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1 /***************************************************************************/
2 /*                                                                         */
3 /*  ftgrays.c                                                              */
4 /*                                                                         */
5 /*    A new `perfect' anti-aliasing renderer (body).                       */
6 /*                                                                         */
7 /*  Copyright 2000-2015 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 -D_STANDALONE_ 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.                           */
49   /*                                                                       */
50   /* It is based on ideas that I initially found in Raph Levien's          */
51   /* excellent LibArt graphics library (see http://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   /* This renderer has the following advantages:                           */
62   /*                                                                       */
63   /* - It doesn't need an intermediate bitmap.  Instead, one can supply a  */
64   /*   callback function that will be called by the renderer to draw gray  */
65   /*   spans on any target surface.  You can thus do direct composition on */
66   /*   any kind of bitmap, provided that you give the renderer the right   */
67   /*   callback.                                                           */
68   /*                                                                       */
69   /* - A perfect anti-aliaser, i.e., it computes the _exact_ coverage on   */
70   /*   each pixel cell.                                                    */
71   /*                                                                       */
72   /* - It performs a single pass on the outline (the `standard' FT2        */
73   /*   renderer makes two passes).                                         */
74   /*                                                                       */
75   /* - It can easily be modified to render to _any_ number of gray levels  */
76   /*   cheaply.                                                            */
77   /*                                                                       */
78   /* - For small (< 20) pixel sizes, it is faster than the standard        */
79   /*   renderer.                                                           */
80   /*                                                                       */
81   /*************************************************************************/
82 
83 
84   /*************************************************************************/
85   /*                                                                       */
86   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
87   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
88   /* messages during execution.                                            */
89   /*                                                                       */
90 #undef  FT_COMPONENT
91 #define FT_COMPONENT  trace_smooth
92 
93 
94 #ifdef _STANDALONE_
95 
96 
97   /* The size in bytes of the render pool used by the scan-line converter  */
98   /* to do all of its work.                                                */
99 #define FT_RENDER_POOL_SIZE  16384L
100 
101 
102   /* Auxiliary macros for token concatenation. */
103 #define FT_ERR_XCAT( x, y )  x ## y
104 #define FT_ERR_CAT( x, y )   FT_ERR_XCAT( x, y )
105 
106 #define FT_BEGIN_STMNT  do {
107 #define FT_END_STMNT    } while ( 0 )
108 
109 #define FT_MAX( a, b )  ( (a) > (b) ? (a) : (b) )
110 #define FT_ABS( a )     ( (a) < 0 ? -(a) : (a) )
111 
112 
113   /*
114    *  Approximate sqrt(x*x+y*y) using the `alpha max plus beta min'
115    *  algorithm.  We use alpha = 1, beta = 3/8, giving us results with a
116    *  largest error less than 7% compared to the exact value.
117    */
118 #define FT_HYPOT( x, y )                 \
119           ( x = FT_ABS( x ),             \
120             y = FT_ABS( y ),             \
121             x > y ? x + ( 3 * y >> 3 )   \
122                   : y + ( 3 * x >> 3 ) )
123 
124 
125   /* define this to dump debugging information */
126 /* #define FT_DEBUG_LEVEL_TRACE */
127 
128 
129 #ifdef FT_DEBUG_LEVEL_TRACE
130 #include <stdio.h>
131 #include <stdarg.h>
132 #endif
133 
134 #include <stddef.h>
135 #include <string.h>
136 #include <setjmp.h>
137 #include <limits.h>
138 #define FT_CHAR_BIT   CHAR_BIT
139 #define FT_UINT_MAX   UINT_MAX
140 #define FT_INT_MAX    INT_MAX
141 #define FT_ULONG_MAX  ULONG_MAX
142 
143 #define ft_memset   memset
144 
145 #define ft_setjmp   setjmp
146 #define ft_longjmp  longjmp
147 #define ft_jmp_buf  jmp_buf
148 
149 typedef ptrdiff_t  FT_PtrDist;
150 
151 
152 #define ErrRaster_Invalid_Mode      -2
153 #define ErrRaster_Invalid_Outline   -1
154 #define ErrRaster_Invalid_Argument  -3
155 #define ErrRaster_Memory_Overflow   -4
156 
157 #define FT_BEGIN_HEADER
158 #define FT_END_HEADER
159 
160 #include "ftimage.h"
161 #include "ftgrays.h"
162 
163 
164   /* This macro is used to indicate that a function parameter is unused. */
165   /* Its purpose is simply to reduce compiler warnings.  Note also that  */
166   /* simply defining it as `(void)x' doesn't avoid warnings with certain */
167   /* ANSI compilers (e.g. LCC).                                          */
168 #define FT_UNUSED( x )  (x) = (x)
169 
170 
171   /* we only use level 5 & 7 tracing messages; cf. ftdebug.h */
172 
173 #ifdef FT_DEBUG_LEVEL_TRACE
174 
175   void
FT_Message(const char * fmt,...)176   FT_Message( const char*  fmt,
177               ... )
178   {
179     va_list  ap;
180 
181 
182     va_start( ap, fmt );
183     vfprintf( stderr, fmt, ap );
184     va_end( ap );
185   }
186 
187 
188   /* empty function useful for setting a breakpoint to catch errors */
189   int
FT_Throw(int error,int line,const char * file)190   FT_Throw( int          error,
191             int          line,
192             const char*  file )
193   {
194     FT_UNUSED( error );
195     FT_UNUSED( line );
196     FT_UNUSED( file );
197 
198     return 0;
199   }
200 
201 
202   /* we don't handle tracing levels in stand-alone mode; */
203 #ifndef FT_TRACE5
204 #define FT_TRACE5( varformat )  FT_Message varformat
205 #endif
206 #ifndef FT_TRACE7
207 #define FT_TRACE7( varformat )  FT_Message varformat
208 #endif
209 #ifndef FT_ERROR
210 #define FT_ERROR( varformat )   FT_Message varformat
211 #endif
212 
213 #define FT_THROW( e )                               \
214           ( FT_Throw( FT_ERR_CAT( ErrRaster, e ),   \
215                       __LINE__,                     \
216                       __FILE__ )                  | \
217             FT_ERR_CAT( ErrRaster, e )            )
218 
219 #else /* !FT_DEBUG_LEVEL_TRACE */
220 
221 #define FT_TRACE5( x )  do { } while ( 0 )     /* nothing */
222 #define FT_TRACE7( x )  do { } while ( 0 )     /* nothing */
223 #define FT_ERROR( x )   do { } while ( 0 )     /* nothing */
224 #define FT_THROW( e )   FT_ERR_CAT( ErrRaster_, e )
225 
226 
227 #endif /* !FT_DEBUG_LEVEL_TRACE */
228 
229 
230 #define FT_DEFINE_OUTLINE_FUNCS( class_,               \
231                                  move_to_, line_to_,   \
232                                  conic_to_, cubic_to_, \
233                                  shift_, delta_ )      \
234           static const FT_Outline_Funcs class_ =       \
235           {                                            \
236             move_to_,                                  \
237             line_to_,                                  \
238             conic_to_,                                 \
239             cubic_to_,                                 \
240             shift_,                                    \
241             delta_                                     \
242          };
243 
244 #define FT_DEFINE_RASTER_FUNCS( class_, glyph_format_,            \
245                                 raster_new_, raster_reset_,       \
246                                 raster_set_mode_, raster_render_, \
247                                 raster_done_ )                    \
248           const FT_Raster_Funcs class_ =                          \
249           {                                                       \
250             glyph_format_,                                        \
251             raster_new_,                                          \
252             raster_reset_,                                        \
253             raster_set_mode_,                                     \
254             raster_render_,                                       \
255             raster_done_                                          \
256          };
257 
