1 /***************************************************************************/
2 /*                                                                         */
3 /*  ttgload.c                                                              */
4 /*                                                                         */
5 /*    TrueType Glyph Loader (body).                                        */
6 /*                                                                         */
7 /*  Copyright 1996-2013                                                    */
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 #include <ft2build.h>
20 #include FT_INTERNAL_DEBUG_H
21 #include FT_INTERNAL_CALC_H
22 #include FT_INTERNAL_STREAM_H
23 #include FT_INTERNAL_SFNT_H
24 #include FT_TRUETYPE_TAGS_H
25 #include FT_OUTLINE_H
26 #include FT_TRUETYPE_DRIVER_H
27 
28 #include "ttgload.h"
29 #include "ttpload.h"
30 
31 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
32 #include "ttgxvar.h"
33 #endif
34 
35 #include "tterrors.h"
36 #include "ttsubpix.h"
37 
38 
39   /*************************************************************************/
40   /*                                                                       */
41   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
42   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
43   /* messages during execution.                                            */
44   /*                                                                       */
45 #undef  FT_COMPONENT
46 #define FT_COMPONENT  trace_ttgload
47 
48 
49   /*************************************************************************/
50   /*                                                                       */
51   /* Composite glyph flags.                                                */
52   /*                                                                       */
53 #define ARGS_ARE_WORDS             0x0001
54 #define ARGS_ARE_XY_VALUES         0x0002
55 #define ROUND_XY_TO_GRID           0x0004
56 #define WE_HAVE_A_SCALE            0x0008
57 /* reserved                        0x0010 */
58 #define MORE_COMPONENTS            0x0020
59 #define WE_HAVE_AN_XY_SCALE        0x0040
60 #define WE_HAVE_A_2X2              0x0080
61 #define WE_HAVE_INSTR              0x0100
62 #define USE_MY_METRICS             0x0200
63 #define OVERLAP_COMPOUND           0x0400
64 #define SCALED_COMPONENT_OFFSET    0x0800
65 #define UNSCALED_COMPONENT_OFFSET  0x1000
66 
67 
68   /*************************************************************************/
69   /*                                                                       */
70   /* Return the horizontal metrics in font units for a given glyph.        */
71   /*                                                                       */
72   FT_LOCAL_DEF( void )
TT_Get_HMetrics(TT_Face face,FT_UInt idx,FT_Short * lsb,FT_UShort * aw)73   TT_Get_HMetrics( TT_Face     face,
74                    FT_UInt     idx,
75                    FT_Short*   lsb,
76                    FT_UShort*  aw )
77   {
78     ( (SFNT_Service)face->sfnt )->get_metrics( face, 0, idx, lsb, aw );
79 
80     FT_TRACE5(( "  advance width (font units): %d\n", *aw ));
81     FT_TRACE5(( "  left side bearing (font units): %d\n", *lsb ));
82   }
83 
84 
85   /*************************************************************************/
86   /*                                                                       */
87   /* Return the vertical metrics in font units for a given glyph.          */
88   /* See macro `TT_LOADER_SET_PP' below for explanations.                  */
89   /*                                                                       */
90   FT_LOCAL_DEF( void )
TT_Get_VMetrics(TT_Face face,FT_UInt idx,FT_Pos yMax,FT_Short * tsb,FT_UShort * ah)91   TT_Get_VMetrics( TT_Face     face,
92                    FT_UInt     idx,
93                    FT_Pos      yMax,
94                    FT_Short*   tsb,
95                    FT_UShort*  ah )
96   {
97     if ( face->vertical_info )
98       ( (SFNT_Service)face->sfnt )->get_metrics( face, 1, idx, tsb, ah );
99 
100     else if ( face->os2.version != 0xFFFFU )
101     {
102       *tsb = face->os2.sTypoAscender - yMax;
103       *ah  = face->os2.sTypoAscender - face->os2.sTypoDescender;
104     }
105 
106     else
107     {
108       *tsb = face->horizontal.Ascender - yMax;
109       *ah  = face->horizontal.Ascender - face->horizontal.Descender;
110     }
111 
112     FT_TRACE5(( "  advance height (font units): %d\n", *ah ));
113     FT_TRACE5(( "  top side bearing (font units): %d\n", *tsb ));
114   }
115 
116 
117   static FT_Error
tt_get_metrics(TT_Loader loader,FT_UInt glyph_index)118   tt_get_metrics( TT_Loader  loader,
119                   FT_UInt    glyph_index )
120   {
121     TT_Face    face   = (TT_Face)loader->face;
122 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
123     TT_Driver  driver = (TT_Driver)FT_FACE_DRIVER( face );
124 #endif
125 
126     FT_Error   error = FT_Err_Ok;
127     FT_Stream  stream = loader->stream;
128 
129     FT_Short   left_bearing = 0, top_bearing = 0;
130     FT_UShort  advance_width = 0, advance_height = 0;
131 
132     /* we must preserve the stream position          */
133     /* (which gets altered by the metrics functions) */
134     FT_ULong  pos = FT_STREAM_POS();
135 
136 
137     TT_Get_HMetrics( face, glyph_index,
138                      &left_bearing,
139                      &advance_width );
140     TT_Get_VMetrics( face, glyph_index,
141                      loader->bbox.yMax,
142                      &top_bearing,
143                      &advance_height );
144 
145     if ( FT_STREAM_SEEK( pos ) )
146       return error;
147 
148     loader->left_bearing = left_bearing;
149     loader->advance      = advance_width;
150     loader->top_bearing  = top_bearing;
151     loader->vadvance     = advance_height;
152 
153 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
154     if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
155     {
156       if ( loader->exec )
157         loader->exec->sph_tweak_flags = 0;
158 
159       /* this may not be the right place for this, but it works */
160       if ( loader->exec && loader->exec->ignore_x_mode )
161         sph_set_tweaks( loader, glyph_index );
162     }
163 #endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */
164 
165     if ( !loader->linear_def )
166     {
167       loader->linear_def = 1;
168       loader->linear     = advance_width;
169     }
170 
171     return FT_Err_Ok;
172   }
173 
174 
175 #ifdef FT_CONFIG_OPTION_INCREMENTAL
176 
177   static void
tt_get_metrics_incr_overrides(TT_Loader loader,FT_UInt glyph_index)178   tt_get_metrics_incr_overrides( TT_Loader  loader,
179                                  FT_UInt    glyph_index )
180   {
181     TT_Face  face = (TT_Face)loader->face;
182 
183     FT_Short   left_bearing = 0, top_bearing = 0;
184     FT_UShort  advance_width = 0, advance_height = 0;
185 
186 
187     /* If this is an incrementally loaded font check whether there are */
188     /* overriding metrics for this glyph.                              */
189     if ( face->root.internal->incremental_interface                           &&
190          face->root.internal->incremental_interface->funcs->get_glyph_metrics )
191     {
192       FT_Incremental_MetricsRec  metrics;
193       FT_Error                   error;
194 
195 
196       metrics.bearing_x = loader->left_bearing;
197       metrics.bearing_y = 0;
198       metrics.advance   = loader->advance;
199       metrics.advance_v = 0;
200 
201       error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
202                 face->root.internal->incremental_interface->object,
203                 glyph_index, FALSE, &metrics );
204       if ( error )
205         goto Exit;
206 
207       left_bearing  = (FT_Short)metrics.bearing_x;
208       advance_width = (FT_UShort)metrics.advance;
209 
210 #if 0
211 
212       /* GWW: Do I do the same for vertical metrics? */
213       metrics.bearing_x = 0;
214       metrics.bearing_y = loader->top_bearing;
215       metrics.advance   = loader->vadvance;
216 
217       error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
218                 face->root.internal->incremental_interface->object,
219                 glyph_index, TRUE, &metrics );
220       if ( error )
221         goto Exit;
222 
223       top_bearing    = (FT_Short)metrics.bearing_y;
224       advance_height = (FT_UShort)metrics.advance;
225 
226 #endif /* 0 */
227 
228       loader->left_bearing = left_bearing;
229       loader->advance      = advance_width;
230       loader->top_bearing  = top_bearing;
231       loader->vadvance     = advance_height;
232 
233       if ( !loader->linear_def )
234       {
235         loader->linear_def = 1;
236         loader->linear     = advance_width;
237       }
238     }
239 
240   Exit:
241     return;
242   }
243 
244 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
245 
246 
247   /*************************************************************************/
248   /*                                                                       */
249   /* Translates an array of coordinates.                                   */
250   /*                                                                       */
251   static void
translate_array(FT_UInt n,FT_Vector * coords,FT_Pos delta_x,FT_Pos delta_y)252   translate_array( FT_UInt     n,
253                    FT_Vector*  coords,
254                    FT_Pos      delta_x,
255                    FT_Pos      delta_y )
256   {
257     FT_UInt  k;
258 
259 
260     if ( delta_x )
261       for ( k = 0; k < n; k++ )
262         coords[k].x += delta_x;
263 
264     if ( delta_y )
265       for ( k = 0; k < n; k++ )
266         coords[k].y += delta_y;
267   }
268 
269 
270   /*************************************************************************/
271   /*                                                                       */
272   /* The following functions are used by default with TrueType fonts.      */
273   /* However, they can be replaced by alternatives if we need to support   */
274   /* TrueType-compressed formats (like MicroType) in the future.           */
275   /*                                                                       */
276   /*************************************************************************/
277 
278   FT_CALLBACK_DEF( FT_Error )
TT_Access_Glyph_Frame(TT_Loader loader,FT_UInt glyph_index,FT_ULong offset,FT_UInt byte_count)279   TT_Access_Glyph_Frame( TT_Loader  loader,
280                          FT_UInt    glyph_index,
281                          FT_ULong   offset,
282                          FT_UInt    byte_count )
283   {
284     FT_Error   error = FT_Err_Ok;
285     FT_Stream  stream = loader->stream;
286 
287     /* for non-debug mode */
288     FT_UNUSED( glyph_index );
289 
290 
291     FT_TRACE4(( "Glyph %ld\n", glyph_index ));
292 
293     /* the following line sets the `error' variable through macros! */
294     if ( FT_STREAM_SEEK( offset ) || FT_FRAME_ENTER( byte_count ) )
295       return error;
296 
297     loader->cursor = stream->cursor;
298     loader->limit  = stream->limit;
299 
300     return FT_Err_Ok;
301   }
302 
303 
304   FT_CALLBACK_DEF( void )
TT_Forget_Glyph_Frame(TT_Loader loader)305   TT_Forget_Glyph_Frame( TT_Loader  loader )
306   {
307     FT_Stream  stream = loader->stream;
308 
309 
