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1 /****************************************************************************
2  *
3  * ftglyph.c
4  *
5  *   FreeType convenience functions to handle glyphs (body).
6  *
7  * Copyright (C) 1996-2020 by
8  * David Turner, Robert Wilhelm, and Werner Lemberg.
9  *
10  * This file is part of the FreeType project, and may only be used,
11  * modified, and distributed under the terms of the FreeType project
12  * license, LICENSE.TXT.  By continuing to use, modify, or distribute
13  * this file you indicate that you have read the license and
14  * understand and accept it fully.
15  *
16  */
17 
18   /**************************************************************************
19    *
20    * This file contains the definition of several convenience functions
21    * that can be used by client applications to easily retrieve glyph
22    * bitmaps and outlines from a given face.
23    *
24    * These functions should be optional if you are writing a font server
25    * or text layout engine on top of FreeType.  However, they are pretty
26    * handy for many other simple uses of the library.
27    *
28    */
29 
30 
31 #include <freetype/internal/ftdebug.h>
32 
33 #include <freetype/ftglyph.h>
34 #include <freetype/ftoutln.h>
35 #include <freetype/ftbitmap.h>
36 #include <freetype/internal/ftobjs.h>
37 
38 #include "ftbase.h"
39 
40 
41   /**************************************************************************
42    *
43    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
44    * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
45    * messages during execution.
46    */
47 #undef  FT_COMPONENT
48 #define FT_COMPONENT  glyph
49 
50 
51   /*************************************************************************/
52   /*************************************************************************/
53   /****                                                                 ****/
54   /****   FT_BitmapGlyph support                                        ****/
55   /****                                                                 ****/
56   /*************************************************************************/
57   /*************************************************************************/
58 
59   FT_CALLBACK_DEF( FT_Error )
ft_bitmap_glyph_init(FT_Glyph bitmap_glyph,FT_GlyphSlot slot)60   ft_bitmap_glyph_init( FT_Glyph      bitmap_glyph,
61                         FT_GlyphSlot  slot )
62   {
63     FT_BitmapGlyph  glyph   = (FT_BitmapGlyph)bitmap_glyph;
64     FT_Error        error   = FT_Err_Ok;
65     FT_Library      library = FT_GLYPH( glyph )->library;
66 
67 
68     if ( slot->format != FT_GLYPH_FORMAT_BITMAP )
69     {
70       error = FT_THROW( Invalid_Glyph_Format );
71       goto Exit;
72     }
73 
74     glyph->left = slot->bitmap_left;
75     glyph->top  = slot->bitmap_top;
76 
77     /* do lazy copying whenever possible */
78     if ( slot->internal->flags & FT_GLYPH_OWN_BITMAP )
79     {
80       glyph->bitmap          = slot->bitmap;
81       slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP;
82     }
83     else
84     {
85       FT_Bitmap_Init( &glyph->bitmap );
86       error = FT_Bitmap_Copy( library, &slot->bitmap, &glyph->bitmap );
87     }
88 
89   Exit:
90     return error;
91   }
92 
93 
94   FT_CALLBACK_DEF( FT_Error )
ft_bitmap_glyph_copy(FT_Glyph bitmap_source,FT_Glyph bitmap_target)95   ft_bitmap_glyph_copy( FT_Glyph  bitmap_source,
96                         FT_Glyph  bitmap_target )
97   {
98     FT_Library      library = bitmap_source->library;
99     FT_BitmapGlyph  source  = (FT_BitmapGlyph)bitmap_source;
100     FT_BitmapGlyph  target  = (FT_BitmapGlyph)bitmap_target;
101 
102 
103     target->left = source->left;
104     target->top  = source->top;
105 
106     return FT_Bitmap_Copy( library, &source->bitmap, &target->bitmap );
107   }
108 
109 
110   FT_CALLBACK_DEF( void )
ft_bitmap_glyph_done(FT_Glyph bitmap_glyph)111   ft_bitmap_glyph_done( FT_Glyph  bitmap_glyph )
112   {
113     FT_BitmapGlyph  glyph   = (FT_BitmapGlyph)bitmap_glyph;
