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.
119 shade_quads(struct llvmpipe_context
*llvmpipe
,
120 struct quad_header
*quads
[],
123 struct lp_fragment_shader
*fs
= llvmpipe
->fs
;
124 struct quad_header
*quad
= quads
[0];
125 const unsigned x
= quad
->input
.x0
;
126 const unsigned y
= quad
->input
.y0
;
130 uint32_t ALIGN16_ATTRIB mask
[4][NUM_CHANNELS
];
139 assert(nr
* QUAD_SIZE
== TILE_VECTOR_HEIGHT
* TILE_VECTOR_WIDTH
);
140 assert(x
% TILE_VECTOR_WIDTH
== 0);
141 assert(y
% TILE_VECTOR_HEIGHT
== 0);
142 for (q
= 0; q
< nr
; ++q
) {
143 assert(quads
[q
]->input
.x0
== x
+ q
*2);
144 assert(quads
[q
]->input
.y0
== y
);
148 for (q
= 0; q
< 4; ++q
)
149 for (chan_index
= 0; chan_index
< NUM_CHANNELS
; ++chan_index
)
150 mask
[q
][chan_index
] = quads
[q
]->inout
.mask
& (1 << chan_index
) ? ~0 : 0;
153 if(llvmpipe
->framebuffer
.nr_cbufs
>= 1 &&
154 llvmpipe
->framebuffer
.cbufs
[0]) {
155 tile
= lp_get_cached_tile(llvmpipe
->cbuf_cache
[0], x
, y
);
156 color
= &TILE_PIXEL(tile
, x
& (TILE_SIZE
-1), y
& (TILE_SIZE
-1), 0);
162 if(llvmpipe
->zsbuf_map
) {
163 assert((x
% 2) == 0);
164 assert((y
% 2) == 0);
165 depth
= llvmpipe
->zsbuf_map
+
166 y
*llvmpipe
->zsbuf_transfer
->stride
+
167 2*x
*llvmpipe
->zsbuf_transfer
->block
.size
;
172 /* XXX: This will most likely fail on 32bit x86 without -mstackrealign */
173 assert(lp_check_alignment(mask
, 16));
175 assert(lp_check_alignment(depth
, 16));
176 assert(lp_check_alignment(color
, 16));
177 assert(lp_check_alignment(llvmpipe
->jit_context
.blend_color
, 16));
180 fs
->current
->jit_function( &llvmpipe
->jit_context
,
194 * Do triangle cull test using tri determinant (sign indicates orientation)
195 * \return true if triangle is to be culled.
197 static INLINE boolean
198 cull_tri(const struct setup_context
*setup
, float det
)
201 /* if (det < 0 then Z points toward camera and triangle is
202 * counter-clockwise winding.
204 unsigned winding
= (det
< 0) ? PIPE_WINDING_CCW
: PIPE_WINDING_CW
;
206 if ((winding
& setup
->winding
) == 0)
218 * Clip setup->quad against the scissor/surface bounds.
221 quad_clip( struct setup_context
*setup
, struct quad_header
*quad
)
223 const struct pipe_scissor_state
*cliprect
= &setup
->llvmpipe
->cliprect
;
224 const int minx
= (int) cliprect
->minx
;
225 const int maxx
= (int) cliprect
->maxx
;
226 const int miny
= (int) cliprect
->miny
;
227 const int maxy
= (int) cliprect
->maxy
;
229 if (quad
->input
.x0
>= maxx
||
230 quad
->input
.y0
>= maxy
||
231 quad
->input
.x0
+ 1 < minx
||
232 quad
->input
.y0
+ 1 < miny
) {
233 /* totally clipped */
234 quad
->inout
.mask
= 0x0;
237 if (quad
->input
.x0
< minx
)
238 quad
->inout
.mask
&= (MASK_BOTTOM_RIGHT
| MASK_TOP_RIGHT
);
239 if (quad
->input
.y0
< miny
)
240 quad
->inout
.mask
&= (MASK_BOTTOM_LEFT
| MASK_BOTTOM_RIGHT
);
241 if (quad
->input
.x0
== maxx
- 1)
242 quad
->inout
.mask
&= (MASK_BOTTOM_LEFT
| MASK_TOP_LEFT
);
243 if (quad
->input
.y0
== maxy
- 1)
244 quad
->inout
.mask
&= (MASK_TOP_LEFT
| MASK_TOP_RIGHT
);
250 * Given an X or Y coordinate, return the block/quad coordinate that it
253 static INLINE
int block( int x
)
258 static INLINE
int block_x( int x
)
260 return x
& ~(TILE_VECTOR_WIDTH
- 1);
265 * Emit a quad (pass to next stage) with clipping.
