1 /* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
2 /* glitter-paths - polygon scan converter
4 * Copyright (c) 2008 M Joonas Pihlaja
5 * Copyright (c) 2007 David Turner
7 * Permission is hereby granted, free of charge, to any person
8 * obtaining a copy of this software and associated documentation
9 * files (the "Software"), to deal in the Software without
10 * restriction, including without limitation the rights to use,
11 * copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following
16 * The above copyright notice and this permission notice shall be
17 * included in all copies or substantial portions of the Software.
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
21 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
23 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
24 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
25 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
26 * OTHER DEALINGS IN THE SOFTWARE.
28 /* This is the Glitter paths scan converter incorporated into cairo.
29 * The source is from commit 734c53237a867a773640bd5b64816249fa1730f8
32 * http://gitweb.freedesktop.org/?p=users/joonas/glitter-paths
34 /* Glitter-paths is a stand alone polygon rasteriser derived from
35 * David Turner's reimplementation of Tor Anderssons's 15x17
36 * supersampling rasteriser from the Apparition graphics library. The
37 * main new feature here is cheaply choosing per-scan line between
38 * doing fully analytical coverage computation for an entire row at a
39 * time vs. using a supersampling approach.
41 * David Turner's code can be found at
43 * http://david.freetype.org/rasterizer-shootout/raster-comparison-20070813.tar.bz2
45 * In particular this file incorporates large parts of ftgrays_tor10.h
46 * from raster-comparison-20070813.tar.bz2
50 * A scan converter's basic purpose to take polygon edges and convert
51 * them into an RLE compressed A8 mask. This one works in two phases:
52 * gathering edges and generating spans.
54 * 1) As the user feeds the scan converter edges they are vertically
55 * clipped and bucketted into a _polygon_ data structure. The edges
56 * are also snapped from the user's coordinates to the subpixel grid
57 * coordinates used during scan conversion.
65 * 2) Generating spans works by performing a vertical sweep of pixel
66 * rows from top to bottom and maintaining an _active_list_ of edges
67 * that intersect the row. From the active list the fill rule
68 * determines which edges are the left and right edges of the start of
69 * each span, and their contribution is then accumulated into a pixel
70 * coverage list (_cell_list_) as coverage deltas. Once the coverage
71 * deltas of all edges are known we can form spans of constant pixel
72 * coverage by summing the deltas during a traversal of the cell list.
73 * At the end of a pixel row the cell list is sent to a coverage
74 * blitter for rendering to some target surface.
76 * The pixel coverages are computed by either supersampling the row
77 * and box filtering a mono rasterisation, or by computing the exact
78 * coverages of edges in the active list. The supersampling method is
79 * used whenever some edge starts or stops within the row or there are
80 * edge intersections in the row.
82 * polygon bucket for \
85 * | activate new edges | Repeat GRID_Y times if we
86 * V \ are supersampling this row,
87 * active list / or just once if we're computing
88 * | | analytical coverage.
91 * pixel coverage list /
97 #include "cairo-spans-private.h"
98 #include "cairo-error-private.h"
105 /*-------------------------------------------------------------------------
106 * cairo specific config
110 /* Prefer cairo's status type. */
111 #define GLITTER_HAVE_STATUS_T 1
112 #define GLITTER_STATUS_SUCCESS CAIRO_STATUS_SUCCESS
113 #define GLITTER_STATUS_NO_MEMORY CAIRO_STATUS_NO_MEMORY
114 typedef cairo_status_t glitter_status_t
;
116 /* The input coordinate scale and the rasterisation grid scales. */
117 #define GLITTER_INPUT_BITS CAIRO_FIXED_FRAC_BITS
118 //#define GRID_X_BITS CAIRO_FIXED_FRAC_BITS
120 #define GRID_X_BITS 2
121 #define GRID_Y_BITS 2
123 /* Set glitter up to use a cairo span renderer to do the coverage
128 /*-------------------------------------------------------------------------
132 /* "Input scaled" numbers are fixed precision reals with multiplier
133 * 2**GLITTER_INPUT_BITS. Input coordinates are given to glitter as
134 * pixel scaled numbers. These get converted to the internal grid
135 * scaled numbers as soon as possible. Internal overflow is possible
136 * if GRID_X/Y inside glitter-paths.c is larger than
137 * 1<<GLITTER_INPUT_BITS. */
138 #ifndef GLITTER_INPUT_BITS
139 # define GLITTER_INPUT_BITS 8
141 #define GLITTER_INPUT_SCALE (1<<GLITTER_INPUT_BITS)
142 typedef int glitter_input_scaled_t
;
144 #if !GLITTER_HAVE_STATUS_T
146 GLITTER_STATUS_SUCCESS
= 0,
147 GLITTER_STATUS_NO_MEMORY
152 # define I /*static*/
155 /* Opaque type for scan converting. */
156 typedef struct glitter_scan_converter glitter_scan_converter_t
;
158 /* Reset a scan converter to accept polygon edges and set the clip box
159 * in pixels. Allocates O(ymax-ymin) bytes of memory. The clip box
160 * is set to integer pixel coordinates xmin <= x < xmax, ymin <= y <
163 glitter_scan_converter_reset(
164 glitter_scan_converter_t
*converter
,
168 /* Render the polygon in the scan converter to the given A8 format
169 * image raster. Only the pixels accessible as pixels[y*stride+x] for
170 * x,y inside the clip box are written to, where xmin <= x < xmax,
171 * ymin <= y < ymax. The image is assumed to be clear on input.
173 * If nonzero_fill is true then the interior of the polygon is
174 * computed with the non-zero fill rule. Otherwise the even-odd fill
177 * The scan converter must be reset or destroyed after this call. */
179 /*-------------------------------------------------------------------------
180 * glitter-paths.c: Implementation internal types
186 /* All polygon coordinates are snapped onto a subsample grid. "Grid
187 * scaled" numbers are fixed precision reals with multiplier GRID_X or
189 typedef int grid_scaled_t
;
190 typedef int grid_scaled_x_t
;
191 typedef int grid_scaled_y_t
;
193 /* Default x/y scale factors.