258 
259 #else /* !_STANDALONE_ */
260 
261 
262 #include <ft2build.h>
263 #include "ftgrays.h"
264 #include FT_INTERNAL_OBJECTS_H
265 #include FT_INTERNAL_DEBUG_H
266 #include FT_OUTLINE_H
267 
268 #include "ftsmerrs.h"
269 
270 #include "ftspic.h"
271 
272 #define Smooth_Err_Invalid_Mode     Smooth_Err_Cannot_Render_Glyph
273 #define Smooth_Err_Memory_Overflow  Smooth_Err_Out_Of_Memory
274 #define ErrRaster_Memory_Overflow   Smooth_Err_Out_Of_Memory
275 
276 
277 #endif /* !_STANDALONE_ */
278 
279 
280 #ifndef FT_MEM_SET
281 #define FT_MEM_SET( d, s, c )  ft_memset( d, s, c )
282 #endif
283 
284 #ifndef FT_MEM_ZERO
285 #define FT_MEM_ZERO( dest, count )  FT_MEM_SET( dest, 0, count )
286 #endif
287 
288   /* as usual, for the speed hungry :-) */
289 
290 #undef RAS_ARG
291 #undef RAS_ARG_
292 #undef RAS_VAR
293 #undef RAS_VAR_
294 
295 #ifndef FT_STATIC_RASTER
296 
297 #define RAS_ARG   gray_PWorker  worker
298 #define RAS_ARG_  gray_PWorker  worker,
299 
300 #define RAS_VAR   worker
301 #define RAS_VAR_  worker,
302 
303 #else /* FT_STATIC_RASTER */
304 
305 #define RAS_ARG   /* empty */
306 #define RAS_ARG_  /* empty */
307 #define RAS_VAR   /* empty */
308 #define RAS_VAR_  /* empty */
309 
310 #endif /* FT_STATIC_RASTER */
311 
312 
313   /* must be at least 6 bits! */
314 #define PIXEL_BITS  8
315 
316 #undef FLOOR
317 #undef CEILING
318 #undef TRUNC
319 #undef SCALED
320 
321 #define ONE_PIXEL       ( 1L << PIXEL_BITS )
322 #define TRUNC( x )      ( (TCoord)( (x) >> PIXEL_BITS ) )
323 #define SUBPIXELS( x )  ( (TPos)(x) << PIXEL_BITS )
324 #define FLOOR( x )      ( (x) & -ONE_PIXEL )
325 #define CEILING( x )    ( ( (x) + ONE_PIXEL - 1 ) & -ONE_PIXEL )
326 #define ROUND( x )      ( ( (x) + ONE_PIXEL / 2 ) & -ONE_PIXEL )
327 
328 #if PIXEL_BITS >= 6
329 #define UPSCALE( x )    ( (x) << ( PIXEL_BITS - 6 ) )
330 #define DOWNSCALE( x )  ( (x) >> ( PIXEL_BITS - 6 ) )
331 #else
332 #define UPSCALE( x )    ( (x) >> ( 6 - PIXEL_BITS ) )
333 #define DOWNSCALE( x )  ( (x) << ( 6 - PIXEL_BITS ) )
334 #endif
335 
336 
337   /* Compute `dividend / divisor' and return both its quotient and     */
338   /* remainder, cast to a specific type.  This macro also ensures that */
339   /* the remainder is always positive.                                 */
340 #define FT_DIV_MOD( type, dividend, divisor, quotient, remainder ) \
341   FT_BEGIN_STMNT                                                   \
342     (quotient)  = (type)( (dividend) / (divisor) );                \
343     (remainder) = (type)( (dividend) % (divisor) );                \
344     if ( (remainder) < 0 )                                         \
345     {                                                              \
346       (quotient)--;                                                \
347       (remainder) += (type)(divisor);                              \
348     }                                                              \
349   FT_END_STMNT
350 
351 #ifdef  __arm__
352   /* Work around a bug specific to GCC which make the compiler fail to */
353   /* optimize a division and modulo operation on the same parameters   */
354   /* into a single call to `__aeabi_idivmod'.  See                     */
355   /*                                                                   */
356   /*  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43721                */
357 #undef FT_DIV_MOD
358 #define FT_DIV_MOD( type, dividend, divisor, quotient, remainder ) \
359   FT_BEGIN_STMNT                                                   \
360     (quotient)  = (type)( (dividend) / (divisor) );                \
361     (remainder) = (type)( (dividend) - (quotient) * (divisor) );   \
362     if ( (remainder) < 0 )                                         \
363     {                                                              \
364       (quotient)--;                                                \
365       (remainder) += (type)(divisor);                              \
366     }                                                              \
367   FT_END_STMNT
368 #endif /* __arm__ */
369 
370 
371   /* These macros speed up repetitive divisions by replacing them */
372   /* with multiplications and right shifts.                       */
373 #define FT_UDIVPREP( b )                                       \
374   long  b ## _r = (long)( FT_ULONG_MAX >> PIXEL_BITS ) / ( b )
375 #define FT_UDIV( a, b )                                        \
376   ( ( (unsigned long)( a ) * (unsigned long)( b ## _r ) ) >>   \
377     ( sizeof( long ) * FT_CHAR_BIT - PIXEL_BITS ) )
378 
379 
380   /*************************************************************************/
381   /*                                                                       */
382   /*   TYPE DEFINITIONS                                                    */
383   /*                                                                       */
384 
385   /* don't change the following types to FT_Int or FT_Pos, since we might */
386   /* need to define them to "float" or "double" when experimenting with   */
387   /* new algorithms                                                       */
388 
389   typedef long  TCoord;   /* integer scanline/pixel coordinate */
390   typedef long  TPos;     /* sub-pixel coordinate              */
391 
392   /* determine the type used to store cell areas.  This normally takes at */
393   /* least PIXEL_BITS*2 + 1 bits.  On 16-bit systems, we need to use      */
394   /* `long' instead of `int', otherwise bad things happen                 */
395 
396 #if PIXEL_BITS <= 7
397 
398   typedef int  TArea;
399 
400 #else /* PIXEL_BITS >= 8 */
401 
402   /* approximately determine the size of integers using an ANSI-C header */
403 #if FT_UINT_MAX == 0xFFFFU
404   typedef long  TArea;
405 #else
406   typedef int   TArea;
407 #endif
408 
409 #endif /* PIXEL_BITS >= 8 */
410 
411 
412   /* maximum number of gray spans in a call to the span callback */
413 #define FT_MAX_GRAY_SPANS  32
414 
415 
416   typedef struct TCell_*  PCell;
417 
418   typedef struct  TCell_
419   {
420     TPos    x;     /* same with gray_TWorker.ex    */
421     TCoord  cover; /* same with gray_TWorker.cover */
422     TArea   area;
423     PCell   next;
424 
425   } TCell;
426 
427 
428 #if defined( _MSC_VER )      /* Visual C++ (and Intel C++) */
429   /* We disable the warning `structure was padded due to   */
430   /* __declspec(align())' in order to compile cleanly with */
431   /* the maximum level of warnings.                        */
432 #pragma warning( push )
433 #pragma warning( disable : 4324 )
434 #endif /* _MSC_VER */
435 
436   typedef struct  gray_TWorker_
437   {
438     ft_jmp_buf  jump_buffer;
439 
440     TCoord  ex, ey;
441     TPos    min_ex, max_ex;
442     TPos    min_ey, max_ey;
443     TPos    count_ex, count_ey;
444 
445     TArea   area;
446     TCoord  cover;
447     int     invalid;
448 
449     PCell       cells;
450     FT_PtrDist  max_cells;
451     FT_PtrDist  num_cells;
452 
453     TPos    x,  y;
454 
455     FT_Vector   bez_stack[32 * 3 + 1];
456     int         lev_stack[32];
457 
458     FT_Outline  outline;
459     FT_Bitmap   target;
460     FT_BBox     clip_box;
461 
462     FT_Span     gray_spans[FT_MAX_GRAY_SPANS];
463     int         num_gray_spans;
464 
465     FT_Raster_Span_Func  render_span;
466     void*                render_span_data;
467     int                  span_y;
468 
469     int  band_size;
470     int  band_shoot;
471 
472     void*       buffer;
473     long        buffer_size;
474 
475     PCell*     ycells;
476     TPos       ycount;
477 
478   } gray_TWorker, *gray_PWorker;
479 
480 #if defined( _MSC_VER )
481 #pragma warning( pop )
482 #endif
483 
484 
485 #ifndef FT_STATIC_RASTER
486 #define ras  (*worker)
487 #else
488   static gray_TWorker  ras;
489 #endif
490 
491 
492   typedef struct gray_TRaster_
493   {
494     void*         memory;
495 
496   } gray_TRaster, *gray_PRaster;
497 
498 
499 
500   /*************************************************************************/
501   /*                                                                       */
502   /* Initialize the cells table.                                           */
503   /*                                                                       */
504   static void
gray_init_cells(RAS_ARG_ void * buffer,long byte_size)505   gray_init_cells( RAS_ARG_ void*  buffer,
506                             long   byte_size )
507   {
508     ras.buffer      = buffer;
509     ras.buffer_size = byte_size;
510 
511     ras.ycells      = (PCell*) buffer;
512     ras.cells       = NULL;
513     ras.max_cells   = 0;
514     ras.num_cells   = 0;
515     ras.area        = 0;
516     ras.cover       = 0;
517     ras.invalid     = 1;
518   }
519 
520 
521   /*************************************************************************/