310     FT_FRAME_EXIT();
311   }
312 
313 
314   FT_CALLBACK_DEF( FT_Error )
TT_Load_Glyph_Header(TT_Loader loader)315   TT_Load_Glyph_Header( TT_Loader  loader )
316   {
317     FT_Byte*  p     = loader->cursor;
318     FT_Byte*  limit = loader->limit;
319 
320 
321     if ( p + 10 > limit )
322       return FT_THROW( Invalid_Outline );
323 
324     loader->n_contours = FT_NEXT_SHORT( p );
325 
326     loader->bbox.xMin = FT_NEXT_SHORT( p );
327     loader->bbox.yMin = FT_NEXT_SHORT( p );
328     loader->bbox.xMax = FT_NEXT_SHORT( p );
329     loader->bbox.yMax = FT_NEXT_SHORT( p );
330 
331     FT_TRACE5(( "  # of contours: %d\n", loader->n_contours ));
332     FT_TRACE5(( "  xMin: %4d  xMax: %4d\n", loader->bbox.xMin,
333                                             loader->bbox.xMax ));
334     FT_TRACE5(( "  yMin: %4d  yMax: %4d\n", loader->bbox.yMin,
335                                             loader->bbox.yMax ));
336     loader->cursor = p;
337 
338     return FT_Err_Ok;
339   }
340 
341 
342   FT_CALLBACK_DEF( FT_Error )
TT_Load_Simple_Glyph(TT_Loader load)343   TT_Load_Simple_Glyph( TT_Loader  load )
344   {
345     FT_Error        error;
346     FT_Byte*        p          = load->cursor;
347     FT_Byte*        limit      = load->limit;
348     FT_GlyphLoader  gloader    = load->gloader;
349     FT_Int          n_contours = load->n_contours;
350     FT_Outline*     outline;
351     FT_UShort       n_ins;
352     FT_Int          n_points;
353     FT_ULong        tmp;
354 
355     FT_Byte         *flag, *flag_limit;
356     FT_Byte         c, count;
357     FT_Vector       *vec, *vec_limit;
358     FT_Pos          x;
359     FT_Short        *cont, *cont_limit, prev_cont;
360     FT_Int          xy_size = 0;
361 
362 
363     /* check that we can add the contours to the glyph */
364     error = FT_GLYPHLOADER_CHECK_POINTS( gloader, 0, n_contours );
365     if ( error )
366       goto Fail;
367 
368     /* reading the contours' endpoints & number of points */
369     cont       = gloader->current.outline.contours;
370     cont_limit = cont + n_contours;
371 
372     /* check space for contours array + instructions count */
373     if ( n_contours >= 0xFFF || p + ( n_contours + 1 ) * 2 > limit )
374       goto Invalid_Outline;
375 
376     prev_cont = FT_NEXT_SHORT( p );
377 
378     if ( n_contours > 0 )
379       cont[0] = prev_cont;
380 
381     if ( prev_cont < 0 )
382       goto Invalid_Outline;
383 
384     for ( cont++; cont < cont_limit; cont++ )
385     {
386       cont[0] = FT_NEXT_SHORT( p );
387       if ( cont[0] <= prev_cont )
388       {
389         /* unordered contours: this is invalid */
390         goto Invalid_Outline;
391       }
392       prev_cont = cont[0];
393     }
394 
395     n_points = 0;
396     if ( n_contours > 0 )
397     {
398       n_points = cont[-1] + 1;
399       if ( n_points < 0 )
400         goto Invalid_Outline;
401     }
402 
403     /* note that we will add four phantom points later */
404     error = FT_GLYPHLOADER_CHECK_POINTS( gloader, n_points + 4, 0 );
405     if ( error )
406       goto Fail;
407 
408     /* reading the bytecode instructions */
409     load->glyph->control_len  = 0;
410     load->glyph->control_data = 0;
411 
412     if ( p + 2 > limit )
413       goto Invalid_Outline;
414 
415     n_ins = FT_NEXT_USHORT( p );
416 
417     FT_TRACE5(( "  Instructions size: %u\n", n_ins ));
418 
419     /* check it */
420     if ( ( limit - p ) < n_ins )
421     {
422       FT_TRACE0(( "TT_Load_Simple_Glyph: instruction count mismatch\n" ));
423       error = FT_THROW( Too_Many_Hints );
424       goto Fail;
425     }
426 
427 #ifdef TT_USE_BYTECODE_INTERPRETER
428 
429     if ( IS_HINTED( load->load_flags ) )
430     {
431       /* we don't trust `maxSizeOfInstructions' in the `maxp' table */
432       /* and thus update the bytecode array size by ourselves       */
433 
434       tmp   = load->exec->glyphSize;
435       error = Update_Max( load->exec->memory,
436                           &tmp,
437                           sizeof ( FT_Byte ),
438                           (void*)&load->exec->glyphIns,
439                           n_ins );
440 
441       load->exec->glyphSize = (FT_UShort)tmp;
442       if ( error )
443         return error;
444 
445       load->glyph->control_len  = n_ins;
446       load->glyph->control_data = load->exec->glyphIns;
447 
448       FT_MEM_COPY( load->exec->glyphIns, p, (FT_Long)n_ins );
449     }
450 
451 #endif /* TT_USE_BYTECODE_INTERPRETER */
452 
453     p += n_ins;
454 
455     outline = &gloader->current.outline;
456 
457     /* reading the point tags */
458     flag       = (FT_Byte*)outline->tags;
459     flag_limit = flag + n_points;
460 
461     FT_ASSERT( flag != NULL );
462 
463     while ( flag < flag_limit )
464     {
465       if ( p + 1 > limit )
466         goto Invalid_Outline;
467 
468       *flag++ = c = FT_NEXT_BYTE( p );
469       if ( c & 8 )
470       {
471         if ( p + 1 > limit )
472           goto Invalid_Outline;
473 
474         count = FT_NEXT_BYTE( p );
475         if ( flag + (FT_Int)count > flag_limit )
476           goto Invalid_Outline;
477 
478         for ( ; count > 0; count-- )
479           *flag++ = c;
480       }
481     }
482 
483     /* reading the X coordinates */
484 
485     vec       = outline->points;
486     vec_limit = vec + n_points;
487     flag      = (FT_Byte*)outline->tags;
488     x         = 0;
489 
490     if ( p + xy_size > limit )
491       goto Invalid_Outline;
492 
493     for ( ; vec < vec_limit; vec++, flag++ )
494     {
495       FT_Pos   y = 0;
496       FT_Byte  f = *flag;
497 
498 
499       if ( f & 2 )
500       {
501         if ( p + 1 > limit )
502           goto Invalid_Outline;
503 
504         y = (FT_Pos)FT_NEXT_BYTE( p );
505         if ( ( f & 16 ) == 0 )
506           y = -y;
507       }
508       else if ( ( f & 16 ) == 0 )
509       {
510         if ( p + 2 > limit )
511           goto Invalid_Outline;
512 
513         y = (FT_Pos)FT_NEXT_SHORT( p );
514       }
515 
516       x     += y;
517       vec->x = x;
518       /* the cast is for stupid compilers */
519       *flag  = (FT_Byte)( f & ~( 2 | 16 ) );
520     }
521 
522     /* reading the Y coordinates */
523 
524     vec       = gloader->current.outline.points;
525     vec_limit = vec + n_points;
526     flag      = (FT_Byte*)outline->tags;
527     x         = 0;
528 
529     for ( ; vec < vec_limit; vec++, flag++ )
530     {
531       FT_Pos   y = 0;
532       FT_Byte  f = *flag;
533 
534 
535       if ( f & 4 )
536       {
537         if ( p + 1 > limit )
538           goto Invalid_Outline;
539 
540         y = (FT_Pos)FT_NEXT_BYTE( p );
541         if ( ( f & 32 ) == 0 )
542           y = -y;
543       }
544       else if ( ( f & 32 ) == 0 )
545       {
546         if ( p + 2 > limit )
547           goto Invalid_Outline;
548 
549         y = (FT_Pos)FT_NEXT_SHORT( p );
550       }
551 
552       x     += y;
553       vec->y = x;
554       /* the cast is for stupid compilers */
555       *flag  = (FT_Byte)( f & FT_CURVE_TAG_ON );
556     }
557 
558     outline->n_points   = (FT_UShort)n_points;
559     outline->n_contours = (FT_Short) n_contours;
560 
561     load->cursor = p;
562 
563   Fail:
564     return error;
565 
566   Invalid_Outline:
567     error = FT_THROW( Invalid_Outline );
568     goto Fail;
569   }
570 
571 
572   FT_CALLBACK_DEF( FT_Error )
TT_Load_Composite_Glyph(TT_Loader loader)573   TT_Load_Composite_Glyph( TT_Loader  loader )
574   {
575     FT_Error        error;
576     FT_Byte*        p       = loader->cursor;
577     FT_Byte*        limit   = loader->limit;
578     FT_GlyphLoader  gloader = loader->gloader;
579     FT_SubGlyph     subglyph;
580     FT_UInt         num_subglyphs;
581 
582 
583     num_subglyphs = 0;
584 
585     do
586     {
587       FT_Fixed  xx, xy, yy, yx;
588       FT_UInt   count;
589 
590 
591       /* check that we can load a new subglyph */
592       error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs + 1 );
593       if ( error )
594         goto Fail;
595 
596       /* check space */
597       if ( p + 4 > limit )
598         goto Invalid_Composite;
599 
600       subglyph = gloader->current.subglyphs + num_subglyphs;
601 
602       subglyph->arg1 = subglyph->arg2 = 0;
603 
604       subglyph->flags = FT_NEXT_USHORT( p );
605       subglyph->index = FT_NEXT_USHORT( p );
606 
607       /* check space */
608       count = 2;
609       if ( subglyph->flags & ARGS_ARE_WORDS )
610         count += 2;
611       if ( subglyph->flags & WE_HAVE_A_SCALE )
612         count += 2;
613       else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
614         count += 4;
615       else if ( subglyph->flags & WE_HAVE_A_2X2 )
616         count += 8;
617 
618       if ( p + count > limit )
619         goto Invalid_Composite;
620 
621       /* read arguments */
622       if ( subglyph->flags & ARGS_ARE_WORDS )
623       {
624         subglyph->arg1 = FT_NEXT_SHORT( p );
625         subglyph->arg2 = FT_NEXT_SHORT( p );
626       }
627       else
628       {
629         subglyph->arg1 = FT_NEXT_CHAR( p );
630         subglyph->arg2 = FT_NEXT_CHAR( p );
631       }
632 
633       /* read transform */
634       xx = yy = 0x10000L;
635       xy = yx = 0;
636 
637       if ( subglyph->flags & WE_HAVE_A_SCALE )
638       {
639         xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
640         yy = xx;
641       }
642       else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
643       {
644         xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
645         yy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
646       }
647       else if ( subglyph->flags & WE_HAVE_A_2X2 )
648       {
649         xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
650         yx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
651         xy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
652         yy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
653       }
654 
655       subglyph->transform.xx = xx;
656       subglyph->transform.xy = xy;
657       subglyph->transform.yx = yx;
658       subglyph->transform.yy = yy;
659 
660       num_subglyphs++;
661 
662     } while ( subglyph->flags & MORE_COMPONENTS );
663 
664     gloader->current.num_subglyphs = num_subglyphs;
665 
666 #ifdef TT_USE_BYTECODE_INTERPRETER
667 
668     {
669       FT_Stream  stream = loader->stream;
670 
671 
672       /* we must undo the FT_FRAME_ENTER in order to point */
673       /* to the composite instructions, if we find some.   */
674       /* We will process them later.                       */
675       /*                                                   */
676       loader->ins_pos = (FT_ULong)( FT_STREAM_POS() +
677                                     p - limit );
678     }
679 
680 #endif
681 
682     loader->cursor = p;
683 
684   Fail:
685     return error;
686 
687   Invalid_Composite:
688     error = FT_THROW( Invalid_Composite );
689     goto Fail;
690   }
691 
692 
693   FT_LOCAL_DEF( void )
TT_Init_Glyph_Loading(TT_Face face)694   TT_Init_Glyph_Loading( TT_Face  face )
695   {
696     face->access_glyph_frame   = TT_Access_Glyph_Frame;
697     face->read_glyph_header    = TT_Load_Glyph_Header;
698     face->read_simple_glyph    = TT_Load_Simple_Glyph;
699     face->read_composite_glyph = TT_Load_Composite_Glyph;
700     face->forget_glyph_frame   = TT_Forget_Glyph_Frame;
701   }
702 
703 
704   static void