194 * You can either define GRID_X/Y_BITS to get a power-of-two scale
195 * or define GRID_X/Y separately. */
196 #if !defined(GRID_X) && !defined(GRID_X_BITS)
197 # define GRID_X_BITS 8
199 #if !defined(GRID_Y) && !defined(GRID_Y_BITS)
203 /* Use GRID_X/Y_BITS to define GRID_X/Y if they're available. */
205 # define GRID_X (1 << GRID_X_BITS)
208 # define GRID_Y (1 << GRID_Y_BITS)
211 /* The GRID_X_TO_INT_FRAC macro splits a grid scaled coordinate into
212 * integer and fractional parts. The integer part is floored. */
213 #if defined(GRID_X_TO_INT_FRAC)
215 #elif defined(GRID_X_BITS)
216 # define GRID_X_TO_INT_FRAC(x, i, f) \
217 _GRID_TO_INT_FRAC_shift(x, i, f, GRID_X_BITS)
219 # define GRID_X_TO_INT_FRAC(x, i, f) \
220 _GRID_TO_INT_FRAC_general(x, i, f, GRID_X)
223 #define _GRID_TO_INT_FRAC_general(t, i, f, m) do { \
232 #define _GRID_TO_INT_FRAC_shift(t, i, f, b) do { \
233 (f) = (t) & ((1 << (b)) - 1); \
237 /* A grid area is a real in [0,1] scaled by 2*GRID_X*GRID_Y. We want
238 * to be able to represent exactly areas of subpixel trapezoids whose
239 * vertices are given in grid scaled coordinates. The scale factor
240 * comes from needing to accurately represent the area 0.5*dx*dy of a
241 * triangle with base dx and height dy in grid scaled numbers. */
242 #define GRID_XY (2*GRID_X*GRID_Y) /* Unit area on the grid. */
244 /* GRID_AREA_TO_ALPHA(area): map [0,GRID_XY] to [0,255]. */
246 # define GRID_AREA_TO_ALPHA(c) (((c)+1) >> 1)
248 # define GRID_AREA_TO_ALPHA(c) (c)
250 # define GRID_AREA_TO_ALPHA(c) (((c) << 2) | -(((c) & 0x40) >> 6))
252 # define GRID_AREA_TO_ALPHA(c) (((c) << 3) | -(((c) & 0x20) >> 5))
254 # define GRID_AREA_TO_ALPHA(c) ((((c) << 1) | -((c) >> 7)) & 255)
256 # define GRID_AREA_TO_ALPHA(c) (((c) | -((c) >> 8)) & 255)
258 # define GRID_AREA_TO_ALPHA(c) (((c) << 4) + (c))
259 #elif GRID_XY == 2*256*15
260 # define GRID_AREA_TO_ALPHA(c) (((c) + ((c)<<4) + 256) >> 9)
262 # define GRID_AREA_TO_ALPHA(c) (((c)*255 + GRID_XY/2) / GRID_XY)
265 #define UNROLL3(x) x x x
272 /* Header for a chunk of memory in a memory pool. */
274 /* # bytes used in this chunk. */
277 /* # bytes total in this chunk */
280 /* Pointer to the previous chunk or %NULL if this is the sentinel
281 * chunk in the pool header. */
282 struct _pool_chunk
*prev_chunk
;
284 /* Actual data starts here. Well aligned for pointers. */
287 /* A memory pool. This is supposed to be embedded on the stack or
288 * within some other structure. It may optionally be followed by an
289 * embedded array from which requests are fulfilled until
290 * malloc needs to be called to allocate a first real chunk. */
292 /* Chunk we're allocating from. */
293 struct _pool_chunk
*current
;
297 /* Free list of previously allocated chunks. All have >= default
299 struct _pool_chunk
*first_free
;
301 /* The default capacity of a chunk. */
302 size_t default_capacity
;
304 /* Header for the sentinel chunk. Directly following the pool
305 * struct should be some space for embedded elements from which
306 * the sentinel chunk allocates from. */
307 struct _pool_chunk sentinel
[1];
310 /* A polygon edge. */
312 /* Next in y-bucket or active list. */
313 struct edge
*next
, *prev
;
315 /* Number of subsample rows remaining to scan convert of this
317 grid_scaled_y_t height_left
;
319 /* Original sign of the edge: +1 for downwards, -1 for upwards
324 /* Current x coordinate while the edge is on the active
325 * list. Initialised to the x coordinate of the top of the
326 * edge. The quotient is in grid_scaled_x_t units and the
327 * remainder is mod dy in grid_scaled_y_t units.*/
330 /* Advance of the current x when moving down a subsample line. */
333 /* The clipped y of the top of the edge. */
334 grid_scaled_y_t ytop
;
336 /* y2-y1 after orienting the edge downwards. */
340 #define EDGE_Y_BUCKET_INDEX(y, ymin) (((y) - (ymin))/GRID_Y)
342 /* A collection of sorted and vertically clipped edges of the polygon.
343 * Edges are moved from the polygon to an active list while scan
346 /* The vertical clip extents. */
347 grid_scaled_y_t ymin
, ymax
;
349 /* Array of edges all starting in the same bucket. An edge is put
350 * into bucket EDGE_BUCKET_INDEX(edge->ytop, polygon->ymin) when
351 * it is added to the polygon. */
352 struct edge
**y_buckets
;
353 struct edge
*y_buckets_embedded
[64];
357 struct edge embedded
[32];
361 /* A cell records the effect on pixel coverage of polygon edges
362 * passing through a pixel. It contains two accumulators of pixel
365 * Consider the effects of a polygon edge on the coverage of a pixel
366 * it intersects and that of the following one. The coverage of the
367 * following pixel is the height of the edge multiplied by the width
368 * of the pixel, and the coverage of the pixel itself is the area of
369 * the trapezoid formed by the edge and the right side of the pixel.