522   /*                                                                       */
523   /* Compute the outline bounding box.                                     */
524   /*                                                                       */
525   static void
gray_compute_cbox(RAS_ARG)526   gray_compute_cbox( RAS_ARG )
527   {
528     FT_Outline*  outline = &ras.outline;
529     FT_Vector*   vec     = outline->points;
530     FT_Vector*   limit   = vec + outline->n_points;
531 
532 
533     if ( outline->n_points <= 0 )
534     {
535       ras.min_ex = ras.max_ex = 0;
536       ras.min_ey = ras.max_ey = 0;
537       return;
538     }
539 
540     ras.min_ex = ras.max_ex = vec->x;
541     ras.min_ey = ras.max_ey = vec->y;
542 
543     vec++;
544 
545     for ( ; vec < limit; vec++ )
546     {
547       TPos  x = vec->x;
548       TPos  y = vec->y;
549 
550 
551       if ( x < ras.min_ex ) ras.min_ex = x;
552       if ( x > ras.max_ex ) ras.max_ex = x;
553       if ( y < ras.min_ey ) ras.min_ey = y;
554       if ( y > ras.max_ey ) ras.max_ey = y;
555     }
556 
557     /* truncate the bounding box to integer pixels */
558     ras.min_ex = ras.min_ex >> 6;
559     ras.min_ey = ras.min_ey >> 6;
560     ras.max_ex = ( ras.max_ex + 63 ) >> 6;
561     ras.max_ey = ( ras.max_ey + 63 ) >> 6;
562   }
563 
564 
565   /*************************************************************************/
566   /*                                                                       */
567   /* Record the current cell in the table.                                 */
568   /*                                                                       */
569   static PCell
gray_find_cell(RAS_ARG)570   gray_find_cell( RAS_ARG )
571   {
572     PCell  *pcell, cell;
573     TPos    x = ras.ex;
574 
575 
576     if ( x > ras.count_ex )
577       x = ras.count_ex;
578 
579     pcell = &ras.ycells[ras.ey];
580     for (;;)
581     {
582       cell = *pcell;
583       if ( cell == NULL || cell->x > x )
584         break;
585 
586       if ( cell->x == x )
587         goto Exit;
588 
589       pcell = &cell->next;
590     }
591 
592     if ( ras.num_cells >= ras.max_cells )
593       ft_longjmp( ras.jump_buffer, 1 );
594 
595     cell        = ras.cells + ras.num_cells++;
596     cell->x     = x;
597     cell->area  = 0;
598     cell->cover = 0;
599 
600     cell->next  = *pcell;
601     *pcell      = cell;
602 
603   Exit:
604     return cell;
605   }
606 
607 
608   static void
gray_record_cell(RAS_ARG)609   gray_record_cell( RAS_ARG )
610   {
611     if ( ras.area | ras.cover )
612     {
613       PCell  cell = gray_find_cell( RAS_VAR );
614 
615 
616       cell->area  += ras.area;
617       cell->cover += ras.cover;
618     }
619   }
620 
621 
622   /*************************************************************************/
623   /*                                                                       */
624   /* Set the current cell to a new position.                               */
625   /*                                                                       */
626   static void
gray_set_cell(RAS_ARG_ TCoord ex,TCoord ey)627   gray_set_cell( RAS_ARG_ TCoord  ex,
628                           TCoord  ey )
629   {
630     /* Move the cell pointer to a new position.  We set the `invalid'      */
631     /* flag to indicate that the cell isn't part of those we're interested */
632     /* in during the render phase.  This means that:                       */
633     /*                                                                     */
634     /* . the new vertical position must be within min_ey..max_ey-1.        */
635     /* . the new horizontal position must be strictly less than max_ex     */
636     /*                                                                     */
637     /* Note that if a cell is to the left of the clipping region, it is    */
638     /* actually set to the (min_ex-1) horizontal position.                 */
639 
640     /* All cells that are on the left of the clipping region go to the */
641     /* min_ex - 1 horizontal position.                                 */
642     ey -= ras.min_ey;
643 
644     if ( ex > ras.max_ex )
645       ex = ras.max_ex;
646 
647     ex -= ras.min_ex;
648     if ( ex < 0 )
649       ex = -1;
650 
651     /* are we moving to a different cell ? */
652     if ( ex != ras.ex || ey != ras.ey )
653     {
654       /* record the current one if it is valid */
655       if ( !ras.invalid )
656         gray_record_cell( RAS_VAR );
657 
658       ras.area  = 0;
659       ras.cover = 0;
660       ras.ex    = ex;
661       ras.ey    = ey;
662     }
663 
664     ras.invalid = ( (unsigned int)ey >= (unsigned int)ras.count_ey ||
665                                   ex >= ras.count_ex               );
666   }
667 
668 
669   /*************************************************************************/
670   /*                                                                       */
671   /* Start a new contour at a given cell.                                  */
672   /*                                                                       */
673   static void
gray_start_cell(RAS_ARG_ TCoord ex,TCoord ey)674   gray_start_cell( RAS_ARG_ TCoord  ex,
675                             TCoord  ey )
676   {
677     if ( ex > ras.max_ex )
678       ex = (TCoord)( ras.max_ex );
679 
680     if ( ex < ras.min_ex )
681       ex = (TCoord)( ras.min_ex - 1 );
682 
683     ras.area    = 0;
684     ras.cover   = 0;
685     ras.ex      = ex - ras.min_ex;
686     ras.ey      = ey - ras.min_ey;
687     ras.invalid = 0;
688 
689     gray_set_cell( RAS_VAR_ ex, ey );
690   }
691 
692 #if 0
693 
694   /*************************************************************************/
695   /*                                                                       */
696   /* Render a scanline as one or more cells.                               */
697   /*                                                                       */
698   static void
699   gray_render_scanline( RAS_ARG_ TCoord  ey,
700                                  TPos    x1,
701                                  TCoord  y1,
702                                  TPos    x2,
703                                  TCoord  y2 )
704   {
705     TCoord  ex1, ex2, fx1, fx2, delta, mod;
706     long    p, first, dx;
707     int     incr;
708 
709 
710     dx = x2 - x1;
711 
712     ex1 = TRUNC( x1 );
713     ex2 = TRUNC( x2 );
714     fx1 = (TCoord)( x1 - SUBPIXELS( ex1 ) );
715     fx2 = (TCoord)( x2 - SUBPIXELS( ex2 ) );
716 
717     /* trivial case.  Happens often */
718     if ( y1 == y2 )
719     {
720       gray_set_cell( RAS_VAR_ ex2, ey );
721       return;
722     }
723 
724     /* everything is located in a single cell.  That is easy! */
725     /*                                                        */
726     if ( ex1 == ex2 )
727     {
728       delta      = y2 - y1;
729       ras.area  += (TArea)(( fx1 + fx2 ) * delta);
730       ras.cover += delta;
731       return;
732     }
733 
734     /* ok, we'll have to render a run of adjacent cells on the same */
735     /* scanline...                                                  */
736     /*                                                              */
737     p     = ( ONE_PIXEL - fx1 ) * ( y2 - y1 );
738     first = ONE_PIXEL;
739     incr  = 1;
740 
741     if ( dx < 0 )
742     {
743       p     = fx1 * ( y2 - y1 );
744       first = 0;
745       incr  = -1;
746       dx    = -dx;
747     }
748 
749     FT_DIV_MOD( TCoord, p, dx, delta, mod );
750 
751     ras.area  += (TArea)(( fx1 + first ) * delta);
752     ras.cover += delta;
753 
754     ex1 += incr;
755     gray_set_cell( RAS_VAR_ ex1, ey );
756     y1  += delta;
757 
758     if ( ex1 != ex2 )
759     {
760       TCoord  lift, rem;
761 
762 
763       p = ONE_PIXEL * ( y2 - y1 + delta );
764       FT_DIV_MOD( TCoord, p, dx, lift, rem );
765 
766       mod -= (int)dx;
767 
768       do
769       {
770         delta = lift;
771         mod  += rem;
772         if ( mod >= 0 )
773         {
774           mod -= (TCoord)dx;
775           delta++;
776         }
777 
778         ras.area  += (TArea)(ONE_PIXEL * delta);
779         ras.cover += delta;
780         y1        += delta;
781         ex1       += incr;
782         gray_set_cell( RAS_VAR_ ex1, ey );
783       } while ( ex1 != ex2 );
784     }
785 
786     delta      = y2 - y1;
787     ras.area  += (TArea)(( fx2 + ONE_PIXEL - first ) * delta);
788     ras.cover += delta;
789   }
790 
791 
792   /*************************************************************************/
793   /*                                                                       */
794   /* Render a given line as a series of scanlines.                         */
795   /*                                                                       */