268 clip_emit_quad( struct setup_context
*setup
, struct quad_header
*quad
)
270 quad_clip( setup
, quad
);
272 if (quad
->inout
.mask
) {
273 struct llvmpipe_context
*lp
= setup
->llvmpipe
;
276 /* XXX: The blender expects 4 quads. This is far from efficient, but
277 * until we codegenerate single-quad variants of the fragment pipeline
278 * we need this hack. */
279 const unsigned nr_quads
= TILE_VECTOR_HEIGHT
*TILE_VECTOR_WIDTH
/QUAD_SIZE
;
280 struct quad_header quads
[nr_quads
];
281 struct quad_header
*quad_ptrs
[nr_quads
];
282 int x0
= block_x(quad
->input
.x0
);
285 for(i
= 0; i
< nr_quads
; ++i
) {
287 if(x
== quad
->input
.x0
)
288 memcpy(&quads
[i
], quad
, sizeof quads
[i
]);
290 memset(&quads
[i
], 0, sizeof quads
[i
]);
291 quads
[i
].input
.x0
= x
;
292 quads
[i
].input
.y0
= quad
->input
.y0
;
293 quads
[i
].coef
= quad
->coef
;
295 quad_ptrs
[i
] = &quads
[i
];
298 shade_quads( lp
, quad_ptrs
, nr_quads
);
300 shade_quads( lp
, &quad
, 1 );
307 * Render a horizontal span of quads
309 static void flush_spans( struct setup_context
*setup
)
311 const int step
= TILE_VECTOR_WIDTH
;
312 const int xleft0
= setup
->span
.left
[0];
313 const int xleft1
= setup
->span
.left
[1];
314 const int xright0
= setup
->span
.right
[0];
315 const int xright1
= setup
->span
.right
[1];
318 int minleft
= block_x(MIN2(xleft0
, xleft1
));
319 int maxright
= MAX2(xright0
, xright1
);
322 for (x
= minleft
; x
< maxright
; x
+= step
) {
323 unsigned skip_left0
= CLAMP(xleft0
- x
, 0, step
);
324 unsigned skip_left1
= CLAMP(xleft1
- x
, 0, step
);
325 unsigned skip_right0
= CLAMP(x
+ step
- xright0
, 0, step
);
326 unsigned skip_right1
= CLAMP(x
+ step
- xright1
, 0, step
);
328 const unsigned nr_quads
= TILE_VECTOR_HEIGHT
*TILE_VECTOR_WIDTH
/QUAD_SIZE
;
331 unsigned skipmask_left0
= (1U << skip_left0
) - 1U;
332 unsigned skipmask_left1
= (1U << skip_left1
) - 1U;
334 /* These calculations fail when step == 32 and skip_right == 0.
336 unsigned skipmask_right0
= ~0U << (unsigned)(step
- skip_right0
);
337 unsigned skipmask_right1
= ~0U << (unsigned)(step
- skip_right1
);
339 unsigned mask0
= ~skipmask_left0
& ~skipmask_right0
;
340 unsigned mask1
= ~skipmask_left1
& ~skipmask_right1
;
343 for(q
= 0; q
< nr_quads
; ++q
) {
344 unsigned quadmask
= (mask0
& 3) | ((mask1
& 3) << 2);
345 setup
->quad
[q
].input
.x0
= lx
;
346 setup
->quad
[q
].input
.y0
= setup
->span
.y
;
347 setup
->quad
[q
].inout
.mask
= quadmask
;
348 setup
->quad_ptrs
[q
] = &setup
->quad
[q
];
353 assert(!(mask0
| mask1
));
355 shade_quads(setup
->llvmpipe
, setup
->quad_ptrs
, nr_quads
);
361 setup
->span
.right
[0] = 0;
362 setup
->span
.right
[1] = 0;
363 setup
->span
.left
[0] = 1000000; /* greater than right[0] */
364 setup
->span
.left
[1] = 1000000; /* greater than right[1] */
369 static void print_vertex(const struct setup_context
*setup
,
373 debug_printf(" Vertex: (%p)\n", v
);
374 for (i
= 0; i
< setup
->quad
[0].nr_attrs
; i
++) {
375 debug_printf(" %d: %f %f %f %f\n", i
,
376 v
[i
][0], v
[i
][1], v
[i
][2], v
[i
][3]);
377 if (util_is_inf_or_nan(v
[i
][0])) {
378 debug_printf(" NaN!\n");
385 * Sort the vertices from top to bottom order, setting up the triangle
386 * edge fields (ebot, emaj, etop).
387 * \return FALSE if coords are inf/nan (cull the tri), TRUE otherwise
389 static boolean
setup_sort_vertices( struct setup_context
*setup
,
391 const float (*v0
)[4],
392 const float (*v1
)[4],
393 const float (*v2
)[4] )
395 setup
->vprovoke
= v2
;
397 /* determine bottom to top order of vertices */
444 setup
->ebot
.dx
= setup
->vmid
[0][0] - setup
->vmin
[0][0];
445 setup
->ebot
.dy
= setup
->vmid
[0][1] - setup
->vmin
[0][1];
446 setup
->emaj
.dx
= setup
->vmax
[0][0] - setup
->vmin
[0][0];
447 setup
->emaj
.dy
= setup
->vmax
[0][1] - setup
->vmin
[0][1];
448 setup
->etop
.dx
= setup
->vmax
[0][0] - setup
->vmid
[0][0];
449 setup
->etop
.dy
= setup
->vmax
[0][1] - setup
->vmid
[0][1];
452 * Compute triangle's area. Use 1/area to compute partial
453 * derivatives of attributes later.
455 * The area will be the same as prim->det, but the sign may be
456 * different depending on how the vertices get sorted above.
458 * To determine whether the primitive is front or back facing we
459 * use the prim->det value because its sign is correct.
462 const float area
= (setup
->emaj
.dx
* setup
->ebot
.dy
-
463 setup
->ebot
.dx
* setup
->emaj
.dy
);
465 setup
->oneoverarea
= 1.0f
/ area
;
468 debug_printf("%s one-over-area %f area %f det %f\n",
469 __FUNCTION__, setup->oneoverarea, area, det );
471 if (util_is_inf_or_nan(setup
->oneoverarea
))
475 /* We need to know if this is a front or back-facing triangle for:
476 * - the GLSL gl_FrontFacing fragment attribute (bool)
477 * - two-sided stencil test
481 (setup
->llvmpipe
->rasterizer
->front_winding
== PIPE_WINDING_CW
));
488 * Compute a0, dadx and dady for a linearly interpolated coefficient,
491 static void tri_pos_coeff( struct setup_context
*setup
,
492 uint vertSlot
, unsigned i
)
494 float botda
= setup
->vmid
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
495 float majda
= setup
->vmax
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
496 float a
= setup
->ebot
.dy
* majda
- botda
* setup
->emaj
.dy
;
497 float b
= setup
->emaj
.dx
* botda
- majda
* setup
->ebot
.dx
;
498 float dadx
= a
* setup
->oneoverarea
;
499 float dady
= b
* setup
->oneoverarea
;
503 setup
->coef
.dadx
[0][i
] = dadx
;
504 setup
->coef
.dady
[0][i
] = dady
;
506 /* calculate a0 as the value which would be sampled for the
507 * fragment at (0,0), taking into account that we want to sample at
508 * pixel centers, in other words (0.5, 0.5).
