
.dady
[0][3];
698 * Compute the setup->coef[] array dadx, dady, a0 values.
699 * Must be called after setup->vmin,vmid,vmax,vprovoke are initialized.
701 static void setup_tri_coefficients( struct setup_context
*setup
)
703 struct llvmpipe_context
*llvmpipe
= setup
->llvmpipe
;
704 const struct lp_fragment_shader
*lpfs
= llvmpipe
->fs
;
705 const struct vertex_info
*vinfo
= llvmpipe_get_vertex_info(llvmpipe
);
708 /* z and w are done by linear interpolation:
710 tri_pos_coeff(setup
, 0, 2);
711 tri_pos_coeff(setup
, 0, 3);
713 /* setup interpolation for all the remaining attributes:
715 for (fragSlot
= 0; fragSlot
< lpfs
->info
.num_inputs
; fragSlot
++) {
716 const uint vertSlot
= vinfo
->attrib
[fragSlot
].src_index
;
718 switch (vinfo
->attrib
[fragSlot
].interp_mode
) {
719 case INTERP_CONSTANT
:
720 const_coeff(setup
, fragSlot
, vertSlot
);
723 tri_linear_coeff(setup
, fragSlot
, vertSlot
);
725 case INTERP_PERSPECTIVE
:
726 tri_persp_coeff(setup
, fragSlot
, vertSlot
);
729 setup_fragcoord_coeff(setup
, fragSlot
);
735 if (lpfs
->info
.input_semantic_name
[fragSlot
] == TGSI_SEMANTIC_FACE
) {
736 setup
->coef
.a0
[1 + fragSlot
][0] = 1.0f
- setup
->facing
;
737 setup
->coef
.dadx
[1 + fragSlot
][0] = 0.0;
738 setup
->coef
.dady
[1 + fragSlot
][0] = 0.0;
745 static void setup_tri_edges( struct setup_context
*setup
)
747 float vmin_x
= setup
->vmin
[0][0] + 0.5f
;
748 float vmid_x
= setup
->vmid
[0][0] + 0.5f
;
750 float vmin_y
= setup
->vmin
[0][1] - 0.5f
;
751 float vmid_y
= setup
->vmid
[0][1] - 0.5f
;
752 float vmax_y
= setup
->vmax
[0][1] - 0.5f
;
754 setup
->emaj
.sy
= ceilf(vmin_y
);
755 setup
->emaj
.lines
= (int) ceilf(vmax_y
- setup
->emaj
.sy
);
756 setup
->emaj
.dxdy
= setup
->emaj
.dx
/ setup
->emaj
.dy
;
757 setup
->emaj
.sx
= vmin_x
+ (setup
->emaj
.sy
- vmin_y
) * setup
->emaj
.dxdy
;
759 setup
->etop
.sy
= ceilf(vmid_y
);
760 setup
->etop
.lines
= (int) ceilf(vmax_y
- setup
->etop
.sy
);
761 setup
->etop
.dxdy
= setup
->etop
.dx
/ setup
->etop
.dy
;
762 setup
->etop
.sx
= vmid_x
+ (setup
->etop
.sy
- vmid_y
) * setup
->etop
.dxdy
;
764 setup
->ebot
.sy
= ceilf(vmin_y
);
765 setup
->ebot
.lines
= (int) ceilf(vmid_y
- setup
->ebot
.sy
);
766 setup
->ebot
.dxdy
= setup
->ebot
.dx
/ setup
->ebot
.dy
;
767 setup
->ebot
.sx
= vmin_x
+ (setup
->ebot
.sy
- vmin_y
) * setup
->ebot
.dxdy
;
772 * Render the upper or lower half of a triangle.
773 * Scissoring/cliprect is applied here too.