796   static void
797   gray_render_line( RAS_ARG_ TPos  to_x,
798                              TPos  to_y )
799   {
800     TCoord  ey1, ey2, fy1, fy2, mod;
801     TPos    dx, dy, x, x2;
802     long    p, first;
803     int     delta, rem, lift, incr;
804 
805 
806     ey1 = TRUNC( ras.y );
807     ey2 = TRUNC( to_y );     /* if (ey2 >= ras.max_ey) ey2 = ras.max_ey-1; */
808     fy1 = (TCoord)( ras.y - SUBPIXELS( ey1 ) );
809     fy2 = (TCoord)( to_y - SUBPIXELS( ey2 ) );
810 
811     dx = to_x - ras.x;
812     dy = to_y - ras.y;
813 
814     /* perform vertical clipping */
815     if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) ||
816          ( ey1 <  ras.min_ey && ey2 <  ras.min_ey ) )
817       goto End;
818 
819     /* everything is on a single scanline */
820     if ( ey1 == ey2 )
821     {
822       gray_render_scanline( RAS_VAR_ ey1, ras.x, fy1, to_x, fy2 );
823       goto End;
824     }
825 
826     /* vertical line - avoid calling gray_render_scanline */
827     incr = 1;
828 
829     if ( dx == 0 )
830     {
831       TCoord  ex     = TRUNC( ras.x );
832       TCoord  two_fx = (TCoord)( ( ras.x - SUBPIXELS( ex ) ) << 1 );
833       TArea   area;
834 
835 
836       first = ONE_PIXEL;
837       if ( dy < 0 )
838       {
839         first = 0;
840         incr  = -1;
841       }
842 
843       delta      = (int)( first - fy1 );
844       ras.area  += (TArea)two_fx * delta;
845       ras.cover += delta;
846       ey1       += incr;
847 
848       gray_set_cell( RAS_VAR_ ex, ey1 );
849 
850       delta = (int)( first + first - ONE_PIXEL );
851       area  = (TArea)two_fx * delta;
852       while ( ey1 != ey2 )
853       {
854         ras.area  += area;
855         ras.cover += delta;
856         ey1       += incr;
857 
858         gray_set_cell( RAS_VAR_ ex, ey1 );
859       }
860 
861       delta      = (int)( fy2 - ONE_PIXEL + first );
862       ras.area  += (TArea)two_fx * delta;
863       ras.cover += delta;
864 
865       goto End;
866     }
867 
868     /* ok, we have to render several scanlines */
869     p     = ( ONE_PIXEL - fy1 ) * dx;
870     first = ONE_PIXEL;
871     incr  = 1;
872 
873     if ( dy < 0 )
874     {
875       p     = fy1 * dx;
876       first = 0;
877       incr  = -1;
878       dy    = -dy;
879     }
880 
881     FT_DIV_MOD( int, p, dy, delta, mod );
882 
883     x = ras.x + delta;
884     gray_render_scanline( RAS_VAR_ ey1, ras.x, fy1, x, (TCoord)first );
885 
886     ey1 += incr;
887     gray_set_cell( RAS_VAR_ TRUNC( x ), ey1 );
888 
889     if ( ey1 != ey2 )
890     {
891       p     = ONE_PIXEL * dx;
892       FT_DIV_MOD( int, p, dy, lift, rem );
893       mod -= (int)dy;
894 
895       do
896       {
897         delta = lift;
898         mod  += rem;
899         if ( mod >= 0 )
900         {
901           mod -= (int)dy;
902           delta++;
903         }
904 
905         x2 = x + delta;
906         gray_render_scanline( RAS_VAR_ ey1, x,
907                                        (TCoord)( ONE_PIXEL - first ), x2,
908                                        (TCoord)first );
909         x = x2;
910 
911         ey1 += incr;
912         gray_set_cell( RAS_VAR_ TRUNC( x ), ey1 );
913       } while ( ey1 != ey2 );
914     }
915 
916     gray_render_scanline( RAS_VAR_ ey1, x,
917                                    (TCoord)( ONE_PIXEL - first ), to_x,
918                                    fy2 );
919 
920   End:
921     ras.x       = to_x;
922     ras.y       = to_y;
923   }
924 
925 #else
926 
927   /*************************************************************************/
928   /*                                                                       */
929   /* Render a straight line across multiple cells in any direction.        */
930   /*                                                                       */
931   static void
gray_render_line(RAS_ARG_ TPos to_x,TPos to_y)932   gray_render_line( RAS_ARG_ TPos  to_x,
933                              TPos  to_y )
934   {
935     TPos    dx, dy, fx1, fy1, fx2, fy2;
936     TCoord  ex1, ex2, ey1, ey2;
937 
938 
939     ex1 = TRUNC( ras.x );
940     ex2 = TRUNC( to_x );
941     ey1 = TRUNC( ras.y );
942     ey2 = TRUNC( to_y );
943 
944     /* perform vertical clipping */
945     if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) ||
946          ( ey1 <  ras.min_ey && ey2 <  ras.min_ey ) )
947       goto End;
948 
949     dx = to_x - ras.x;
950     dy = to_y - ras.y;
951 
952     fx1 = ras.x - SUBPIXELS( ex1 );
953     fy1 = ras.y - SUBPIXELS( ey1 );
954 
955     if ( ex1 == ex2 && ey1 == ey2 )       /* inside one cell */
956       ;
957     else if ( dy == 0 ) /* ex1 != ex2 */  /* any horizontal line */
958     {
959       ex1 = ex2;
960       gray_set_cell( RAS_VAR_ ex1, ey1 );
961     }
962     else if ( dx == 0 )
963     {
964       if ( dy > 0 )                       /* vertical line up */
965         do
966         {
967           fy2 = ONE_PIXEL;
968           ras.cover += ( fy2 - fy1 );
969           ras.area  += ( fy2 - fy1 ) * fx1 * 2;
970           fy1 = 0;
971           ey1++;
972           gray_set_cell( RAS_VAR_ ex1, ey1 );
973         } while ( ey1 != ey2 );
974       else                                /* vertical line down */
975         do
976         {
977           fy2 = 0;
978           ras.cover += ( fy2 - fy1 );
979           ras.area  += ( fy2 - fy1 ) * fx1 * 2;
980           fy1 = ONE_PIXEL;
981           ey1--;
982           gray_set_cell( RAS_VAR_ ex1, ey1 );
983         } while ( ey1 != ey2 );
984     }
985     else                                  /* any other line */
986     {
987       TArea  prod = dx * fy1 - dy * fx1;
988       FT_UDIVPREP( dx );
989       FT_UDIVPREP( dy );
990 
991 
992       /* The fundamental value `prod' determines which side and the  */
993       /* exact coordinate where the line exits current cell.  It is  */
994       /* also easily updated when moving from one cell to the next.  */
995       do
996       {
997         if      ( prod                                   <= 0 &&
998                   prod - dx * ONE_PIXEL                  >  0 ) /* left */
999         {
1000           fx2 = 0;
1001           fy2 = (TPos)FT_UDIV( -prod, -dx );
1002           prod -= dy * ONE_PIXEL;
1003           ras.cover += ( fy2 - fy1 );
1004           ras.area  += ( fy2 - fy1 ) * ( fx1 + fx2 );
1005           fx1 = ONE_PIXEL;
1006           fy1 = fy2;
1007           ex1--;
1008         }
1009         else if ( prod - dx * ONE_PIXEL                  <= 0 &&
1010                   prod - dx * ONE_PIXEL + dy * ONE_PIXEL >  0 ) /* up */
1011         {
1012           prod -= dx * ONE_PIXEL;
1013           fx2 = (TPos)FT_UDIV( -prod, dy );
1014           fy2 = ONE_PIXEL;
1015           ras.cover += ( fy2 - fy1 );
1016           ras.area  += ( fy2 - fy1 ) * ( fx1 + fx2 );
1017           fx1 = fx2;
1018           fy1 = 0;
1019           ey1++;
1020         }
1021         else if ( prod - dx * ONE_PIXEL + dy * ONE_PIXEL <= 0 &&
1022                   prod                  + dy * ONE_PIXEL >= 0 ) /* right */
1023         {
1024           prod += dy * ONE_PIXEL;
1025           fx2 = ONE_PIXEL;
1026           fy2 = (TPos)FT_UDIV( prod, dx );
1027           ras.cover += ( fy2 - fy1 );
1028           ras.area  += ( fy2 - fy1 ) * ( fx1 + fx2 );
1029           fx1 = 0;
1030           fy1 = fy2;
1031           ex1++;
1032         }
1033         else /* ( prod                  + dy * ONE_PIXEL <  0 &&
1034                   prod                                   >  0 )    down */
1035         {
1036           fx2 = (TPos)FT_UDIV( prod, -dy );
1037           fy2 = 0;
1038           prod += dx * ONE_PIXEL;
1039           ras.cover += ( fy2 - fy1 );
1040           ras.area  += ( fy2 - fy1 ) * ( fx1 + fx2 );
1041           fx1 = fx2;
1042           fy1 = ONE_PIXEL;
1043           ey1--;
1044         }
1045 
1046         gray_set_cell( RAS_VAR_ ex1, ey1 );
1047       } while ( ex1 != ex2 || ey1 != ey2 );
1048     }
1049 
1050     fx2 = to_x - SUBPIXELS( ex2 );
1051     fy2 = to_y - SUBPIXELS( ey2 );
1052 
1053     ras.cover += ( fy2 - fy1 );
1054     ras.area  += ( fy2 - fy1 ) * ( fx1 + fx2 );
1055 
1056   End:
1057     ras.x       = to_x;
1058     ras.y       = to_y;
1059   }
1060 
1061 #endif
1062 
1063   static void
gray_split_conic(FT_Vector * base)1064   gray_split_conic( FT_Vector*  base )
1065   {
1066     TPos  a, b;
1067 
1068 
1069     base[4].x = base[2].x;
1070     b = base[1].x;
1071     a = base[3].x = ( base[2].x + b ) / 2;
1072     b = base[1].x = ( base[0].x + b ) / 2;
1073     base[2].x = ( a + b ) / 2;
1074 
1075     base[4].y = base[2].y;
1076     b = base[1].y;
1077     a = base[3].y = ( base[2].y + b ) / 2;
1078     b = base[1].y = ( base[0].y + b ) / 2;
1079     base[2].y = ( a + b ) / 2;
1080   }
1081 
1082 
1083   static void
