1/****************************************************************************
2 *
3 * ftgrays.c
4 *
5 * A new `perfect' anti-aliasing renderer (body).
6 *
7 * Copyright (C) 2000-2023 by
8 * David Turner, Robert Wilhelm, and Werner Lemberg.
9 *
10 * This file is part of the FreeType project, and may only be used,
11 * modified, and distributed under the terms of the FreeType project
12 * license, LICENSE.TXT. By continuing to use, modify, or distribute
13 * this file you indicate that you have read the license and
14 * understand and accept it fully.
15 *
16 */
17
18 /**************************************************************************
19 *
20 * This file can be compiled without the rest of the FreeType engine, by
21 * defining the STANDALONE_ macro when compiling it. You also need to
22 * put the files `ftgrays.h' and `ftimage.h' into the current
23 * compilation directory. Typically, you could do something like
24 *
25 * - copy `src/smooth/ftgrays.c' (this file) to your current directory
26 *
27 * - copy `include/freetype/ftimage.h' and `src/smooth/ftgrays.h' to the
28 * same directory
29 *
30 * - compile `ftgrays' with the STANDALONE_ macro defined, as in
31 *
32 * cc -c -DSTANDALONE_ ftgrays.c
33 *
34 * The renderer can be initialized with a call to
35 * `ft_gray_raster.raster_new'; an anti-aliased bitmap can be generated
36 * with a call to `ft_gray_raster.raster_render'.
37 *
38 * See the comments and documentation in the file `ftimage.h' for more
39 * details on how the raster works.
40 *
41 */
42
43 /**************************************************************************
44 *
45 * This is a new anti-aliasing scan-converter for FreeType 2. The
46 * algorithm used here is _very_ different from the one in the standard
47 * `ftraster' module. Actually, `ftgrays' computes the _exact_
48 * coverage of the outline on each pixel cell by straight segments.
49 *
50 * It is based on ideas that I initially found in Raph Levien's
51 * excellent LibArt graphics library (see https://www.levien.com/libart
52 * for more information, though the web pages do not tell anything
53 * about the renderer; you'll have to dive into the source code to
54 * understand how it works).
55 *
56 * Note, however, that this is a _very_ different implementation
57 * compared to Raph's. Coverage information is stored in a very
58 * different way, and I don't use sorted vector paths. Also, it doesn't
59 * use floating point values.
60 *
61 * Bézier segments are flattened by splitting them until their deviation
62 * from straight line becomes much smaller than a pixel. Therefore, the
63 * pixel coverage by a Bézier curve is calculated approximately. To
64 * estimate the deviation, we use the distance from the control point
65 * to the conic chord centre or the cubic chord trisection. These
66 * distances vanish fast after each split. In the conic case, they vanish
67 * predictably and the number of necessary splits can be calculated.
68 *
69 * This renderer has the following advantages:
70 *
71 * - It doesn't need an intermediate bitmap. Instead, one can supply a
72 * callback function that will be called by the renderer to draw gray
73 * spans on any target surface. You can thus do direct composition on
74 * any kind of bitmap, provided that you give the renderer the right
75 * callback.
76 *
77 * - A perfect anti-aliaser, i.e., it computes the _exact_ coverage on
78 * each pixel cell by straight segments.
79 *
80 * - It performs a single pass on the outline (the `standard' FT2
81 * renderer makes two passes).
82 *
83 * - It can easily be modified to render to _any_ number of gray levels
84 * cheaply.
85 *
86 * - For small (< 80) pixel sizes, it is faster than the standard
87 * renderer.
88 *
89 */
90
91
92 /**************************************************************************
93 *
94 * The macro FT_COMPONENT is used in trace mode. It is an implicit
95 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
96 * messages during execution.
97 */
98#undef FT_COMPONENT
99#define FT_COMPONENT smooth
100
101
102#ifdef STANDALONE_
103
104
105 /* The size in bytes of the render pool used by the scan-line converter */
106 /* to do all of its work. */
107#define FT_RENDER_POOL_SIZE 16384L
108
109
110 /* Auxiliary macros for token concatenation. */
111#define FT_ERR_XCAT( x, y ) x ## y
112#define FT_ERR_CAT( x, y ) FT_ERR_XCAT( x, y )
113
114#define FT_BEGIN_STMNT do {
115#define FT_END_STMNT } while ( 0 )
116
117#define FT_MIN( a, b ) ( (a) < (b) ? (a) : (b) )
118#define FT_MAX( a, b ) ( (a) > (b) ? (a) : (b) )
119#define FT_ABS( a ) ( (a) < 0 ? -(a) : (a) )
120
121
122 /*
123 * Approximate sqrt(x*x+y*y) using the `alpha max plus beta min'
124 * algorithm. We use alpha = 1, beta = 3/8, giving us results with a
125 * largest error less than 7% compared to the exact value.
126 */
127#define FT_HYPOT( x, y ) \
128 ( x = FT_ABS( x ), \
129 y = FT_ABS( y ), \
130 x > y ? x + ( 3 * y >> 3 ) \
131 : y + ( 3 * x >> 3 ) )
132
133
134 /* define this to dump debugging information */
135/* #define FT_DEBUG_LEVEL_TRACE */
136
137
138#ifdef FT_DEBUG_LEVEL_TRACE
139#include <stdio.h>
140#include <stdarg.h>
141#endif
142
143#include <stddef.h>
144#include <string.h>
145#include <setjmp.h>
146#include <limits.h>
147#define FT_CHAR_BIT CHAR_BIT
148#define FT_UINT_MAX UINT_MAX
149#define FT_INT_MAX INT_MAX
150#define FT_ULONG_MAX ULONG_MAX
151
152#define ADD_INT( a, b ) \
153 (int)( (unsigned int)(a) + (unsigned int)(b) )
154
155#define FT_STATIC_BYTE_CAST( type, var ) (type)(unsigned char)(var)
156
157
158#define ft_memset memset
159
160#define ft_setjmp setjmp
161#define ft_longjmp longjmp
162#define ft_jmp_buf jmp_buf
163
164typedef ptrdiff_t FT_PtrDist;
165
166
167#define Smooth_Err_Ok 0
168#define Smooth_Err_Invalid_Outline -1
169#define Smooth_Err_Cannot_Render_Glyph -2
170#define Smooth_Err_Invalid_Argument -3
171#define Smooth_Err_Raster_Overflow -4
172
173#define FT_BEGIN_HEADER
174#define FT_END_HEADER
175
176#include "ftimage.h"
177#include "ftgrays.h"
178
179
180 /* This macro is used to indicate that a function parameter is unused. */
181 /* Its purpose is simply to reduce compiler warnings. Note also that */
182 /* simply defining it as `(void)x' doesn't avoid warnings with certain */
183 /* ANSI compilers (e.g. LCC). */
184#define FT_UNUSED( x ) (x) = (x)
185
186
187 /* we only use level 5 & 7 tracing messages; cf. ftdebug.h */
188
189#ifdef FT_DEBUG_LEVEL_TRACE
190
191 void
192 FT_Message( const char* fmt,
193 ... )
194 {
195 va_list ap;
196
197
198 va_start( ap, fmt );
199 vfprintf( stderr, fmt, ap );
200 va_end( ap );
201 }
202
203
204 /* empty function useful for setting a breakpoint to catch errors */
205 int
206 FT_Throw( int error,
207 int line,
208 const char* file )
209 {
210 FT_UNUSED( error );
211 FT_UNUSED( line );
212 FT_UNUSED( file );
213
214 return 0;
215 }
216
217
218 /* we don't handle tracing levels in stand-alone mode; */
219#ifndef FT_TRACE5
220#define FT_TRACE5( varformat ) FT_Message varformat
221#endif
222#ifndef FT_TRACE7
223#define FT_TRACE7( varformat ) FT_Message varformat
224#endif
225#ifndef FT_ERROR
226#define FT_ERROR( varformat ) FT_Message varformat
227#endif
228
229#define FT_THROW( e ) \
230 ( FT_Throw( FT_ERR_CAT( Smooth_Err_, e ), \
231 __LINE__, \
232 __FILE__ ) | \
233 FT_ERR_CAT( Smooth_Err_, e ) )
234
235#else /* !FT_DEBUG_LEVEL_TRACE */
236
237#define FT_TRACE5( x ) do { } while ( 0 ) /* nothing */
238#define FT_TRACE7( x ) do { } while ( 0 ) /* nothing */
239#define FT_ERROR( x ) do { } while ( 0 ) /* nothing */
240#define FT_THROW( e ) FT_ERR_CAT( Smooth_Err_, e )
241
242#endif /* !FT_DEBUG_LEVEL_TRACE */
243
244
245#define FT_Trace_Enable() do { } while ( 0 ) /* nothing */
246#define FT_Trace_Disable() do { } while ( 0 ) /* nothing */
247
248
249#define FT_DEFINE_OUTLINE_FUNCS( class_, \
250 move_to_, line_to_, \
251 conic_to_, cubic_to_, \
252 shift_, delta_ ) \
253 static const FT_Outline_Funcs class_ = \
254 { \
255 move_to_, \
256 line_to_, \
257 conic_to_, \
258 cubic_to_, \
259 shift_, \
260 delta_ \
261 };
262
263#define FT_DEFINE_RASTER_FUNCS( class_, glyph_format_, \
264 raster_new_, raster_reset_, \
265 raster_set_mode_, raster_render_, \
266 raster_done_ ) \
267 const FT_Raster_Funcs class_ = \
268 { \
269 glyph_format_, \
270 raster_new_, \
271 raster_reset_, \
272 raster_set_mode_, \
273 raster_render_, \
274 raster_done_ \
275 };
276
277
278#else /* !STANDALONE_ */
279
280
281#include <ft2build.h>
282#include FT_CONFIG_CONFIG_H
283#include "ftgrays.h"
284#include <freetype/internal/ftobjs.h>
285#include <freetype/internal/ftdebug.h>
286#include <freetype/internal/ftcalc.h>
287#include <freetype/ftoutln.h>
288