371 * +-----------------------+-----------------------+
374 * |_______________________|_______________________|
375 * | \...................|.......................|\
376 * | \..................|.......................| |
377 * | \.................|.......................| |
378 * | \....covered.....|.......................| |
379 * | \....area.......|.......................| } covered height
380 * | \..............|.......................| |
381 * |uncovered\.............|.......................| |
382 * | area \............|.......................| |
383 * |___________\...........|.......................|/
387 * +-----------------------+-----------------------+
389 * Since the coverage of the following pixel will always be a multiple
390 * of the width of the pixel, we can store the height of the covered
391 * area instead. The coverage of the pixel itself is the total
392 * coverage minus the area of the uncovered area to the left of the
393 * edge. As it's faster to compute the uncovered area we only store
394 * that and subtract it from the total coverage later when forming
397 * The heights and areas are signed, with left edges of the polygon
398 * having positive sign and right edges having negative sign. When
399 * two edges intersect they swap their left/rightness so their
400 * contribution above and below the intersection point must be
401 * computed separately. */
405 int16_t uncovered_area
;
406 int16_t covered_height
;
409 /* A cell list represents the scan line sparsely as cells ordered by
410 * ascending x. It is geared towards scanning the cells in order
411 * using an internal cursor. */
414 struct cell head
, tail
;
416 /* Cursor state for iterating through the cell list. */
417 struct cell
*cursor
, *rewind
;
419 /* Cells in the cell list are owned by the cell list and are
420 * allocated from this pool. */
423 struct cell embedded
[32];
432 /* The active list contains edges in the current scan line ordered by
433 * the x-coordinate of the intercept of the edge and the scan line. */
435 /* Leftmost edge on the current scan line. */
436 struct edge head
, tail
;
438 /* A lower bound on the height of the active edges is used to
439 * estimate how soon some active edge ends. We can't advance the
440 * scan conversion by a full pixel row if an edge ends somewhere
442 grid_scaled_y_t min_height
;
446 struct glitter_scan_converter
{
447 struct polygon polygon
[1];
448 struct active_list active
[1];
449 struct cell_list coverages
[1];
451 cairo_half_open_span_t
*spans
;
452 cairo_half_open_span_t spans_embedded
[64];
455 grid_scaled_x_t xmin
, xmax
;
456 grid_scaled_y_t ymin
, ymax
;
459 /* Compute the floored division a/b. Assumes / and % perform symmetric
461 inline static struct quorem
462 floored_divrem(int a
, int b
)
467 if ((a
^b
)<0 && qr
.rem
) {
474 /* Compute the floored division (x*a)/b. Assumes / and % perform symmetric
477 floored_muldivrem(int x
, int a
, int b
)
480 long long xa
= (long long)x
*a
;
483 if ((xa
>=0) != (b
>=0) && qr
.rem
) {
490 static struct _pool_chunk
*
492 struct _pool_chunk
*p
,
493 struct _pool_chunk
*prev_chunk
,
496 p
->prev_chunk
= prev_chunk
;
498 p
->capacity
= capacity
;
502 static struct _pool_chunk
*
503 _pool_chunk_create(struct pool
*pool
, size_t size
)
505 struct _pool_chunk
*p
;
507 p
= malloc(size
+ sizeof(struct _pool_chunk
));
508 if (unlikely (NULL
== p
))
509 longjmp (*pool
->jmp
, _cairo_error (CAIRO_STATUS_NO_MEMORY
));
511 return _pool_chunk_init(p
, pool
->current
, size
);
515 pool_init(struct pool
*pool
,
517 size_t default_capacity
,
518 size_t embedded_capacity
)
521 pool
->current
= pool
->sentinel
;
522 pool
->first_free
= NULL
;
523 pool
->default_capacity
= default_capacity
;
524 _pool_chunk_init(pool
->sentinel
, NULL
, embedded_capacity
);
528 pool_fini(struct pool
*pool
)
530 struct _pool_chunk
*p
= pool
->current
;
533 struct _pool_chunk
*prev
= p
->prev_chunk
;
534 if (p
!= pool
->sentinel
)
538 p
= pool
->first_free
;
539 pool
->first_free
= NULL
;
543 /* Satisfy an allocation by first allocating a new large enough chunk
544 * and adding it to the head of the pool's chunk list. This function
545 * is called as a fallback if pool_alloc() couldn't do a quick
546 * allocation from the current chunk in the pool. */
548 _pool_alloc_from_new_chunk(
552 struct _pool_chunk
*chunk
;
556 /* If the allocation is smaller than the default chunk size then
557 * try getting a chunk off the free list. Force alloc of a new
558 * chunk for large requests. */
561 if (size
< pool
->default_capacity
) {
562 capacity
= pool
->default_capacity
;
563 chunk
= pool
->first_free
;
565 pool
->first_free
= chunk
->prev_chunk
;
566 _pool_chunk_init(chunk
, pool
->current
, chunk
->capacity
);
571 chunk
= _pool_chunk_create (pool
, capacity
);
572 pool
->current
= chunk
;
574 obj
= ((unsigned char*)chunk
+ sizeof(*chunk
) + chunk
->size
);
579 /* Allocate size bytes from the pool. The first allocated address
580 * returned from a pool is aligned to sizeof(void*). Subsequent
581 * addresses will maintain alignment as long as multiples of void* are
582 * allocated. Returns the address of a new memory area or %NULL on