775 static void subtriangle( struct setup_context
*setup
,
780 const struct pipe_scissor_state
*cliprect
= &setup
->llvmpipe
->cliprect
;
781 const int minx
= (int) cliprect
->minx
;
782 const int maxx
= (int) cliprect
->maxx
;
783 const int miny
= (int) cliprect
->miny
;
784 const int maxy
= (int) cliprect
->maxy
;
785 int y
, start_y
, finish_y
;
786 int sy
= (int)eleft
->sy
;
788 assert((int)eleft
->sy
== (int) eright
->sy
);
790 /* clip top/bottom */
795 finish_y
= sy
+ lines
;
803 debug_printf("%s %d %d\n", __FUNCTION__, start_y, finish_y);
806 for (y
= start_y
; y
< finish_y
; y
++) {
808 /* avoid accumulating adds as floats don't have the precision to
809 * accurately iterate large triangle edges that way. luckily we
810 * can just multiply these days.
812 * this is all drowned out by the attribute interpolation anyway.
814 int left
= (int)(eleft
->sx
+ y
* eleft
->dxdy
);
815 int right
= (int)(eright
->sx
+ y
* eright
->dxdy
);
817 /* clip left/right */
825 if (block(_y
) != setup
->span
.y
) {
827 setup
->span
.y
= block(_y
);
830 setup
->span
.left
[_y
&1] = left
;
831 setup
->span
.right
[_y
&1] = right
;
836 /* save the values so that emaj can be restarted:
838 eleft
->sx
+= lines
* eleft
->dxdy
;
839 eright
->sx
+= lines
* eright
->dxdy
;
846 * Recalculate prim's determinant. This is needed as we don't have
847 * get this information through the vbuf_render interface & we must
851 calc_det( const float (*v0
)[4],
852 const float (*v1
)[4],
853 const float (*v2
)[4] )
855 /* edge vectors e = v0 - v2, f = v1 - v2 */
856 const float ex
= v0
[0][0] - v2
[0][0];
857 const float ey
= v0
[0][1] - v2
[0][1];
858 const float fx
= v1
[0][0] - v2
[0][0];
859 const float fy
= v1
[0][1] - v2
[0][1];
861 /* det = cross(e,f).z */
862 return ex
* fy
- ey
* fx
;
867 * Do setup for triangle rasterization, then render the triangle.
869 void llvmpipe_setup_tri( struct setup_context
*setup
,
870 const float (*v0
)[4],
871 const float (*v1
)[4],
872 const float (*v2
)[4] )
877 debug_printf("Setup triangle:\n");
878 print_vertex(setup
, v0
);
879 print_vertex(setup
, v1
);
880 print_vertex(setup
, v2
);
883 if (setup
->llvmpipe
->no_rast
)
886 det
= calc_det(v0
, v1
, v2
);
888 debug_printf("%s\n", __FUNCTION__ );
892 setup
->numFragsEmitted
= 0;
893 setup
->numFragsWritten
= 0;
896 if (cull_tri( setup
, det
))
899 if (!setup_sort_vertices( setup
, det
, v0
, v1
, v2
))
901 setup_tri_coefficients( setup
);
902 setup_tri_edges( setup
);
904 assert(setup
->llvmpipe
->reduced_prim
== PIPE_PRIM_TRIANGLES
);
907 setup
->span
.right
[0] = 0;
908 setup
->span
.right
[1] = 0;
909 /* setup->span.z_mode = tri_z_mode( setup->ctx ); */
911 /* init_constant_attribs( setup ); */
913 if (setup
->oneoverarea
< 0.0) {
916 subtriangle( setup
, &setup
->emaj
, &setup
->ebot
, setup
->ebot
.lines
);
917 subtriangle( setup
, &setup
->emaj
, &setup
->etop
, setup
->etop
.lines
);
922 subtriangle( setup
, &setup
->ebot
, &setup
->emaj
, setup
->ebot
.lines
);