tt_prepare_zone(TT_GlyphZone zone,FT_GlyphLoad load,FT_UInt start_point,FT_UInt start_contour)705   tt_prepare_zone( TT_GlyphZone  zone,
706                    FT_GlyphLoad  load,
707                    FT_UInt       start_point,
708                    FT_UInt       start_contour )
709   {
710     zone->n_points    = (FT_UShort)( load->outline.n_points - start_point );
711     zone->n_contours  = (FT_Short) ( load->outline.n_contours -
712                                        start_contour );
713     zone->org         = load->extra_points + start_point;
714     zone->cur         = load->outline.points + start_point;
715     zone->orus        = load->extra_points2 + start_point;
716     zone->tags        = (FT_Byte*)load->outline.tags + start_point;
717     zone->contours    = (FT_UShort*)load->outline.contours + start_contour;
718     zone->first_point = (FT_UShort)start_point;
719   }
720 
721 
722   /*************************************************************************/
723   /*                                                                       */
724   /* <Function>                                                            */
725   /*    TT_Hint_Glyph                                                      */
726   /*                                                                       */
727   /* <Description>                                                         */
728   /*    Hint the glyph using the zone prepared by the caller.  Note that   */
729   /*    the zone is supposed to include four phantom points.               */
730   /*                                                                       */
731   static FT_Error
TT_Hint_Glyph(TT_Loader loader,FT_Bool is_composite)732   TT_Hint_Glyph( TT_Loader  loader,
733                  FT_Bool    is_composite )
734   {
735 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
736     TT_Face    face   = (TT_Face)loader->face;
737     TT_Driver  driver = (TT_Driver)FT_FACE_DRIVER( face );
738 #endif
739 
740     TT_GlyphZone  zone = &loader->zone;
741 
742 #ifdef TT_USE_BYTECODE_INTERPRETER
743     FT_UInt       n_ins;
744 #else
745     FT_UNUSED( is_composite );
746 #endif
747 
748 
749 #ifdef TT_USE_BYTECODE_INTERPRETER
750     if ( loader->glyph->control_len > 0xFFFFL )
751     {
752       FT_TRACE1(( "TT_Hint_Glyph: too long instructions" ));
753       FT_TRACE1(( " (0x%lx byte) is truncated\n",
754                  loader->glyph->control_len ));
755     }
756     n_ins = (FT_UInt)( loader->glyph->control_len );
757 
758     /* save original point position in org */
759     if ( n_ins > 0 )
760       FT_ARRAY_COPY( zone->org, zone->cur, zone->n_points );
761 
762     /* Reset graphics state. */
763     loader->exec->GS = ((TT_Size)loader->size)->GS;
764 
765     /* XXX: UNDOCUMENTED! Hinting instructions of a composite glyph */
766     /*      completely refer to the (already) hinted subglyphs.     */
767     if ( is_composite )
768     {
769       loader->exec->metrics.x_scale = 1 << 16;
770       loader->exec->metrics.y_scale = 1 << 16;
771 
772       FT_ARRAY_COPY( zone->orus, zone->cur, zone->n_points );
773     }
774     else
775     {
776       loader->exec->metrics.x_scale =
777         ((TT_Size)loader->size)->metrics.x_scale;
778       loader->exec->metrics.y_scale =
779         ((TT_Size)loader->size)->metrics.y_scale;
780     }
781 #endif
782 
783     /* round phantom points */
784     zone->cur[zone->n_points - 4].x =
785       FT_PIX_ROUND( zone->cur[zone->n_points - 4].x );
786     zone->cur[zone->n_points - 3].x =
787       FT_PIX_ROUND( zone->cur[zone->n_points - 3].x );
788     zone->cur[zone->n_points - 2].y =
789       FT_PIX_ROUND( zone->cur[zone->n_points - 2].y );
790     zone->cur[zone->n_points - 1].y =
791       FT_PIX_ROUND( zone->cur[zone->n_points - 1].y );
792 
793 #ifdef TT_USE_BYTECODE_INTERPRETER
794 
795     if ( n_ins > 0 )
796     {
797       FT_Bool   debug;
798       FT_Error  error;
799 
800       FT_GlyphLoader  gloader         = loader->gloader;
801       FT_Outline      current_outline = gloader->current.outline;
802 
803 
804       error = TT_Set_CodeRange( loader->exec, tt_coderange_glyph,
805                                 loader->exec->glyphIns, n_ins );
806       if ( error )
807         return error;
808 
809       loader->exec->is_composite = is_composite;
810       loader->exec->pts          = *zone;
811 
812       debug = FT_BOOL( !( loader->load_flags & FT_LOAD_NO_SCALE ) &&
813                        ((TT_Size)loader->size)->debug             );
814 
815       error = TT_Run_Context( loader->exec, debug );
816       if ( error && loader->exec->pedantic_hinting )
817         return error;
818 
819       /* store drop-out mode in bits 5-7; set bit 2 also as a marker */
820       current_outline.tags[0] |=
821         ( loader->exec->GS.scan_type << 5 ) | FT_CURVE_TAG_HAS_SCANMODE;
822     }
823 
824 #endif
825 
826     /* save glyph phantom points */
827     loader->pp1 = zone->cur[zone->n_points - 4];
828     loader->pp2 = zone->cur[zone->n_points - 3];
829     loader->pp3 = zone->cur[zone->n_points - 2];
830     loader->pp4 = zone->cur[zone->n_points - 1];
831 
832 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
833     if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
834     {
835       if ( loader->exec->sph_tweak_flags & SPH_TWEAK_DEEMBOLDEN )
836         FT_Outline_EmboldenXY( &loader->gloader->current.outline, -24, 0 );
837 
838       else if ( loader->exec->sph_tweak_flags & SPH_TWEAK_EMBOLDEN )
839         FT_Outline_EmboldenXY( &loader->gloader->current.outline, 24, 0 );
840     }
841 #endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */
842 
843     return FT_Err_Ok;
844   }
845 
846 
847   /*************************************************************************/
848   /*                                                                       */
849   /* <Function>                                                            */
850   /*    TT_Process_Simple_Glyph                                            */
851   /*                                                                       */
852   /* <Description>                                                         */
853   /*    Once a simple glyph has been loaded, it needs to be processed.     */
854   /*    Usually, this means scaling and hinting through bytecode           */
855   /*    interpretation.                                                    */
856   /*                                                                       */
857   static FT_Error
TT_Process_Simple_Glyph(TT_Loader loader)858   TT_Process_Simple_Glyph( TT_Loader  loader )
859   {
860     FT_GlyphLoader  gloader = loader->gloader;
861     FT_Error        error   = FT_Err_Ok;
862     FT_Outline*     outline;
863     FT_Int          n_points;
864 
865 
866     outline  = &gloader->current.outline;
867     n_points = outline->n_points;
868 
869     /* set phantom points */
870 
871     outline->points[n_points    ] = loader->pp1;
872     outline->points[n_points + 1] = loader->pp2;
873     outline->points[n_points + 2] = loader->pp3;
874     outline->points[n_points + 3] = loader->pp4;
875 
876     outline->tags[n_points    ] = 0;
877     outline->tags[n_points + 1] = 0;
878     outline->tags[n_points + 2] = 0;
879     outline->tags[n_points + 3] = 0;
880 
881     n_points += 4;
882 
883 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
884 
885     if ( ((TT_Face)loader->face)->doblend )
886     {
887       /* Deltas apply to the unscaled data. */
888       FT_Vector*  deltas;
889       FT_Memory   memory = loader->face->memory;
890       FT_Int      i;
891 
892 
893       error = TT_Vary_Get_Glyph_Deltas( (TT_Face)(loader->face),
894                                         loader->glyph_index,
895                                         &deltas,
896                                         n_points );
897       if ( error )
898         return error;
899 
900       for ( i = 0; i < n_points; ++i )
901       {
902         outline->points[i].x += deltas[i].x;
903         outline->points[i].y += deltas[i].y;
904       }
905 
906       FT_FREE( deltas );
907     }
908 
909 #endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
910 
911     if ( IS_HINTED( loader->load_flags ) )
912     {
913       tt_prepare_zone( &loader->zone, &gloader->current, 0, 0 );
914 
915       FT_ARRAY_COPY( loader->zone.orus, loader->zone.cur,
916                      loader->zone.n_points + 4 );
917     }
918 
919     {
920 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
921       TT_Face    face   = (TT_Face)loader->face;
922       TT_Driver  driver = (TT_Driver)FT_FACE_DRIVER( face );
923 
924       FT_String*  family         = face->root.family_name;
925       FT_Int      ppem           = loader->size->metrics.x_ppem;
926       FT_String*  style          = face->root.style_name;
927       FT_Int      x_scale_factor = 1000;
928 #endif
929 
930       FT_Vector*  vec   = outline->points;
931       FT_Vector*  limit = outline->points + n_points;
932 
933       FT_Fixed  x_scale = 0; /* pacify compiler */
934       FT_Fixed  y_scale = 0;
935 
936       FT_Bool  do_scale = FALSE;
937 
938 
939 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
940 
941       if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
942       {
943         /* scale, but only if enabled and only if TT hinting is being used */
944         if ( IS_HINTED( loader->load_flags ) )
945           x_scale_factor = sph_test_tweak_x_scaling( face,
946                                                      family,
947                                                      ppem,
948                                                      style,
949                                                      loader->glyph_index );
950         /* scale the glyph */
951         if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 ||
952              x_scale_factor != 1000                         )
953         {
954           x_scale = FT_MulDiv( ((TT_Size)loader->size)->metrics.x_scale,
955                                x_scale_factor, 1000 );
956           y_scale = ((TT_Size)loader->size)->metrics.y_scale;
957 
958           /* compensate for any scaling by de/emboldening; */
959           /* the amount was determined via experimentation */
960           if ( x_scale_factor != 1000 && ppem > 11 )
961             FT_Outline_EmboldenXY( outline,
962                                    FT_MulFix( 1280 * ppem,
963                                               1000 - x_scale_factor ),
964                                    0 );
965           do_scale = TRUE;
966         }
967       }
968       else
969 
970 #endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */
971 
972       {
973         /* scale the glyph */
974         if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
975         {
976           x_scale = ((TT_Size)loader->size)->metrics.x_scale;
977           y_scale = ((TT_Size)loader->size)->metrics.y_scale;
978 
979           do_scale = TRUE;
980         }
981       }
982 
983       if ( do_scale )
984       {
985         for ( ; vec < limit; vec++ )
986         {
987           vec->x = FT_MulFix( vec->x, x_scale );
988           vec->y = FT_MulFix( vec->y, y_scale );
989         }
990 
991         loader->pp1 = outline->points[n_points - 4];
992         loader->pp2 = outline->points[n_points - 3];
993         loader->pp3 = outline->points[n_points - 2];