583 * allocation failures. The pool retains ownership of the returned
586 pool_alloc (struct pool
*pool
, size_t size
)
588 struct _pool_chunk
*chunk
= pool
->current
;
590 if (size
<= chunk
->capacity
- chunk
->size
) {
591 void *obj
= ((unsigned char*)chunk
+ sizeof(*chunk
) + chunk
->size
);
595 return _pool_alloc_from_new_chunk(pool
, size
);
599 /* Relinquish all pool_alloced memory back to the pool. */
601 pool_reset (struct pool
*pool
)
603 /* Transfer all used chunks to the chunk free list. */
604 struct _pool_chunk
*chunk
= pool
->current
;
605 if (chunk
!= pool
->sentinel
) {
606 while (chunk
->prev_chunk
!= pool
->sentinel
) {
607 chunk
= chunk
->prev_chunk
;
609 chunk
->prev_chunk
= pool
->first_free
;
610 pool
->first_free
= pool
->current
;
612 /* Reset the sentinel as the current chunk. */
613 pool
->current
= pool
->sentinel
;
614 pool
->sentinel
->size
= 0;
617 /* Rewinds the cell list's cursor to the beginning. After rewinding
618 * we're good to cell_list_find() the cell any x coordinate. */
620 cell_list_rewind (struct cell_list
*cells
)
622 cells
->cursor
= &cells
->head
;
626 cell_list_maybe_rewind (struct cell_list
*cells
, int x
)
628 if (x
< cells
->cursor
->x
) {
629 cells
->cursor
= cells
->rewind
;
630 if (x
< cells
->cursor
->x
)
631 cells
->cursor
= &cells
->head
;
636 cell_list_set_rewind (struct cell_list
*cells
)
638 cells
->rewind
= cells
->cursor
;
642 cell_list_init(struct cell_list
*cells
, jmp_buf *jmp
)
644 pool_init(cells
->cell_pool
.base
, jmp
,
645 256*sizeof(struct cell
),
646 sizeof(cells
->cell_pool
.embedded
));
647 cells
->tail
.next
= NULL
;
648 cells
->tail
.x
= INT_MAX
;
649 cells
->head
.x
= INT_MIN
;
650 cells
->head
.next
= &cells
->tail
;
651 cell_list_rewind (cells
);
655 cell_list_fini(struct cell_list
*cells
)
657 pool_fini (cells
->cell_pool
.base
);
660 /* Empty the cell list. This is called at the start of every pixel
663 cell_list_reset (struct cell_list
*cells
)
665 cell_list_rewind (cells
);
666 cells
->head
.next
= &cells
->tail
;
667 pool_reset (cells
->cell_pool
.base
);
670 inline static struct cell
*
671 cell_list_alloc (struct cell_list
*cells
,
677 cell
= pool_alloc (cells
->cell_pool
.base
, sizeof (struct cell
));
678 cell
->next
= tail
->next
;
681 *(uint32_t *)&cell
->uncovered_area
= 0;
686 /* Find a cell at the given x-coordinate. Returns %NULL if a new cell
687 * needed to be allocated but couldn't be. Cells must be found with
688 * non-decreasing x-coordinate until the cell list is rewound using
689 * cell_list_rewind(). Ownership of the returned cell is retained by
691 inline static struct cell
*
692 cell_list_find (struct cell_list
*cells
, int x
)
694 struct cell
*tail
= cells
->cursor
;
701 if (tail
->next
->x
> x
)
708 tail
= cell_list_alloc (cells
, tail
, x
);
709 return cells
->cursor
= tail
;
713 /* Find two cells at x1 and x2. This is exactly equivalent
716 * pair.cell1 = cell_list_find(cells, x1);
717 * pair.cell2 = cell_list_find(cells, x2);
719 * except with less function call overhead. */
720 inline static struct cell_pair
721 cell_list_find_pair(struct cell_list
*cells
, int x1
, int x2
)
723 struct cell_pair pair
;
725 pair
.cell1
= cells
->cursor
;
728 if (pair
.cell1
->next
->x
> x1
)
730 pair
.cell1
= pair
.cell1
->next
;
733 if (pair
.cell1
->x
!= x1
)
734 pair
.cell1
= cell_list_alloc (cells
, pair
.cell1
, x1
);
736 pair
.cell2
= pair
.cell1
;
739 if (pair
.cell2
->next
->x
> x2
)
741 pair
.cell2
= pair
.cell2
->next
;
744 if (pair
.cell2
->x
!= x2
)
745 pair
.cell2
= cell_list_alloc (cells
, pair
.cell2
, x2
);
747 cells
->cursor
= pair
.cell2
;
751 /* Add a subpixel span covering [x1, x2) to the coverage cells. */
753 cell_list_add_subspan(struct cell_list
*cells
,
763 GRID_X_TO_INT_FRAC(x1
, ix1
, fx1
);
764 GRID_X_TO_INT_FRAC(x2
, ix2
, fx2
);
768 p
= cell_list_find_pair(cells
, ix1
, ix2
);
769 p
.cell1
->uncovered_area
+= 2*fx1
;
770 ++p
.cell1
->covered_height
;
771 p
.cell2
->uncovered_area
-= 2*fx2
;
772 --p
.cell2
->covered_height
;
774 struct cell
*cell
= cell_list_find(cells
, ix1
);
775 cell
->uncovered_area
+= 2*(fx1
-fx2
);
779 /* Adds the analytical coverage of an edge crossing the current pixel
780 * row to the coverage cells and advances the edge's x position to the
783 * This function is only called when we know that during this pixel row:
785 * 1) The relative order of all edges on the active list doesn't
786 * change. In particular, no edges intersect within this row to pixel
789 * 2) No new edges start in this row.
791 * 3) No existing edges end mid-row.
793 * This function depends on being called with all edges from the
794 * active list in the order they appear on the list (i.e. with
795 * non-decreasing x-coordinate.) */
797 cell_list_render_edge(struct cell_list
*cells
,
805 GRID_X_TO_INT_FRAC(edge
->x
.quo
, ix
, fx
);
807 /* We always know that ix1 is >= the cell list cursor in this
808 * case due to the no-intersections precondition. */
809 cell
= cell_list_find(cells
, ix
);
810 cell
->covered_height
+= sign
*GRID_Y
;
811 cell
->uncovered_area
+= sign
*2*fx
*GRID_Y
;
815 polygon_init (struct polygon
*polygon
, jmp_buf *jmp
)
817 polygon
->ymin
= polygon
->ymax
= 0;
818 polygon
->y_buckets
= polygon