510 * this is neat but unfortunately not a good way to do things for
511 * triangles with very large values of dadx or dady as it will
512 * result in the subtraction and re-addition from a0 of a very
513 * large number, which means we'll end up loosing a lot of the
514 * fractional bits and precision from a0. the way to fix this is
515 * to define a0 as the sample at a pixel center somewhere near vmin
516 * instead - i'll switch to this later.
518 setup
->coef
.a0
[0][i
] = (setup
->vmin
[vertSlot
][i
] -
519 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
520 dady
* (setup
->vmin
[0][1] - 0.5f
)));
523 debug_printf("attr[%d].%c: %f dx:%f dy:%f\n",
525 setup->coef[slot].a0[i],
526 setup->coef[slot].dadx[i],
527 setup->coef[slot].dady[i]);
533 * Compute a0 for a constant-valued coefficient (GL_FLAT shading).
534 * The value value comes from vertex[slot][i].
535 * The result will be put into setup->coef[slot].a0[i].
536 * \param slot which attribute slot
537 * \param i which component of the slot (0..3)
539 static void const_pos_coeff( struct setup_context
*setup
,
540 uint vertSlot
, unsigned i
)
542 setup
->coef
.dadx
[0][i
] = 0;
543 setup
->coef
.dady
[0][i
] = 0;
545 /* need provoking vertex info!
547 setup
->coef
.a0
[0][i
] = setup
->vprovoke
[vertSlot
][i
];
552 * Compute a0 for a constant-valued coefficient (GL_FLAT shading).
553 * The value value comes from vertex[slot][i].
554 * The result will be put into setup->coef[slot].a0[i].
555 * \param slot which attribute slot
556 * \param i which component of the slot (0..3)
558 static void const_coeff( struct setup_context
*setup
,
563 for (i
= 0; i
< NUM_CHANNELS
; ++i
) {
564 setup
->coef
.dadx
[1 + attrib
][i
] = 0;
565 setup
->coef
.dady
[1 + attrib
][i
] = 0;
567 /* need provoking vertex info!
569 setup
->coef
.a0
[1 + attrib
][i
] = setup
->vprovoke
[vertSlot
][i
];
575 * Compute a0, dadx and dady for a linearly interpolated coefficient,
578 static void tri_linear_coeff( struct setup_context
*setup
,
583 for (i
= 0; i
< NUM_CHANNELS
; ++i
) {
584 float botda
= setup
->vmid
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
585 float majda
= setup
->vmax
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
586 float a
= setup
->ebot
.dy
* majda
- botda
* setup
->emaj
.dy
;
587 float b
= setup
->emaj
.dx
* botda
- majda
* setup
->ebot
.dx
;
588 float dadx
= a
* setup
->oneoverarea
;
589 float dady
= b
* setup
->oneoverarea
;
593 setup
->coef
.dadx
[1 + attrib
][i
] = dadx
;
594 setup
->coef
.dady
[1 + attrib
][i
] = dady
;
596 /* calculate a0 as the value which would be sampled for the
597 * fragment at (0,0), taking into account that we want to sample at
598 * pixel centers, in other words (0.5, 0.5).
600 * this is neat but unfortunately not a good way to do things for
601 * triangles with very large values of dadx or dady as it will
602 * result in the subtraction and re-addition from a0 of a very
603 * large number, which means we'll end up loosing a lot of the
604 * fractional bits and precision from a0. the way to fix this is
605 * to define a0 as the sample at a pixel center somewhere near vmin
606 * instead - i'll switch to this later.
608 setup
->coef
.a0
[1 + attrib
][i
] = (setup
->vmin
[vertSlot
][i
] -
609 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
610 dady
* (setup
->vmin
[0][1] - 0.5f
)));
613 debug_printf("attr[%d].%c: %f dx:%f dy:%f\n",
615 setup->coef[slot].a0[i],
616 setup->coef[slot].dadx[i],
617 setup->coef[slot].dady[i]);
624 * Compute a0, dadx and dady for a perspective-corrected interpolant,
626 * We basically multiply the vertex value by 1/w before computing
627 * the plane coefficients (a0, dadx, dady).
628 * Later, when we compute the value at a particular fragment position we'll
629 * divide the interpolated value by the interpolated W at that fragment.
631 static void tri_persp_coeff( struct setup_context
*setup
,
636 for (i
= 0; i
< NUM_CHANNELS
; ++i
) {
637 /* premultiply by 1/w (v[0][3] is always W):
639 float mina
= setup
->vmin
[vertSlot
][i
] * setup
->vmin
[0][3];
640 float mida
= setup
->vmid
[vertSlot
][i
] * setup
->vmid
[0][3];
641 float maxa
= setup
->vmax
[vertSlot
][i
] * setup
->vmax
[0][3];
642 float botda
= mida
- mina
;
643 float majda
= maxa
- mina
;
644 float a
= setup
->ebot
.dy
* majda
- botda
* setup
->emaj
.dy
;
645 float b
= setup
->emaj
.dx
* botda
- majda
* setup
->ebot
.dx
;
646 float dadx
= a
* setup
->oneoverarea
;
647 float dady
= b
* setup
->oneoverarea
;
650 debug_printf("tri persp %d,%d: %f %f %f\n", vertSlot, i,
651 setup->vmin[vertSlot][i],
652 setup->vmid[vertSlot][i],
653 setup->vmax[vertSlot][i]
658 setup
->coef
.dadx
[1 + attrib
][i
] = dadx
;
659 setup
->coef
.dady
[1 + attrib
][i
] = dady
;
660 setup
->coef
.a0
[1 + attrib
][i
] = (mina
-
661 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
662 dady
* (setup
->vmin
[0][1] - 0.5f
)));
668 * Special coefficient setup for gl_FragCoord.