289#include "ftsmerrs.h"
290
291
292#endif /* !STANDALONE_ */
293
294
295#ifndef FT_MEM_SET
296#define FT_MEM_SET( d, s, c ) ft_memset( d, s, c )
297#endif
298
299#ifndef FT_MEM_ZERO
300#define FT_MEM_ZERO( dest, count ) FT_MEM_SET( dest, 0, count )
301#endif
302
303#ifndef FT_ZERO
304#define FT_ZERO( p ) FT_MEM_ZERO( p, sizeof ( *(p) ) )
305#endif
306
307 /* as usual, for the speed hungry :-) */
308
309#undef RAS_ARG
310#undef RAS_ARG_
311#undef RAS_VAR
312#undef RAS_VAR_
313
314#ifndef FT_STATIC_RASTER
315
316#define RAS_ARG gray_PWorker worker
317#define RAS_ARG_ gray_PWorker worker,
318
319#define RAS_VAR worker
320#define RAS_VAR_ worker,
321
322#else /* FT_STATIC_RASTER */
323
324#define RAS_ARG void
325#define RAS_ARG_ /* empty */
326#define RAS_VAR /* empty */
327#define RAS_VAR_ /* empty */
328
329#endif /* FT_STATIC_RASTER */
330
331
332 /* must be at least 6 bits! */
333#define PIXEL_BITS 8
334
335#define ONE_PIXEL ( 1 << PIXEL_BITS )
336#undef TRUNC
337#define TRUNC( x ) (TCoord)( (x) >> PIXEL_BITS )
338#undef FRACT
339#define FRACT( x ) (TCoord)( (x) & ( ONE_PIXEL - 1 ) )
340
341#if PIXEL_BITS >= 6
342#define UPSCALE( x ) ( (x) * ( ONE_PIXEL >> 6 ) )
343#define DOWNSCALE( x ) ( (x) >> ( PIXEL_BITS - 6 ) )
344#else
345#define UPSCALE( x ) ( (x) >> ( 6 - PIXEL_BITS ) )
346#define DOWNSCALE( x ) ( (x) * ( 64 >> PIXEL_BITS ) )
347#endif
348
349
350 /* Compute `dividend / divisor' and return both its quotient and */
351 /* remainder, cast to a specific type. This macro also ensures that */
352 /* the remainder is always positive. We use the remainder to keep */
353 /* track of accumulating errors and compensate for them. */
354#define FT_DIV_MOD( type, dividend, divisor, quotient, remainder ) \
355 FT_BEGIN_STMNT \
356 (quotient) = (type)( (dividend) / (divisor) ); \
357 (remainder) = (type)( (dividend) % (divisor) ); \
358 if ( (remainder) < 0 ) \
359 { \
360 (quotient)--; \
361 (remainder) += (type)(divisor); \
362 } \
363 FT_END_STMNT
364
365#if defined( __GNUC__ ) && __GNUC__ < 7 && defined( __arm__ )
366 /* Work around a bug specific to GCC which make the compiler fail to */
367 /* optimize a division and modulo operation on the same parameters */
368 /* into a single call to `__aeabi_idivmod'. See */
369 /* */
370 /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43721 */
371#undef FT_DIV_MOD
372#define FT_DIV_MOD( type, dividend, divisor, quotient, remainder ) \
373 FT_BEGIN_STMNT \
374 (quotient) = (type)( (dividend) / (divisor) ); \
375 (remainder) = (type)( (dividend) - (quotient) * (divisor) ); \
376 if ( (remainder) < 0 ) \
377 { \
378 (quotient)--; \
379 (remainder) += (type)(divisor); \
380 } \
381 FT_END_STMNT
382#endif /* __arm__ */
383
384
385 /* Calculating coverages for a slanted line requires a division each */
386 /* time the line crosses from cell to cell. These macros speed up */
387 /* the repetitive divisions by replacing them with multiplications */
388 /* and right shifts so that at most two divisions are performed for */
389 /* each slanted line. Nevertheless, these divisions are noticeable */
390 /* in the overall performance because flattened curves produce a */
391 /* very large number of slanted lines. */
392 /* */
393 /* The division results here are always within ONE_PIXEL. Therefore */
394 /* the shift magnitude should be at least PIXEL_BITS wider than the */
395 /* divisors to provide sufficient accuracy of the multiply-shift. */
396 /* It should not exceed (64 - PIXEL_BITS) to prevent overflowing and */
397 /* leave enough room for 64-bit unsigned multiplication however. */
398#define FT_UDIVPREP( c, b ) \
399 FT_Int64 b ## _r = c ? (FT_Int64)0xFFFFFFFF / ( b ) : 0
400#define FT_UDIV( a, b ) \
401 (TCoord)( ( (FT_UInt64)( a ) * (FT_UInt64)( b ## _r ) ) >> 32 )
402
403
404 /* Scale area and apply fill rule to calculate the coverage byte. */
405 /* The top fill bit is used for the non-zero rule. The eighth */
406 /* fill bit is used for the even-odd rule. The higher coverage */
407 /* bytes are either clamped for the non-zero-rule or discarded */
408 /* later for the even-odd rule. */
409#define FT_FILL_RULE( coverage, area, fill ) \
410 FT_BEGIN_STMNT \
411 coverage = (int)( area >> ( PIXEL_BITS * 2 + 1 - 8 ) ); \
412 if ( coverage & fill ) \
413 coverage = ~coverage; \
414 if ( coverage > 255 && fill & INT_MIN ) \
415 coverage = 255; \
416 FT_END_STMNT
417
418
419 /* It is faster to write small spans byte-by-byte than calling */
420 /* `memset'. This is mainly due to the cost of the function call. */
421#define FT_GRAY_SET( d, s, count ) \
422 FT_BEGIN_STMNT \
423 unsigned char* q = d; \
424 switch ( count ) \
425 { \
426 case 7: *q++ = (unsigned char)s; FALL_THROUGH; \
427 case 6: *q++ = (unsigned char)s; FALL_THROUGH; \
428 case 5: *q++ = (unsigned char)s; FALL_THROUGH; \
429 case 4: *q++ = (unsigned char)s; FALL_THROUGH; \
430 case 3: *q++ = (unsigned char)s; FALL_THROUGH; \
431 case 2: *q++ = (unsigned char)s; FALL_THROUGH; \
432 case 1: *q = (unsigned char)s; FALL_THROUGH; \
433 case 0: break; \
434 default: FT_MEM_SET( d, s, count ); \
435 } \
436 FT_END_STMNT
437
438
439 /**************************************************************************
440 *
441 * TYPE DEFINITIONS
442 */
443
444 /* don't change the following types to FT_Int or FT_Pos, since we might */
445 /* need to define them to "float" or "double" when experimenting with */
446 /* new algorithms */
447
448 typedef long TPos; /* subpixel coordinate */
449 typedef int TCoord; /* integer scanline/pixel coordinate */
450 typedef int TArea; /* cell areas, coordinate products */
451
452
453 typedef struct TCell_* PCell;
454
455 typedef struct TCell_
456 {
457 TCoord x; /* same with gray_TWorker.ex */
458 TCoord cover; /* same with gray_TWorker.cover */
459 TArea area;
460 PCell next;
461
462 } TCell;
463
464 typedef struct TPixmap_
465 {
466 unsigned char* origin; /* pixmap origin at the bottom-left */
467 int pitch; /* pitch to go down one row */
468
469 } TPixmap;
470
471 /* maximum number of gray cells in the buffer */
472#if FT_RENDER_POOL_SIZE > 2048
473#define FT_MAX_GRAY_POOL ( FT_RENDER_POOL_SIZE / sizeof ( TCell ) )
474#else
475#define FT_MAX_GRAY_POOL ( 2048 / sizeof ( TCell ) )
476#endif
477
478 /* FT_Span buffer size for direct rendering only */
479#define FT_MAX_GRAY_SPANS 16
480
481
482#if defined( _MSC_VER ) /* Visual C++ (and Intel C++) */
483 /* We disable the warning `structure was padded due to */
484 /* __declspec(align())' in order to compile cleanly with */
485 /* the maximum level of warnings. */
486#pragma warning( push )
487#pragma warning( disable : 4324 )
488#endif /* _MSC_VER */
489
490 typedef struct gray_TWorker_
491 {
492 ft_jmp_buf jump_buffer;
493
494 TCoord min_ex, max_ex; /* min and max integer pixel coordinates */
495 TCoord min_ey, max_ey;
496 TCoord count_ey; /* same as (max_ey - min_ey) */
497
498 PCell cell; /* current cell */
499 PCell cell_free; /* call allocation next free slot */
500 PCell cell_null; /* last cell, used as dumpster and limit */
501
502 PCell* ycells; /* array of cell linked-lists; one per */
503 /* vertical coordinate in the current band */
504
505 TPos x, y; /* last point position */
506
507 FT_Outline outline; /* input outline */
508 TPixmap target; /* target pixmap */
509
510 FT_Raster_Span_Func render_span;
511 void* render_span_data;
512
513 } gray_TWorker, *gray_PWorker;
514
515#if defined( _MSC_VER )
516#pragma warning( pop )
517#endif
518
519#ifndef FT_STATIC_RASTER
520#define ras (*worker)
521#else
522 static gray_TWorker ras;
523#endif
524
525 /* The |x| value of the null cell. Must be the largest possible */
526 /* integer value stored in a `TCell.x` field. */
527#define CELL_MAX_X_VALUE INT_MAX
528
529
530#define FT_INTEGRATE( ras, a, b ) \
531 ras.cell->cover = ADD_INT( ras.cell->cover, a ), \
532 ras.cell->area = ADD_INT( ras.cell->area, (a) * (TArea)(b) )
533
534
535 typedef struct gray_TRaster_
536 {
537 void* memory;
538
539 } gray_TRaster, *gray_PRaster;
540
541
542#ifdef FT_DEBUG_LEVEL_TRACE
543
544 /* to be called while in the debugger -- */
545 /* this function causes a compiler warning since it is unused otherwise */
546 static void
547 gray_dump_cells( RAS_ARG )
548 {
549 int y;
550
551
552 for ( y = ras.min_ey; y < ras.max_ey; y++ )
553 {
554 PCell cell = ras.ycells[y - ras.min_ey];
555
556
557 printf( "%3d:", y );
558
559 for ( ; cell != ras.cell_null; cell = cell->next )
560 printf( " (%3d, c:%4d, a:%6d)",
561 cell->x, cell->cover, cell->area );
562 printf( "\n" );
563 }
564 }
565
566#endif /* FT_DEBUG_LEVEL_TRACE */
567
568
569 /**************************************************************************
570 *
571 * Set the current cell to a new position.