->y_buckets_embedded
;
819 pool_init (polygon
->edge_pool
.base
, jmp
,
820 8192 - sizeof (struct _pool_chunk
),
821 sizeof (polygon
->edge_pool
.embedded
));
825 polygon_fini (struct polygon
*polygon
)
827 if (polygon
->y_buckets
!= polygon
->y_buckets_embedded
)
828 free (polygon
->y_buckets
);
830 pool_fini (polygon
->edge_pool
.base
);
833 /* Empties the polygon of all edges. The polygon is then prepared to
834 * receive new edges and clip them to the vertical range
836 static glitter_status_t
837 polygon_reset (struct polygon
*polygon
,
838 grid_scaled_y_t ymin
,
839 grid_scaled_y_t ymax
)
841 unsigned h
= ymax
- ymin
;
842 unsigned num_buckets
= EDGE_Y_BUCKET_INDEX(ymax
+ GRID_Y
-1, ymin
);
844 pool_reset(polygon
->edge_pool
.base
);
846 if (unlikely (h
> 0x7FFFFFFFU
- GRID_Y
))
847 goto bail_no_mem
; /* even if you could, you wouldn't want to. */
849 if (polygon
->y_buckets
!= polygon
->y_buckets_embedded
)
850 free (polygon
->y_buckets
);
852 polygon
->y_buckets
= polygon
->y_buckets_embedded
;
853 if (num_buckets
> ARRAY_LENGTH (polygon
->y_buckets_embedded
)) {
854 polygon
->y_buckets
= _cairo_malloc_ab (num_buckets
,
855 sizeof (struct edge
*));
856 if (unlikely (NULL
== polygon
->y_buckets
))
859 memset (polygon
->y_buckets
, 0, num_buckets
* sizeof (struct edge
*));
861 polygon
->ymin
= ymin
;
862 polygon
->ymax
= ymax
;
863 return GLITTER_STATUS_SUCCESS
;
868 return GLITTER_STATUS_NO_MEMORY
;
872 _polygon_insert_edge_into_its_y_bucket(struct polygon
*polygon
,
875 unsigned ix
= EDGE_Y_BUCKET_INDEX(e
->ytop
, polygon
->ymin
);
876 struct edge
**ptail
= &polygon
->y_buckets
[ix
];
882 polygon_add_edge (struct polygon
*polygon
,
883 const cairo_edge_t
*edge
)
888 grid_scaled_y_t ytop
, ybot
;
889 grid_scaled_y_t ymin
= polygon
->ymin
;
890 grid_scaled_y_t ymax
= polygon
->ymax
;
892 if (unlikely (edge
->top
>= ymax
|| edge
->bottom
<= ymin
))
895 e
= pool_alloc (polygon
->edge_pool
.base
, sizeof (struct edge
));
897 dx
= edge
->line
.p2
.x
- edge
->line
.p1
.x
;
898 dy
= edge
->line
.p2
.y
- edge
->line
.p1
.y
;
902 ytop
= edge
->top
>= ymin
? edge
->top
: ymin
;
903 ybot
= edge
->bottom
<= ymax
? edge
->bottom
: ymax
;
905 e
->height_left
= ybot
- ytop
;
909 e
->x
.quo
= edge
->line
.p1
.x
;
915 e
->dxdy
= floored_divrem (dx
, dy
);
916 if (ytop
== edge
->line
.p1
.y
) {
917 e
->x
.quo
= edge
->line
.p1
.x
;
920 e
->x
= floored_muldivrem (ytop
- edge
->line
.p1
.y
, dx
, dy
);
921 e
->x
.quo
+= edge
->line
.p1
.x
;
925 _polygon_insert_edge_into_its_y_bucket (polygon
, e
);
927 e
->x
.rem
-= dy
; /* Bias the remainder for faster
928 * edge advancement. */
932 active_list_reset (struct active_list
*active
)
934 active
->head
.vertical
= 1;
935 active
->head
.height_left
= INT_MAX
;
936 active
->head
.x
.quo
= INT_MIN
;
937 active
->head
.prev
= NULL
;
938 active
->head
.next
= &active
->tail
;
939 active
->tail
.prev
= &active
->head
;
940 active
->tail
.next
= NULL
;
941 active
->tail
.x
.quo
= INT_MAX
;
942 active
->tail
.height_left
= INT_MAX
;
943 active
->tail
.vertical
= 1;
944 active
->min_height
= 0;
945 active
->is_vertical
= 1;
949 active_list_init(struct active_list
*active
)
951 active_list_reset(active
);
955 * Merge two sorted edge lists.
957 * - head_a: The head of the first list.
958 * - head_b: The head of the second list; head_b cannot be NULL.
960 * Returns the head of the merged list.
962 * Implementation notes:
963 * To make it fast (in particular, to reduce to an insertion sort whenever
964 * one of the two input lists only has a single element) we iterate through
965 * a list until its head becomes greater than the head of the other list,
966 * then we switch their roles. As soon as one of the two lists is empty, we
967 * just attach the other one to the current list and exit.
968 * Writes to memory are only needed to "switch" lists (as it also requires
969 * attaching to the output list the list which we will be iterating next) and
970 * to attach the last non-empty list.
973 merge_sorted_edges (struct edge
*head_a
, struct edge
*head_b
)
975 struct edge
*head
, **next
, *prev
;
980 if (head_a
->x
.quo
<= head_b
->x
.quo
) {
990 while (head_a
!= NULL
&& head_a
->x
.quo
<= x
) {
992 next
= &head_a
->next
;
993 head_a
= head_a
->next
;
1003 while (head_b
!= NULL
&& head_b
->x
.quo
<= x
) {
1005 next
= &head_b
->next
;
1006 head_b
= head_b
->next
;
1009 head_a
->prev
= prev
;
1017 * Sort (part of) a list.
1019 * - list: The list to be sorted; list cannot be NULL.
1020 * - limit: Recursion limit.
1022 * - head_out: The head of the sorted list containing the first 2^(level+1) elements of the
1023 * input list; if the input list has fewer elements, head_out be a sorted list
1024 * containing all the elements of the input list.
1025 * Returns the head of the list of unprocessed elements (NULL if the sorted list contains
1026 * all the elements of the input list).
1028 * Implementation notes:
1029 * Special case single element list, unroll/inline the sorting of the first two elements.
1030 * Some tail recursion is used since we iterate on the bottom-up solution of the problem
1031 * (we start with a small sorted list and keep merging other lists of the same size to it).