923 subtriangle( setup
, &setup
->etop
, &setup
->emaj
, setup
->etop
.lines
);
926 flush_spans( setup
);
929 printf("Tri: %u frags emitted, %u written\n",
930 setup
->numFragsEmitted
,
931 setup
->numFragsWritten
);
938 * Compute a0, dadx and dady for a linearly interpolated coefficient,
942 linear_pos_coeff(struct setup_context
*setup
,
943 uint vertSlot
, uint i
)
945 const float da
= setup
->vmax
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
946 const float dadx
= da
* setup
->emaj
.dx
* setup
->oneoverarea
;
947 const float dady
= da
* setup
->emaj
.dy
* setup
->oneoverarea
;
948 setup
->coef
.dadx
[0][i
] = dadx
;
949 setup
->coef
.dady
[0][i
] = dady
;
950 setup
->coef
.a0
[0][i
] = (setup
->vmin
[vertSlot
][i
] -
951 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
952 dady
* (setup
->vmin
[0][1] - 0.5f
)));
957 * Compute a0, dadx and dady for a linearly interpolated coefficient,
961 line_linear_coeff(struct setup_context
*setup
,
966 for (i
= 0; i
< NUM_CHANNELS
; ++i
) {
967 const float da
= setup
->vmax
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
968 const float dadx
= da
* setup
->emaj
.dx
* setup
->oneoverarea
;
969 const float dady
= da
* setup
->emaj
.dy
* setup
->oneoverarea
;
970 setup
->coef
.dadx
[1 + attrib
][i
] = dadx
;
971 setup
->coef
.dady
[1 + attrib
][i
] = dady
;
972 setup
->coef
.a0
[1 + attrib
][i
] = (setup
->vmin
[vertSlot
][i
] -
973 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
974 dady
* (setup
->vmin
[0][1] - 0.5f
)));
980 * Compute a0, dadx and dady for a perspective-corrected interpolant,
984 line_persp_coeff(struct setup_context
*setup
,
989 for (i
= 0; i
< NUM_CHANNELS
; ++i
) {
990 /* XXX double-check/verify this arithmetic */
991 const float a0
= setup
->vmin
[vertSlot
][i
] * setup
->vmin
[0][3];
992 const float a1
= setup
->vmax
[vertSlot
][i
] * setup
->vmax
[0][3];
993 const float da
= a1
- a0
;
994 const float dadx
= da
* setup
->emaj
.dx
* setup
->oneoverarea
;
995 const float dady
= da
* setup
->emaj
.dy
* setup
->oneoverarea
;
996 setup
->coef
.dadx
[1 + attrib
][i
] = dadx
;
997 setup
->coef
.dady
[1 + attrib
][i
] = dady
;
998 setup
->coef
.a0
[1 + attrib
][i
] = (setup
->vmin
[vertSlot
][i
] -
999 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
1000 dady
* (setup
->vmin
[0][1] - 0.5f
)));
1006 * Compute the setup->coef[] array dadx, dady, a0 values.
1007 * Must be called after setup->vmin,vmax are initialized.
1009 static INLINE boolean
1010 setup_line_coefficients(struct setup_context
*setup
,
1011 const float (*v0
)[4],
1012 const float (*v1
)[4])
1014 struct llvmpipe_context
*llvmpipe
= setup
->llvmpipe
;
1015 const struct lp_fragment_shader
*lpfs
= llvmpipe
->fs
;
1016 const struct vertex_info
*vinfo
= llvmpipe_get_vertex_info(llvmpipe
);
1020 /* use setup->vmin, vmax to point to vertices */
1021 if (llvmpipe
->rasterizer
->flatshade_first
)
1022 setup
->vprovoke
= v0
;
1024 setup
->vprovoke
= v1
;
1028 setup
->emaj
.dx
= setup
->vmax
[0][0] - setup
->vmin