gray_render_conic(RAS_ARG_ const FT_Vector * control,const FT_Vector * to)1084   gray_render_conic( RAS_ARG_ const FT_Vector*  control,
1085                               const FT_Vector*  to )
1086   {
1087     TPos        dx, dy;
1088     TPos        min, max, y;
1089     int         top, level;
1090     int*        levels;
1091     FT_Vector*  arc;
1092 
1093 
1094     levels = ras.lev_stack;
1095 
1096     arc      = ras.bez_stack;
1097     arc[0].x = UPSCALE( to->x );
1098     arc[0].y = UPSCALE( to->y );
1099     arc[1].x = UPSCALE( control->x );
1100     arc[1].y = UPSCALE( control->y );
1101     arc[2].x = ras.x;
1102     arc[2].y = ras.y;
1103     top      = 0;
1104 
1105     dx = FT_ABS( arc[2].x + arc[0].x - 2 * arc[1].x );
1106     dy = FT_ABS( arc[2].y + arc[0].y - 2 * arc[1].y );
1107     if ( dx < dy )
1108       dx = dy;
1109 
1110     if ( dx < ONE_PIXEL / 4 )
1111       goto Draw;
1112 
1113     /* short-cut the arc that crosses the current band */
1114     min = max = arc[0].y;
1115 
1116     y = arc[1].y;
1117     if ( y < min ) min = y;
1118     if ( y > max ) max = y;
1119 
1120     y = arc[2].y;
1121     if ( y < min ) min = y;
1122     if ( y > max ) max = y;
1123 
1124     if ( TRUNC( min ) >= ras.max_ey || TRUNC( max ) < ras.min_ey )
1125       goto Draw;
1126 
1127     level = 0;
1128     do
1129     {
1130       dx >>= 2;
1131       level++;
1132     } while ( dx > ONE_PIXEL / 4 );
1133 
1134     levels[0] = level;
1135 
1136     do
1137     {
1138       level = levels[top];
1139       if ( level > 0 )
1140       {
1141         gray_split_conic( arc );
1142         arc += 2;
1143         top++;
1144         levels[top] = levels[top - 1] = level - 1;
1145         continue;
1146       }
1147 
1148     Draw:
1149       gray_render_line( RAS_VAR_ arc[0].x, arc[0].y );
1150       top--;
1151       arc -= 2;
1152 
1153     } while ( top >= 0 );
1154   }
1155 
1156 
1157   static void
gray_split_cubic(FT_Vector * base)1158   gray_split_cubic( FT_Vector*  base )
1159   {
1160     TPos  a, b, c, d;
1161 
1162 
1163     base[6].x = base[3].x;
1164     c = base[1].x;
1165     d = base[2].x;
1166     base[1].x = a = ( base[0].x + c ) / 2;
1167     base[5].x = b = ( base[3].x + d ) / 2;
1168     c = ( c + d ) / 2;
1169     base[2].x = a = ( a + c ) / 2;
1170     base[4].x = b = ( b + c ) / 2;
1171     base[3].x = ( a + b ) / 2;
1172 
1173     base[6].y = base[3].y;
1174     c = base[1].y;
1175     d = base[2].y;
1176     base[1].y = a = ( base[0].y + c ) / 2;
1177     base[5].y = b = ( base[3].y + d ) / 2;
1178     c = ( c + d ) / 2;
1179     base[2].y = a = ( a + c ) / 2;
1180     base[4].y = b = ( b + c ) / 2;
1181     base[3].y = ( a + b ) / 2;
1182   }
1183 
1184 
1185   static void
gray_render_cubic(RAS_ARG_ const FT_Vector * control1,const FT_Vector * control2,const FT_Vector * to)1186   gray_render_cubic( RAS_ARG_ const FT_Vector*  control1,
1187                               const FT_Vector*  control2,
1188                               const FT_Vector*  to )
1189   {
1190     FT_Vector*  arc;
1191     TPos        min, max, y;
1192 
1193 
1194     arc      = ras.bez_stack;
1195     arc[0].x = UPSCALE( to->x );
1196     arc[0].y = UPSCALE( to->y );
1197     arc[1].x = UPSCALE( control2->x );
1198     arc[1].y = UPSCALE( control2->y );
1199     arc[2].x = UPSCALE( control1->x );
1200     arc[2].y = UPSCALE( control1->y );
1201     arc[3].x = ras.x;
1202     arc[3].y = ras.y;
1203 
1204     /* Short-cut the arc that crosses the current band. */
1205     min = max = arc[0].y;
1206 
1207     y = arc[1].y;
1208     if ( y < min )
1209       min = y;
1210     if ( y > max )
1211       max = y;
1212 
1213     y = arc[2].y;
1214     if ( y < min )
1215       min = y;
1216     if ( y > max )
1217       max = y;
1218 
1219     y = arc[3].y;
1220     if ( y < min )
1221       min = y;
1222     if ( y > max )
1223       max = y;
1224 
1225     if ( TRUNC( min ) >= ras.max_ey || TRUNC( max ) < ras.min_ey )
1226       goto Draw;
1227 
1228     for (;;)
1229     {
1230       /* Decide whether to split or draw. See `Rapid Termination          */
1231       /* Evaluation for Recursive Subdivision of Bezier Curves' by Thomas */
1232       /* F. Hain, at                                                      */
1233       /* http://www.cis.southalabama.edu/~hain/general/Publications/Bezier/Camera-ready%20CISST02%202.pdf */
1234 
1235       {
1236         TPos  dx, dy, dx_, dy_;
1237         TPos  dx1, dy1, dx2, dy2;
1238         TPos  L, s, s_limit;
1239 
1240 
1241         /* dx and dy are x and y components of the P0-P3 chord vector. */
1242         dx = dx_ = arc[3].x - arc[0].x;
1243         dy = dy_ = arc[3].y - arc[0].y;
1244 
1245         L = FT_HYPOT( dx_, dy_ );
1246 
1247         /* Avoid possible arithmetic overflow below by splitting. */
1248         if ( L > 32767 )
1249           goto Split;
1250 
1251         /* Max deviation may be as much as (s/L) * 3/4 (if Hain's v = 1). */
1252         s_limit = L * (TPos)( ONE_PIXEL / 6 );
1253 
1254         /* s is L * the perpendicular distance from P1 to the line P0-P3. */
1255         dx1 = arc[1].x - arc[0].x;
1256         dy1 = arc[1].y - arc[0].y;
1257         s = FT_ABS( dy * dx1 - dx * dy1 );
1258 
1259         if ( s > s_limit )
1260           goto Split;
1261 
1262         /* s is L * the perpendicular distance from P2 to the line P0-P3. */
1263         dx2 = arc[2].x - arc[0].x;
1264         dy2 = arc[2].y - arc[0].y;
1265         s = FT_ABS( dy * dx2 - dx * dy2 );
1266 
1267         if ( s > s_limit )
1268           goto Split;
1269 
1270         /* Split super curvy segments where the off points are so far
1271            from the chord that the angles P0-P1-P3 or P0-P2-P3 become
1272            acute as detected by appropriate dot products. */
1273         if ( dx1 * ( dx1 - dx ) + dy1 * ( dy1 - dy ) > 0 ||
1274              dx2 * ( dx2 - dx ) + dy2 * ( dy2 - dy ) > 0 )
1275           goto Split;
1276 
1277         /* No reason to split. */
1278         goto Draw;
1279       }
1280 
1281     Split:
1282       gray_split_cubic( arc );
1283       arc += 3;
1284       continue;
1285 
1286     Draw:
1287       gray_render_line( RAS_VAR_ arc[0].x, arc[0].y );
1288 
1289       if ( arc == ras.bez_stack )
1290         return;
1291 
1292       arc -= 3;
1293     }
1294   }
1295 
1296 
1297   static int
gray_move_to(const FT_Vector * to,gray_PWorker worker)1298   gray_move_to( const FT_Vector*  to,
1299                 gray_PWorker      worker )
1300   {
1301     TPos  x, y;
1302 
1303 
1304     /* record current cell, if any */
1305     if ( !ras.invalid )
1306       gray_record_cell( RAS_VAR );
1307 
1308     /* start to a new position */
1309     x = UPSCALE( to->x );
1310     y = UPSCALE( to->y );
1311 
1312     gray_start_cell( RAS_VAR_ TRUNC( x ), TRUNC( y ) );
1313 
1314     worker->x = x;
1315     worker->y = y;
1316     return 0;
1317   }
1318 
1319 
1320   static int
gray_line_to(const FT_Vector * to,gray_PWorker worker)1321   gray_line_to( const FT_Vector*  to,
1322                 gray_PWorker      worker )
1323   {
1324     gray_render_line( RAS_VAR_ UPSCALE( to->x ), UPSCALE( to->y ) );
1325     return 0;
1326   }
1327 
1328 
1329   static int
gray_conic_to(const FT_Vector * control,const FT_Vector * to,gray_PWorker worker)1330   gray_conic_to( const FT_Vector*  control,
1331                  const FT_Vector*  to,
1332                  gray_PWorker      worker )
1333   {
1334     gray_render_conic( RAS_VAR_ control, to );
1335     return 0;
1336   }
1337 
1338 
1339   static int
gray_cubic_to(const FT_Vector * control1,const FT_Vector * control2,const FT_Vector * to,gray_PWorker worker)1340   gray_cubic_to( const FT_Vector*  control1,
1341                  const FT_Vector*  control2,
1342                  const FT_Vector*  to,
1343                  gray_PWorker      worker )
1344   {
1345     gray_render_cubic( RAS_VAR_ control1, control2, to );
1346     return 0;
1347   }
1348 
1349 
1350   static void
gray_render_span(int y,int count,const FT_Span * spans,gray_PWorker worker)1351   gray_render_span( int             y,
1352                     int             count,
1353                     const FT_Span*  spans,
1354                     gray_PWorker    worker )
1355   {
1356     unsigned char*  p;
1357     FT_Bitmap*      map = &worker->target;
1358 
1359 
1360     /* first of all, compute the scanline offset */
1361     p = (unsigned char*)map->buffer - y * map->pitch;
1362     if ( map->pitch >= 0 )
1363       p += ( map->rows - 1 ) * (unsigned int)map->pitch;
1364 
1365     for ( ; count > 0; count--, spans++ )
1366     {
1367       unsigned char  coverage = spans->coverage;
1368 
1369 
1370       if ( coverage )
1371       {
1372         /* For small-spans it is faster to do it by ourselves than
1373          * calling `memset'.  This is mainly due to the cost of the
1374          * function call.