994         loader->pp4 = outline->points[n_points - 1];
995       }
996     }
997 
998     if ( IS_HINTED( loader->load_flags ) )
999     {
1000       loader->zone.n_points += 4;
1001 
1002       error = TT_Hint_Glyph( loader, 0 );
1003     }
1004 
1005     return error;
1006   }
1007 
1008 
1009   /*************************************************************************/
1010   /*                                                                       */
1011   /* <Function>                                                            */
1012   /*    TT_Process_Composite_Component                                     */
1013   /*                                                                       */
1014   /* <Description>                                                         */
1015   /*    Once a composite component has been loaded, it needs to be         */
1016   /*    processed.  Usually, this means transforming and translating.      */
1017   /*                                                                       */
1018   static FT_Error
TT_Process_Composite_Component(TT_Loader loader,FT_SubGlyph subglyph,FT_UInt start_point,FT_UInt num_base_points)1019   TT_Process_Composite_Component( TT_Loader    loader,
1020                                   FT_SubGlyph  subglyph,
1021                                   FT_UInt      start_point,
1022                                   FT_UInt      num_base_points )
1023   {
1024     FT_GlyphLoader  gloader    = loader->gloader;
1025     FT_Vector*      base_vec   = gloader->base.outline.points;
1026     FT_UInt         num_points = gloader->base.outline.n_points;
1027     FT_Bool         have_scale;
1028     FT_Pos          x, y;
1029 
1030 
1031     have_scale = FT_BOOL( subglyph->flags & ( WE_HAVE_A_SCALE     |
1032                                               WE_HAVE_AN_XY_SCALE |
1033                                               WE_HAVE_A_2X2       ) );
1034 
1035     /* perform the transform required for this subglyph */
1036     if ( have_scale )
1037     {
1038       FT_UInt  i;
1039 
1040 
1041       for ( i = num_base_points; i < num_points; i++ )
1042         FT_Vector_Transform( base_vec + i, &subglyph->transform );
1043     }
1044 
1045     /* get offset */
1046     if ( !( subglyph->flags & ARGS_ARE_XY_VALUES ) )
1047     {
1048       FT_UInt     k = subglyph->arg1;
1049       FT_UInt     l = subglyph->arg2;
1050       FT_Vector*  p1;
1051       FT_Vector*  p2;
1052 
1053 
1054       /* match l-th point of the newly loaded component to the k-th point */
1055       /* of the previously loaded components.                             */
1056 
1057       /* change to the point numbers used by our outline */
1058       k += start_point;
1059       l += num_base_points;
1060       if ( k >= num_base_points ||
1061            l >= num_points      )
1062         return FT_THROW( Invalid_Composite );
1063 
1064       p1 = gloader->base.outline.points + k;
1065       p2 = gloader->base.outline.points + l;
1066 
1067       x = p1->x - p2->x;
1068       y = p1->y - p2->y;
1069     }
1070     else
1071     {
1072       x = subglyph->arg1;
1073       y = subglyph->arg2;
1074 
1075       if ( !x && !y )
1076         return FT_Err_Ok;
1077 
1078       /* Use a default value dependent on                                  */
1079       /* TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED.  This is useful for old */
1080       /* TT fonts which don't set the xxx_COMPONENT_OFFSET bit.            */
1081 
1082       if ( have_scale &&
1083 #ifdef TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED
1084            !( subglyph->flags & UNSCALED_COMPONENT_OFFSET ) )
1085 #else
1086             ( subglyph->flags & SCALED_COMPONENT_OFFSET ) )
1087 #endif
1088       {
1089 
1090 #if 0
1091 
1092         /*******************************************************************/
1093         /*                                                                 */
1094         /* This algorithm is what Apple documents.  But it doesn't work.   */
1095         /*                                                                 */
1096         int  a = subglyph->transform.xx > 0 ?  subglyph->transform.xx
1097                                             : -subglyph->transform.xx;
1098         int  b = subglyph->transform.yx > 0 ?  subglyph->transform.yx
1099                                             : -subglyph->transform.yx;
1100         int  c = subglyph->transform.xy > 0 ?  subglyph->transform.xy
1101                                             : -subglyph->transform.xy;
1102         int  d = subglyph->transform.yy > 0 ? subglyph->transform.yy
1103                                             : -subglyph->transform.yy;
1104         int  m = a > b ? a : b;
1105         int  n = c > d ? c : d;
1106 
1107 
1108         if ( a - b <= 33 && a - b >= -33 )
1109           m *= 2;
1110         if ( c - d <= 33 && c - d >= -33 )
1111           n *= 2;
1112         x = FT_MulFix( x, m );
1113         y = FT_MulFix( y, n );
1114 
1115 #else /* 1 */
1116 
1117         /*******************************************************************/
1118         /*                                                                 */
1119         /* This algorithm is a guess and works much better than the above. */
1120         /*                                                                 */
1121         FT_Fixed  mac_xscale = FT_Hypot( subglyph->transform.xx,
1122                                          subglyph->transform.xy );
1123         FT_Fixed  mac_yscale = FT_Hypot( subglyph->transform.yy,
1124                                          subglyph->transform.yx );
1125 
1126 
1127         x = FT_MulFix( x, mac_xscale );
1128         y = FT_MulFix( y, mac_yscale );
1129 
1130 #endif /* 1 */
1131 
1132       }
1133 
1134       if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
1135       {
1136         FT_Fixed  x_scale = ((TT_Size)loader->size)->metrics.x_scale;
1137         FT_Fixed  y_scale = ((TT_Size)loader->size)->metrics.y_scale;
1138 
1139 
1140         x = FT_MulFix( x, x_scale );
1141         y = FT_MulFix( y, y_scale );
1142 
1143         if ( subglyph->flags & ROUND_XY_TO_GRID )
1144         {
1145           x = FT_PIX_ROUND( x );
1146           y = FT_PIX_ROUND( y );
1147         }
1148       }
1149     }
1150 
1151     if ( x || y )
1152       translate_array( num_points - num_base_points,
1153                        base_vec + num_base_points,
1154                        x, y );
1155 
1156     return FT_Err_Ok;
1157   }
1158 
1159 
1160   /*************************************************************************/
1161   /*                                                                       */
1162   /* <Function>                                                            */
1163   /*    TT_Process_Composite_Glyph                                         */
1164   /*                                                                       */
1165   /* <Description>                                                         */
1166   /*    This is slightly different from TT_Process_Simple_Glyph, in that   */
1167   /*    its sole purpose is to hint the glyph.  Thus this function is      */
1168   /*    only available when bytecode interpreter is enabled.               */
1169   /*                                                                       */
1170   static FT_Error
TT_Process_Composite_Glyph(TT_Loader loader,FT_UInt start_point,FT_UInt start_contour)1171   TT_Process_Composite_Glyph( TT_Loader  loader,
1172                               FT_UInt    start_point,
1173                               FT_UInt    start_contour )
1174   {
1175     FT_Error     error;
1176     FT_Outline*  outline;
1177     FT_UInt      i;
1178 
1179 
1180     outline = &loader->gloader->base.outline;
1181 
1182     /* make room for phantom points */
1183     error = FT_GLYPHLOADER_CHECK_POINTS( loader->gloader,
1184                                          outline->n_points + 4,
1185                                          0 );
1186     if ( error )
1187       return error;
1188 
1189     outline->points[outline->n_points    ] = loader->pp1;
1190     outline->points[outline->n_points + 1] = loader->pp2;
1191     outline->points[outline->n_points + 2] = loader->pp3;
1192     outline->points[outline->n_points + 3] = loader->pp4;
1193 
1194     outline->tags[outline->n_points    ] = 0;
1195     outline->tags[outline->n_points + 1] = 0;
1196     outline->tags[outline->n_points + 2] = 0;
1197     outline->tags[outline->n_points + 3] = 0;
1198 
1199 #ifdef TT_USE_BYTECODE_INTERPRETER
1200 
1201     {
1202       FT_Stream  stream = loader->stream;
1203       FT_UShort  n_ins, max_ins;
1204       FT_ULong   tmp;
1205 
1206 
1207       /* TT_Load_Composite_Glyph only gives us the offset of instructions */
1208       /* so we read them here                                             */
1209       if ( FT_STREAM_SEEK( loader->ins_pos ) ||
1210            FT_READ_USHORT( n_ins )           )
1211         return error;
1212 
1213       FT_TRACE5(( "  Instructions size = %d\n", n_ins ));
1214 
1215       /* check it */
1216       max_ins = ((TT_Face)loader->face)->max_profile.maxSizeOfInstructions;
1217       if ( n_ins > max_ins )
1218       {
1219         /* don't trust `maxSizeOfInstructions'; */
1220         /* only do a rough safety check         */
1221         if ( (FT_Int)n_ins > loader->byte_len )
1222         {
1223           FT_TRACE1(( "TT_Process_Composite_Glyph:"
1224                       " too many instructions (%d) for glyph with length %d\n",
1225                       n_ins, loader->byte_len ));
1226           return FT_THROW( Too_Many_Hints );
1227         }
1228 
1229         tmp   = loader->exec->glyphSize;
1230         error = Update_Max( loader->exec->memory,
1231                             &tmp,
1232                             sizeof ( FT_Byte ),
1233                             (void*)&loader->exec->glyphIns,
1234                             n_ins );
1235 
1236         loader->exec->glyphSize = (FT_UShort)tmp;
1237         if ( error )
1238           return error;
1239       }
1240       else if ( n_ins == 0 )
1241         return FT_Err_Ok;
1242 
1243       if ( FT_STREAM_READ( loader->exec->glyphIns, n_ins ) )
1244         return error;
1245 
1246       loader->glyph->control_data = loader->exec->glyphIns;
1247       loader->glyph->control_len  = n_ins;
1248     }
1249 
1250 #endif
1251 
1252     tt_prepare_zone( &loader->zone, &loader->gloader->base,
1253                      start_point, start_contour );
1254 
1255     /* Some points are likely touched during execution of  */
1256     /* instructions on components.  So let's untouch them. */
1257     for ( i = 0; i < loader->zone.n_points; i++ )
1258       loader->zone.tags[i] &= ~FT_CURVE_TAG_TOUCH_BOTH;
1259 
1260     loader->zone.n_points += 4;
1261 
1262     return TT_Hint_Glyph( loader, 1 );
1263   }
1264 
1265 
1266   /*
1267    * Calculate the phantom points
1268    *
1269    * Defining the right side bearing (rsb) as
1270    *
1271    *   rsb = aw - (lsb + xmax - xmin)
1272    *
1273    * (with `aw' the advance width, `lsb' the left side bearing, and `xmin'
1274    * and `xmax' the glyph's minimum and maximum x value), the OpenType
1275    * specification defines the initial position of horizontal phantom points
1276    * as
1277    *
1278    *   pp1 = (round(xmin - lsb), 0)      ,
1279    *   pp2 = (round(pp1 + aw), 0)        .