669 * X and Y are trivial, though Y has to be inverted for OpenGL.
670 * Z and W are copied from posCoef which should have already been computed.
671 * We could do a bit less work if we'd examine gl_FragCoord's swizzle mask.
674 setup_fragcoord_coeff(struct setup_context
*setup
, uint slot
)
677 setup
->coef
.a0
[1 + slot
][0] = 0;
678 setup
->coef
.dadx
[1 + slot
][0] = 1.0;
679 setup
->coef
.dady
[1 + slot
][0] = 0.0;
681 setup
->coef
.a0
[1 + slot
][1] = 0.0;
682 setup
->coef
.dadx
[1 + slot
][1] = 0.0;
683 setup
->coef
.dady
[1 + slot
][1] = 1.0;
685 setup
->coef
.a0
[1 + slot
][2] = setup
->coef
.a0
[0][2];
686 setup
->coef
.dadx
[1 + slot
][2] = setup
->coef
.dadx
[0][2];
687 setup
->coef
.dady
[1 + slot
][2] = setup
->coef
.dady
[0][2];
689 setup
->coef
.a0
[1 + slot
][3] = setup
->coef
.a0
[0][3];
690 setup
->coef
.dadx
[1 + slot
][3] = setup
->coef
.dadx
[0][3];
691 setup
->coef
.dady
[1 + slot
][3] = setup
->coef
.dady
[0][3];
697 * Compute the setup->coef[] array dadx, dady, a0 values.
698 * Must be called after setup->vmin,vmid,vmax,vprovoke are initialized.
700 static void setup_tri_coefficients( struct setup_context
*setup
)
702 struct llvmpipe_context
*llvmpipe
= setup
->llvmpipe
;
703 const struct lp_fragment_shader
*lpfs
= llvmpipe
->fs
;
704 const struct vertex_info
*vinfo
= llvmpipe_get_vertex_info(llvmpipe
);
707 /* z and w are done by linear interpolation:
709 tri_pos_coeff(setup
, 0, 2);
710 tri_pos_coeff(setup
, 0, 3);
712 /* setup interpolation for all the remaining attributes:
714 for (fragSlot
= 0; fragSlot
< lpfs
->info
.num_inputs
; fragSlot
++) {
715 const uint vertSlot
= vinfo
->attrib
[fragSlot
].src_index
;
717 switch (vinfo
->attrib
[fragSlot
].interp_mode
) {
718 case INTERP_CONSTANT
:
719 const_coeff(setup
, fragSlot
, vertSlot
);
722 tri_linear_coeff(setup
, fragSlot
, vertSlot
);
724 case INTERP_PERSPECTIVE
:
725 tri_persp_coeff(setup
, fragSlot
, vertSlot
);
728 setup_fragcoord_coeff(setup
, fragSlot
);
734 if (lpfs
->info
.input_semantic_name
[fragSlot
] == TGSI_SEMANTIC_FACE
) {
735 setup
->coef
.a0
[1 + fragSlot
][0] = 1.0f
- setup
->facing
;
736 setup
->coef
.dadx
[1 + fragSlot
][0] = 0.0;
737 setup
->coef
.dady
[1 + fragSlot
][0] = 0.0;
744 static void setup_tri_edges( struct setup_context
*setup
)
746 float vmin_x
= setup
->vmin
[0][0] + 0.5f
;
747 float vmid_x
= setup
->vmid
[0][0] + 0.5f
;
749 float vmin_y
= setup
->vmin
[0][1] - 0.5f
;
750 float vmid_y
= setup
->vmid
[0][1] - 0.5f
;
751 float vmax_y
= setup
->vmax
[0][1] - 0.5f
;
753 setup
->emaj
.sy
= ceilf(vmin_y
);
754 setup
->emaj
.lines
= (int) ceilf(vmax_y
- setup
->emaj
.sy
);
755 setup
->emaj
.dxdy
= setup
->emaj
.dx
/ setup
->emaj
.dy
;
756 setup
->emaj
.sx
= vmin_x
+ (setup
->emaj
.sy
- vmin_y
) * setup
->emaj
.dxdy
;
758 setup
->etop
.sy
= ceilf(vmid_y
);
759 setup
->etop
.lines
= (int) ceilf(vmax_y
- setup
->etop
.sy
);
760 setup
->etop
.dxdy
= setup
->etop
.dx
/ setup
->etop
.dy
;
761 setup
->etop
.sx
= vmid_x
+ (setup
->etop
.sy
- vmid_y
) * setup
->etop
.dxdy
;
763 setup
->ebot
.sy
= ceilf(vmin_y
);
764 setup
->ebot
.lines
= (int) ceilf(vmid_y
- setup
->ebot
.sy
);
765 setup
->ebot
.dxdy
= setup
->ebot
.dx
/ setup
->ebot
.dy
;
766 setup
->ebot
.sx
= vmin_x
+ (setup
->ebot
.sy
- vmin_y
) * setup
->ebot
.dxdy
;
771 * Render the upper or lower half of a triangle.
772 * Scissoring/cliprect is applied here too.
774 static void subtriangle( struct setup_context
*setup
,
779 const struct pipe_scissor_state
*cliprect
= &setup
->llvmpipe
->cliprect
;
780 const int minx
= (int) cliprect
->minx
;
781 const int maxx
= (int) cliprect
->maxx
;
782 const int miny
= (int) cliprect
->miny
;
783 const int maxy
= (int) cliprect
->maxy
;
784 int y
, start_y
, finish_y
;
785 int sy
= (int)eleft
->sy
;
787 assert((int)eleft
->sy
== (int) eright
->sy
);
789 /* clip top/bottom */
794 finish_y
= sy
+ lines
;
802 debug_printf("%s %d %d\n", __FUNCTION__, start_y, finish_y);
805 for (y
= start_y
; y
< finish_y
; y
++) {
807 /* avoid accumulating adds as floats don't have the precision to
808 * accurately iterate large triangle edges that way. luckily we
809 * can just multiply these days.