1375          */
1376         if ( spans->len >= 8 )
1377           FT_MEM_SET( p + spans->x, (unsigned char)coverage, spans->len );
1378         else
1379         {
1380           unsigned char*  q = p + spans->x;
1381 
1382 
1383           switch ( spans->len )
1384           {
1385           case 7: *q++ = (unsigned char)coverage;
1386           case 6: *q++ = (unsigned char)coverage;
1387           case 5: *q++ = (unsigned char)coverage;
1388           case 4: *q++ = (unsigned char)coverage;
1389           case 3: *q++ = (unsigned char)coverage;
1390           case 2: *q++ = (unsigned char)coverage;
1391           case 1: *q   = (unsigned char)coverage;
1392           default:
1393             ;
1394           }
1395         }
1396       }
1397     }
1398   }
1399 
1400 
1401   static void
gray_hline(RAS_ARG_ TCoord x,TCoord y,TPos area,TCoord acount)1402   gray_hline( RAS_ARG_ TCoord  x,
1403                        TCoord  y,
1404                        TPos    area,
1405                        TCoord  acount )
1406   {
1407     int  coverage;
1408 
1409 
1410     /* compute the coverage line's coverage, depending on the    */
1411     /* outline fill rule                                         */
1412     /*                                                           */
1413     /* the coverage percentage is area/(PIXEL_BITS*PIXEL_BITS*2) */
1414     /*                                                           */
1415     coverage = (int)( area >> ( PIXEL_BITS * 2 + 1 - 8 ) );
1416                                                     /* use range 0..256 */
1417     if ( coverage < 0 )
1418       coverage = -coverage;
1419 
1420     if ( ras.outline.flags & FT_OUTLINE_EVEN_ODD_FILL )
1421     {
1422       coverage &= 511;
1423 
1424       if ( coverage > 256 )
1425         coverage = 512 - coverage;
1426       else if ( coverage == 256 )
1427         coverage = 255;
1428     }
1429     else
1430     {
1431       /* normal non-zero winding rule */
1432       if ( coverage >= 256 )
1433         coverage = 255;
1434     }
1435 
1436     y += (TCoord)ras.min_ey;
1437     x += (TCoord)ras.min_ex;
1438 
1439     /* FT_Span.x is a 16-bit short, so limit our coordinates appropriately */
1440     if ( x >= 32767 )
1441       x = 32767;
1442 
1443     /* FT_Span.y is an integer, so limit our coordinates appropriately */
1444     if ( y >= FT_INT_MAX )
1445       y = FT_INT_MAX;
1446 
1447     if ( coverage )
1448     {
1449       FT_Span*  span;
1450       int       count;
1451 
1452 
1453       /* see whether we can add this span to the current list */
1454       count = ras.num_gray_spans;
1455       span  = ras.gray_spans + count - 1;
1456       if ( count > 0                          &&
1457            ras.span_y == y                    &&
1458            (int)span->x + span->len == (int)x &&
1459            span->coverage == coverage         )
1460       {
1461         span->len = (unsigned short)( span->len + acount );
1462         return;
1463       }
1464 
1465       if ( ras.span_y != y || count >= FT_MAX_GRAY_SPANS )
1466       {
1467         if ( ras.render_span && count > 0 )
1468           ras.render_span( ras.span_y, count, ras.gray_spans,
1469                            ras.render_span_data );
1470 
1471 #ifdef FT_DEBUG_LEVEL_TRACE
1472 
1473         if ( count > 0 )
1474         {
1475           int  n;
1476 
1477 
1478           FT_TRACE7(( "y = %3d ", ras.span_y ));
1479           span = ras.gray_spans;
1480           for ( n = 0; n < count; n++, span++ )
1481             FT_TRACE7(( "[%d..%d]:%02x ",
1482                         span->x, span->x + span->len - 1, span->coverage ));
1483           FT_TRACE7(( "\n" ));
1484         }
1485 
1486 #endif /* FT_DEBUG_LEVEL_TRACE */
1487 
1488         ras.num_gray_spans = 0;
1489         ras.span_y         = (int)y;
1490 
1491         span  = ras.gray_spans;
1492       }
1493       else
1494         span++;
1495 
1496       /* add a gray span to the current list */
1497       span->x        = (short)x;
1498       span->len      = (unsigned short)acount;
1499       span->coverage = (unsigned char)coverage;
1500 
1501       ras.num_gray_spans++;
1502     }
1503   }
1504 
1505 
1506 #ifdef FT_DEBUG_LEVEL_TRACE
1507 
1508   /* to be called while in the debugger --                                */
1509   /* this function causes a compiler warning since it is unused otherwise */
1510   static void
gray_dump_cells(RAS_ARG)1511   gray_dump_cells( RAS_ARG )
1512   {
1513     int  yindex;
1514 
1515 
1516     for ( yindex = 0; yindex < ras.ycount; yindex++ )
1517     {
1518       PCell  cell;
1519 
1520 
1521       printf( "%3d:", yindex );
1522 
1523       for ( cell = ras.ycells[yindex]; cell != NULL; cell = cell->next )
1524         printf( " (%3ld, c:%4ld, a:%6d)", cell->x, cell->cover, cell->area );
1525       printf( "\n" );
1526     }
1527   }
1528 
1529 #endif /* FT_DEBUG_LEVEL_TRACE */
1530 
1531 
1532   static void
gray_sweep(RAS_ARG_ const FT_Bitmap * target)1533   gray_sweep( RAS_ARG_ const FT_Bitmap*  target )
1534   {
1535     int  yindex;
1536 
1537     FT_UNUSED( target );
1538 
1539 
1540     if ( ras.num_cells == 0 )
1541       return;
1542 
1543     ras.num_gray_spans = 0;
1544 
1545     FT_TRACE7(( "gray_sweep: start\n" ));
1546 
1547     for ( yindex = 0; yindex < ras.ycount; yindex++ )
1548     {
1549       PCell   cell  = ras.ycells[yindex];
1550       TCoord  cover = 0;
1551       TCoord  x     = 0;
1552 
1553 
1554       for ( ; cell != NULL; cell = cell->next )
1555       {
1556         TPos  area;
1557 
1558 
1559         if ( cell->x > x && cover != 0 )
1560           gray_hline( RAS_VAR_ x, yindex, cover * ( ONE_PIXEL * 2 ),
1561                       cell->x - x );
1562 
1563         cover += cell->cover;
1564         area   = cover * ( ONE_PIXEL * 2 ) - cell->area;
1565 
1566         if ( area != 0 && cell->x >= 0 )
1567           gray_hline( RAS_VAR_ cell->x, yindex, area, 1 );
1568 
1569         x = cell->x + 1;
1570       }
1571 
1572       if ( cover != 0 )
1573         gray_hline( RAS_VAR_ x, yindex, cover * ( ONE_PIXEL * 2 ),
1574                     ras.count_ex - x );
1575     }
1576 
1577     if ( ras.render_span && ras.num_gray_spans > 0 )
1578       ras.render_span( ras.span_y, ras.num_gray_spans,
1579                        ras.gray_spans, ras.render_span_data );
1580 
1581 #ifdef FT_DEBUG_LEVEL_TRACE
1582 
1583     if ( ras.num_gray_spans > 0 )
1584     {
1585       FT_Span*  span;
1586       int       n;
1587 
1588 
1589       FT_TRACE7(( "y = %3d ", ras.span_y ));
1590       span = ras.gray_spans;
1591       for ( n = 0; n < ras.num_gray_spans; n++, span++ )
1592         FT_TRACE7(( "[%d..%d]:%02x ",
1593                     span->x, span->x + span->len - 1, span->coverage ));
1594       FT_TRACE7(( "\n" ));
1595     }
1596 
1597     FT_TRACE7(( "gray_sweep: end\n" ));
1598 
1599 #endif /* FT_DEBUG_LEVEL_TRACE */
1600 
1601   }
1602 
1603 
1604 #ifdef _STANDALONE_
1605 
1606   /*************************************************************************/
1607   /*                                                                       */
1608   /*  The following function should only compile in stand-alone mode,      */
1609   /*  i.e., when building this component without the rest of FreeType.     */
1610   /*                                                                       */
1611   /*************************************************************************/
1612 
1613   /*************************************************************************/
1614   /*                                                                       */
1615   /* <Function>                                                            */
1616   /*    FT_Outline_Decompose                                               */
1617   /*                                                                       */
1618   /* <Description>                                                         */
1619   /*    Walk over an outline's structure to decompose it into individual   */
1620   /*    segments and Bézier arcs.  This function is also able to emit      */
1621   /*    `move to' and `close to' operations to indicate the start and end  */
1622   /*    of new contours in the outline.                                    */
1623   /*                                                                       */
1624   /* <Input>                                                               */
1625   /*    outline        :: A pointer to the source target.                  */
1626   /*                                                                       */
1627   /*    func_interface :: A table of `emitters', i.e., function pointers   */
1628   /*                      called during decomposition to indicate path     */
1629   /*                      operations.                                      */
1630   /*                                                                       */
1631   /* <InOut>                                                               */
1632   /*    user           :: A typeless pointer which is passed to each       */
1633   /*                      emitter during the decomposition.  It can be     */
1634   /*                      used to store the state during the               */
1635   /*                      decomposition.                                   */
1636   /*                                                                       */
1637   /* <Return>                                                              */
1638   /*    Error code.  0 means success.                                      */
1639   /*                                                                       */
1640   static int
FT_Outline_Decompose(const FT_Outline * outline,const FT_Outline_Funcs * func_interface,void * user)1641   FT_Outline_Decompose( const FT_Outline*        outline,