1280    *
1281    * Note that the rounding to the grid (in the device space) is not
1282    * documented currently in the specification.
1283    *
1284    * However, the specification lacks the precise definition of vertical
1285    * phantom points.  Greg Hitchcock provided the following explanation.
1286    *
1287    * - a `vmtx' table is present
1288    *
1289    *   For any glyph, the minimum and maximum y values (`ymin' and `ymax')
1290    *   are given in the `glyf' table, the top side bearing (tsb) and advance
1291    *   height (ah) are given in the `vmtx' table.  The bottom side bearing
1292    *   (bsb) is then calculated as
1293    *
1294    *     bsb = ah - (tsb + ymax - ymin)       ,
1295    *
1296    *   and the initial position of vertical phantom points is
1297    *
1298    *     pp3 = (x, round(ymax + tsb))       ,
1299    *     pp4 = (x, round(pp3 - ah))         .
1300    *
1301    *   See below for value `x'.
1302    *
1303    * - no `vmtx' table in the font
1304    *
1305    *   If there is an `OS/2' table, we set
1306    *
1307    *     DefaultAscender = sTypoAscender       ,
1308    *     DefaultDescender = sTypoDescender     ,
1309    *
1310    *   otherwise we use data from the `hhea' table:
1311    *
1312    *     DefaultAscender = Ascender         ,
1313    *     DefaultDescender = Descender       .
1314    *
1315    *   With these two variables we can now set
1316    *
1317    *     ah = DefaultAscender - sDefaultDescender    ,
1318    *     tsb = DefaultAscender - yMax                ,
1319    *
1320    *   and proceed as if a `vmtx' table was present.
1321    *
1322    * Usually we have
1323    *
1324    *   x = aw / 2      ,                                                (1)
1325    *
1326    * but there is one compatibility case where it can be set to
1327    *
1328    *   x = -DefaultDescender -
1329    *         ((DefaultAscender - DefaultDescender - aw) / 2)     .      (2)
1330    *
1331    * and another one with
1332    *
1333    *   x = 0     .                                                      (3)
1334    *
1335    * In Windows, the history of those values is quite complicated,
1336    * depending on the hinting engine (that is, the graphics framework).
1337    *
1338    *   framework        from                 to       formula
1339    *  ----------------------------------------------------------
1340    *    GDI       Windows 98               current      (1)
1341    *              (Windows 2000 for NT)
1342    *    GDI+      Windows XP               Windows 7    (2)
1343    *    GDI+      Windows 8                current      (3)
1344    *    DWrite    Windows 7                current      (3)
1345    *
1346    * For simplicity, FreeType uses (1) for grayscale subpixel hinting and
1347    * (3) for everything else.
1348    *
1349    */
1350 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
1351 
1352 #define TT_LOADER_SET_PP( loader )                                          \
1353           do                                                                \
1354           {                                                                 \
1355             FT_Bool  subpixel_  = loader->exec ? loader->exec->subpixel     \
1356                                                : 0;                         \
1357             FT_Bool  grayscale_ = loader->exec ? loader->exec->grayscale    \
1358                                                : 0;                         \
1359             FT_Bool  use_aw_2_  = (FT_Bool)( subpixel_ && grayscale_ );     \
1360                                                                             \
1361                                                                             \
1362             (loader)->pp1.x = (loader)->bbox.xMin - (loader)->left_bearing; \
1363             (loader)->pp1.y = 0;                                            \
1364             (loader)->pp2.x = (loader)->pp1.x + (loader)->advance;          \
1365             (loader)->pp2.y = 0;                                            \
1366                                                                             \
1367             (loader)->pp3.x = use_aw_2_ ? (loader)->advance / 2 : 0;        \
1368             (loader)->pp3.y = (loader)->bbox.yMax + (loader)->top_bearing;  \
1369             (loader)->pp4.x = use_aw_2_ ? (loader)->advance / 2 : 0;        \
1370             (loader)->pp4.y = (loader)->pp3.y - (loader)->vadvance;         \
1371           } while ( 0 )
1372 
1373 #else /* !TT_CONFIG_OPTION_SUBPIXEL_HINTING */
1374 
1375 #define TT_LOADER_SET_PP( loader )                                          \
1376           do                                                                \
1377           {                                                                 \
1378             (loader)->pp1.x = (loader)->bbox.xMin - (loader)->left_bearing; \
1379             (loader)->pp1.y = 0;                                            \
1380             (loader)->pp2.x = (loader)->pp1.x + (loader)->advance;          \
1381             (loader)->pp2.y = 0;                                            \
1382                                                                             \
1383             (loader)->pp3.x = 0;                                            \
1384             (loader)->pp3.y = (loader)->bbox.yMax + (loader)->top_bearing;  \
1385             (loader)->pp4.x = 0;                                            \
1386             (loader)->pp4.y = (loader)->pp3.y - (loader)->vadvance;         \
1387           } while ( 0 )
1388 
1389 #endif /* !TT_CONFIG_OPTION_SUBPIXEL_HINTING */
1390 
1391 
1392   /*************************************************************************/
1393   /*                                                                       */
1394   /* <Function>                                                            */
1395   /*    load_truetype_glyph                                                */
1396   /*                                                                       */
1397   /* <Description>                                                         */
1398   /*    Loads a given truetype glyph.  Handles composites and uses a       */
1399   /*    TT_Loader object.                                                  */
1400   /*                                                                       */
1401   static FT_Error
load_truetype_glyph(TT_Loader loader,FT_UInt glyph_index,FT_UInt recurse_count,FT_Bool header_only)1402   load_truetype_glyph( TT_Loader  loader,
1403                        FT_UInt    glyph_index,
1404                        FT_UInt    recurse_count,
1405                        FT_Bool    header_only )
1406   {
1407     FT_Error        error        = FT_Err_Ok;
1408     FT_Fixed        x_scale, y_scale;
1409     FT_ULong        offset;
1410     TT_Face         face         = (TT_Face)loader->face;
1411     FT_GlyphLoader  gloader      = loader->gloader;
1412     FT_Bool         opened_frame = 0;
1413 
1414 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
1415     FT_Vector*      deltas       = NULL;
1416 #endif
1417 
1418 #ifdef FT_CONFIG_OPTION_INCREMENTAL
1419     FT_StreamRec    inc_stream;
1420     FT_Data         glyph_data;
1421     FT_Bool         glyph_data_loaded = 0;
1422 #endif
1423 
1424 
1425     /* some fonts have an incorrect value of `maxComponentDepth', */
1426     /* thus we allow depth 1 to catch the majority of them        */
1427     if ( recurse_count > 1                                   &&
1428          recurse_count > face->max_profile.maxComponentDepth )
1429     {
1430       error = FT_THROW( Invalid_Composite );
1431       goto Exit;
1432     }
1433 
1434     /* check glyph index */
1435     if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
1436     {
1437       error = FT_THROW( Invalid_Glyph_Index );
1438       goto Exit;
1439     }
1440 
1441     loader->glyph_index = glyph_index;
1442 
1443     if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
1444     {
1445       x_scale = ((TT_Size)loader->size)->metrics.x_scale;
1446       y_scale = ((TT_Size)loader->size)->metrics.y_scale;
1447     }
1448     else
1449     {
1450       x_scale = 0x10000L;
1451       y_scale = 0x10000L;
1452     }
1453 
1454     /* Set `offset' to the start of the glyph relative to the start of */
1455     /* the `glyf' table, and `byte_len' to the length of the glyph in  */
1456     /* bytes.                                                          */
1457 
1458 #ifdef FT_CONFIG_OPTION_INCREMENTAL
1459 
1460     /* If we are loading glyph data via the incremental interface, set */
1461     /* the loader stream to a memory stream reading the data returned  */
1462     /* by the interface.                                               */
1463     if ( face->root.internal->incremental_interface )
1464     {
1465       error = face->root.internal->incremental_interface->funcs->get_glyph_data(
1466                 face->root.internal->incremental_interface->object,
1467                 glyph_index, &glyph_data );
1468       if ( error )
1469         goto Exit;
1470 
1471       glyph_data_loaded = 1;
1472       offset            = 0;
1473       loader->byte_len  = glyph_data.length;
1474 
1475       FT_MEM_ZERO( &inc_stream, sizeof ( inc_stream ) );
1476       FT_Stream_OpenMemory( &inc_stream,
1477                             glyph_data.pointer, glyph_data.length );
1478 
1479       loader->stream = &inc_stream;
1480     }
1481     else
1482 
1483 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
1484 
1485       offset = tt_face_get_location( face, glyph_index,
1486                                      (FT_UInt*)&loader->byte_len );
1487 
1488     if ( loader->byte_len > 0 )
1489     {
1490 #ifdef FT_CONFIG_OPTION_INCREMENTAL
1491       /* for the incremental interface, `glyf_offset' is always zero */
1492       if ( !loader->glyf_offset                        &&
1493            !face->root.internal->incremental_interface )
1494 #else
1495       if ( !loader->glyf_offset )
1496 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
1497       {
1498         FT_TRACE2(( "no `glyf' table but non-zero `loca' entry\n" ));
1499         error = FT_THROW( Invalid_Table );
1500         goto Exit;
1501       }
1502 
1503       error = face->access_glyph_frame( loader, glyph_index,
1504                                         loader->glyf_offset + offset,
1505                                         loader->byte_len );
1506       if ( error )
1507         goto Exit;
1508 
1509       opened_frame = 1;
1510 
1511       /* read glyph header first */
1512       error = face->read_glyph_header( loader );
1513       if ( error )
1514         goto Exit;
1515 
1516       /* the metrics must be computed after loading the glyph header */
1517       /* since we need the glyph's `yMax' value in case the vertical */
1518       /* metrics must be emulated                                    */
1519       error = tt_get_metrics( loader, glyph_index );
1520       if ( error )
1521         goto Exit;
1522 
1523       if ( header_only )
1524         goto Exit;
1525     }
1526 
1527     if ( loader->byte_len == 0 || loader->n_contours == 0 )
1528     {
1529       loader->bbox.xMin = 0;
1530       loader->bbox.xMax = 0;
1531       loader->bbox.yMin = 0;
1532       loader->bbox.yMax = 0;
1533 
1534       error = tt_get_metrics( loader, glyph_index );
1535       if ( error )
1536         goto Exit;
1537 
1538       if ( header_only )
1539         goto Exit;
1540 
1541       /* must initialize points before (possibly) overriding */
1542       /* glyph metrics from the incremental interface        */
1543       TT_LOADER_SET_PP( loader );
1544 
1545 #ifdef FT_CONFIG_OPTION_INCREMENTAL
1546       tt_get_metrics_incr_overrides( loader, glyph_index );
1547 #endif
1548 
1549 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
1550 
1551       if ( ((TT_Face)(loader->face))->doblend )