811 * this is all drowned out by the attribute interpolation anyway.
813 int left
= (int)(eleft
->sx
+ y
* eleft
->dxdy
);
814 int right
= (int)(eright
->sx
+ y
* eright
->dxdy
);
816 /* clip left/right */
824 if (block(_y
) != setup
->span
.y
) {
826 setup
->span
.y
= block(_y
);
829 setup
->span
.left
[_y
&1] = left
;
830 setup
->span
.right
[_y
&1] = right
;
835 /* save the values so that emaj can be restarted:
837 eleft
->sx
+= lines
* eleft
->dxdy
;
838 eright
->sx
+= lines
* eright
->dxdy
;
845 * Recalculate prim's determinant. This is needed as we don't have
846 * get this information through the vbuf_render interface & we must
850 calc_det( const float (*v0
)[4],
851 const float (*v1
)[4],
852 const float (*v2
)[4] )
854 /* edge vectors e = v0 - v2, f = v1 - v2 */
855 const float ex
= v0
[0][0] - v2
[0][0];
856 const float ey
= v0
[0][1] - v2
[0][1];
857 const float fx
= v1
[0][0] - v2
[0][0];
858 const float fy
= v1
[0][1] - v2
[0][1];
860 /* det = cross(e,f).z */
861 return ex
* fy
- ey
* fx
;
866 * Do setup for triangle rasterization, then render the triangle.
868 void llvmpipe_setup_tri( struct setup_context
*setup
,
869 const float (*v0
)[4],
870 const float (*v1
)[4],
871 const float (*v2
)[4] )
876 debug_printf("Setup triangle:\n");
877 print_vertex(setup
, v0
);
878 print_vertex(setup
, v1
);
879 print_vertex(setup
, v2
);
882 if (setup
->llvmpipe
->no_rast
)
885 det
= calc_det(v0
, v1
, v2
);
887 debug_printf("%s\n", __FUNCTION__ );
891 setup
->numFragsEmitted
= 0;
892 setup
->numFragsWritten
= 0;
895 if (cull_tri( setup
, det
))
898 if (!setup_sort_vertices( setup
, det
, v0
, v1
, v2
))
900 setup_tri_coefficients( setup
);
901 setup_tri_edges( setup
);
903 assert(setup
->llvmpipe
->reduced_prim
== PIPE_PRIM_TRIANGLES
);
906 setup
->span
.right
[0] = 0;
907 setup
->span
.right
[1] = 0;
908 /* setup->span.z_mode = tri_z_mode( setup->ctx ); */
910 /* init_constant_attribs( setup ); */
912 if (setup
->oneoverarea
< 0.0) {
915 subtriangle( setup
, &setup
->emaj
, &setup
->ebot
, setup
->ebot
.lines
);
916 subtriangle( setup
, &setup
->emaj
, &setup
->etop
, setup
->etop
.lines
);
921 subtriangle( setup
, &setup
->ebot
, &setup
->emaj
, setup
->ebot
.lines
);
922 subtriangle( setup
, &setup
->etop
, &setup
->emaj
, setup
->etop
.lines
);
925 flush_spans( setup
);
928 printf("Tri: %u frags emitted, %u written\n",
929 setup
->numFragsEmitted
,
930 setup
->numFragsWritten
);
937 * Compute a0, dadx and dady for a linearly interpolated coefficient,
941 linear_pos_coeff(struct setup_context
*setup
,
942 uint vertSlot
, uint i
)
944 const float da
= setup
->vmax
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
945 const float dadx
= da
* setup
->emaj
.dx
* setup
->oneoverarea
;
946 const float dady
= da
* setup
->emaj
.dy
* setup
->oneoverarea
;
947 setup
->coef
.dadx
[0][i
] = dadx
;
948 setup
->coef
.dady
[0][i
] = dady
;
949 setup
->coef
.a0
[0][i
] = (setup
->vmin
[vertSlot
][i
] -
950 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
951 dady
* (setup
->vmin
[0][1] - 0.5f
)));
956 * Compute a0, dadx and dady for a linearly interpolated coefficient,
960 line_linear_coeff(struct setup_context
*setup
,
965 for (i
= 0; i
< NUM_CHANNELS
; ++i
) {
966 const float da
= setup
->vmax
[vertSlot
][i
] - setup
->vmin
[vertSlot
][i
];
967 const float dadx
= da
* setup
->emaj
.dx
* setup
->oneoverarea
;
968 const float dady
= da
* setup
->emaj
.dy
* setup
->oneoverarea
;
969 setup
->coef
.dadx
[1 + attrib
][i
] = dadx
;
970 setup
->coef
.dady
[1 + attrib
][i
] = dady
;
971 setup
->coef
.a0
[1 + attrib
][i
] = (setup
->vmin
[vertSlot
][i
] -
972 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
973 dady
* (setup
->vmin
[0][1] - 0.5f
)));
979 * Compute a0, dadx and dady for a perspective-corrected interpolant,
983 line_persp_coeff(struct setup_context
*setup
,
988 for (i
= 0; i
< NUM_CHANNELS
; ++i
) {
989 /* XXX double-check/verify this arithmetic */
990 const float a0
= setup
->vmin
[vertSlot
][i
] * setup
->vmin
[0][3];
991 const float a1
= setup
->vmax
[vertSlot
][i
] * setup
->vmax
[0][3];
992 const float da
= a1
- a0
;
993 const float dadx
= da
* setup
->emaj
.dx
* setup
->oneoverarea
;
994 const float dady
= da
* setup
->emaj
.dy
* setup
->oneoverarea
;
995 setup
->coef
.dadx
[1 + attrib
][i
] = dadx
;
996 setup
->coef
.dady
[1 + attrib
][i
] = dady
;
997 setup
->coef
.a0
[1 + attrib
][i
] = (setup
->vmin
[vertSlot
][i
] -
998 (dadx
* (setup
->vmin
[0][0] - 0.5f
) +
999 dady
* (setup
->vmin
[0][1] - 0.5f
)));
1005 * Compute the setup->coef[] array dadx, dady, a0 values.