114     FT_Library      library = FT_GLYPH( glyph )->library;
115 
116 
117     FT_Bitmap_Done( library, &glyph->bitmap );
118   }
119 
120 
121   FT_CALLBACK_DEF( void )
ft_bitmap_glyph_bbox(FT_Glyph bitmap_glyph,FT_BBox * cbox)122   ft_bitmap_glyph_bbox( FT_Glyph  bitmap_glyph,
123                         FT_BBox*  cbox )
124   {
125     FT_BitmapGlyph  glyph = (FT_BitmapGlyph)bitmap_glyph;
126 
127 
128     cbox->xMin = glyph->left * 64;
129     cbox->xMax = cbox->xMin + (FT_Pos)( glyph->bitmap.width * 64 );
130     cbox->yMax = glyph->top * 64;
131     cbox->yMin = cbox->yMax - (FT_Pos)( glyph->bitmap.rows * 64 );
132   }
133 
134 
FT_DEFINE_GLYPH(ft_bitmap_glyph_class,sizeof (FT_BitmapGlyphRec),FT_GLYPH_FORMAT_BITMAP,ft_bitmap_glyph_init,ft_bitmap_glyph_done,ft_bitmap_glyph_copy,NULL,ft_bitmap_glyph_bbox,NULL)135   FT_DEFINE_GLYPH(
136     ft_bitmap_glyph_class,
137 
138     sizeof ( FT_BitmapGlyphRec ),
139     FT_GLYPH_FORMAT_BITMAP,
140 
141     ft_bitmap_glyph_init,    /* FT_Glyph_InitFunc       glyph_init      */
142     ft_bitmap_glyph_done,    /* FT_Glyph_DoneFunc       glyph_done      */
143     ft_bitmap_glyph_copy,    /* FT_Glyph_CopyFunc       glyph_copy      */
144     NULL,                    /* FT_Glyph_TransformFunc  glyph_transform */
145     ft_bitmap_glyph_bbox,    /* FT_Glyph_GetBBoxFunc    glyph_bbox      */
146     NULL                     /* FT_Glyph_PrepareFunc    glyph_prepare   */
147   )
148 
149 
150   /*************************************************************************/
151   /*************************************************************************/
152   /****                                                                 ****/
153   /****   FT_OutlineGlyph support                                       ****/
154   /****                                                                 ****/
155   /*************************************************************************/
156   /*************************************************************************/
157 
158 
159   FT_CALLBACK_DEF( FT_Error )
160   ft_outline_glyph_init( FT_Glyph      outline_glyph,
161                          FT_GlyphSlot  slot )
162   {
163     FT_OutlineGlyph  glyph   = (FT_OutlineGlyph)outline_glyph;
164     FT_Error         error   = FT_Err_Ok;
165     FT_Library       library = FT_GLYPH( glyph )->library;
166     FT_Outline*      source  = &slot->outline;
167     FT_Outline*      target  = &glyph->outline;
168 
169 
170     /* check format in glyph slot */
171     if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
172     {
173       error = FT_THROW( Invalid_Glyph_Format );
174       goto Exit;
175     }
176 
177     /* allocate new outline */
178     error = FT_Outline_New( library,
179                             (FT_UInt)source->n_points,
180                             source->n_contours,
181                             &glyph->outline );
182     if ( error )
183       goto Exit;
184 
185     FT_Outline_Copy( source, target );
186 
187   Exit:
188     return error;
189   }
190 
191 
192   FT_CALLBACK_DEF( void )
ft_outline_glyph_done(FT_Glyph outline_glyph)193   ft_outline_glyph_done( FT_Glyph  outline_glyph )
194   {
195     FT_OutlineGlyph  glyph = (FT_OutlineGlyph)outline_glyph;
196 
197 
198     FT_Outline_Done( FT_GLYPH( glyph )->library, &glyph->outline );
199   }
200 
201 
202   FT_CALLBACK_DEF( FT_Error )
ft_outline_glyph_copy(FT_Glyph outline_source,FT_Glyph outline_target)203   ft_outline_glyph_copy( FT_Glyph  outline_source,
204                          FT_Glyph  outline_target )
205   {
206     FT_OutlineGlyph  source  = (FT_OutlineGlyph)outline_source;
207     FT_OutlineGlyph  target  = (FT_OutlineGlyph)outline_target;
208     FT_Error         error;
209     FT_Library       library = FT_GLYPH( source )->library;
210 
211 
212     error = FT_Outline_New( library,
213                             (FT_UInt)source->outline.n_points,
214                             source->outline.n_contours,
215                             &target->outline );