572 */
573 static void
574 gray_set_cell( RAS_ARG_ TCoord ex,
575 TCoord ey )
576 {
577 /* Move the cell pointer to a new position in the linked list. We use */
578 /* a dumpster null cell for everything outside of the clipping region */
579 /* during the render phase. This means that: */
580 /* */
581 /* . the new vertical position must be within min_ey..max_ey-1. */
582 /* . the new horizontal position must be strictly less than max_ex */
583 /* */
584 /* Note that if a cell is to the left of the clipping region, it is */
585 /* actually set to the (min_ex-1) horizontal position. */
586
587 TCoord ey_index = ey - ras.min_ey;
588
589
590 if ( ey_index < 0 || ey_index >= ras.count_ey || ex >= ras.max_ex )
591 ras.cell = ras.cell_null;
592 else
593 {
594 PCell* pcell = ras.ycells + ey_index;
595 PCell cell;
596
597
598 ex = FT_MAX( ex, ras.min_ex - 1 );
599
600 while ( 1 )
601 {
602 cell = *pcell;
603
604 if ( cell->x > ex )
605 break;
606
607 if ( cell->x == ex )
608 goto Found;
609
610 pcell = &cell->next;
611 }
612
613 /* insert new cell */
614 cell = ras.cell_free++;
615 if ( cell >= ras.cell_null )
616 ft_longjmp( ras.jump_buffer, 1 );
617
618 cell->x = ex;
619 cell->area = 0;
620 cell->cover = 0;
621
622 cell->next = *pcell;
623 *pcell = cell;
624
625 Found:
626 ras.cell = cell;
627 }
628 }
629
630
631#ifndef FT_INT64
632
633 /**************************************************************************
634 *
635 * Render a scanline as one or more cells.
636 */
637 static void
638 gray_render_scanline( RAS_ARG_ TCoord ey,
639 TPos x1,
640 TCoord y1,
641 TPos x2,
642 TCoord y2 )
643 {
644 TCoord ex1, ex2, fx1, fx2, first, dy, delta, mod;
645 TPos p, dx;
646 int incr;
647
648
649 ex1 = TRUNC( x1 );
650 ex2 = TRUNC( x2 );
651
652 /* trivial case. Happens often */
653 if ( y1 == y2 )
654 {
655 gray_set_cell( RAS_VAR_ ex2, ey );
656 return;
657 }
658
659 fx1 = FRACT( x1 );
660 fx2 = FRACT( x2 );
661
662 /* everything is located in a single cell. That is easy! */
663 /* */
664 if ( ex1 == ex2 )
665 goto End;
666
667 /* ok, we'll have to render a run of adjacent cells on the same */
668 /* scanline... */
669 /* */
670 dx = x2 - x1;
671 dy = y2 - y1;
672
673 if ( dx > 0 )
674 {
675 p = ( ONE_PIXEL - fx1 ) * dy;
676 first = ONE_PIXEL;
677 incr = 1;
678 }
679 else
680 {
681 p = fx1 * dy;
682 first = 0;
683 incr = -1;
684 dx = -dx;
685 }
686
687 /* the fractional part of y-delta is mod/dx. It is essential to */
688 /* keep track of its accumulation for accurate rendering. */
689 /* XXX: y-delta and x-delta below should be related. */
690 FT_DIV_MOD( TCoord, p, dx, delta, mod );
691
692 FT_INTEGRATE( ras, delta, fx1 + first );
693 y1 += delta;
694 ex1 += incr;
695 gray_set_cell( RAS_VAR_ ex1, ey );
696
697 if ( ex1 != ex2 )
698 {
699 TCoord lift, rem;
700
701
702 p = ONE_PIXEL * dy;
703 FT_DIV_MOD( TCoord, p, dx, lift, rem );
704
705 do
706 {
707 delta = lift;
708 mod += rem;
709 if ( mod >= (TCoord)dx )
710 {
711 mod -= (TCoord)dx;
712 delta++;
713 }
714
715 FT_INTEGRATE( ras, delta, ONE_PIXEL );
716 y1 += delta;
717 ex1 += incr;
718 gray_set_cell( RAS_VAR_ ex1, ey );
719 } while ( ex1 != ex2 );
720 }
721
722 fx1 = ONE_PIXEL - first;
723
724 End:
725 FT_INTEGRATE( ras, y2 - y1, fx1 + fx2 );
726 }
727
728
729 /**************************************************************************
730 *
731 * Render a given line as a series of scanlines.
732 */
733 static void
734 gray_render_line( RAS_ARG_ TPos to_x,
735 TPos to_y )
736 {
737 TCoord ey1, ey2, fy1, fy2, first, delta, mod;
738 TPos p, dx, dy, x, x2;
739 int incr;
740
741
742 ey1 = TRUNC( ras.y );
743 ey2 = TRUNC( to_y ); /* if (ey2 >= ras.max_ey) ey2 = ras.max_ey-1; */
744
745 /* perform vertical clipping */
746 if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) ||
747 ( ey1 < ras.min_ey && ey2 < ras.min_ey ) )
748 goto End;
749
750 fy1 = FRACT( ras.y );
751 fy2 = FRACT( to_y );
752
753 /* everything is on a single scanline */
754 if ( ey1 == ey2 )
755 {
756 gray_render_scanline( RAS_VAR_ ey1, ras.x, fy1, to_x, fy2 );
757 goto End;
758 }
759
760 dx = to_x - ras.x;
761 dy = to_y - ras.y;
762
763 /* vertical line - avoid calling gray_render_scanline */
764 if ( dx == 0 )
765 {
766 TCoord ex = TRUNC( ras.x );
767 TCoord two_fx = FRACT( ras.x ) << 1;
768
769
770 if ( dy > 0)
771 {
772 first = ONE_PIXEL;
773 incr = 1;
774 }
775 else
776 {
777 first = 0;
778 incr = -1;
779 }
780
781 delta = first - fy1;
782 FT_INTEGRATE( ras, delta, two_fx);
783 ey1 += incr;
784
785 gray_set_cell( RAS_VAR_ ex, ey1 );
786
787 delta = first + first - ONE_PIXEL;
788 while ( ey1 != ey2 )
789 {
790 FT_INTEGRATE( ras, delta, two_fx);
791 ey1 += incr;
792
793 gray_set_cell( RAS_VAR_ ex, ey1 );
794 }
795
796 delta = fy2 - ONE_PIXEL + first;
797 FT_INTEGRATE( ras, delta, two_fx);
798
799 goto End;
800 }
801
802 /* ok, we have to render several scanlines */
803 if ( dy > 0)
804 {
805 p = ( ONE_PIXEL - fy1 ) * dx;
806 first = ONE_PIXEL;
807 incr = 1;
808 }
809 else
810 {
811 p = fy1 * dx;
812 first = 0;
813 incr = -1;
814 dy = -dy;
815 }
816
817 /* the fractional part of x-delta is mod/dy. It is essential to */
818 /* keep track of its accumulation for accurate rendering. */
819 FT_DIV_MOD( TCoord, p, dy, delta, mod );
820
821 x = ras.x + delta;
822 gray_render_scanline( RAS_VAR_ ey1, ras.x, fy1, x, first );
823
824 ey1 += incr;
825 gray_set_cell( RAS_VAR_ TRUNC( x ), ey1 );
826
827 if ( ey1 != ey2 )
828 {
829 TCoord lift, rem;
830
831
832 p = ONE_PIXEL * dx;
833 FT_DIV_MOD( TCoord, p, dy, lift, rem );
834
835 do
836 {
837 delta = lift;
838 mod += rem;
839 if ( mod >= (TCoord)dy )
840 {
841 mod -= (TCoord)dy;
842 delta++;
843 }
844
845 x2 = x + delta;
846 gray_render_scanline( RAS_VAR_ ey1,
847 x, ONE_PIXEL - first,
848 x2, first );
849 x = x2;
850
851 ey1 += incr;
852 gray_set_cell( RAS_VAR_ TRUNC( x ), ey1 );
853 } while ( ey1 != ey2 );
854 }
855
856 gray_render_scanline( RAS_VAR_ ey1,
857 x, ONE_PIXEL - first,
858 to_x, fy2 );
859
860 End:
861 ras.x = to_x;
862 ras.y = to_y;
863 }
864
865#else
866
867 /**************************************************************************
868 *
869 * Render a straight line across multiple cells in any direction.