[0][0];
1029 setup
->emaj
.dy
= setup
->vmax
[0][1] - setup
->vmin
[0][1];
1031 /* NOTE: this is not really area but something proportional to it */
1032 area
= setup
->emaj
.dx
* setup
->emaj
.dx
+ setup
->emaj
.dy
* setup
->emaj
.dy
;
1033 if (area
== 0.0f
|| util_is_inf_or_nan(area
))
1035 setup
->oneoverarea
= 1.0f
/ area
;
1037 /* z and w are done by linear interpolation:
1039 linear_pos_coeff(setup
, 0, 2);
1040 linear_pos_coeff(setup
, 0, 3);
1042 /* setup interpolation for all the remaining attributes:
1044 for (fragSlot
= 0; fragSlot
< lpfs
->info
.num_inputs
; fragSlot
++) {
1045 const uint vertSlot
= vinfo
->attrib
[fragSlot
].src_index
;
1047 switch (vinfo
->attrib
[fragSlot
].interp_mode
) {
1048 case INTERP_CONSTANT
:
1049 const_coeff(setup
, fragSlot
, vertSlot
);
1052 line_linear_coeff(setup
, fragSlot
, vertSlot
);
1054 case INTERP_PERSPECTIVE
:
1055 line_persp_coeff(setup
, fragSlot
, vertSlot
);
1058 setup_fragcoord_coeff(setup
, fragSlot
);
1064 if (lpfs
->info
.input_semantic_name
[fragSlot
] == TGSI_SEMANTIC_FACE
) {
1065 setup
->coef
.a0
[1 + fragSlot
][0] = 1.0f
- setup
->facing
;
1066 setup
->coef
.dadx
[1 + fragSlot
][0] = 0.0;
1067 setup
->coef
.dady
[1 + fragSlot
][0] = 0.0;
1075 * Plot a pixel in a line segment.
1078 plot(struct setup_context
*setup
, int x
, int y
)
1080 const int iy
= y
& 1;
1081 const int ix
= x
& 1;
1082 const int quadX
= x
- ix
;
1083 const int quadY
= y
- iy
;
1084 const int mask
= (1 << ix
) << (2 * iy
);
1086 if (quadX
!= setup
->quad
[0].input
.x0
||
1087 quadY
!= setup
->quad
[0].input
.y0
)
1089 /* flush prev quad, start new quad */
1091 if (setup
->quad
[0].input
.x0
!= -1)
1092 clip_emit_quad( setup
, &setup
->quad
[0] );
1094 setup
->quad
[0].input
.x0
= quadX
;
1095 setup
->quad
[0].input
.y0
= quadY
;
1096 setup
->quad
[0].inout
.mask
= 0x0;
1099 setup
->quad
[0].inout
.mask
|= mask
;
1104 * Do setup for line rasterization, then render the line.
1105 * Single-pixel width, no stipple, etc. We rely on the 'draw' module
1106 * to handle stippling and wide lines.
1109 llvmpipe_setup_line(struct setup_context
*setup
,
1110 const float (*v0
)[4],
1111 const float (*v1
)[4])
1113 int x0
= (int) v0
[0][0];
1114 int x1
= (int) v1
[0][0];
1115 int y0
= (int) v0
[0][1];
1116 int y1
= (int) v1
[0][1];
1122 debug_printf("Setup line:\n");
1123 print_vertex(setup
, v0
);
1124 print_vertex(setup
, v1
);
1127 if (setup
->llvmpipe
->no_rast
)
1130 if (dx
== 0 && dy
== 0)
1133 if (!setup_line_coefficients(setup
, v0
, v1
))
1136 assert(v0
[0][0] < 1.0e9
);
1137 assert(v0
[0][1] < 1.0e9
);
1138 assert(v1
[0][0] < 1.0e9
);
1139 assert(v1
[0][1] < 1.0e9
);
1142 dx
= -dx
; /* make positive */
1150 dy
= -dy
; /* make positive */
1159 assert(setup
->llvmpipe
->reduced_prim
== PIPE_PRIM_LINES
);
1161 setup
->quad
[0].input
.x0
= setup
->quad
[0].input
.y0
= -1;
1162 setup
->quad
[0].inout
.mask
= 0x0;
1164 /* XXX temporary: set coverage to 1.0 so the line appears
1165 * if AA mode happens to be enabled.