1552       {
1553         /* this must be done before scaling */
1554         FT_Memory  memory = loader->face->memory;
1555 
1556 
1557         error = TT_Vary_Get_Glyph_Deltas( (TT_Face)(loader->face),
1558                                           glyph_index, &deltas, 4 );
1559         if ( error )
1560           goto Exit;
1561 
1562         loader->pp1.x += deltas[0].x;
1563         loader->pp1.y += deltas[0].y;
1564         loader->pp2.x += deltas[1].x;
1565         loader->pp2.y += deltas[1].y;
1566 
1567         loader->pp3.x += deltas[2].x;
1568         loader->pp3.y += deltas[2].y;
1569         loader->pp4.x += deltas[3].x;
1570         loader->pp4.y += deltas[3].y;
1571 
1572         FT_FREE( deltas );
1573       }
1574 
1575 #endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
1576 
1577       /* scale phantom points, if necessary; */
1578       /* they get rounded in `TT_Hint_Glyph' */
1579       if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
1580       {
1581         loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
1582         loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
1583         /* pp1.y and pp2.y are always zero */
1584 
1585         loader->pp3.x = FT_MulFix( loader->pp3.x, x_scale );
1586         loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
1587         loader->pp4.x = FT_MulFix( loader->pp4.x, x_scale );
1588         loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
1589       }
1590 
1591       error = FT_Err_Ok;
1592       goto Exit;
1593     }
1594 
1595     /* must initialize phantom points before (possibly) overriding */
1596     /* glyph metrics from the incremental interface                */
1597     TT_LOADER_SET_PP( loader );
1598 
1599 #ifdef FT_CONFIG_OPTION_INCREMENTAL
1600     tt_get_metrics_incr_overrides( loader, glyph_index );
1601 #endif
1602 
1603     /***********************************************************************/
1604     /***********************************************************************/
1605     /***********************************************************************/
1606 
1607     /* if it is a simple glyph, load it */
1608 
1609     if ( loader->n_contours > 0 )
1610     {
1611       error = face->read_simple_glyph( loader );
1612       if ( error )
1613         goto Exit;
1614 
1615       /* all data have been read */
1616       face->forget_glyph_frame( loader );
1617       opened_frame = 0;
1618 
1619       error = TT_Process_Simple_Glyph( loader );
1620       if ( error )
1621         goto Exit;
1622 
1623       FT_GlyphLoader_Add( gloader );
1624     }
1625 
1626     /***********************************************************************/
1627     /***********************************************************************/
1628     /***********************************************************************/
1629 
1630     /* otherwise, load a composite! */
1631     else if ( loader->n_contours == -1 )
1632     {
1633       FT_UInt   start_point;
1634       FT_UInt   start_contour;
1635       FT_ULong  ins_pos;  /* position of composite instructions, if any */
1636 
1637 
1638       start_point   = gloader->base.outline.n_points;
1639       start_contour = gloader->base.outline.n_contours;
1640 
1641       /* for each subglyph, read composite header */
1642       error = face->read_composite_glyph( loader );
1643       if ( error )
1644         goto Exit;
1645 
1646       /* store the offset of instructions */
1647       ins_pos = loader->ins_pos;
1648 
1649       /* all data we need are read */
1650       face->forget_glyph_frame( loader );
1651       opened_frame = 0;
1652 
1653 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
1654 
1655       if ( face->doblend )
1656       {
1657         FT_Int       i, limit;
1658         FT_SubGlyph  subglyph;
1659         FT_Memory    memory = face->root.memory;
1660 
1661 
1662         /* this provides additional offsets */
1663         /* for each component's translation */
1664 
1665         if ( ( error = TT_Vary_Get_Glyph_Deltas(
1666                          face,
1667                          glyph_index,
1668                          &deltas,
1669                          gloader->current.num_subglyphs + 4 ) ) != 0 )
1670           goto Exit;
1671 
1672         subglyph = gloader->current.subglyphs + gloader->base.num_subglyphs;
1673         limit    = gloader->current.num_subglyphs;
1674 
1675         for ( i = 0; i < limit; ++i, ++subglyph )
1676         {
1677           if ( subglyph->flags & ARGS_ARE_XY_VALUES )
1678           {
1679             /* XXX: overflow check for subglyph->{arg1,arg2}.   */
1680             /* deltas[i].{x,y} must be within signed 16-bit,    */
1681             /* but the restriction of summed delta is not clear */
1682             subglyph->arg1 += (FT_Int16)deltas[i].x;
1683             subglyph->arg2 += (FT_Int16)deltas[i].y;
1684           }
1685         }
1686 
1687         loader->pp1.x += deltas[i + 0].x;
1688         loader->pp1.y += deltas[i + 0].y;
1689         loader->pp2.x += deltas[i + 1].x;
1690         loader->pp2.y += deltas[i + 1].y;
1691 
1692         loader->pp3.x += deltas[i + 2].x;
1693         loader->pp3.y += deltas[i + 2].y;
1694         loader->pp4.x += deltas[i + 3].x;
1695         loader->pp4.y += deltas[i + 3].y;
1696 
1697         FT_FREE( deltas );
1698       }
1699 
1700 #endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
1701 
1702       /* scale phantom points, if necessary; */
1703       /* they get rounded in `TT_Hint_Glyph' */
1704       if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
1705       {
1706         loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
1707         loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
1708         /* pp1.y and pp2.y are always zero */
1709 
1710         loader->pp3.x = FT_MulFix( loader->pp3.x, x_scale );
1711         loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
1712         loader->pp4.x = FT_MulFix( loader->pp4.x, x_scale );
1713         loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
1714       }
1715 
1716       /* if the flag FT_LOAD_NO_RECURSE is set, we return the subglyph */
1717       /* `as is' in the glyph slot (the client application will be     */
1718       /* responsible for interpreting these data)...                   */
1719       if ( loader->load_flags & FT_LOAD_NO_RECURSE )
1720       {
1721         FT_GlyphLoader_Add( gloader );
1722         loader->glyph->format = FT_GLYPH_FORMAT_COMPOSITE;
1723 
1724         goto Exit;
1725       }
1726 
1727       /*********************************************************************/
1728       /*********************************************************************/
1729       /*********************************************************************/
1730 
1731       {
1732         FT_UInt      n, num_base_points;
1733         FT_SubGlyph  subglyph       = 0;
1734 
1735         FT_UInt      num_points     = start_point;
1736         FT_UInt      num_subglyphs  = gloader->current.num_subglyphs;
1737         FT_UInt      num_base_subgs = gloader->base.num_subglyphs;
1738 
1739         FT_Stream    old_stream     = loader->stream;
1740         FT_Int       old_byte_len   = loader->byte_len;
1741 
1742 
1743         FT_GlyphLoader_Add( gloader );
1744 
1745         /* read each subglyph independently */
1746         for ( n = 0; n < num_subglyphs; n++ )
1747         {
1748           FT_Vector  pp[4];
1749 
1750 
1751           /* Each time we call load_truetype_glyph in this loop, the   */
1752           /* value of `gloader.base.subglyphs' can change due to table */
1753           /* reallocations.  We thus need to recompute the subglyph    */
1754           /* pointer on each iteration.                                */
1755           subglyph = gloader->base.subglyphs + num_base_subgs + n;
1756 
1757           pp[0] = loader->pp1;
1758           pp[1] = loader->pp2;
1759           pp[2] = loader->pp3;
1760           pp[3] = loader->pp4;
1761 
1762           num_base_points = gloader->base.outline.n_points;
1763 
1764           error = load_truetype_glyph( loader, subglyph->index,
1765                                        recurse_count + 1, FALSE );
1766           if ( error )
1767             goto Exit;
1768 
1769           /* restore subglyph pointer */
1770           subglyph = gloader->base.subglyphs + num_base_subgs + n;
1771 
1772           /* restore phantom points if necessary */
1773           if ( !( subglyph->flags & USE_MY_METRICS ) )
1774           {
1775             loader->pp1 = pp[0];
1776             loader->pp2 = pp[1];
1777             loader->pp3 = pp[2];
1778             loader->pp4 = pp[3];
1779           }
1780 
1781           num_points = gloader->base.outline.n_points;
1782 
1783           if ( num_points == num_base_points )
1784             continue;
1785 
1786           /* gloader->base.outline consists of three parts:               */
1787           /* 0 -(1)-> start_point -(2)-> num_base_points -(3)-> n_points. */
1788           /*                                                              */
1789           /* (1): exists from the beginning                               */
1790           /* (2): components that have been loaded so far                 */
1791           /* (3): the newly loaded component                              */
1792           TT_Process_Composite_Component( loader, subglyph, start_point,
1793                                           num_base_points );
1794         }
1795 
1796         loader->stream   = old_stream;
1797         loader->byte_len = old_byte_len;
1798 
1799         /* process the glyph */
1800         loader->ins_pos = ins_pos;
1801         if ( IS_HINTED( loader->load_flags ) &&
1802 
1803 #ifdef TT_USE_BYTECODE_INTERPRETER
1804 
1805              subglyph->flags & WE_HAVE_INSTR &&
1806 
1807 #endif
1808 
1809              num_points > start_point )
1810           TT_Process_Composite_Glyph( loader, start_point, start_contour );
1811 
1812       }
1813     }
1814     else
1815     {
1816       /* invalid composite count (negative but not -1) */
1817       error = FT_THROW( Invalid_Outline );
1818       goto Exit;
1819     }
1820 
1821     /***********************************************************************/
1822     /***********************************************************************/
1823     /***********************************************************************/
1824 
1825   Exit:
1826 
1827     if ( opened_frame )
1828       face->forget_glyph_frame( loader );
1829 
1830 #ifdef FT_CONFIG_OPTION_INCREMENTAL
1831 
1832     if ( glyph_data_loaded )
1833       face->root.internal->incremental_interface->funcs->free_glyph_data(
1834         face->root.internal->incremental_interface->object,
1835         &glyph_data );
1836 
1837 #endif
1838 
1839     return error;
1840   }
1841 
1842 
1843   static FT_Error
compute_glyph_metrics(TT_Loader loader,FT_UInt glyph_index)1844   compute_glyph_metrics( TT_Loader  loader,
1845                          FT_UInt    glyph_index )
1846   {
1847     TT_Face    face   = (TT_Face)loader->face;
1848 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
1849     TT_Driver  driver = (TT_Driver)FT_FACE_DRIVER( face );
1850 #endif
1851 
1852     FT_BBox       bbox;
1853     FT_Fixed      y_scale;
1854     TT_GlyphSlot  glyph = loader->glyph;
1855     TT_Size       size  = (TT_Size)loader->size;
1856 
1857 
1858     y_scale = 0x10000L;
1859     if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
1860       y_scale = size->root.metrics.y_scale;
1861 
1862     if ( glyph->format != FT_GLYPH_FORMAT_COMPOSITE )
1863       FT_Outline_Get_CBox( &glyph->outline, &bbox );
1864     else
1865       bbox = loader->bbox;
1866 
1867     /* get the device-independent horizontal advance; it is scaled later */
1868     /* by the base layer.                                                */