1006 * Must be called after setup->vmin,vmax are initialized.
1008 static INLINE boolean
1009 setup_line_coefficients(struct setup_context
*setup
,
1010 const float (*v0
)[4],
1011 const float (*v1
)[4])
1013 struct llvmpipe_context
*llvmpipe
= setup
->llvmpipe
;
1014 const struct lp_fragment_shader
*lpfs
= llvmpipe
->fs
;
1015 const struct vertex_info
*vinfo
= llvmpipe_get_vertex_info(llvmpipe
);
1019 /* use setup->vmin, vmax to point to vertices */
1020 if (llvmpipe
->rasterizer
->flatshade_first
)
1021 setup
->vprovoke
= v0
;
1023 setup
->vprovoke
= v1
;
1027 setup
->emaj
.dx
= setup
->vmax
[0][0] - setup
->vmin
[0][0];
1028 setup
->emaj
.dy
= setup
->vmax
[0][1] - setup
->vmin
[0][1];
1030 /* NOTE: this is not really area but something proportional to it */
1031 area
= setup
->emaj
.dx
* setup
->emaj
.dx
+ setup
->emaj
.dy
* setup
->emaj
.dy
;
1032 if (area
== 0.0f
|| util_is_inf_or_nan(area
))
1034 setup
->oneoverarea
= 1.0f
/ area
;
1036 /* z and w are done by linear interpolation:
1038 linear_pos_coeff(setup
, 0, 2);
1039 linear_pos_coeff(setup
, 0, 3);
1041 /* setup interpolation for all the remaining attributes:
1043 for (fragSlot
= 0; fragSlot
< lpfs
->info
.num_inputs
; fragSlot
++) {
1044 const uint vertSlot
= vinfo
->attrib
[fragSlot
].src_index
;
1046 switch (vinfo
->attrib
[fragSlot
].interp_mode
) {
1047 case INTERP_CONSTANT
:
1048 const_coeff(setup
, fragSlot
, vertSlot
);
1051 line_linear_coeff(setup
, fragSlot
, vertSlot
);
1053 case INTERP_PERSPECTIVE
:
1054 line_persp_coeff(setup
, fragSlot
, vertSlot
);
1057 setup_fragcoord_coeff(setup
, fragSlot
);
1063 if (lpfs
->info
.input_semantic_name
[fragSlot
] == TGSI_SEMANTIC_FACE
) {
1064 setup
->coef
.a0
[1 + fragSlot
][0] = 1.0f
- setup
->facing
;
1065 setup
->coef
.dadx
[1 + fragSlot
][0] = 0.0;
1066 setup
->coef
.dady
[1 + fragSlot
][0] = 0.0;
1074 * Plot a pixel in a line segment.
1077 plot(struct setup_context
*setup
, int x
, int y
)
1079 const int iy
= y
& 1;
1080 const int ix
= x
& 1;
1081 const int quadX
= x
- ix
;
1082 const int quadY
= y
- iy
;
1083 const int mask
= (1 << ix
) << (2 * iy
);
1085 if (quadX
!= setup
->quad
[0].input
.x0
||
1086 quadY
!= setup
->quad
[0].input
.y0
)
1088 /* flush prev quad, start new quad */
1090 if (setup
->quad
[0].input
.x0
!= -1)
1091 clip_emit_quad( setup
, &setup
->quad
[0] );
1093 setup
->quad
[0].input
.x0
= quadX
;
1094 setup
->quad
[0].input
.y0
= quadY
;
1095 setup
->quad
[0].inout
.mask
= 0x0;
1098 setup
->quad
[0].inout
.mask
|= mask
;
1103 * Do setup for line rasterization, then render the line.
1104 * Single-pixel width, no stipple, etc. We rely on the 'draw' module
1105 * to handle stippling and wide lines.
1108 llvmpipe_setup_line(struct setup_context
*setup
,
1109 const float (*v0
)[4],
1110 const float (*v1
)[4])
1112 int x0
= (int) v0
[0][0];
1113 int x1
= (int) v1
[0][0];
1114 int y0
= (int) v0
[0][1];
1115 int y1
= (int) v1
[0][1];
1121 debug_printf("Setup line:\n");
1122 print_vertex(setup
, v0
);
1123 print_vertex(setup
, v1
);
1126 if (setup
->llvmpipe
->no_rast
)
1129 if (dx
== 0 && dy
== 0)
1132 if (!setup_line_coefficients(setup
, v0
, v1
))
1135 assert(v0
[0][0] < 1.0e9
);
1136 assert(v0
[0][1] < 1.0e9
);
1137 assert(v1
[0][0] < 1.0e9
);
1138 assert(v1
[0][1] < 1.0e9
);
1141 dx
= -dx
; /* make positive */
1149 dy
= -dy
; /* make positive */
1158 assert(setup
->llvmpipe
->reduced_prim
== PIPE_PRIM_LINES
);
1160 setup
->quad
[0].input
.x0
= setup
->quad
[0].input
.y0
= -1;
1161 setup
->quad
[0].inout
.mask
= 0x0;
1163 /* XXX temporary: set coverage to 1.0 so the line appears
1164 * if AA mode happens to be enabled.