870 */
871 static void
872 gray_render_line( RAS_ARG_ TPos to_x,
873 TPos to_y )
874 {
875 TPos dx, dy;
876 TCoord fx1, fy1, fx2, fy2;
877 TCoord ex1, ey1, ex2, ey2;
878
879
880 ey1 = TRUNC( ras.y );
881 ey2 = TRUNC( to_y );
882
883 /* perform vertical clipping */
884 if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) ||
885 ( ey1 < ras.min_ey && ey2 < ras.min_ey ) )
886 goto End;
887
888 ex1 = TRUNC( ras.x );
889 ex2 = TRUNC( to_x );
890
891 fx1 = FRACT( ras.x );
892 fy1 = FRACT( ras.y );
893
894 dx = to_x - ras.x;
895 dy = to_y - ras.y;
896
897 if ( ex1 == ex2 && ey1 == ey2 ) /* inside one cell */
898 ;
899 else if ( dy == 0 ) /* ex1 != ex2 */ /* any horizontal line */
900 {
901 gray_set_cell( RAS_VAR_ ex2, ey2 );
902 goto End;
903 }
904 else if ( dx == 0 )
905 {
906 if ( dy > 0 ) /* vertical line up */
907 do
908 {
909 fy2 = ONE_PIXEL;
910 FT_INTEGRATE( ras, fy2 - fy1, fx1 * 2 );
911 fy1 = 0;
912 ey1++;
913 gray_set_cell( RAS_VAR_ ex1, ey1 );
914 } while ( ey1 != ey2 );
915 else /* vertical line down */
916 do
917 {
918 fy2 = 0;
919 FT_INTEGRATE( ras, fy2 - fy1, fx1 * 2 );
920 fy1 = ONE_PIXEL;
921 ey1--;
922 gray_set_cell( RAS_VAR_ ex1, ey1 );
923 } while ( ey1 != ey2 );
924 }
925 else /* any other line */
926 {
927 FT_Int64 prod = dx * (FT_Int64)fy1 - dy * (FT_Int64)fx1;
928 FT_UDIVPREP( ex1 != ex2, dx );
929 FT_UDIVPREP( ey1 != ey2, dy );
930
931
932 /* The fundamental value `prod' determines which side and the */
933 /* exact coordinate where the line exits current cell. It is */
934 /* also easily updated when moving from one cell to the next. */
935 do
936 {
937 if ( prod - dx * ONE_PIXEL > 0 &&
938 prod <= 0 ) /* left */
939 {
940 fx2 = 0;
941 fy2 = FT_UDIV( -prod, -dx );
942 prod -= dy * ONE_PIXEL;
943 FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 );
944 fx1 = ONE_PIXEL;
945 fy1 = fy2;
946 ex1--;
947 }
948 else if ( prod - dx * ONE_PIXEL + dy * ONE_PIXEL > 0 &&
949 prod - dx * ONE_PIXEL <= 0 ) /* up */
950 {
951 prod -= dx * ONE_PIXEL;
952 fx2 = FT_UDIV( -prod, dy );
953 fy2 = ONE_PIXEL;
954 FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 );
955 fx1 = fx2;
956 fy1 = 0;
957 ey1++;
958 }
959 else if ( prod + dy * ONE_PIXEL >= 0 &&
960 prod - dx * ONE_PIXEL + dy * ONE_PIXEL <= 0 ) /* right */
961 {
962 prod += dy * ONE_PIXEL;
963 fx2 = ONE_PIXEL;
964 fy2 = FT_UDIV( prod, dx );
965 FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 );
966 fx1 = 0;
967 fy1 = fy2;
968 ex1++;
969 }
970 else /* ( prod > 0 &&
971 prod + dy * ONE_PIXEL < 0 ) down */
972 {
973 fx2 = FT_UDIV( prod, -dy );
974 fy2 = 0;
975 prod += dx * ONE_PIXEL;
976 FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 );
977 fx1 = fx2;
978 fy1 = ONE_PIXEL;
979 ey1--;
980 }
981
982 gray_set_cell( RAS_VAR_ ex1, ey1 );
983
984 } while ( ex1 != ex2 || ey1 != ey2 );
985 }
986
987 fx2 = FRACT( to_x );
988 fy2 = FRACT( to_y );
989
990 FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 );
991
992 End:
993 ras.x = to_x;
994 ras.y = to_y;
995 }
996
997#endif
998
999 /*
1000 * Benchmarking shows that using DDA to flatten the quadratic Bézier arcs
1001 * is slightly faster in the following cases:
1002 *
1003 * - When the host CPU is 64-bit.
1004 * - When SSE2 SIMD registers and instructions are available (even on
1005 * x86).
1006 *
1007 * For other cases, using binary splits is actually slightly faster.
1008 */
1009#if ( defined( __SSE2__ ) || \
1010 defined( __x86_64__ ) || \
1011 defined( _M_AMD64 ) || \
1012 ( defined( _M_IX86_FP ) && _M_IX86_FP >= 2 ) ) && \
1013 !defined( __VMS )
1014# define FT_SSE2 1
1015#else
1016# define FT_SSE2 0
1017#endif
1018
1019#if FT_SSE2 || \
1020 defined( __aarch64__ ) || \
1021 defined( _M_ARM64 )
1022# define BEZIER_USE_DDA 1
1023#else
1024# define BEZIER_USE_DDA 0
1025#endif
1026
1027 /*
1028 * For now, the code that depends on `BEZIER_USE_DDA` requires `FT_Int64`
1029 * to be defined. If `FT_INT64` is not defined, meaning there is no
1030 * 64-bit type available, disable it to avoid compilation errors. See for
1031 * example https://gitlab.freedesktop.org/freetype/freetype/-/issues/1071.
1032 */
1033#if !defined( FT_INT64 )
1034# undef BEZIER_USE_DDA
1035# define BEZIER_USE_DDA 0
1036#endif
1037
1038#if BEZIER_USE_DDA
1039
1040#if FT_SSE2
1041# include <emmintrin.h>
1042#endif
1043
1044#define LEFT_SHIFT( a, b ) (FT_Int64)( (FT_UInt64)(a) << (b) )
1045
1046
1047 static void
1048 gray_render_conic( RAS_ARG_ const FT_Vector* control,
1049 const FT_Vector* to )
1050 {
1051 FT_Vector p0, p1, p2;
1052 TPos ax, ay, bx, by, dx, dy;
1053 int shift;
1054
1055 FT_Int64 rx, ry;
1056 FT_Int64 qx, qy;
1057 FT_Int64 px, py;
1058
1059 FT_UInt count;
1060
1061
1062 p0.x = ras.x;
1063 p0.y = ras.y;
1064 p1.x = UPSCALE( control->x );
1065 p1.y = UPSCALE( control->y );
1066 p2.x = UPSCALE( to->x );
1067 p2.y = UPSCALE( to->y );
1068
1069 /* short-cut the arc that crosses the current band */
1070 if ( ( TRUNC( p0.y ) >= ras.max_ey &&
1071 TRUNC( p1.y ) >= ras.max_ey &&
1072 TRUNC( p2.y ) >= ras.max_ey ) ||
1073 ( TRUNC( p0.y ) < ras.min_ey &&
1074 TRUNC( p1.y ) < ras.min_ey &&
1075 TRUNC( p2.y ) < ras.min_ey ) )
1076 {
1077 ras.x = p2.x;
1078 ras.y = p2.y;
1079 return;
1080 }
1081
1082 bx = p1.x - p0.x;
1083 by = p1.y - p0.y;
1084 ax = p2.x - p1.x - bx; /* p0.x + p2.x - 2 * p1.x */
1085 ay = p2.y - p1.y - by; /* p0.y + p2.y - 2 * p1.y */
1086
1087 dx = FT_ABS( ax );
1088 dy = FT_ABS( ay );
1089 if ( dx < dy )
1090 dx = dy;
1091
1092 if ( dx <= ONE_PIXEL / 4 )
1093 {
1094 gray_render_line( RAS_VAR_ p2.x, p2.y );
1095 return;
1096 }
1097
1098 /* We can calculate the number of necessary bisections because */
1099 /* each bisection predictably reduces deviation exactly 4-fold. */
1100 /* Even 32-bit deviation would vanish after 16 bisections. */
1101 shift = 0;
1102 do
1103 {
1104 dx >>= 2;
1105 shift += 1;
1106
1107 } while ( dx > ONE_PIXEL / 4 );
1108
1109 /*
1110 * The (P0,P1,P2) arc equation, for t in [0,1] range:
1111 *
1112 * P(t) = P0*(1-t)^2 + P1*2*t*(1-t) + P2*t^2
1113 *
1114 * P(t) = P0 + 2*(P1-P0)*t + (P0+P2-2*P1)*t^2
1115 * = P0 + 2*B*t + A*t^2
1116 *
1117 * for A = P0 + P2 - 2*P1
1118 * and B = P1 - P0
1119 *
1120 * Let's consider the difference when advancing by a small
1121 * parameter h:
1122 *
1123 * Q(h,t) = P(t+h) - P(t) = 2*B*h + A*h^2 + 2*A*h*t
1124 *
1125 * And then its own difference:
1126 *
1127 * R(h,t) = Q(h,t+h) - Q(h,t) = 2*A*h*h = R (constant)
1128 *
1129 * Since R is always a constant, it is possible to compute
1130 * successive positions with:
1131 *
1132 * P = P0
1133 * Q = Q(h,0) = 2*B*h + A*h*h
1134 * R = 2*A*h*h
1135 *
1136 * loop:
1137 * P += Q
1138 * Q += R
1139 * EMIT(P)
1140 *
1141 * To ensure accurate results, perform computations on 64-bit
1142 * values, after scaling them by 2^32.