1869     glyph->linearHoriAdvance = loader->linear;
1870 
1871     glyph->metrics.horiBearingX = bbox.xMin;
1872     glyph->metrics.horiBearingY = bbox.yMax;
1873     glyph->metrics.horiAdvance  = loader->pp2.x - loader->pp1.x;
1874 
1875     /* adjust advance width to the value contained in the hdmx table */
1876     if ( !face->postscript.isFixedPitch  &&
1877          IS_HINTED( loader->load_flags ) )
1878     {
1879       FT_Byte*  widthp;
1880 
1881 
1882       widthp = tt_face_get_device_metrics( face,
1883                                            size->root.metrics.x_ppem,
1884                                            glyph_index );
1885 
1886 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
1887 
1888       if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
1889       {
1890         FT_Bool  ignore_x_mode;
1891 
1892 
1893         ignore_x_mode = FT_BOOL( FT_LOAD_TARGET_MODE( loader->load_flags ) !=
1894                                  FT_RENDER_MODE_MONO );
1895 
1896         if ( widthp                                                   &&
1897              ( ( ignore_x_mode && loader->exec->compatible_widths ) ||
1898                 !ignore_x_mode                                      ||
1899                 SPH_OPTION_BITMAP_WIDTHS                            ) )
1900           glyph->metrics.horiAdvance = *widthp << 6;
1901       }
1902       else
1903 
1904 #endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */
1905 
1906       {
1907         if ( widthp )
1908           glyph->metrics.horiAdvance = *widthp << 6;
1909       }
1910     }
1911 
1912     /* set glyph dimensions */
1913     glyph->metrics.width  = bbox.xMax - bbox.xMin;
1914     glyph->metrics.height = bbox.yMax - bbox.yMin;
1915 
1916     /* Now take care of vertical metrics.  In the case where there is */
1917     /* no vertical information within the font (relatively common),   */
1918     /* create some metrics manually                                   */
1919     {
1920       FT_Pos  top;      /* scaled vertical top side bearing  */
1921       FT_Pos  advance;  /* scaled vertical advance height    */
1922 
1923 
1924       /* Get the unscaled top bearing and advance height. */
1925       if ( face->vertical_info                   &&
1926            face->vertical.number_Of_VMetrics > 0 )
1927       {
1928         top = (FT_Short)FT_DivFix( loader->pp3.y - bbox.yMax,
1929                                    y_scale );
1930 
1931         if ( loader->pp3.y <= loader->pp4.y )
1932           advance = 0;
1933         else
1934           advance = (FT_UShort)FT_DivFix( loader->pp3.y - loader->pp4.y,
1935                                           y_scale );
1936       }
1937       else
1938       {
1939         FT_Pos  height;
1940 
1941 
1942         /* XXX Compute top side bearing and advance height in  */
1943         /*     Get_VMetrics instead of here.                   */
1944 
1945         /* NOTE: The OS/2 values are the only `portable' ones, */
1946         /*       which is why we use them, if there is an OS/2 */
1947         /*       table in the font.  Otherwise, we use the     */
1948         /*       values defined in the horizontal header.      */
1949 
1950         height = (FT_Short)FT_DivFix( bbox.yMax - bbox.yMin,
1951                                       y_scale );
1952         if ( face->os2.version != 0xFFFFU )
1953           advance = (FT_Pos)( face->os2.sTypoAscender -
1954                               face->os2.sTypoDescender );
1955         else
1956           advance = (FT_Pos)( face->horizontal.Ascender -
1957                               face->horizontal.Descender );
1958 
1959         top = ( advance - height ) / 2;
1960       }
1961 
1962 #ifdef FT_CONFIG_OPTION_INCREMENTAL
1963       {
1964         FT_Incremental_InterfaceRec*  incr;
1965         FT_Incremental_MetricsRec     metrics;
1966         FT_Error                      error;
1967 
1968 
1969         incr = face->root.internal->incremental_interface;
1970 
1971         /* If this is an incrementally loaded font see if there are */
1972         /* overriding metrics for this glyph.                       */
1973         if ( incr && incr->funcs->get_glyph_metrics )
1974         {
1975           metrics.bearing_x = 0;
1976           metrics.bearing_y = top;
1977           metrics.advance   = advance;
1978 
1979           error = incr->funcs->get_glyph_metrics( incr->object,
1980                                                   glyph_index,
1981                                                   TRUE,
1982                                                   &metrics );
1983           if ( error )
1984             return error;
1985 
1986           top     = metrics.bearing_y;
1987           advance = metrics.advance;
1988         }
1989       }
1990 
1991       /* GWW: Do vertical metrics get loaded incrementally too? */
1992 
1993 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
1994 
1995       glyph->linearVertAdvance = advance;
1996 
1997       /* scale the metrics */
1998       if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
1999       {
2000         top     = FT_MulFix( top,     y_scale );
2001         advance = FT_MulFix( advance, y_scale );
2002       }
2003 
2004       /* XXX: for now, we have no better algorithm for the lsb, but it */
2005       /*      should work fine.                                        */
2006       /*                                                               */
2007       glyph->metrics.vertBearingX = glyph->metrics.horiBearingX -
2008                                       glyph->metrics.horiAdvance / 2;
2009       glyph->metrics.vertBearingY = top;
2010       glyph->metrics.vertAdvance  = advance;
2011     }
2012 
2013     return 0;
2014   }
2015 
2016 
2017 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
2018 
2019   static FT_Error
load_sbit_image(TT_Size size,TT_GlyphSlot glyph,FT_UInt glyph_index,FT_Int32 load_flags)2020   load_sbit_image( TT_Size       size,
2021                    TT_GlyphSlot  glyph,
2022                    FT_UInt       glyph_index,
2023                    FT_Int32      load_flags )
2024   {
2025     TT_Face             face;
2026     SFNT_Service        sfnt;
2027     FT_Stream           stream;
2028     FT_Error            error;
2029     TT_SBit_MetricsRec  metrics;
2030 
2031 
2032     face   = (TT_Face)glyph->face;
2033     sfnt   = (SFNT_Service)face->sfnt;
2034     stream = face->root.stream;
2035 
2036     error = sfnt->load_sbit_image( face,
2037                                    size->strike_index,
2038                                    glyph_index,
2039                                    (FT_Int)load_flags,
2040                                    stream,
2041                                    &glyph->bitmap,
2042                                    &metrics );
2043     if ( !error )
2044     {
2045       glyph->outline.n_points   = 0;
2046       glyph->outline.n_contours = 0;
2047 
2048       glyph->metrics.width  = (FT_Pos)metrics.width  << 6;
2049       glyph->metrics.height = (FT_Pos)metrics.height << 6;
2050 
2051       glyph->metrics.horiBearingX = (FT_Pos)metrics.horiBearingX << 6;
2052       glyph->metrics.horiBearingY = (FT_Pos)metrics.horiBearingY << 6;
2053       glyph->metrics.horiAdvance  = (FT_Pos)metrics.horiAdvance  << 6;
2054 
2055       glyph->metrics.vertBearingX = (FT_Pos)metrics.vertBearingX << 6;
2056       glyph->metrics.vertBearingY = (FT_Pos)metrics.vertBearingY << 6;
2057       glyph->metrics.vertAdvance  = (FT_Pos)metrics.vertAdvance  << 6;
2058 
2059       glyph->format = FT_GLYPH_FORMAT_BITMAP;
2060 
2061       if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
2062       {
2063         glyph->bitmap_left = metrics.vertBearingX;
2064         glyph->bitmap_top  = metrics.vertBearingY;
2065       }
2066       else
2067       {
2068         glyph->bitmap_left = metrics.horiBearingX;
2069         glyph->bitmap_top  = metrics.horiBearingY;
2070       }
2071     }
2072 
2073     return error;
2074   }
2075 
2076 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
2077 
2078 
2079   static FT_Error
tt_loader_init(TT_Loader loader,TT_Size size,TT_GlyphSlot glyph,FT_Int32 load_flags,FT_Bool glyf_table_only)2080   tt_loader_init( TT_Loader     loader,
2081                   TT_Size       size,
2082                   TT_GlyphSlot  glyph,
2083                   FT_Int32      load_flags,
2084                   FT_Bool       glyf_table_only )
2085   {
2086     TT_Face    face;
2087     FT_Stream  stream;
2088 #ifdef TT_USE_BYTECODE_INTERPRETER
2089     FT_Bool    pedantic = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
2090 #endif
2091 
2092 
2093     face   = (TT_Face)glyph->face;
2094     stream = face->root.stream;
2095 
2096     FT_MEM_ZERO( loader, sizeof ( TT_LoaderRec ) );
2097 
2098 #ifdef TT_USE_BYTECODE_INTERPRETER
2099 
2100     /* load execution context */
2101     if ( IS_HINTED( load_flags ) && !glyf_table_only )
2102     {
2103       TT_ExecContext  exec;
2104       FT_Bool         grayscale;
2105 
2106 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
2107       TT_Driver  driver = (TT_Driver)FT_FACE_DRIVER( face );
2108 
2109       FT_Bool  subpixel = FALSE;
2110 
2111 #if 0
2112       /* not used yet */
2113       FT_Bool  compatible_widths;
2114       FT_Bool  symmetrical_smoothing;
2115       FT_Bool  bgr;
2116       FT_Bool  subpixel_positioned;
2117 #endif
2118 #endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */
2119 
2120       FT_Bool  reexecute = FALSE;
2121 
2122 
2123       if ( !size->cvt_ready )
2124       {
2125         FT_Error  error = tt_size_ready_bytecode( size, pedantic );
2126 
2127 
2128         if ( error )
2129           return error;
2130       }
2131 
2132       /* query new execution context */
2133       exec = size->debug ? size->context
2134                          : ( (TT_Driver)FT_FACE_DRIVER( face ) )->context;
2135       if ( !exec )
2136         return FT_THROW( Could_Not_Find_Context );
2137 
2138 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
2139 
2140       if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
2141       {
2142         subpixel = FT_BOOL( ( FT_LOAD_TARGET_MODE( load_flags ) !=
2143                               FT_RENDER_MODE_MONO               )  &&
2144                             SPH_OPTION_SET_SUBPIXEL                );
2145 
2146         if ( subpixel )
2147           grayscale = FALSE;
2148         else if ( SPH_OPTION_SET_GRAYSCALE )
2149         {
2150           grayscale = TRUE;
2151           subpixel  = FALSE;
2152         }
2153         else
2154           grayscale = FALSE;
2155 
2156         if ( FT_IS_TRICKY( glyph->face ) )
2157           subpixel = FALSE;
2158 
2159         exec->ignore_x_mode      = subpixel || grayscale;
2160         exec->rasterizer_version = SPH_OPTION_SET_RASTERIZER_VERSION;
2161         if ( exec->sph_tweak_flags & SPH_TWEAK_RASTERIZER_35 )
2162           exec->rasterizer_version = TT_INTERPRETER_VERSION_35;
2163 
2164 #if 1
2165         exec->compatible_widths     = SPH_OPTION_SET_COMPATIBLE_WIDTHS;
2166         exec->symmetrical_smoothing = FALSE;
2167         exec->bgr                   = FALSE;
2168         exec->subpixel_positioned   = TRUE;
2169 #else /* 0 */
2170         exec->compatible_widths =
2171           FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
2172                    TT_LOAD_COMPATIBLE_WIDTHS );
2173         exec->symmetrical_smoothing =
2174           FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
2175                    TT_LOAD_SYMMETRICAL_SMOOTHING );
2176         exec->bgr =
2177           FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
2178                    TT_LOAD_BGR );
2179         exec->subpixel_positioned =
2180           FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
2181                    TT_LOAD_SUBPIXEL_POSITIONED );