1167 setup
->quad
[0].input
.coverage
[0] =
1168 setup
->quad
[0].input
.coverage
[1] =
1169 setup
->quad
[0].input
.coverage
[2] =
1170 setup
->quad
[0].input
.coverage
[3] = 1.0;
1173 /*** X-major line ***/
1175 const int errorInc
= dy
+ dy
;
1176 int error
= errorInc
- dx
;
1177 const int errorDec
= error
- dx
;
1179 for (i
= 0; i
< dx
; i
++) {
1180 plot(setup
, x0
, y0
);
1193 /*** Y-major line ***/
1195 const int errorInc
= dx
+ dx
;
1196 int error
= errorInc
- dy
;
1197 const int errorDec
= error
- dy
;
1199 for (i
= 0; i
< dy
; i
++) {
1200 plot(setup
, x0
, y0
);
1213 /* draw final quad */
1214 if (setup
->quad
[0].inout
.mask
) {
1215 clip_emit_quad( setup
, &setup
->quad
[0] );
1221 point_persp_coeff(struct setup_context
*setup
,
1222 const float (*vert
)[4],
1227 for(i
= 0; i
< NUM_CHANNELS
; ++i
) {
1228 setup
->coef
.dadx
[1 + attrib
][i
] = 0.0F
;
1229 setup
->coef
.dady
[1 + attrib
][i
] = 0.0F
;
1230 setup
->coef
.a0
[1 + attrib
][i
] = vert
[vertSlot
][i
] * vert
[0][3];
1236 * Do setup for point rasterization, then render the point.
1237 * Round or square points...
1238 * XXX could optimize a lot for 1-pixel points.
1241 llvmpipe_setup_point( struct setup_context
*setup
,
1242 const float (*v0
)[4] )
1244 struct llvmpipe_context
*llvmpipe
= setup
->llvmpipe
;
1245 const struct lp_fragment_shader
*lpfs
= llvmpipe
->fs
;
1246 const int sizeAttr
= setup
->llvmpipe
->psize_slot
;
1248 = sizeAttr
> 0 ? v0
[sizeAttr
][0]
1249 : setup
->llvmpipe
->rasterizer
->point_size
;
1250 const float halfSize
= 0.5F
* size
;
1251 const boolean round
= (boolean
) setup
->llvmpipe
->rasterizer
->point_smooth
;
1252 const float x
= v0
[0][0]; /* Note: data[0] is always position */
1253 const float y
= v0
[0][1];
1254 const struct vertex_info
*vinfo
= llvmpipe_get_vertex_info(llvmpipe
);
1258 debug_printf("Setup point:\n");
1259 print_vertex(setup
, v0
);
1262 if (llvmpipe
->no_rast
)
1265 assert(setup
->llvmpipe
->reduced_prim
== PIPE_PRIM_POINTS
);
1267 /* For points, all interpolants are constant-valued.
1268 * However, for point sprites, we'll need to setup texcoords appropriately.
1269 * XXX: which coefficients are the texcoords???
1270 * We may do point sprites as textured quads...
1272 * KW: We don't know which coefficients are texcoords - ultimately
1273 * the choice of what interpolation mode to use for each attribute
1274 * should be determined by the fragment program, using
1275 * per-attribute declaration statements that include interpolation
1276 * mode as a parameter. So either the fragment program will have
1277 * to be adjusted for pointsprite vs normal point behaviour, or
1278 * otherwise a special interpolation mode will have to be defined
1279 * which matches the required behaviour for point sprites. But -
1280 * the latter is not a feature of normal hardware, and as such
1281 * probably should be ruled out on that basis.