1166 setup
->quad
[0].input
.coverage
[0] =
1167 setup
->quad
[0].input
.coverage
[1] =
1168 setup
->quad
[0].input
.coverage
[2] =
1169 setup
->quad
[0].input
.coverage
[3] = 1.0;
1172 /*** X-major line ***/
1174 const int errorInc
= dy
+ dy
;
1175 int error
= errorInc
- dx
;
1176 const int errorDec
= error
- dx
;
1178 for (i
= 0; i
< dx
; i
++) {
1179 plot(setup
, x0
, y0
);
1192 /*** Y-major line ***/
1194 const int errorInc
= dx
+ dx
;
1195 int error
= errorInc
- dy
;
1196 const int errorDec
= error
- dy
;
1198 for (i
= 0; i
< dy
; i
++) {
1199 plot(setup
, x0
, y0
);
1212 /* draw final quad */
1213 if (setup
->quad
[0].inout
.mask
) {
1214 clip_emit_quad( setup
, &setup
->quad
[0] );
1220 point_persp_coeff(struct setup_context
*setup
,
1221 const float (*vert
)[4],
1226 for(i
= 0; i
< NUM_CHANNELS
; ++i
) {
1227 setup
->coef
.dadx
[1 + attrib
][i
] = 0.0F
;
1228 setup
->coef
.dady
[1 + attrib
][i
] = 0.0F
;
1229 setup
->coef
.a0
[1 + attrib
][i
] = vert
[vertSlot
][i
] * vert
[0][3];
1235 * Do setup for point rasterization, then render the point.
1236 * Round or square points...
1237 * XXX could optimize a lot for 1-pixel points.
1240 llvmpipe_setup_point( struct setup_context
*setup
,
1241 const float (*v0
)[4] )
1243 struct llvmpipe_context
*llvmpipe
= setup
->llvmpipe
;
1244 const struct lp_fragment_shader
*lpfs
= llvmpipe
->fs
;
1245 const int sizeAttr
= setup
->llvmpipe
->psize_slot
;
1247 = sizeAttr
> 0 ? v0
[sizeAttr
][0]
1248 : setup
->llvmpipe
->rasterizer
->point_size
;
1249 const float halfSize
= 0.5F
* size
;
1250 const boolean round
= (boolean
) setup
->llvmpipe
->rasterizer
->point_smooth
;
1251 const float x
= v0
[0][0]; /* Note: data[0] is always position */
1252 const float y
= v0
[0][1];
1253 const struct vertex_info
*vinfo
= llvmpipe_get_vertex_info(llvmpipe
);
1257 debug_printf("Setup point:\n");
1258 print_vertex(setup
, v0
);
1261 if (llvmpipe
->no_rast
)
1264 assert(setup
->llvmpipe
->reduced_prim
== PIPE_PRIM_POINTS
);
1266 /* For points, all interpolants are constant-valued.
1267 * However, for point sprites, we'll need to setup texcoords appropriately.
1268 * XXX: which coefficients are the texcoords???
1269 * We may do point sprites as textured quads...
1271 * KW: We don't know which coefficients are texcoords - ultimately
1272 * the choice of what interpolation mode to use for each attribute
1273 * should be determined by the fragment program, using
1274 * per-attribute declaration statements that include interpolation
1275 * mode as a parameter. So either the fragment program will have
1276 * to be adjusted for pointsprite vs normal point behaviour, or
1277 * otherwise a special interpolation mode will have to be defined
1278 * which matches the required behaviour for point sprites. But -
1279 * the latter is not a feature of normal hardware, and as such
1280 * probably should be ruled out on that basis.
1282 setup
->vprovoke
= v0
;
1285 const_pos_coeff(setup
, 0, 2);
1286 const_pos_coeff(setup
, 0, 3);
1288 for (fragSlot
= 0; fragSlot
< lpfs
->info
.num_inputs
; fragSlot
++) {
1289 const uint vertSlot
= vinfo
->attrib
[fragSlot
].src_index
;
1291 switch (vinfo
->attrib
[fragSlot
].interp_mode
) {
1292 case INTERP_CONSTANT
:
1295 const_coeff(setup
, fragSlot
, vertSlot
);
1297 case INTERP_PERSPECTIVE
:
1298 point_persp_coeff(setup
, setup
->vprovoke
, fragSlot
, vertSlot
);
1301 setup_fragcoord_coeff(setup
, fragSlot
);
1307 if (lpfs
->info
.input_semantic_name
[fragSlot
] == TGSI_SEMANTIC_FACE
) {
1308 setup
->coef
.a0
[1 + fragSlot
][0] = 1.0f
- setup
->facing
;
1309 setup
->coef
.dadx
[1 + fragSlot
][0] = 0.0;
1310 setup
->coef
.dady
[1 + fragSlot
][0] = 0.0;
1315 if (halfSize
<= 0.5 && !round
) {
1316 /* special case for 1-pixel points */
1317 const int ix
= ((int) x
) & 1;
1318 const int iy
= ((int) y
) & 1;
1319 setup
->quad
[0].input
.x0
= (int) x
- ix
;
1320 setup
->quad
[0].input
.y0
= (int) y
- iy
;
1321 setup
->quad
[0].inout
.mask
= (1 << ix
) << (2 * iy
);
1322 clip_emit_quad( setup
, &setup
->quad
[0] );
1326 /* rounded points */
1327 const int ixmin
= block((int) (x
- halfSize
));
1328 const int ixmax
= block((int) (x
+ halfSize
));
1329 const int iymin
= block((int) (y
- halfSize