1642                         const FT_Outline_Funcs*  func_interface,
1643                         void*                    user )
1644   {
1645 #undef SCALED
1646 #define SCALED( x )  ( ( (x) << shift ) - delta )
1647 
1648     FT_Vector   v_last;
1649     FT_Vector   v_control;
1650     FT_Vector   v_start;
1651 
1652     FT_Vector*  point;
1653     FT_Vector*  limit;
1654     char*       tags;
1655 
1656     int         error;
1657 
1658     int   n;         /* index of contour in outline     */
1659     int   first;     /* index of first point in contour */
1660     char  tag;       /* current point's state           */
1661 
1662     int   shift;
1663     TPos  delta;
1664 
1665 
1666     if ( !outline )
1667       return FT_THROW( Invalid_Outline );
1668 
1669     if ( !func_interface )
1670       return FT_THROW( Invalid_Argument );
1671 
1672     shift = func_interface->shift;
1673     delta = func_interface->delta;
1674     first = 0;
1675 
1676     for ( n = 0; n < outline->n_contours; n++ )
1677     {
1678       int  last;  /* index of last point in contour */
1679 
1680 
1681       FT_TRACE5(( "FT_Outline_Decompose: Outline %d\n", n ));
1682 
1683       last  = outline->contours[n];
1684       if ( last < 0 )
1685         goto Invalid_Outline;
1686       limit = outline->points + last;
1687 
1688       v_start   = outline->points[first];
1689       v_start.x = SCALED( v_start.x );
1690       v_start.y = SCALED( v_start.y );
1691 
1692       v_last   = outline->points[last];
1693       v_last.x = SCALED( v_last.x );
1694       v_last.y = SCALED( v_last.y );
1695 
1696       v_control = v_start;
1697 
1698       point = outline->points + first;
1699       tags  = outline->tags   + first;
1700       tag   = FT_CURVE_TAG( tags[0] );
1701 
1702       /* A contour cannot start with a cubic control point! */
1703       if ( tag == FT_CURVE_TAG_CUBIC )
1704         goto Invalid_Outline;
1705 
1706       /* check first point to determine origin */
1707       if ( tag == FT_CURVE_TAG_CONIC )
1708       {
1709         /* first point is conic control.  Yes, this happens. */
1710         if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON )
1711         {
1712           /* start at last point if it is on the curve */
1713           v_start = v_last;
1714           limit--;
1715         }
1716         else
1717         {
1718           /* if both first and last points are conic,         */
1719           /* start at their middle and record its position    */
1720           /* for closure                                      */
1721           v_start.x = ( v_start.x + v_last.x ) / 2;
1722           v_start.y = ( v_start.y + v_last.y ) / 2;
1723 
1724           v_last = v_start;
1725         }
1726         point--;
1727         tags--;
1728       }
1729 
1730       FT_TRACE5(( "  move to (%.2f, %.2f)\n",
1731                   v_start.x / 64.0, v_start.y / 64.0 ));
1732       error = func_interface->move_to( &v_start, user );
1733       if ( error )
1734         goto Exit;
1735 
1736       while ( point < limit )
1737       {
1738         point++;
1739         tags++;
1740 
1741         tag = FT_CURVE_TAG( tags[0] );
1742         switch ( tag )
1743         {
1744         case FT_CURVE_TAG_ON:  /* emit a single line_to */
1745           {
1746             FT_Vector  vec;
1747 
1748 
1749             vec.x = SCALED( point->x );
1750             vec.y = SCALED( point->y );
1751 
1752             FT_TRACE5(( "  line to (%.2f, %.2f)\n",
1753                         vec.x / 64.0, vec.y / 64.0 ));
1754             error = func_interface->line_to( &vec, user );
1755             if ( error )
1756               goto Exit;
1757             continue;
1758           }
1759 
1760         case FT_CURVE_TAG_CONIC:  /* consume conic arcs */
1761           v_control.x = SCALED( point->x );
1762           v_control.y = SCALED( point->y );
1763 
1764         Do_Conic:
1765           if ( point < limit )
1766           {
1767             FT_Vector  vec;
1768             FT_Vector  v_middle;
1769 
1770 
1771             point++;
1772             tags++;
1773             tag = FT_CURVE_TAG( tags[0] );
1774 
1775             vec.x = SCALED( point->x );
1776             vec.y = SCALED( point->y );
1777 
1778             if ( tag == FT_CURVE_TAG_ON )
1779             {
1780               FT_TRACE5(( "  conic to (%.2f, %.2f)"
1781                           " with control (%.2f, %.2f)\n",
1782                           vec.x / 64.0, vec.y / 64.0,
1783                           v_control.x / 64.0, v_control.y / 64.0 ));
1784               error = func_interface->conic_to( &v_control, &vec, user );
1785               if ( error )
1786                 goto Exit;
1787               continue;
1788             }
1789 
1790             if ( tag != FT_CURVE_TAG_CONIC )
1791               goto Invalid_Outline;
1792 
1793             v_middle.x = ( v_control.x + vec.x ) / 2;
1794             v_middle.y = ( v_control.y + vec.y ) / 2;
1795 
1796             FT_TRACE5(( "  conic to (%.2f, %.2f)"
1797                         " with control (%.2f, %.2f)\n",
1798                         v_middle.x / 64.0, v_middle.y / 64.0,
1799                         v_control.x / 64.0, v_control.y / 64.0 ));
1800             error = func_interface->conic_to( &v_control, &v_middle, user );
1801             if ( error )
1802               goto Exit;
1803 
1804             v_control = vec;
1805             goto Do_Conic;
1806           }
1807 
1808           FT_TRACE5(( "  conic to (%.2f, %.2f)"
1809                       " with control (%.2f, %.2f)\n",
1810                       v_start.x / 64.0, v_start.y / 64.0,
1811                       v_control.x / 64.0, v_control.y / 64.0 ));
1812           error = func_interface->conic_to( &v_control, &v_start, user );
1813           goto Close;
1814 
1815         default:  /* FT_CURVE_TAG_CUBIC */
1816           {
1817             FT_Vector  vec1, vec2;
1818 
1819 
1820             if ( point + 1 > limit                             ||
1821                  FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC )
1822               goto Invalid_Outline;
1823 
1824             point += 2;
1825             tags  += 2;
1826 
1827             vec1.x = SCALED( point[-2].x );
1828             vec1.y = SCALED( point[-2].y );
1829 
1830             vec2.x = SCALED( point[-1].x );
1831             vec2.y = SCALED( point[-1].y );
1832 
1833             if ( point <= limit )
1834             {
1835               FT_Vector  vec;
1836 
1837 
1838               vec.x = SCALED( point->x );
1839               vec.y = SCALED( point->y );
1840 
1841               FT_TRACE5(( "  cubic to (%.2f, %.2f)"
1842                           " with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
1843                           vec.x / 64.0, vec.y / 64.0,
1844                           vec1.x / 64.0, vec1.y / 64.0,
1845                           vec2.x / 64.0, vec2.y / 64.0 ));
1846               error = func_interface->cubic_to( &vec1, &vec2, &vec, user );
1847               if ( error )
1848                 goto Exit;
1849               continue;
1850             }
1851 
1852             FT_TRACE5(( "  cubic to (%.2f, %.2f)"
1853                         " with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
1854                         v_start.x / 64.0, v_start.y / 64.0,
1855                         vec1.x / 64.0, vec1.y / 64.0,
1856                         vec2.x / 64.0, vec2.y / 64.0 ));
1857             error = func_interface->cubic_to( &vec1, &vec2, &v_start, user );
1858             goto Close;
1859           }
1860         }
1861       }
1862 
1863       /* close the contour with a line segment */
1864       FT_TRACE5(( "  line to (%.2f, %.2f)\n",
1865                   v_start.x / 64.0, v_start.y / 64.0 ));
1866       error = func_interface->line_to( &v_start, user );
1867 
1868    Close:
1869       if ( error )
1870         goto Exit;
1871 
1872       first = last + 1;
1873     }
1874 
1875     FT_TRACE5(( "FT_Outline_Decompose: Done\n", n ));
1876     return 0;
1877 
1878   Exit:
1879     FT_TRACE5(( "FT_Outline_Decompose: Error %d\n", error ));
1880     return error;
1881 
1882   Invalid_Outline:
1883     return FT_THROW( Invalid_Outline );
1884   }
1885 
1886 #endif /* _STANDALONE_ */
1887 
1888 
1889   typedef struct  gray_TBand_
1890   {
1891     TPos  min, max;
1892 
1893   } gray_TBand;
1894 
1895 
1896   FT_DEFINE_OUTLINE_FUNCS(
1897     func_interface,
1898 
1899     (FT_Outline_MoveTo_Func) gray_move_to,
1900     (FT_Outline_LineTo_Func) gray_line_to,
1901     (FT_Outline_ConicTo_Func)gray_conic_to,
1902     (FT_Outline_CubicTo_Func)gray_cubic_to,
1903     0,
1904     0 )
1905 
1906 
1907   static int
gray_convert_glyph_inner(RAS_ARG)1908   gray_convert_glyph_inner( RAS_ARG )
1909   {
1910 
1911     volatile int  error = 0;
1912 
1913 #ifdef FT_CONFIG_OPTION_PIC
1914       FT_Outline_Funcs func_interface;
1915       Init_Class_func_interface(&func_interface);
1916 #endif
1917 
1918     if ( ft_setjmp( ras.jump_buffer ) == 0 )
1919     {
1920       error = FT_Outline_Decompose( &ras.outline, &func_interface, &ras );
1921       if ( !ras.invalid )
1922         gray_record_cell( RAS_VAR );
1923     }
1924     else
1925       error = FT_THROW( Memory_Overflow );
1926 
1927     return error;
1928   }
1929 
1930 
1931   static int
gray_convert_glyph(RAS_ARG)1932   gray_convert_glyph( RAS_ARG )
1933   {
1934     gray_TBand            bands[40];
1935     gray_TBand* volatile  band;
1936     int volatile          n, num_bands;
1937     TPos volatile         min, max, max_y;
1938     FT_BBox*              clip;
1939 
1940 
1941     /* Set up state in the raster object */
1942     gray_compute_cbox( RAS_VAR );
1943 
1944     /* clip to target bitmap, exit if nothing to do */
1945     clip = &ras.clip_box;
1946 
1947     if ( ras.max_ex <= clip->xMin || ras.min_ex >= clip->xMax ||