1283 setup
->vprovoke
= v0
;
1286 const_pos_coeff(setup
, 0, 2);
1287 const_pos_coeff(setup
, 0, 3);
1289 for (fragSlot
= 0; fragSlot
< lpfs
->info
.num_inputs
; fragSlot
++) {
1290 const uint vertSlot
= vinfo
->attrib
[fragSlot
].src_index
;
1292 switch (vinfo
->attrib
[fragSlot
].interp_mode
) {
1293 case INTERP_CONSTANT
:
1296 const_coeff(setup
, fragSlot
, vertSlot
);
1298 case INTERP_PERSPECTIVE
:
1299 point_persp_coeff(setup
, setup
->vprovoke
, fragSlot
, vertSlot
);
1302 setup_fragcoord_coeff(setup
, fragSlot
);
1308 if (lpfs
->info
.input_semantic_name
[fragSlot
] == TGSI_SEMANTIC_FACE
) {
1309 setup
->coef
.a0
[1 + fragSlot
][0] = 1.0f
- setup
->facing
;
1310 setup
->coef
.dadx
[1 + fragSlot
][0] = 0.0;
1311 setup
->coef
.dady
[1 + fragSlot
][0] = 0.0;
1316 if (halfSize
<= 0.5 && !round
) {
1317 /* special case for 1-pixel points */
1318 const int ix
= ((int) x
) & 1;
1319 const int iy
= ((int) y
) & 1;
1320 setup
->quad
[0].input
.x0
= (int) x
- ix
;
1321 setup
->quad
[0].input
.y0
= (int) y
- iy
;
1322 setup
->quad
[0].inout
.mask
= (1 << ix
) << (2 * iy
);
1323 clip_emit_quad( setup
, &setup
->quad
[0] );
1327 /* rounded points */
1328 const int ixmin
= block((int) (x
- halfSize
));
1329 const int ixmax
= block((int) (x
+ halfSize
));
1330 const int iymin
= block((int) (y
- halfSize
));
1331 const int iymax
= block((int) (y
+ halfSize
));
1332 const float rmin
= halfSize
- 0.7071F
; /* 0.7071 = sqrt(2)/2 */
1333 const float rmax
= halfSize
+ 0.7071F
;
1334 const float rmin2
= MAX2(0.0F
, rmin
* rmin
);
1335 const float rmax2
= rmax
* rmax
;
1336 const float cscale
= 1.0F
/ (rmax2
- rmin2
);
1339 for (iy
= iymin
; iy
<= iymax
; iy
+= 2) {
1340 for (ix
= ixmin
; ix
<= ixmax
; ix
+= 2) {
1341 float dx
, dy
, dist2
, cover
;
1343 setup
->quad
[0].inout
.mask
= 0x0;
1345 dx
= (ix
+ 0.5f
) - x
;
1346 dy
= (iy
+ 0.5f
) - y
;
1347 dist2
= dx
* dx
+ dy
* dy
;
1348 if (dist2
<= rmax2
) {
1349 cover
= 1.0F
- (dist2
- rmin2
) * cscale
;
1350 setup
->quad
[0].input
.coverage
[QUAD_TOP_LEFT
] = MIN2(cover
, 1.0f
);
1351 setup
->quad
[0].inout
.mask
|= MASK_TOP_LEFT
;
1354 dx
= (ix
+ 1.5f
) - x
;
1355 dy
= (iy
+ 0.5f
) - y
;
1356 dist2
= dx
* dx
+ dy
* dy
;
1357 if (dist2
<= rmax2
) {
1358 cover
= 1.0F
- (dist2
- rmin2
) * cscale
;
1359 setup
->quad
[0].input
.coverage
[QUAD_TOP_RIGHT
] = MIN2(cover
, 1.0f
);
1360 setup
->quad
[0].inout
.mask
|= MASK_TOP_RIGHT
;
1363 dx
= (ix
+ 0.5f
) - x
;
1364 dy
= (iy
+ 1.5f
) - y
;
1365 dist2
= dx
* dx
+ dy
* dy
;
1366 if (dist2
<= rmax2
) {
1367 cover
= 1.0F
- (dist2
- rmin2
) * cscale
;
1368 setup
->quad
[0].input
.coverage
[QUAD_BOTTOM_LEFT
] = MIN2(cover
, 1.0f
);
1369 setup
->quad
[0].inout
.mask
|= MASK_BOTTOM_LEFT
;
1372 dx
= (ix
+ 1.5f
) - x
;
1373 dy
= (iy
+ 1.5f