));
1330 const int iymax
= block((int) (y
+ halfSize
));
1331 const float rmin
= halfSize
- 0.7071F
; /* 0.7071 = sqrt(2)/2 */
1332 const float rmax
= halfSize
+ 0.7071F
;
1333 const float rmin2
= MAX2(0.0F
, rmin
* rmin
);
1334 const float rmax2
= rmax
* rmax
;
1335 const float cscale
= 1.0F
/ (rmax2
- rmin2
);
1338 for (iy
= iymin
; iy
<= iymax
; iy
+= 2) {
1339 for (ix
= ixmin
; ix
<= ixmax
; ix
+= 2) {
1340 float dx
, dy
, dist2
, cover
;
1342 setup
->quad
[0].inout
.mask
= 0x0;
1344 dx
= (ix
+ 0.5f
) - x
;
1345 dy
= (iy
+ 0.5f
) - y
;
1346 dist2
= dx
* dx
+ dy
* dy
;
1347 if (dist2
<= rmax2
) {
1348 cover
= 1.0F
- (dist2
- rmin2
) * cscale
;
1349 setup
->quad
[0].input
.coverage
[QUAD_TOP_LEFT
] = MIN2(cover
, 1.0f
);
1350 setup
->quad
[0].inout
.mask
|= MASK_TOP_LEFT
;
1353 dx
= (ix
+ 1.5f
) - x
;
1354 dy
= (iy
+ 0.5f
) - y
;
1355 dist2
= dx
* dx
+ dy
* dy
;
1356 if (dist2
<= rmax2
) {
1357 cover
= 1.0F
- (dist2
- rmin2
) * cscale
;
1358 setup
->quad
[0].input
.coverage
[QUAD_TOP_RIGHT
] = MIN2(cover
, 1.0f
);
1359 setup
->quad
[0].inout
.mask
|= MASK_TOP_RIGHT
;
1362 dx
= (ix
+ 0.5f
) - x
;
1363 dy
= (iy
+ 1.5f
) - y
;
1364 dist2
= dx
* dx
+ dy
* dy
;
1365 if (dist2
<= rmax2
) {
1366 cover
= 1.0F
- (dist2
- rmin2
) * cscale
;
1367 setup
->quad
[0].input
.coverage
[QUAD_BOTTOM_LEFT
] = MIN2(cover
, 1.0f
);
1368 setup
->quad
[0].inout
.mask
|= MASK_BOTTOM_LEFT
;
1371 dx
= (ix
+ 1.5f
) - x
;
1372 dy
= (iy
+ 1.5f
) - y
;
1373 dist2
= dx
* dx
+ dy
* dy
;
1374 if (dist2
<= rmax2
) {
1375 cover
= 1.0F
- (dist2
- rmin2
) * cscale
;
1376 setup
->quad
[0].input
.coverage
[QUAD_BOTTOM_RIGHT
] = MIN2(cover
, 1.0f
);
1377 setup
->quad
[0].inout
.mask
|= MASK_BOTTOM_RIGHT
;
1380 if (setup
->quad
[0].inout
.mask
) {
1381 setup
->quad
[0].input
.x0
= ix
;
1382 setup
->quad
[0].input
.y0
= iy
;
1383 clip_emit_quad( setup
, &setup
->quad
[0] );
1390 const int xmin
= (int) (x
+ 0.75 - halfSize
);
1391 const int ymin
= (int) (y
+ 0.25 - halfSize
);
1392 const int xmax
= xmin
+ (int) size
;
1393 const int ymax
= ymin
+ (int) size
;
1394 /* XXX could apply scissor to xmin,ymin,xmax,ymax now */
1395 const int ixmin
= block(xmin
);
1396 const int ixmax
= block(xmax
- 1);
1397 const int iymin
= block(ymin
);
1398 const int iymax
= block(ymax
- 1);
1402 debug_printf("(%f, %f) -> X:%d..%d Y:%d..%d\n", x, y, xmin, xmax,ymin,ymax);
1404 for (iy
= iymin
; iy
<= iymax
; iy
+= 2) {
1407 /* above the top edge */
1408 rowMask
&= (MASK_BOTTOM_LEFT
| MASK_BOTTOM_RIGHT
);
1410 if (iy
+ 1 >= ymax
) {
1411 /* below the bottom edge */
1412 rowMask
&= (MASK_TOP_LEFT
| MASK_TOP_RIGHT
);
1415 for (ix
= ixmin
; ix
<= ixmax
; ix
+= 2) {
1416 uint mask
= rowMask
;
1419 /* fragment is past left edge of point, turn off left bits */
1420 mask
&= (MASK_BOTTOM_RIGHT
| MASK_TOP_RIGHT
);
1422 if (ix
+ 1 >= xmax
) {
1423 /* past the right edge */
1424 mask
&= (MASK_BOTTOM_LEFT
| MASK_TOP_LEFT
);
1427 setup
->quad
[0].inout
.mask
= mask
;
1428 setup
->quad
[0].input
.x0
= ix
;
1429 setup
->quad
[0].input
.y0
= iy
;
1430 clip_emit_quad( setup
, &setup
->quad
[0] );
1437 void llvmpipe_setup_prepare( struct setup_context
*setup
)
1439 struct llvmpipe_context
*lp
= setup
->llvmpipe
;
1442 llvmpipe_update_derived(lp
);
1445 if (lp
->reduced_api_prim
== PIPE_PRIM_TRIANGLES
&&
1446 lp
->rasterizer
->fill_cw
== PIPE_POLYGON_MODE_FILL
&&
1447 lp
->rasterizer
->fill_ccw
== PIPE_POLYGON_MODE_FILL
) {
1448 /* we'll do culling */
1449 setup
->winding
= lp
->rasterizer
->cull_mode
;
1452 /* 'draw' will do culling */
1453 setup
->winding
= PIPE_WINDING_NONE
;
1459 void llvmpipe_setup_destroy_context( struct setup_context
*setup
)
1461 align_free( setup
);
1466 * Create a new primitive setup/render stage.
1468 struct setup_context
*llvmpipe_setup_create_context( struct llvmpipe_context
*llvmpipe
)
1470 struct setup_context
*setup
;
1473 setup
= align_malloc(sizeof(struct setup_context
), 16);
1477 memset(setup
, 0, sizeof *setup
);
1478 setup
->llvmpipe
= llvmpipe
;
1480 for (i
= 0; i
< MAX_QUADS
; i
++) {
1481 setup
->quad
[i
].coef
= &setup
->coef
;
1484 setup
->span
.left
[0] = 1000000; /* greater than right[0] */
1485 setup
->span
.left
[1] = 1000000; /* greater than right[1] */