1948          ras.max_ey <= clip->yMin || ras.min_ey >= clip->yMax )
1949       return 0;
1950 
1951     if ( ras.min_ex < clip->xMin ) ras.min_ex = clip->xMin;
1952     if ( ras.min_ey < clip->yMin ) ras.min_ey = clip->yMin;
1953 
1954     if ( ras.max_ex > clip->xMax ) ras.max_ex = clip->xMax;
1955     if ( ras.max_ey > clip->yMax ) ras.max_ey = clip->yMax;
1956 
1957     ras.count_ex = ras.max_ex - ras.min_ex;
1958     ras.count_ey = ras.max_ey - ras.min_ey;
1959 
1960     /* set up vertical bands */
1961     num_bands = (int)( ( ras.max_ey - ras.min_ey ) / ras.band_size );
1962     if ( num_bands == 0 )
1963       num_bands = 1;
1964     if ( num_bands >= 39 )
1965       num_bands = 39;
1966 
1967     ras.band_shoot = 0;
1968 
1969     min   = ras.min_ey;
1970     max_y = ras.max_ey;
1971 
1972     for ( n = 0; n < num_bands; n++, min = max )
1973     {
1974       max = min + ras.band_size;
1975       if ( n == num_bands - 1 || max > max_y )
1976         max = max_y;
1977 
1978       bands[0].min = min;
1979       bands[0].max = max;
1980       band         = bands;
1981 
1982       do
1983       {
1984         TPos  bottom, top, middle;
1985         int   error;
1986 
1987         {
1988           PCell  cells_max;
1989           int    yindex;
1990           long   cell_start, cell_end, cell_mod;
1991 
1992 
1993           ras.ycells = (PCell*)ras.buffer;
1994           ras.ycount = band->max - band->min;
1995 
1996           cell_start = (long)sizeof ( PCell ) * ras.ycount;
1997           cell_mod   = cell_start % (long)sizeof ( TCell );
1998           if ( cell_mod > 0 )
1999             cell_start += (long)sizeof ( TCell ) - cell_mod;
2000 
2001           cell_end  = ras.buffer_size;
2002           cell_end -= cell_end % (long)sizeof ( TCell );
2003 
2004           cells_max = (PCell)( (char*)ras.buffer + cell_end );
2005           ras.cells = (PCell)( (char*)ras.buffer + cell_start );
2006           if ( ras.cells >= cells_max )
2007             goto ReduceBands;
2008 
2009           ras.max_cells = cells_max - ras.cells;
2010           if ( ras.max_cells < 2 )
2011             goto ReduceBands;
2012 
2013           for ( yindex = 0; yindex < ras.ycount; yindex++ )
2014             ras.ycells[yindex] = NULL;
2015         }
2016 
2017         ras.num_cells = 0;
2018         ras.invalid   = 1;
2019         ras.min_ey    = band->min;
2020         ras.max_ey    = band->max;
2021         ras.count_ey  = band->max - band->min;
2022 
2023         error = gray_convert_glyph_inner( RAS_VAR );
2024 
2025         if ( !error )
2026         {
2027           gray_sweep( RAS_VAR_ &ras.target );
2028           band--;
2029           continue;
2030         }
2031         else if ( error != ErrRaster_Memory_Overflow )
2032           return 1;
2033 
2034       ReduceBands:
2035         /* render pool overflow; we will reduce the render band by half */
2036         bottom = band->min;
2037         top    = band->max;
2038         middle = bottom + ( ( top - bottom ) >> 1 );
2039 
2040         /* This is too complex for a single scanline; there must */
2041         /* be some problems.                                     */
2042         if ( middle == bottom )
2043         {
2044 #ifdef FT_DEBUG_LEVEL_TRACE
2045           FT_TRACE7(( "gray_convert_glyph: rotten glyph\n" ));
2046 #endif
2047           return 1;
2048         }
2049 
2050         if ( bottom-top >= ras.band_size )
2051           ras.band_shoot++;
2052 
2053         band[1].min = bottom;
2054         band[1].max = middle;
2055         band[0].min = middle;
2056         band[0].max = top;
2057         band++;
2058       } while ( band >= bands );
2059     }
2060 
2061     if ( ras.band_shoot > 8 && ras.band_size > 16 )
2062       ras.band_size = ras.band_size / 2;
2063 
2064     return 0;
2065   }
2066 
2067 
2068   static int
gray_raster_render(gray_PRaster raster,const FT_Raster_Params * params)2069   gray_raster_render( gray_PRaster             raster,
2070                       const FT_Raster_Params*  params )
2071   {
2072     const FT_Outline*  outline     = (const FT_Outline*)params->source;
2073     const FT_Bitmap*   target_map  = params->target;
2074 
2075     gray_TWorker  worker[1];
2076 
2077     TCell  buffer[FT_MAX( FT_RENDER_POOL_SIZE, 2048 ) / sizeof ( TCell )];
2078     long   buffer_size = sizeof ( buffer );
2079     int    band_size   = (int)( buffer_size /
2080                                 (long)( sizeof ( TCell ) * 8 ) );
2081 
2082 
2083     if ( !raster )
2084       return FT_THROW( Invalid_Argument );
2085 
2086     if ( !outline )
2087       return FT_THROW( Invalid_Outline );
2088 
2089     /* return immediately if the outline is empty */
2090     if ( outline->n_points == 0 || outline->n_contours <= 0 )
2091       return 0;
2092 
2093     if ( !outline->contours || !outline->points )
2094       return FT_THROW( Invalid_Outline );
2095 
2096     if ( outline->n_points !=
2097            outline->contours[outline->n_contours - 1] + 1 )
2098       return FT_THROW( Invalid_Outline );
2099 
2100     /* if direct mode is not set, we must have a target bitmap */
2101     if ( !( params->flags & FT_RASTER_FLAG_DIRECT ) )
2102     {
2103       if ( !target_map )
2104         return FT_THROW( Invalid_Argument );
2105 
2106       /* nothing to do */
2107       if ( !target_map->width || !target_map->rows )
2108         return 0;
2109 
2110       if ( !target_map->buffer )
2111         return FT_THROW( Invalid_Argument );
2112     }
2113 
2114     /* this version does not support monochrome rendering */
2115     if ( !( params->flags & FT_RASTER_FLAG_AA ) )
2116       return FT_THROW( Invalid_Mode );
2117 
2118     /* compute clipping box */
2119     if ( !( params->flags & FT_RASTER_FLAG_DIRECT ) )
2120     {
2121       /* compute clip box from target pixmap */
2122       ras.clip_box.xMin = 0;
2123       ras.clip_box.yMin = 0;
2124       ras.clip_box.xMax = (FT_Pos)target_map->width;
2125       ras.clip_box.yMax = (FT_Pos)target_map->rows;
2126     }
2127     else if ( params->flags & FT_RASTER_FLAG_CLIP )
2128       ras.clip_box = params->clip_box;
2129     else
2130     {
2131       ras.clip_box.xMin = -32768L;
2132       ras.clip_box.yMin = -32768L;
2133       ras.clip_box.xMax =  32767L;
2134       ras.clip_box.yMax =  32767L;
2135     }
2136 
2137     gray_init_cells( RAS_VAR_ buffer, buffer_size );
2138 
2139     ras.outline        = *outline;
2140     ras.num_cells      = 0;
2141     ras.invalid        = 1;
2142     ras.band_size      = band_size;
2143     ras.num_gray_spans = 0;
2144     ras.span_y         = 0;
2145 
2146     if ( params->flags & FT_RASTER_FLAG_DIRECT )
2147     {
2148       ras.render_span      = (FT_Raster_Span_Func)params->gray_spans;
2149       ras.render_span_data = params->user;
2150     }
2151     else
2152     {
2153       ras.target           = *target_map;
2154       ras.render_span      = (FT_Raster_Span_Func)gray_render_span;
2155       ras.render_span_data = &ras;
2156     }
2157 
2158     return gray_convert_glyph( RAS_VAR );
2159   }
2160 
2161 
2162   /**** RASTER OBJECT CREATION: In stand-alone mode, we simply use *****/
2163   /****                         a static object.                   *****/
2164 
2165 #ifdef _STANDALONE_
2166 
2167   static int
gray_raster_new(void * memory,FT_Raster * araster)2168   gray_raster_new( void*       memory,
2169                    FT_Raster*  araster )
2170   {
2171     static gray_TRaster  the_raster;
2172 
2173     FT_UNUSED( memory );
2174 
2175 
2176     *araster = (FT_Raster)&the_raster;
2177     FT_MEM_ZERO( &the_raster, sizeof ( the_raster ) );
2178 
2179     return 0;
2180   }
2181 
2182 
2183   static void
gray_raster_done(FT_Raster raster)2184   gray_raster_done( FT_Raster  raster )
2185   {
2186     /* nothing */
2187     FT_UNUSED( raster );
2188   }
2189 
2190 #else /* !_STANDALONE_ */
2191 
2192   static int
gray_raster_new(FT_Memory memory,FT_Raster * araster)2193   gray_raster_new( FT_Memory   memory,
2194                    FT_Raster*  araster )
2195   {
2196     FT_Error      error;
2197     gray_PRaster  raster = NULL;
2198 
2199 
2200     *araster = 0;
2201     if ( !FT_ALLOC( raster, sizeof ( gray_TRaster ) ) )
2202     {
2203       raster->memory = memory;
2204       *araster       = (FT_Raster)raster;
2205     }
2206 
2207     return error;
2208   }
2209 
2210 
2211   static void
gray_raster_done(FT_Raster raster)2212   gray_raster_done( FT_Raster  raster )
2213   {
2214     FT_Memory  memory = (FT_Memory)((gray_PRaster)raster)->memory;
2215 
2216 
2217     FT_FREE( raster );
2218   }
2219 
2220 #endif /* !_STANDALONE_ */
2221 
2222 
2223   static void
gray_raster_reset(FT_Raster raster,char * pool_base,long pool_size)2224   gray_raster_reset( FT_Raster  raster,
2225                      char*      pool_base,
2226                      long       pool_size )
2227   {
2228     FT_UNUSED( raster );
2229     FT_UNUSED( pool_base );
2230     FT_UNUSED( pool_size );
2231   }
2232 
2233 
2234   static int
gray_raster_set_mode(FT_Raster raster,unsigned long mode,void * args)2235   gray_raster_set_mode( FT_Raster      raster,
2236                         unsigned long  mode,
2237                         void*          args )
2238   {
2239     FT_UNUSED( raster );
2240     FT_UNUSED( mode );
2241     FT_UNUSED( args );
2242 
2243 
2244     return 0; /* nothing to do */
2245   }
2246 
2247 
2248   FT_DEFINE_RASTER_FUNCS(
2249     ft_grays_raster,
2250 
2251     FT_GLYPH_FORMAT_OUTLINE,
2252 
2253     (FT_Raster_New_Func)     gray_raster_new,
2254     (FT_Raster_Reset_Func)   gray_raster_reset,
2255     (FT_Raster_Set_Mode_Func)gray_raster_set_mode,
2256     (FT_Raster_Render_Func)  gray_raster_render,
2257     (FT_Raster_Done_Func)    gray_raster_done )
2258 
2259 
2260 /* END */
2261 
2262 
2263 /* Local Variables: */
2264 /* coding: utf-8    */
2265 /* End:             */
2266