) - y
;
1374 dist2
= dx
* dx
+ dy
* dy
;
1375 if (dist2
<= rmax2
) {
1376 cover
= 1.0F
- (dist2
- rmin2
) * cscale
;
1377 setup
->quad
[0].input
.coverage
[QUAD_BOTTOM_RIGHT
] = MIN2(cover
, 1.0f
);
1378 setup
->quad
[0].inout
.mask
|= MASK_BOTTOM_RIGHT
;
1381 if (setup
->quad
[0].inout
.mask
) {
1382 setup
->quad
[0].input
.x0
= ix
;
1383 setup
->quad
[0].input
.y0
= iy
;
1384 clip_emit_quad( setup
, &setup
->quad
[0] );
1391 const int xmin
= (int) (x
+ 0.75 - halfSize
);
1392 const int ymin
= (int) (y
+ 0.25 - halfSize
);
1393 const int xmax
= xmin
+ (int) size
;
1394 const int ymax
= ymin
+ (int) size
;
1395 /* XXX could apply scissor to xmin,ymin,xmax,ymax now */
1396 const int ixmin
= block(xmin
);
1397 const int ixmax
= block(xmax
- 1);
1398 const int iymin
= block(ymin
);
1399 const int iymax
= block(ymax
- 1);
1403 debug_printf("(%f, %f) -> X:%d..%d Y:%d..%d\n", x, y, xmin, xmax,ymin,ymax);
1405 for (iy
= iymin
; iy
<= iymax
; iy
+= 2) {
1408 /* above the top edge */
1409 rowMask
&= (MASK_BOTTOM_LEFT
| MASK_BOTTOM_RIGHT
);
1411 if (iy
+ 1 >= ymax
) {
1412 /* below the bottom edge */
1413 rowMask
&= (MASK_TOP_LEFT
| MASK_TOP_RIGHT
);
1416 for (ix
= ixmin
; ix
<= ixmax
; ix
+= 2) {
1417 uint mask
= rowMask
;
1420 /* fragment is past left edge of point, turn off left bits */
1421 mask
&= (MASK_BOTTOM_RIGHT
| MASK_TOP_RIGHT
);
1423 if (ix
+ 1 >= xmax
) {
1424 /* past the right edge */
1425 mask
&= (MASK_BOTTOM_LEFT
| MASK_TOP_LEFT
);
1428 setup
->quad
[0].inout
.mask
= mask
;
1429 setup
->quad
[0].input
.x0
= ix
;
1430 setup
->quad
[0].input
.y0
= iy
;
1431 clip_emit_quad( setup
, &setup
->quad
[0] );
1438 void llvmpipe_setup_prepare( struct setup_context
*setup
)
1440 struct llvmpipe_context
*lp
= setup
->llvmpipe
;
1443 llvmpipe_update_derived(lp
);
1446 if (lp
->reduced_api_prim
== PIPE_PRIM_TRIANGLES
&&
1447 lp
->rasterizer
->fill_cw
== PIPE_POLYGON_MODE_FILL
&&
1448 lp
->rasterizer
->fill_ccw
== PIPE_POLYGON_MODE_FILL
) {
1449 /* we'll do culling */
1450 setup
->winding
= lp
->rasterizer
->cull_mode
;
1453 /* 'draw' will do culling */
1454 setup
->winding
= PIPE_WINDING_NONE
;
1460 void llvmpipe_setup_destroy_context( struct setup_context
*setup
)
1462 align_free( setup
);
1467 * Create a new primitive setup/render stage.
1469 struct setup_context
*llvmpipe_setup_create_context( struct llvmpipe_context
*llvmpipe
)
1471 struct setup_context
*setup
;
1474 setup
= align_malloc(sizeof(struct setup_context
), 16);
1478 memset(setup
, 0, sizeof *setup
);
1479 setup
->llvmpipe
= llvmpipe
;
1481 for (i
= 0; i
< MAX_QUADS
; i
++) {
1482 setup
->quad
[i
].coef
= &setup
->coef
;
1485 setup
->span
.left
[0] = 1000000; /* greater than right[0] */
1486 setup
->span
.left
[1] = 1000000; /* greater than right[1] */