2182 #endif /* 0 */
2183 
2184       }
2185       else
2186 
2187 #endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */
2188 
2189       {
2190         grayscale = FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
2191                              FT_RENDER_MODE_MONO );
2192       }
2193 
2194       TT_Load_Context( exec, face, size );
2195 
2196 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
2197 
2198       if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
2199       {
2200         /* a change from mono to subpixel rendering (and vice versa) */
2201         /* requires a re-execution of the CVT program                */
2202         if ( subpixel != exec->subpixel )
2203         {
2204           FT_TRACE4(( "tt_loader_init: subpixel hinting change,"
2205                       " re-executing `prep' table\n" ));
2206 
2207           exec->subpixel = subpixel;
2208           reexecute      = TRUE;
2209         }
2210 
2211         /* a change from mono to grayscale rendering (and vice versa) */
2212         /* requires a re-execution of the CVT program                 */
2213         if ( grayscale != exec->grayscale )
2214         {
2215           FT_TRACE4(( "tt_loader_init: grayscale hinting change,"
2216                       " re-executing `prep' table\n" ));
2217 
2218           exec->grayscale = grayscale;
2219           reexecute       = TRUE;
2220         }
2221       }
2222       else
2223 
2224 #endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */
2225 
2226       {
2227         /* a change from mono to grayscale rendering (and vice versa) */
2228         /* requires a re-execution of the CVT program                 */
2229         if ( grayscale != exec->grayscale )
2230         {
2231           FT_TRACE4(( "tt_loader_init: grayscale change,"
2232                       " re-executing `prep' table\n" ));
2233 
2234           exec->grayscale = grayscale;
2235           reexecute       = TRUE;
2236         }
2237       }
2238 
2239       if ( reexecute )
2240       {
2241         FT_UInt  i;
2242 
2243 
2244         for ( i = 0; i < size->cvt_size; i++ )
2245           size->cvt[i] = FT_MulFix( face->cvt[i], size->ttmetrics.scale );
2246         tt_size_run_prep( size, pedantic );
2247       }
2248 
2249       /* see whether the cvt program has disabled hinting */
2250       if ( exec->GS.instruct_control & 1 )
2251         load_flags |= FT_LOAD_NO_HINTING;
2252 
2253       /* load default graphics state -- if needed */
2254       if ( exec->GS.instruct_control & 2 )
2255         exec->GS = tt_default_graphics_state;
2256 
2257       exec->pedantic_hinting = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
2258       loader->exec = exec;
2259       loader->instructions = exec->glyphIns;
2260     }
2261 
2262 #endif /* TT_USE_BYTECODE_INTERPRETER */
2263 
2264     /* seek to the beginning of the glyph table -- for Type 42 fonts     */
2265     /* the table might be accessed from a Postscript stream or something */
2266     /* else...                                                           */
2267 
2268 #ifdef FT_CONFIG_OPTION_INCREMENTAL
2269 
2270     if ( face->root.internal->incremental_interface )
2271       loader->glyf_offset = 0;
2272     else
2273 
2274 #endif
2275 
2276     {
2277       FT_Error  error = face->goto_table( face, TTAG_glyf, stream, 0 );
2278 
2279 
2280       if ( FT_ERR_EQ( error, Table_Missing ) )
2281         loader->glyf_offset = 0;
2282       else if ( error )
2283       {
2284         FT_ERROR(( "tt_loader_init: could not access glyph table\n" ));
2285         return error;
2286       }
2287       else
2288         loader->glyf_offset = FT_STREAM_POS();
2289     }
2290 
2291     /* get face's glyph loader */
2292     if ( !glyf_table_only )
2293     {
2294       FT_GlyphLoader  gloader = glyph->internal->loader;
2295 
2296 
2297       FT_GlyphLoader_Rewind( gloader );
2298       loader->gloader = gloader;
2299     }
2300 
2301     loader->load_flags = load_flags;
2302 
2303     loader->face   = (FT_Face)face;
2304     loader->size   = (FT_Size)size;
2305     loader->glyph  = (FT_GlyphSlot)glyph;
2306     loader->stream = stream;
2307 
2308     return FT_Err_Ok;
2309   }
2310 
2311 
2312   /*************************************************************************/
2313   /*                                                                       */
2314   /* <Function>                                                            */
2315   /*    TT_Load_Glyph                                                      */
2316   /*                                                                       */
2317   /* <Description>                                                         */
2318   /*    A function used to load a single glyph within a given glyph slot,  */
2319   /*    for a given size.                                                  */
2320   /*                                                                       */
2321   /* <Input>                                                               */
2322   /*    glyph       :: A handle to a target slot object where the glyph    */
2323   /*                   will be loaded.                                     */
2324   /*                                                                       */
2325   /*    size        :: A handle to the source face size at which the glyph */
2326   /*                   must be scaled/loaded.                              */
2327   /*                                                                       */
2328   /*    glyph_index :: The index of the glyph in the font file.            */
2329   /*                                                                       */
2330   /*    load_flags  :: A flag indicating what to load for this glyph.  The */
2331   /*                   FT_LOAD_XXX constants can be used to control the    */
2332   /*                   glyph loading process (e.g., whether the outline    */
2333   /*                   should be scaled, whether to load bitmaps or not,   */
2334   /*                   whether to hint the outline, etc).                  */
2335   /*                                                                       */
2336   /* <Return>                                                              */
2337   /*    FreeType error code.  0 means success.                             */
2338   /*                                                                       */
2339   FT_LOCAL_DEF( FT_Error )
TT_Load_Glyph(TT_Size size,TT_GlyphSlot glyph,FT_UInt glyph_index,FT_Int32 load_flags)2340   TT_Load_Glyph( TT_Size       size,
2341                  TT_GlyphSlot  glyph,
2342                  FT_UInt       glyph_index,
2343                  FT_Int32      load_flags )
2344   {
2345     FT_Error      error;
2346     TT_LoaderRec  loader;
2347 
2348 
2349     FT_TRACE1(( "TT_Load_Glyph: glyph index %d\n", glyph_index ));
2350 
2351 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
2352 
2353     /* try to load embedded bitmap if any              */
2354     /*                                                 */
2355     /* XXX: The convention should be emphasized in     */
2356     /*      the documents because it can be confusing. */
2357     if ( size->strike_index != 0xFFFFFFFFUL      &&
2358          ( load_flags & FT_LOAD_NO_BITMAP ) == 0 )
2359     {
2360       error = load_sbit_image( size, glyph, glyph_index, load_flags );
2361       if ( !error )
2362       {
2363         if ( FT_IS_SCALABLE( glyph->face ) )
2364         {
2365           /* for the bbox we need the header only */
2366           (void)tt_loader_init( &loader, size, glyph, load_flags, TRUE );
2367           (void)load_truetype_glyph( &loader, glyph_index, 0, TRUE );
2368           glyph->linearHoriAdvance = loader.linear;
2369           glyph->linearVertAdvance = loader.top_bearing + loader.bbox.yMax -
2370                                        loader.vadvance;
2371 
2372           /* sanity check: if `horiAdvance' in the sbit metric */
2373           /* structure isn't set, use `linearHoriAdvance'      */
2374           if ( !glyph->metrics.horiAdvance && glyph->linearHoriAdvance )
2375             glyph->metrics.horiAdvance =
2376               FT_MulFix( glyph->linearHoriAdvance,
2377                          size->root.metrics.x_scale );
2378         }
2379 
2380         return FT_Err_Ok;
2381       }
2382     }
2383 
2384 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
2385 
2386     /* if FT_LOAD_NO_SCALE is not set, `ttmetrics' must be valid */
2387     if ( !( load_flags & FT_LOAD_NO_SCALE ) && !size->ttmetrics.valid )
2388       return FT_THROW( Invalid_Size_Handle );
2389 
2390     if ( load_flags & FT_LOAD_SBITS_ONLY )
2391       return FT_THROW( Invalid_Argument );
2392 
2393     error = tt_loader_init( &loader, size, glyph, load_flags, FALSE );
2394     if ( error )
2395       return error;
2396 
2397     glyph->format        = FT_GLYPH_FORMAT_OUTLINE;
2398     glyph->num_subglyphs = 0;
2399     glyph->outline.flags = 0;
2400 
2401     /* main loading loop */
2402     error = load_truetype_glyph( &loader, glyph_index, 0, FALSE );
2403     if ( !error )
2404     {
2405       if ( glyph->format == FT_GLYPH_FORMAT_COMPOSITE )
2406       {
2407         glyph->num_subglyphs = loader.gloader->base.num_subglyphs;
2408         glyph->subglyphs     = loader.gloader->base.subglyphs;
2409       }
2410       else
2411       {
2412         glyph->outline        = loader.gloader->base.outline;
2413         glyph->outline.flags &= ~FT_OUTLINE_SINGLE_PASS;
2414 
2415         /* Translate array so that (0,0) is the glyph's origin.  Note  */
2416         /* that this behaviour is independent on the value of bit 1 of */
2417         /* the `flags' field in the `head' table -- at least major     */
2418         /* applications like Acroread indicate that.                   */
2419         if ( loader.pp1.x )
2420           FT_Outline_Translate( &glyph->outline, -loader.pp1.x, 0 );
2421       }
2422 
2423 #ifdef TT_USE_BYTECODE_INTERPRETER
2424 
2425       if ( IS_HINTED( load_flags ) )
2426       {
2427         if ( loader.exec->GS.scan_control )
2428         {
2429           /* convert scan conversion mode to FT_OUTLINE_XXX flags */
2430           switch ( loader.exec->GS.scan_type )
2431           {
2432           case 0: /* simple drop-outs including stubs */
2433             glyph->outline.flags |= FT_OUTLINE_INCLUDE_STUBS;
2434             break;
2435           case 1: /* simple drop-outs excluding stubs */
2436             /* nothing; it's the default rendering mode */
2437             break;
2438           case 4: /* smart drop-outs including stubs */
2439             glyph->outline.flags |= FT_OUTLINE_SMART_DROPOUTS |
2440                                     FT_OUTLINE_INCLUDE_STUBS;
2441             break;
2442           case 5: /* smart drop-outs excluding stubs  */
2443             glyph->outline.flags |= FT_OUTLINE_SMART_DROPOUTS;
2444             break;
2445 
2446           default: /* no drop-out control */
2447             glyph->outline.flags |= FT_OUTLINE_IGNORE_DROPOUTS;
2448             break;
2449           }
2450         }
2451         else
2452           glyph->outline.flags |= FT_OUTLINE_IGNORE_DROPOUTS;
2453       }
2454 
2455 #endif /* TT_USE_BYTECODE_INTERPRETER */
2456 
2457       compute_glyph_metrics( &loader, glyph_index );
2458     }
2459 
2460     /* Set the `high precision' bit flag.                           */
2461     /* This is _critical_ to get correct output for monochrome      */
2462     /* TrueType glyphs at all sizes using the bytecode interpreter. */
2463     /*                                                              */
2464     if ( !( load_flags & FT_LOAD_NO_SCALE ) &&
2465          size->root.metrics.y_ppem < 24     )
2466       glyph->outline.flags |= FT_OUTLINE_HIGH_PRECISION;
2467 
2468     return error;
2469   }
2470 
2471 
2472 /* END */
2473