1143 *
1144 * h = 1 / 2^N
1145 *
1146 * R << 32 = 2 * A << (32 - N - N)
1147 * = A << (33 - 2*N)
1148 *
1149 * Q << 32 = (2 * B << (32 - N)) + (A << (32 - N - N))
1150 * = (B << (33 - N)) + (A << (32 - 2*N))
1151 */
1152
1153#if FT_SSE2
1154 /* Experience shows that for small shift values, */
1155 /* SSE2 is actually slower. */
1156 if ( shift > 2 )
1157 {
1158 union
1159 {
1160 struct { FT_Int64 ax, ay, bx, by; } i;
1161 struct { __m128i a, b; } vec;
1162
1163 } u;
1164
1165 union
1166 {
1167 struct { FT_Int32 px_lo, px_hi, py_lo, py_hi; } i;
1168 __m128i vec;
1169
1170 } v;
1171
1172 __m128i a, b;
1173 __m128i r, q, q2;
1174 __m128i p;
1175
1176
1177 u.i.ax = ax;
1178 u.i.ay = ay;
1179 u.i.bx = bx;
1180 u.i.by = by;
1181
1182 a = _mm_load_si128( &u.vec.a );
1183 b = _mm_load_si128( &u.vec.b );
1184
1185 r = _mm_slli_epi64( a, 33 - 2 * shift );
1186 q = _mm_slli_epi64( b, 33 - shift );
1187 q2 = _mm_slli_epi64( a, 32 - 2 * shift );
1188
1189 q = _mm_add_epi64( q2, q );
1190
1191 v.i.px_lo = 0;
1192 v.i.px_hi = p0.x;
1193 v.i.py_lo = 0;
1194 v.i.py_hi = p0.y;
1195
1196 p = _mm_load_si128( &v.vec );
1197
1198 for ( count = 1U << shift; count > 0; count-- )
1199 {
1200 p = _mm_add_epi64( p, q );
1201 q = _mm_add_epi64( q, r );
1202
1203 _mm_store_si128( &v.vec, p );
1204
1205 gray_render_line( RAS_VAR_ v.i.px_hi, v.i.py_hi );
1206 }
1207
1208 return;
1209 }
1210#endif /* FT_SSE2 */
1211
1212 rx = LEFT_SHIFT( ax, 33 - 2 * shift );
1213 ry = LEFT_SHIFT( ay, 33 - 2 * shift );
1214
1215 qx = LEFT_SHIFT( bx, 33 - shift ) + LEFT_SHIFT( ax, 32 - 2 * shift );
1216 qy = LEFT_SHIFT( by, 33 - shift ) + LEFT_SHIFT( ay, 32 - 2 * shift );
1217
1218 px = LEFT_SHIFT( p0.x, 32 );
1219 py = LEFT_SHIFT( p0.y, 32 );
1220
1221 for ( count = 1U << shift; count > 0; count-- )
1222 {
1223 px += qx;
1224 py += qy;
1225 qx += rx;
1226 qy += ry;
1227
1228 gray_render_line( RAS_VAR_ (FT_Pos)( px >> 32 ),
1229 (FT_Pos)( py >> 32 ) );
1230 }
1231 }
1232
1233#else /* !BEZIER_USE_DDA */
1234
1235 /*
1236 * Note that multiple attempts to speed up the function below
1237 * with SSE2 intrinsics, using various data layouts, have turned
1238 * out to be slower than the non-SIMD code below.
1239 */
1240 static void
1241 gray_split_conic( FT_Vector* base )
1242 {
1243 TPos a, b;
1244
1245
1246 base[4].x = base[2].x;
1247 a = base[0].x + base[1].x;
1248 b = base[1].x + base[2].x;
1249 base[3].x = b >> 1;
1250 base[2].x = ( a + b ) >> 2;
1251 base[1].x = a >> 1;
1252
1253 base[4].y = base[2].y;
1254 a = base[0].y + base[1].y;
1255 b = base[1].y + base[2].y;
1256 base[3].y = b >> 1;
1257 base[2].y = ( a + b ) >> 2;
1258 base[1].y = a >> 1;
1259 }
1260
1261
1262 static void
1263 gray_render_conic( RAS_ARG_ const FT_Vector* control,
1264 const FT_Vector* to )
1265 {
1266 FT_Vector bez_stack[16 * 2 + 1]; /* enough to accommodate bisections */
1267 FT_Vector* arc = bez_stack;
1268 TPos dx, dy;
1269 int draw;
1270
1271
1272 arc[0].x = UPSCALE( to->x );
1273 arc[0].y = UPSCALE( to->y );
1274 arc[1].x = UPSCALE( control->x );
1275 arc[1].y = UPSCALE( control->y );
1276 arc[2].x = ras.x;
1277 arc[2].y = ras.y;
1278
1279 /* short-cut the arc that crosses the current band */
1280 if ( ( TRUNC( arc[0].y ) >= ras.max_ey &&
1281 TRUNC( arc[1].y ) >= ras.max_ey &&
1282 TRUNC( arc[2].y ) >= ras.max_ey ) ||
1283 ( TRUNC( arc[0].y ) < ras.min_ey &&
1284 TRUNC( arc[1].y ) < ras.min_ey &&
1285 TRUNC( arc[2].y ) < ras.min_ey ) )
1286 {
1287 ras.x = arc[0].x;
1288 ras.y = arc[0].y;
1289 return;
1290 }
1291
1292 dx = FT_ABS( arc[2].x + arc[0].x - 2 * arc[1].x );
1293 dy = FT_ABS( arc[2].y + arc[0].y - 2 * arc[1].y );
1294 if ( dx < dy )
1295 dx = dy;
1296
1297 /* We can calculate the number of necessary bisections because */
1298 /* each bisection predictably reduces deviation exactly 4-fold. */
1299 /* Even 32-bit deviation would vanish after 16 bisections. */
1300 draw = 1;
1301 while ( dx > ONE_PIXEL / 4 )
1302 {
1303 dx >>= 2;
1304 draw <<= 1;
1305 }
1306
1307 /* We use decrement counter to count the total number of segments */
1308 /* to draw starting from 2^level. Before each draw we split as */
1309 /* many times as there are trailing zeros in the counter. */
1310 do
1311 {
1312 int split = draw & ( -draw ); /* isolate the rightmost 1-bit */
1313
1314
1315 while ( ( split >>= 1 ) )
1316 {
1317 gray_split_conic( arc );
1318 arc += 2;
1319 }
1320
1321 gray_render_line( RAS_VAR_ arc[0].x, arc[0].y );
1322 arc -= 2;
1323
1324 } while ( --draw );
1325 }
1326
1327#endif /* !BEZIER_USE_DDA */
1328
1329
1330 /*
1331 * For cubic Bézier, binary splits are still faster than DDA
1332 * because the splits are adaptive to how quickly each sub-arc
1333 * approaches their chord trisection points.
1334 *
1335 * It might be useful to experiment with SSE2 to speed up
1336 * `gray_split_cubic`, though.