1033 static struct edge
*
1034 sort_edges (struct edge
*list
,
1036 struct edge
**head_out
)
1038 struct edge
*head_other
, *remaining
;
1041 head_other
= list
->next
;
1043 if (head_other
== NULL
) {
1048 remaining
= head_other
->next
;
1049 if (list
->x
.quo
<= head_other
->x
.quo
) {
1051 head_other
->next
= NULL
;
1053 *head_out
= head_other
;
1054 head_other
->prev
= list
->prev
;
1055 head_other
->next
= list
;
1056 list
->prev
= head_other
;
1060 for (i
= 0; i
< level
&& remaining
; i
++) {
1061 remaining
= sort_edges (remaining
, i
, &head_other
);
1062 *head_out
= merge_sorted_edges (*head_out
, head_other
);
1068 static struct edge
*
1069 merge_unsorted_edges (struct edge
*head
, struct edge
*unsorted
)
1071 sort_edges (unsorted
, UINT_MAX
, &unsorted
);
1072 return merge_sorted_edges (head
, unsorted
);
1075 /* Test if the edges on the active list can be safely advanced by a
1076 * full row without intersections or any edges ending. */
1078 can_do_full_row (struct active_list
*active
)
1080 const struct edge
*e
;
1082 /* Recomputes the minimum height of all edges on the active
1083 * list if we have been dropping edges. */
1084 if (active
->min_height
<= 0) {
1085 int min_height
= INT_MAX
;
1086 int is_vertical
= 1;
1088 e
= active
->head
.next
;
1090 if (e
->height_left
< min_height
)
1091 min_height
= e
->height_left
;
1092 is_vertical
&= e
->vertical
;
1096 active
->is_vertical
= is_vertical
;
1097 active
->min_height
= min_height
;
1100 if (active
->min_height
< GRID_Y
)
1103 return active
->is_vertical
;
1106 /* Merges edges on the given subpixel row from the polygon to the
1109 active_list_merge_edges_from_bucket(struct active_list
*active
,
1112 active
->head
.next
= merge_unsorted_edges (active
->head
.next
, edges
);
1116 polygon_fill_buckets (struct active_list
*active
,
1119 struct edge
**buckets
)
1121 grid_scaled_y_t min_height
= active
->min_height
;
1122 int is_vertical
= active
->is_vertical
;
1125 struct edge
*next
= edge
->next
;
1126 int suby
= edge
->ytop
- y
;
1128 buckets
[suby
]->prev
= edge
;
1129 edge
->next
= buckets
[suby
];
1131 buckets
[suby
] = edge
;
1132 if (edge
->height_left
< min_height
)
1133 min_height
= edge
->height_left
;
1134 is_vertical
&= edge
->vertical
;
1138 active
->is_vertical
= is_vertical
;
1139 active
->min_height
= min_height
;
1143 sub_row (struct active_list
*active
,
1144 struct cell_list
*coverages
,
1147 struct edge
*edge
= active
->head
.next
;
1148 int xstart
= INT_MIN
, prev_x
= INT_MIN
;
1151 cell_list_rewind (coverages
);
1153 while (&active
->tail
!= edge
) {
1154 struct edge
*next
= edge
->next
;
1155 int xend
= edge
->x
.quo
;
1157 if (--edge
->height_left
) {
1158 edge
->x
.quo
+= edge
->dxdy
.quo
;
1159 edge
->x
.rem
+= edge
->dxdy
.rem
;
1160 if (edge
->x
.rem
>= 0) {
1162 edge
->x
.rem
-= edge
->dy
;
1165 if (edge
->x
.quo
< prev_x
) {
1166 struct edge
*pos
= edge
->prev
;
1171 } while (edge
->x
.quo
< pos
->x
.quo
);
1172 pos
->next
->prev
= edge
;
1173 edge
->next
= pos
->next
;
1177 prev_x
= edge
->x
.quo
;
1179 edge
->prev
->next
= next
;
1180 next
->prev
= edge
->prev
;
1183 winding
+= edge
->dir
;
1184 if ((winding
& mask
) == 0) {
1185 if (next
->x
.quo
!= xend
) {
1186 cell_list_add_subspan (coverages
, xstart
, xend
);
1189 } else if (xstart
== INT_MIN
)
1196 inline static void dec (struct edge
*e
, int h
)
1198 e
->height_left
-= h
;
1199 if (e
->height_left
== 0) {
1200 e
->prev
->next
= e
->next
;
1201 e
->next
->prev
= e
->prev
;
1206 full_row (struct active_list
*active
,
1207 struct cell_list
*coverages
,
1210 struct edge
*left
= active
->head
.next
;
1212 while (&active
->tail
!= left
) {
1218 winding
= left
->dir
;
1221 dec (right
, GRID_Y
);
1223 winding
+= right
->dir
;
1224 if ((winding
& mask
) == 0 && right
->next
->x
.quo
!= right
->x
.quo
)
1227 right
= right
->next
;
1230 cell_list_set_rewind (coverages
);
1231 cell_list_render_edge (coverages
, left
, +1);
1232 cell_list_render_edge (coverages
, right
, -1);
1239 _glitter_scan_converter_init(glitter_scan_converter_t
*converter
, jmp_buf *jmp
)
1241 polygon_init(converter
->polygon
, jmp
);
1242 active_list_init(converter
->active
);
1243 cell_list_init(converter
->coverages
, jmp
);
1251 _glitter_scan_converter_fini(glitter_scan_converter_t
*self
)
1253 if (self
->spans
!= self
->spans_embedded
)
1256 polygon_fini(self
->polygon
);
1257 cell_list_fini(self
->coverages
);
1265 static grid_scaled_t
1266 int_to_grid_scaled(int i
, int scale
)
1268 /* Clamp to max/min representable scaled number. */
1270 if (i
>= INT_MAX
/scale
)
1274 if (i
<= INT_MIN
/scale
)
1280 #define int_to_grid_scaled_x(x) int_to_grid_scaled((x), GRID_X)
1281 #define int_to_grid_scaled_y(x) int_to_grid_scaled((x), GRID_Y)
1284 glitter_scan_converter_reset(
1285 glitter_scan_converter_t
*converter
,
1289 glitter_status_t status
;
1291 converter
->xmin
= 0; converter
->xmax
= 0;
1292 converter
->ymin
= 0; converter
->ymax
= 0;
1294 if (xmax
- xmin
> ARRAY_LENGTH(converter
->spans_embedded
)) {
1295 converter
->spans
= _cairo_malloc_ab (xmax
- xmin
,
1296 sizeof (cairo_half_open_span_t
));
1297 if (unlikely (converter
->spans
== NULL
))
1298 return _cairo_error (CAIRO_STATUS_NO_MEMORY
);
1300 converter
->spans
= converter
->spans_embedded
;
1302 xmin
= int_to_grid_scaled_x(xmin
);
1303 ymin
= int_to_grid_scaled_y(ymin
);
1304 xmax
= int_to_grid_scaled_x(xmax
);
1305 ymax
= int_to_grid_scaled_y(ymax
);
1307 active_list_reset(converter
->active
);
1308 cell_list_reset(converter
->coverages
);
1309 status
= polygon_reset(converter
->polygon
, ymin
, ymax
);
1313 converter
->xmin
= xmin
;
1314 converter
->xmax
= xmax
;
1315 converter
->ymin
= ymin
;
1316 converter
->ymax
= ymax
;
1317 return GLITTER_STATUS_SUCCESS
;
1320 /* INPUT_TO_GRID_X/Y (in_coord, out_grid_scaled, grid_scale)
1321 * These macros convert an input coordinate in the client's
1322 * device space to the rasterisation grid.