1337 */
1338 static void
1339 gray_split_cubic( FT_Vector* base )
1340 {
1341 TPos a, b, c;
1342
1343
1344 base[6].x = base[3].x;
1345 a = base[0].x + base[1].x;
1346 b = base[1].x + base[2].x;
1347 c = base[2].x + base[3].x;
1348 base[5].x = c >> 1;
1349 c += b;
1350 base[4].x = c >> 2;
1351 base[1].x = a >> 1;
1352 a += b;
1353 base[2].x = a >> 2;
1354 base[3].x = ( a + c ) >> 3;
1355
1356 base[6].y = base[3].y;
1357 a = base[0].y + base[1].y;
1358 b = base[1].y + base[2].y;
1359 c = base[2].y + base[3].y;
1360 base[5].y = c >> 1;
1361 c += b;
1362 base[4].y = c >> 2;
1363 base[1].y = a >> 1;
1364 a += b;
1365 base[2].y = a >> 2;
1366 base[3].y = ( a + c ) >> 3;
1367 }
1368
1369
1370 static void
1371 gray_render_cubic( RAS_ARG_ const FT_Vector* control1,
1372 const FT_Vector* control2,
1373 const FT_Vector* to )
1374 {
1375 FT_Vector bez_stack[16 * 3 + 1]; /* enough to accommodate bisections */
1376 FT_Vector* arc = bez_stack;
1377
1378
1379 arc[0].x = UPSCALE( to->x );
1380 arc[0].y = UPSCALE( to->y );
1381 arc[1].x = UPSCALE( control2->x );
1382 arc[1].y = UPSCALE( control2->y );
1383 arc[2].x = UPSCALE( control1->x );
1384 arc[2].y = UPSCALE( control1->y );
1385 arc[3].x = ras.x;
1386 arc[3].y = ras.y;
1387
1388 /* short-cut the arc that crosses the current band */
1389 if ( ( TRUNC( arc[0].y ) >= ras.max_ey &&
1390 TRUNC( arc[1].y ) >= ras.max_ey &&
1391 TRUNC( arc[2].y ) >= ras.max_ey &&
1392 TRUNC( arc[3].y ) >= ras.max_ey ) ||
1393 ( TRUNC( arc[0].y ) < ras.min_ey &&
1394 TRUNC( arc[1].y ) < ras.min_ey &&
1395 TRUNC( arc[2].y ) < ras.min_ey &&
1396 TRUNC( arc[3].y ) < ras.min_ey ) )
1397 {
1398 ras.x = arc[0].x;
1399 ras.y = arc[0].y;
1400 return;
1401 }
1402
1403 for (;;)
1404 {
1405 /* with each split, control points quickly converge towards */
1406 /* chord trisection points and the vanishing distances below */
1407 /* indicate when the segment is flat enough to draw */
1408 if ( FT_ABS( 2 * arc[0].x - 3 * arc[1].x + arc[3].x ) > ONE_PIXEL / 2 ||
1409 FT_ABS( 2 * arc[0].y - 3 * arc[1].y + arc[3].y ) > ONE_PIXEL / 2 ||
1410 FT_ABS( arc[0].x - 3 * arc[2].x + 2 * arc[3].x ) > ONE_PIXEL / 2 ||
1411 FT_ABS( arc[0].y - 3 * arc[2].y + 2 * arc[3].y ) > ONE_PIXEL / 2 )
1412 goto Split;
1413
1414 gray_render_line( RAS_VAR_ arc[0].x, arc[0].y );
1415
1416 if ( arc == bez_stack )
1417 return;
1418
1419 arc -= 3;
1420 continue;
1421
1422 Split:
1423 gray_split_cubic( arc );
1424 arc += 3;
1425 }
1426 }
1427
1428
1429 static int
1430 gray_move_to( const FT_Vector* to,
1431 void* worker_ ) /* gray_PWorker */
1432 {
1433 gray_PWorker worker = (gray_PWorker)worker_;
1434
1435 TPos x, y;
1436
1437
1438 /* start to a new position */
1439 x = UPSCALE( to->x );
1440 y = UPSCALE( to->y );
1441
1442 gray_set_cell( RAS_VAR_ TRUNC( x ), TRUNC( y ) );
1443
1444 ras.x = x;
1445 ras.y = y;
1446 return 0;
1447 }
1448
1449
1450 static int
1451 gray_line_to( const FT_Vector* to,
1452 void* worker_ ) /* gray_PWorker */
1453 {
1454 gray_PWorker worker = (gray_PWorker)worker_;
1455
1456
1457 gray_render_line( RAS_VAR_ UPSCALE( to->x ), UPSCALE( to->y ) );
1458 return 0;
1459 }
1460
1461
1462 static int
1463 gray_conic_to( const FT_Vector* control,
1464 const FT_Vector* to,
1465 void* worker_ ) /* gray_PWorker */
1466 {
1467 gray_PWorker worker = (gray_PWorker)worker_;
1468
1469
1470 gray_render_conic( RAS_VAR_ control, to );
1471 return 0;
1472 }
1473
1474
1475 static int
1476 gray_cubic_to( const FT_Vector* control1,
1477 const FT_Vector* control2,
1478 const FT_Vector* to,
1479 void* worker_ ) /* gray_PWorker */
1480 {
1481 gray_PWorker worker = (gray_PWorker)worker_;
1482
1483
1484 gray_render_cubic( RAS_VAR_ control1, control2, to );
1485 return 0;
1486 }
1487
1488
1489 static void
1490 gray_sweep( RAS_ARG )
1491 {
1492 int fill = ( ras.outline.flags & FT_OUTLINE_EVEN_ODD_FILL ) ? 0x100
1493 : INT_MIN;
1494 int coverage;
1495 int y;
1496
1497
1498 for ( y = ras.min_ey; y < ras.max_ey; y++ )
1499 {
1500 PCell cell = ras.ycells[y - ras.min_ey];
1501 TCoord x = ras.min_ex;
1502 TArea cover = 0;
1503
1504 unsigned char* line = ras.target.origin - ras.target.pitch * y;
1505
1506
1507 for ( ; cell != ras.cell_null; cell = cell->next )
1508 {
1509 TArea area;
1510
1511
1512 if ( cover != 0 && cell->x > x )
1513 {
1514 FT_FILL_RULE( coverage, cover, fill );
1515 FT_GRAY_SET( line + x, coverage, cell->x - x );
1516 }
1517
1518 cover += (TArea)cell->cover * ( ONE_PIXEL * 2 );
1519 area = cover - cell->area;
1520
1521 if ( area != 0 && cell->x >= ras.min_ex )
1522 {
1523 FT_FILL_RULE( coverage, area, fill );
1524 line[cell->x] = (unsigned char)coverage;
1525 }
1526
1527 x = cell->x + 1;
1528 }
1529
1530 if ( cover != 0 ) /* only if cropped */
1531 {
1532 FT_FILL_RULE( coverage, cover, fill );
1533 FT_GRAY_SET( line + x, coverage, ras.max_ex - x );
1534 }
1535 }
1536 }
1537
1538
1539 static void
1540 gray_sweep_direct( RAS_ARG )
1541 {
1542 int fill = ( ras.outline.flags & FT_OUTLINE_EVEN_ODD_FILL ) ? 0x100
1543 : INT_MIN;
1544 int coverage;
1545 int y;
1546
1547 FT_Span span[FT_MAX_GRAY_SPANS];
1548 int n = 0;
1549
1550
1551 for ( y = ras.min_ey; y < ras.max_ey; y++ )
1552 {
1553 PCell cell = ras.ycells[y - ras.min_ey];
1554 TCoord x = ras.min_ex;
1555 TArea cover = 0;
1556
1557
1558 for ( ; cell != ras.cell_null; cell = cell->next )
1559 {
1560 TArea area;
1561
1562
1563 if ( cover != 0 && cell->x > x )
1564 {
1565 FT_FILL_RULE( coverage, cover, fill );
1566
1567 span[n].coverage = (unsigned char)coverage;
1568 span[n].x = (short)x;
1569 span[n].len = (unsigned short)( cell->x - x );
1570
1571 if ( ++n == FT_MAX_GRAY_SPANS )
1572 {
1573 /* flush the span buffer and reset the count */
1574 ras.render_span( y, n, span, ras.render_span_data );
1575 n = 0;
1576 }
1577 }
1578
1579 cover += (TArea)cell->cover * ( ONE_PIXEL * 2 );
1580 area = cover - cell->area;
1581
1582 if ( area != 0 && cell->x >= ras.min_ex )
1583 {
1584 FT_FILL_RULE( coverage, area, fill );
1585
1586 span[n].coverage = (unsigned char)coverage;
1587 span[n].x = (short)cell->x;
1588 span[n].len = 1;
1589
1590 if ( ++n == FT_MAX_GRAY_SPANS )
1591 {
1592 /* flush the span buffer and reset the count */
1593 ras.render_span( y, n, span, ras.render_span_data );
1594 n = 0;
1595 }
1596 }
1597
1598 x = cell->x + 1;
1599 }
1600
1601 if ( cover != 0 ) /* only if cropped */
1602 {
1603 FT_FILL_RULE( coverage, cover, fill );
1604
1605 span[n].coverage = (unsigned char)coverage;
1606 span[n].x = (short)x;
1607 span[n].len = (unsigned short)( ras.max_ex - x );
1608
1609 ++n;
1610 }
1611
1612 if ( n )
1613 {
1614 /* flush the span buffer and reset the count */
1615 ras.render_span( y, n, span, ras.render_span_data );
1616 n = 0;
1617 }
1618 }
1619 }
1620
1621
1622#ifdef STANDALONE_
1623
1624 /**************************************************************************
1625 *
1626 * The following functions should only compile in stand-alone mode,
1627 * i.e., when building this component without the rest of FreeType.
1628 *
1629 */
1630
1631 /**************************************************************************
1632 *
1633 * @Function:
1634 * FT_Outline_Decompose
1635 *
1636 * @Description:
1637 * Walk over an outline's structure to decompose it into individual
1638 * segments and Bézier arcs. This function is also able to emit
1639 * `move to' and `close to' operations to indicate the start and end
1640 * of new contours in the outline.
1641 *
1642 * @Input:
1643 * outline ::
1644 * A pointer to the source target.
1645 *
1646 * func_interface ::
1647 * A table of `emitters', i.e., function pointers
1648 * called during decomposition to indicate path
1649 * operations.
1650 *
1651 * @InOut:
1652 * user ::
1653 * A typeless pointer which is passed to each
1654 * emitter during the decomposition. It can be
1655 * used to store the state during the
1656 * decomposition.
1657 *
1658 * @Return:
1659 * Error code. 0 means success.