1324 /* Gah.. this bit of ugly defines INPUT_TO_GRID_X/Y so as to use
1325 * shifts if possible, and something saneish if not.
1327 #if !defined(INPUT_TO_GRID_Y) && defined(GRID_Y_BITS) && GRID_Y_BITS <= GLITTER_INPUT_BITS
1328 # define INPUT_TO_GRID_Y(in, out) (out) = (in) >> (GLITTER_INPUT_BITS - GRID_Y_BITS)
1330 # define INPUT_TO_GRID_Y(in, out) INPUT_TO_GRID_general(in, out, GRID_Y)
1333 #if !defined(INPUT_TO_GRID_X) && defined(GRID_X_BITS) && GRID_X_BITS <= GLITTER_INPUT_BITS
1334 # define INPUT_TO_GRID_X(in, out) (out) = (in) >> (GLITTER_INPUT_BITS - GRID_X_BITS)
1336 # define INPUT_TO_GRID_X(in, out) INPUT_TO_GRID_general(in, out, GRID_X)
1339 #define INPUT_TO_GRID_general(in, out, grid_scale) do { \
1340 long long tmp__ = (long long)(grid_scale) * (in); \
1341 tmp__ >>= GLITTER_INPUT_BITS; \
1345 /* Add a new polygon edge from pixel (x1,y1) to (x2,y2) to the scan
1346 * converter. The coordinates represent pixel positions scaled by
1347 * 2**GLITTER_PIXEL_BITS. If this function fails then the scan
1348 * converter should be reset or destroyed. Dir must be +1 or -1,
1349 * with the latter reversing the orientation of the edge. */
1351 glitter_scan_converter_add_edge (glitter_scan_converter_t
*converter
,
1352 const cairo_edge_t
*edge
)
1356 INPUT_TO_GRID_Y (edge
->top
, e
.top
);
1357 INPUT_TO_GRID_Y (edge
->bottom
, e
.bottom
);
1358 if (e
.top
>= e
.bottom
)
1361 /* XXX: possible overflows if GRID_X/Y > 2**GLITTER_INPUT_BITS */
1362 INPUT_TO_GRID_Y (edge
->line
.p1
.y
, e
.line
.p1
.y
);
1363 INPUT_TO_GRID_Y (edge
->line
.p2
.y
, e
.line
.p2
.y
);
1364 if (e
.line
.p1
.y
== e
.line
.p2
.y
)
1365 e
.line
.p2
.y
++; /* Fudge to prevent div-by-zero */
1367 INPUT_TO_GRID_X (edge
->line
.p1
.x
, e
.line
.p1
.x
);
1368 INPUT_TO_GRID_X (edge
->line
.p2
.x
, e
.line
.p2
.x
);
1372 polygon_add_edge (converter
->polygon
, &e
);
1376 step_edges (struct active_list
*active
, int count
)
1381 for (edge
= active
->head
.next
; edge
!= &active
->tail
; edge
= edge
->next
) {
1382 edge
->height_left
-= count
;
1383 if (! edge
->height_left
) {
1384 edge
->prev
->next
= edge
->next
;
1385 edge
->next
->prev
= edge
->prev
;
1390 static glitter_status_t
1391 blit_a8 (struct cell_list
*cells
,
1392 cairo_span_renderer_t
*renderer
,
1393 cairo_half_open_span_t
*spans
,
1397 struct cell
*cell
= cells
->head
.next
;
1398 int prev_x
= xmin
, last_x
= -1;
1399 int16_t cover
= 0, last_cover
= 0;
1402 if (cell
== &cells
->tail
)
1403 return CAIRO_STATUS_SUCCESS
;
1405 /* Skip cells to the left of the clip region. */
1406 while (cell
->x
< xmin
) {
1407 cover
+= cell
->covered_height
;
1412 /* Form the spans from the coverages and areas. */
1414 for (; cell
->x
< xmax
; cell
= cell
->next
) {
1418 if (x
> prev_x
&& cover
!= last_cover
) {
1419 spans
[num_spans
].x
= prev_x
;
1420 spans
[num_spans
].coverage
= GRID_AREA_TO_ALPHA (cover
);
1426 cover
+= cell
->covered_height
*GRID_X
*2;
1427 area
= cover
- cell
->uncovered_area
;
1429 if (area
!= last_cover
) {
1430 spans
[num_spans
].x
= x
;
1431 spans
[num_spans
].coverage
= GRID_AREA_TO_ALPHA (area
);
1440 if (prev_x
<= xmax
&& cover
!= last_cover
) {
1441 spans
[num_spans
].x
= prev_x
;
1442 spans
[num_spans
].coverage
= GRID_AREA_TO_ALPHA (cover
);
1448 if (last_x
< xmax
&& last_cover
) {
1449 spans
[num_spans
].x
= xmax
;
1450 spans
[num_spans
].coverage
= 0;
1454 /* Dump them into the renderer. */
1455 return renderer
->render_rows (renderer
, y
, height
, spans
, num_spans
);
1458 #define GRID_AREA_TO_A1(A) ((GRID_AREA_TO_ALPHA (A) > 127) ? 255 : 0)
1459 static glitter_status_t
1460 blit_a1 (struct cell_list
*cells
,
1461 cairo_span_renderer_t
*renderer
,
1462 cairo_half_open_span_t
*spans
,
1466 struct cell
*cell
= cells
->head
.next
;
1467 int prev_x
= xmin
, last_x
= -1;
1469 uint8_t coverage
, last_cover
= 0;
1472 if (cell
== &cells
->tail
)
1473 return CAIRO_STATUS_SUCCESS
;
1475 /* Skip cells to the left of the clip region. */
1476 while (cell
->x
< xmin
) {
1477 cover
+= cell
->covered_height
;
1482 /* Form the spans from the coverages and areas. */
1484 for (; cell
->x
< xmax
; cell
= cell
->next
) {
1488 coverage
= GRID_AREA_TO_A1 (cover
);
1489 if (x
> prev_x
&& coverage
!= last_cover
) {
1490 last_x
= spans
[num_spans
].x
= prev_x
;
1491 last_cover
= spans
[num_spans
].coverage
= coverage
;
1495 cover
+= cell
->covered_height
*GRID_X
*2;
1496 area
= cover
- cell
->uncovered_area
;
1498 coverage
= GRID_AREA_TO_A1 (area
);
1499 if (coverage
!= last_cover
) {
1500 last_x
= spans
[num_spans
].x
= x
;
1501 last_cover
= spans
[num_spans
].coverage
= coverage
;