1660 */
1661 static int
1662 FT_Outline_Decompose( const FT_Outline* outline,
1663 const FT_Outline_Funcs* func_interface,
1664 void* user )
1665 {
1666#undef SCALED
1667#define SCALED( x ) ( (x) * ( 1L << shift ) - delta )
1668
1669 FT_Vector v_last;
1670 FT_Vector v_control;
1671 FT_Vector v_start;
1672
1673 FT_Vector* point;
1674 FT_Vector* limit;
1675 char* tags;
1676
1677 int error;
1678
1679 int n; /* index of contour in outline */
1680 int first; /* index of first point in contour */
1681 int last; /* index of last point in contour */
1682
1683 char tag; /* current point's state */
1684
1685 int shift;
1686 TPos delta;
1687
1688
1689 if ( !outline )
1690 return FT_THROW( Invalid_Outline );
1691
1692 if ( !func_interface )
1693 return FT_THROW( Invalid_Argument );
1694
1695 shift = func_interface->shift;
1696 delta = func_interface->delta;
1697
1698 last = -1;
1699 for ( n = 0; n < outline->n_contours; n++ )
1700 {
1701 FT_TRACE5(( "FT_Outline_Decompose: Contour %d\n", n ));
1702
1703 first = last + 1;
1704 last = outline->contours[n];
1705 if ( last < first )
1706 goto Invalid_Outline;
1707
1708 limit = outline->points + last;
1709
1710 v_start = outline->points[first];
1711 v_start.x = SCALED( v_start.x );
1712 v_start.y = SCALED( v_start.y );
1713
1714 v_last = outline->points[last];
1715 v_last.x = SCALED( v_last.x );
1716 v_last.y = SCALED( v_last.y );
1717
1718 v_control = v_start;
1719
1720 point = outline->points + first;
1721 tags = outline->tags + first;
1722 tag = FT_CURVE_TAG( tags[0] );
1723
1724 /* A contour cannot start with a cubic control point! */
1725 if ( tag == FT_CURVE_TAG_CUBIC )
1726 goto Invalid_Outline;
1727
1728 /* check first point to determine origin */
1729 if ( tag == FT_CURVE_TAG_CONIC )
1730 {
1731 /* first point is conic control. Yes, this happens. */
1732 if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON )
1733 {
1734 /* start at last point if it is on the curve */
1735 v_start = v_last;
1736 limit--;
1737 }
1738 else
1739 {
1740 /* if both first and last points are conic, */
1741 /* start at their middle and record its position */
1742 /* for closure */
1743 v_start.x = ( v_start.x + v_last.x ) / 2;
1744 v_start.y = ( v_start.y + v_last.y ) / 2;
1745
1746 v_last = v_start;
1747 }
1748 point--;
1749 tags--;
1750 }
1751
1752 FT_TRACE5(( " move to (%.2f, %.2f)\n",
1753 v_start.x / 64.0, v_start.y / 64.0 ));
1754 error = func_interface->move_to( &v_start, user );
1755 if ( error )
1756 goto Exit;
1757
1758 while ( point < limit )
1759 {
1760 point++;
1761 tags++;
1762
1763 tag = FT_CURVE_TAG( tags[0] );
1764 switch ( tag )
1765 {
1766 case FT_CURVE_TAG_ON: /* emit a single line_to */
1767 {
1768 FT_Vector vec;
1769
1770
1771 vec.x = SCALED( point->x );
1772 vec.y = SCALED( point->y );
1773
1774 FT_TRACE5(( " line to (%.2f, %.2f)\n",
1775 vec.x / 64.0, vec.y / 64.0 ));
1776 error = func_interface->line_to( &vec, user );
1777 if ( error )
1778 goto Exit;
1779 continue;
1780 }
1781
1782 case FT_CURVE_TAG_CONIC: /* consume conic arcs */
1783 v_control.x = SCALED( point->x );
1784 v_control.y = SCALED( point->y );
1785
1786 Do_Conic:
1787 if ( point < limit )
1788 {
1789 FT_Vector vec;
1790 FT_Vector v_middle;
1791
1792
1793 point++;
1794 tags++;
1795 tag = FT_CURVE_TAG( tags[0] );
1796
1797 vec.x = SCALED( point->x );
1798 vec.y = SCALED( point->y );
1799
1800 if ( tag == FT_CURVE_TAG_ON )
1801 {
1802 FT_TRACE5(( " conic to (%.2f, %.2f)"
1803 " with control (%.2f, %.2f)\n",
1804 vec.x / 64.0, vec.y / 64.0,
1805 v_control.x / 64.0, v_control.y / 64.0 ));
1806 error = func_interface->conic_to( &v_control, &vec, user );
1807 if ( error )
1808 goto Exit;
1809 continue;
1810 }
1811
1812 if ( tag != FT_CURVE_TAG_CONIC )
1813 goto Invalid_Outline;
1814
1815 v_middle.x = ( v_control.x + vec.x ) / 2;
1816 v_middle.y = ( v_control.y + vec.y ) / 2;
1817
1818 FT_TRACE5(( " conic to (%.2f, %.2f)"
1819 " with control (%.2f, %.2f)\n",
1820 v_middle.x / 64.0, v_middle.y / 64.0,
1821 v_control.x / 64.0, v_control.y / 64.0 ));
1822 error = func_interface->conic_to( &v_control, &v_middle, user );
1823 if ( error )
1824 goto Exit;
1825
1826 v_control = vec;
1827 goto Do_Conic;
1828 }
1829
1830 FT_TRACE5(( " conic to (%.2f, %.2f)"
1831 " with control (%.2f, %.2f)\n",
1832 v_start.x / 64.0, v_start.y / 64.0,
1833 v_control.x / 64.0, v_control.y / 64.0 ));
1834 error = func_interface->conic_to( &v_control, &v_start, user );
1835 goto Close;
1836
1837 default: /* FT_CURVE_TAG_CUBIC */
1838 {
1839 FT_Vector vec1, vec2;
1840
1841
1842 if ( point + 1 > limit ||
1843 FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC )
1844 goto Invalid_Outline;
1845
1846 point += 2;
1847 tags += 2;
1848
1849 vec1.x = SCALED( point[-2].x );
1850 vec1.y = SCALED( point[-2].y );
1851
1852 vec2.x = SCALED( point[-1].x );
1853 vec2.y = SCALED( point[-1].y );
1854
1855 if ( point <= limit )
1856 {
1857 FT_Vector vec;
1858
1859
1860 vec.x = SCALED( point->x );
1861 vec.y = SCALED( point->y );
1862
1863 FT_TRACE5(( " cubic to (%.2f, %.2f)"
1864 " with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
1865 vec.x / 64.0, vec.y / 64.0,
1866 vec1.x / 64.0, vec1.y / 64.0,
1867 vec2.x / 64.0, vec2.y / 64.0 ));
1868 error = func_interface->cubic_to( &vec1, &vec2, &vec, user );
1869 if ( error )
1870 goto Exit;
1871 continue;
1872 }
1873
1874 FT_TRACE5(( " cubic to (%.2f, %.2f)"
1875 " with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
1876 v_start.x / 64.0, v_start.y / 64.0,
1877 vec1.x / 64.0, vec1.y / 64.0,
1878 vec2.x / 64.0, vec2.y / 64.0 ));
1879 error = func_interface->cubic_to( &vec1, &vec2, &v_start, user );
1880 goto Close;
1881 }
1882 }
1883 }
1884
1885 /* close the contour with a line segment */
1886 FT_TRACE5(( " line to (%.2f, %.2f)\n",
1887 v_start.x / 64.0, v_start.y / 64.0 ));
1888 error = func_interface->line_to( &v_start, user );
1889
1890 Close:
1891 if ( error )
1892 goto Exit;
1893 }
1894
1895 FT_TRACE5(( "FT_Outline_Decompose: Done\n", n ));
1896 return Smooth_Err_Ok;
1897
1898 Exit:
1899 FT_TRACE5(( "FT_Outline_Decompose: Error 0x%x\n", error ));
1900 return error;
1901
1902 Invalid_Outline:
1903 return FT_THROW( Invalid_Outline );
1904 }
1905
1906#endif /* STANDALONE_ */
1907
1908
1909 FT_DEFINE_OUTLINE_FUNCS(
1910 func_interface,
1911
1912 (FT_Outline_MoveTo_Func) gray_move_to, /* move_to */
1913 (FT_Outline_LineTo_Func) gray_line_to, /* line_to */
1914 (FT_Outline_ConicTo_Func)gray_conic_to, /* conic_to */
1915 (FT_Outline_CubicTo_Func)gray_cubic_to, /* cubic_to */
1916
1917 0, /* shift */
1918 0 /* delta */
1919 )
1920
1921
1922 static int
1923 gray_convert_glyph_inner( RAS_ARG_
1924 int continued )
1925 {
1926 volatile int error;
1927
1928
1929 if ( ft_setjmp( ras.jump_buffer ) == 0 )
1930 {
1931 if ( continued )
1932 FT_Trace_Disable();
1933 error = FT_Outline_Decompose( &ras.outline, &func_interface, &ras );
1934 if ( continued )
1935 FT_Trace_Enable();
1936
1937 FT_TRACE7(( "band [%d..%d]: %td cell%s remaining/\n",
1938 ras.min_ey,
1939 ras.max_ey,
1940 ras.cell_null - ras.cell_free,
1941 ras.cell_null - ras.cell_free == 1 ? "" : "s" ));
1942 }
1943 else
1944 {
1945 error = FT_THROW( Raster_Overflow );
1946
1947 FT_TRACE7(( "band [%d..%d]: to be bisected\n",
1948 ras.min_ey, ras.max_ey ));
1949 }
1950
1951 return error;
1952 }
1953
1954
1955 static int
1956 gray_convert_glyph( RAS_ARG )
1957 {
1958 const TCoord yMin = ras.min_ey;
1959 const TCoord yMax = ras.max_ey;
1960
1961 TCell buffer[FT_MAX_GRAY_POOL];
1962 size_t height = (size_t)( yMax - yMin );
1963 size_t n = FT_MAX_GRAY_POOL / 8;
1964 TCoord y;
1965 TCoord bands[32]; /* enough to accommodate bisections */
1966 TCoord* band;
1967
1968 int continued = 0;
1969
1970
1971 /* Initialize the null cell at the end of the poll. */
1972 ras.cell_null = buffer + FT_MAX_GRAY_POOL - 1;
1973 ras.cell_null->x = CELL_MAX_X_VALUE;
1974 ras.cell_null->area = 0;
1975 ras.cell_null->cover = 0;
1976 ras.cell_null->next = NULL;
1977
1978 /* set up vertical bands */
1979 ras.ycells = (PCell*)buffer;
1980
1981 if ( height > n )
1982 {
1983 /* two divisions rounded up */
1984 n = ( height + n - 1 ) / n;
1985 height = ( height + n - 1 ) / n;
1986 }
1987
1988 for ( y = yMin; y < yMax; )
1989 {
1990 ras.min_ey = y;
1991 y += height;
1992 ras.max_ey = FT_MIN( y, yMax );
1993
1994 band = bands;
1995 band[1] = ras.min_ey;
1996 band[0] = ras.max_ey;
1997
1998 do
1999 {
2000 TCoord width = band[0] - band[1];
2001 TCoord w;
2002 int error;
2003
2004
2005 for ( w = 0; w < width; ++w )
2006 ras.ycells[w] = ras.cell_null;
2007
2008 /* memory management: skip ycells */
2009 n = ( (size_t)width * sizeof ( PCell ) + sizeof ( TCell ) - 1 ) /
2010 sizeof ( TCell );
2011
2012 ras.cell_free = buffer + n;
2013 ras.cell = ras.cell_null;
2014 ras.min_ey = band[1];
2015 ras.max_ey = band[0];
2016 ras.count_ey = width;
2017
2018 error = gray_convert_glyph_inner( RAS_VAR_ continued );
2019 continued = 1;
2020
2021 if ( !error )
2022 {
2023 if ( ras.render_span ) /* for FT_RASTER_FLAG_DIRECT only */
2024 gray_sweep_direct( RAS_VAR );
2025 else
2026 gray_sweep( RAS_VAR );
2027 band--;
2028 continue;
2029 }
2030 else if ( error != Smooth_Err_Raster_Overflow )
2031 return error;
2032
2033 /* render pool overflow; we will reduce the render band by half */
2034 width >>= 1;
2035
2036 /* this should never happen even with tiny rendering pool */
2037 if ( width == 0 )
2038 {
2039 FT_TRACE7(( "gray_convert_glyph: rotten glyph\n" ));
2040 return FT_THROW( Raster_Overflow );
2041 }
2042
2043 band++;
2044 band[1] = band[0];
2045 band[0] += width;
2046 } while ( band >= bands );
2047 }
2048
2049 return Smooth_Err_Ok;
2050 }
2051
2052
2053 static int
2054 gray_raster_render( FT_Raster raster,
2055 const FT_Raster_Params* params )
2056 {
2057 const FT_Outline* outline = (const FT_Outline*)params->source;
2058 const FT_Bitmap* target_map = params->target;
2059
2060#ifndef FT_STATIC_RASTER
2061 gray_TWorker worker[1];
2062#endif
2063
2064
2065 if ( !raster )
2066 return FT_THROW( Invalid_Argument );
2067
2068 /* this version does not support monochrome rendering */
2069 if ( !( params->flags & FT_RASTER_FLAG_AA ) )
2070 return FT_THROW( Cannot_Render_Glyph );
2071
2072 if ( !outline )
2073 return FT_THROW( Invalid_Outline );
2074
2075 /* return immediately if the outline is empty */
2076 if ( outline->n_points == 0 || outline->n_contours <= 0 )
2077 return Smooth_Err_Ok;
2078
2079 if ( !outline->contours || !outline->points )
2080 return FT_THROW( Invalid_Outline );
2081
2082 if ( outline->n_points !=
2083 outline->contours[outline->n_contours - 1] + 1 )
2084 return FT_THROW( Invalid_Outline );
2085
2086 ras.outline = *outline;
2087
2088 if ( params->flags & FT_RASTER_FLAG_DIRECT )
2089 {
2090 if ( !params->gray_spans )
2091 return Smooth_Err_Ok;
2092
2093 ras.render_span = (FT_Raster_Span_Func)params->gray_spans;
2094 ras.render_span_data = params->user;
2095
2096 ras.min_ex = params->clip_box.xMin;
2097 ras.min_ey = params->clip_box.yMin;
2098 ras.max_ex = params->clip_box.xMax;
2099 ras.max_ey = params->clip_box.yMax;
2100 }
2101 else
2102 {
2103 /* if direct mode is not set, we must have a target bitmap */
2104 if ( !target_map )
2105 return FT_THROW( Invalid_Argument );
2106
2107 /* nothing to do */
2108 if ( !target_map->width || !target_map->rows )
2109 return Smooth_Err_Ok;
2110
2111 if ( !target_map->buffer )
2112 return FT_THROW( Invalid_Argument );
2113
2114 if ( target_map->pitch < 0 )
2115 ras.target.origin = target_map->buffer;
2116 else
2117 ras.target.origin = target_map->buffer
2118 + ( target_map->rows - 1 ) * (unsigned int)target_map->pitch;
2119
2120 ras.target.pitch = target_map->pitch;
2121
2122 ras.render_span = (FT_Raster_Span_Func)NULL;
2123 ras.render_span_data = NULL;
2124
2125 ras.min_ex = 0;
2126 ras.min_ey = 0;
2127 ras.max_ex = (FT_Pos)target_map->width;
2128 ras.max_ey = (FT_Pos)target_map->rows;
2129 }
2130
2131 /* exit if nothing to do */
2132 if ( ras.max_ex <= ras.min_ex || ras.max_ey <= ras.min_ey )
2133 return Smooth_Err_Ok;
2134
2135 return gray_convert_glyph( RAS_VAR );
2136 }
2137
2138
2139 /**** RASTER OBJECT CREATION: In stand-alone mode, we simply use *****/
2140 /**** a static object. *****/
2141
2142#ifdef STANDALONE_
2143
2144 static int
2145 gray_raster_new( void* memory,
2146 FT_Raster* araster )
2147 {
2148 static gray_TRaster the_raster;
2149
2150 FT_UNUSED( memory );
2151
2152
2153 *araster = (FT_Raster)&the_raster;
2154 FT_ZERO( &the_raster );
2155
2156 return 0;
2157 }
2158
2159
2160 static void
2161 gray_raster_done( FT_Raster raster )
2162 {
2163 /* nothing */
2164 FT_UNUSED( raster );
2165 }
2166
2167#else /* !STANDALONE_ */
2168
2169 static int
2170 gray_raster_new( void* memory_,
2171 FT_Raster* araster_ )
2172 {
2173 FT_Memory memory = (FT_Memory)memory_;
2174 gray_PRaster* araster = (gray_PRaster*)araster_;
2175
2176 FT_Error error;
2177 gray_PRaster raster = NULL;
2178
2179
2180 if ( !FT_NEW( raster ) )
2181 raster->memory = memory;
2182
2183 *araster = raster;
2184
2185 return error;
2186 }
2187
2188
2189 static void
2190 gray_raster_done( FT_Raster raster )
2191 {
2192 FT_Memory memory = (FT_Memory)((gray_PRaster)raster)->memory;
2193
2194
2195 FT_FREE( raster );
2196 }
2197
2198#endif /* !STANDALONE_ */
2199
2200
2201 static void
2202 gray_raster_reset( FT_Raster raster,
2203 unsigned char* pool_base,
2204 unsigned long pool_size )
2205 {
2206 FT_UNUSED( raster );
2207 FT_UNUSED( pool_base );
2208 FT_UNUSED( pool_size );
2209 }
2210
2211
2212 static int
2213 gray_raster_set_mode( FT_Raster raster,
2214 unsigned long mode,
2215 void* args )
2216 {
2217 FT_UNUSED( raster );
2218 FT_UNUSED( mode );
2219 FT_UNUSED( args );
2220
2221
2222 return 0; /* nothing to do */
2223 }
2224
2225
2226 FT_DEFINE_RASTER_FUNCS(
2227 ft_grays_raster,
2228
2229 FT_GLYPH_FORMAT_OUTLINE,
2230
2231 (FT_Raster_New_Func) gray_raster_new, /* raster_new */
2232 (FT_Raster_Reset_Func) gray_raster_reset, /* raster_reset */
2233 (FT_Raster_Set_Mode_Func)gray_raster_set_mode, /* raster_set_mode */
2234 (FT_Raster_Render_Func) gray_raster_render, /* raster_render */
2235 (FT_Raster_Done_Func) gray_raster_done /* raster_done */
2236 )
2237
2238
2239/* END */
2240
2241
2242/* Local Variables: */
2243/* coding: utf-8 */
2244/* End: */
2245