1508 coverage
= GRID_AREA_TO_A1 (cover
);
1509 if (prev_x
<= xmax
&& coverage
!= last_cover
) {
1510 last_x
= spans
[num_spans
].x
= prev_x
;
1511 last_cover
= spans
[num_spans
].coverage
= coverage
;
1515 if (last_x
< xmax
&& last_cover
) {
1516 spans
[num_spans
].x
= xmax
;
1517 spans
[num_spans
].coverage
= 0;
1521 return CAIRO_STATUS_SUCCESS
;
1523 /* Dump them into the renderer. */
1524 return renderer
->render_rows (renderer
, y
, height
, spans
, num_spans
);
1529 glitter_scan_converter_render(glitter_scan_converter_t
*converter
,
1530 unsigned int winding_mask
,
1532 cairo_span_renderer_t
*renderer
)
1535 int ymax_i
= converter
->ymax
/ GRID_Y
;
1536 int ymin_i
= converter
->ymin
/ GRID_Y
;
1538 int h
= ymax_i
- ymin_i
;
1539 struct polygon
*polygon
= converter
->polygon
;
1540 struct cell_list
*coverages
= converter
->coverages
;
1541 struct active_list
*active
= converter
->active
;
1542 struct edge
*buckets
[GRID_Y
] = { 0 };
1544 xmin_i
= converter
->xmin
/ GRID_X
;
1545 xmax_i
= converter
->xmax
/ GRID_X
;
1546 if (xmin_i
>= xmax_i
)
1549 /* Render each pixel row. */
1550 for (i
= 0; i
< h
; i
= j
) {
1551 int do_full_row
= 0;
1555 /* Determine if we can ignore this row or use the full pixel
1557 if (! polygon
->y_buckets
[i
]) {
1558 if (active
->head
.next
== &active
->tail
) {
1559 active
->min_height
= INT_MAX
;
1560 active
->is_vertical
= 1;
1561 for (; j
< h
&& ! polygon
->y_buckets
[j
]; j
++)
1566 do_full_row
= can_do_full_row (active
);
1570 /* Step by a full pixel row's worth. */
1571 full_row (active
, coverages
, winding_mask
);
1573 if (active
->is_vertical
) {
1575 polygon
->y_buckets
[j
] == NULL
&&
1576 active
->min_height
>= 2*GRID_Y
)
1578 active
->min_height
-= GRID_Y
;
1582 step_edges (active
, j
- (i
+ 1));
1587 polygon_fill_buckets (active
,
1588 polygon
->y_buckets
[i
],
1592 /* Subsample this row. */
1593 for (sub
= 0; sub
< GRID_Y
; sub
++) {
1595 active_list_merge_edges_from_bucket (active
, buckets
[sub
]);
1596 buckets
[sub
] = NULL
;
1599 sub_row (active
, coverages
, winding_mask
);
1604 blit_a8 (coverages
, renderer
, converter
->spans
,
1605 i
+ymin_i
, j
-i
, xmin_i
, xmax_i
);
1607 blit_a1 (coverages
, renderer
, converter
->spans
,
1608 i
+ymin_i
, j
-i
, xmin_i
, xmax_i
);
1609 cell_list_reset (coverages
);
1611 active
->min_height
-= GRID_Y
;
1615 struct _cairo_tor22_scan_converter
{
1616 cairo_scan_converter_t base
;
1618 glitter_scan_converter_t converter
[1];
1619 cairo_fill_rule_t fill_rule
;
1620 cairo_antialias_t antialias
;
1625 typedef struct _cairo_tor22_scan_converter cairo_tor22_scan_converter_t
;
1628 _cairo_tor22_scan_converter_destroy (void *converter
)
1630 cairo_tor22_scan_converter_t
*self
= converter
;
1634 _glitter_scan_converter_fini (self
->converter
);
1639 _cairo_tor22_scan_converter_add_polygon (void *converter
,
1640 const cairo_polygon_t
*polygon
)
1642 cairo_tor22_scan_converter_t
*self
= converter
;
1646 FILE *file
= fopen ("polygon.txt", "w");
1647 _cairo_debug_print_polygon (file
, polygon
);
1651 for (i
= 0; i
< polygon
->num_edges
; i
++)
1652 glitter_scan_converter_add_edge (self
->converter
, &polygon
->edges
[i
]);
1654 return CAIRO_STATUS_SUCCESS
;
1657 static cairo_status_t
1658 _cairo_tor22_scan_converter_generate (void *converter
,
1659 cairo_span_renderer_t
*renderer
)
1661 cairo_tor22_scan_converter_t
*self
= converter
;
1662 cairo_status_t status
;
1664 if ((status
= setjmp (self
->jmp
)))
1665 return _cairo_scan_converter_set_error (self
, _cairo_error (status
));
1667 glitter_scan_converter_render (self
->converter
,
1668 self
->fill_rule
== CAIRO_FILL_RULE_WINDING
? ~0 : 1,
1669 self
->antialias
!= CAIRO_ANTIALIAS_NONE
,
1671 return CAIRO_STATUS_SUCCESS
;
1674 cairo_scan_converter_t
*
1675 _cairo_tor22_scan_converter_create (int xmin
,
1679 cairo_fill_rule_t fill_rule
,
1680 cairo_antialias_t antialias
)
1682 cairo_tor22_scan_converter_t
*self
;
1683 cairo_status_t status
;
1685 self
= malloc (sizeof(struct _cairo_tor22_scan_converter
));
1686 if (unlikely (self
== NULL
)) {
1687 status
= _cairo_error (CAIRO_STATUS_NO_MEMORY
);
1691 self
->base
.destroy
= _cairo_tor22_scan_converter_destroy
;
1692 self
->base
.generate
= _cairo_tor22_scan_converter_generate
;
1694 _glitter_scan_converter_init (self
->converter
, &self
->jmp
);
1695 status
= glitter_scan_converter_reset (self
->converter
,
1696 xmin
, ymin
, xmax
, ymax
);
1697 if (unlikely (status
))
1700 self
->fill_rule
= fill_rule
;
1701 self
->antialias
= antialias
;
1706 self
->base
.destroy(&self
->base
);
1708 return _cairo_scan_converter_create_in_error (status
);