216     if ( !error )
217       FT_Outline_Copy( &source->outline, &target->outline );
218 
219     return error;
220   }
221 
222 
223   FT_CALLBACK_DEF( void )
ft_outline_glyph_transform(FT_Glyph outline_glyph,const FT_Matrix * matrix,const FT_Vector * delta)224   ft_outline_glyph_transform( FT_Glyph          outline_glyph,
225                               const FT_Matrix*  matrix,
226                               const FT_Vector*  delta )
227   {
228     FT_OutlineGlyph  glyph = (FT_OutlineGlyph)outline_glyph;
229 
230 
231     if ( matrix )
232       FT_Outline_Transform( &glyph->outline, matrix );
233 
234     if ( delta )
235       FT_Outline_Translate( &glyph->outline, delta->x, delta->y );
236   }
237 
238 
239   FT_CALLBACK_DEF( void )
ft_outline_glyph_bbox(FT_Glyph outline_glyph,FT_BBox * bbox)240   ft_outline_glyph_bbox( FT_Glyph  outline_glyph,
241                          FT_BBox*  bbox )
242   {
243     FT_OutlineGlyph  glyph = (FT_OutlineGlyph)outline_glyph;
244 
245 
246     FT_Outline_Get_CBox( &glyph->outline, bbox );
247   }
248 
249 
250   FT_CALLBACK_DEF( FT_Error )
ft_outline_glyph_prepare(FT_Glyph outline_glyph,FT_GlyphSlot slot)251   ft_outline_glyph_prepare( FT_Glyph      outline_glyph,
252                             FT_GlyphSlot  slot )
253   {
254     FT_OutlineGlyph  glyph = (FT_OutlineGlyph)outline_glyph;
255 
256 
257     slot->format         = FT_GLYPH_FORMAT_OUTLINE;
258     slot->outline        = glyph->outline;
259     slot->outline.flags &= ~FT_OUTLINE_OWNER;
260 
261     return FT_Err_Ok;
262   }
263 
264 
FT_DEFINE_GLYPH(ft_outline_glyph_class,sizeof (FT_OutlineGlyphRec),FT_GLYPH_FORMAT_OUTLINE,ft_outline_glyph_init,ft_outline_glyph_done,ft_outline_glyph_copy,ft_outline_glyph_transform,ft_outline_glyph_bbox,ft_outline_glyph_prepare)265   FT_DEFINE_GLYPH(
266     ft_outline_glyph_class,
267 
268     sizeof ( FT_OutlineGlyphRec ),
269     FT_GLYPH_FORMAT_OUTLINE,
270 
271     ft_outline_glyph_init,      /* FT_Glyph_InitFunc       glyph_init      */
272     ft_outline_glyph_done,      /* FT_Glyph_DoneFunc       glyph_done      */
273     ft_outline_glyph_copy,      /* FT_Glyph_CopyFunc       glyph_copy      */
274     ft_outline_glyph_transform, /* FT_Glyph_TransformFunc  glyph_transform */
275     ft_outline_glyph_bbox,      /* FT_Glyph_GetBBoxFunc    glyph_bbox      */
276     ft_outline_glyph_prepare    /* FT_Glyph_PrepareFunc    glyph_prepare   */
277   )
278 
279 
280   /*************************************************************************/
281   /*************************************************************************/
282   /****                                                                 ****/
283   /****   FT_Glyph class and API                                        ****/
284   /****                                                                 ****/
285   /*************************************************************************/
286   /*************************************************************************/
287 
288    static FT_Error
289    ft_new_glyph( FT_Library             library,
290                  const FT_Glyph_Class*  clazz,
291                  FT_Glyph*              aglyph )
292    {
293      FT_Memory  memory = library->memory;
294      FT_Error   error;
295      FT_Glyph   glyph  = NULL;
296 
297 
298      *aglyph = NULL;
299 
300      if ( !FT_ALLOC( glyph, clazz->glyph_size ) )
301      {
302        glyph->library = library;
303        glyph->clazz   = clazz;
304        glyph->format  = clazz->glyph_format;
305 
306        *aglyph = glyph;
307      }
308 
309      return error;
310    }
311 
312 
313   /* documentation is in ftglyph.h */
314 
315   FT_EXPORT_DEF( FT_Error )
FT_Glyph_Copy(FT_Glyph source,FT_Glyph * target)316   FT_Glyph_Copy( FT_Glyph   source,
317                  FT_Glyph  *target )
318   {
319     FT_Glyph               copy;
320     FT_Error               error;
321     const FT_Glyph_Class*  clazz;
322 
323 
324     /* check arguments */
325     if ( !target || !source || !source->clazz )
326     {
327       error = FT_THROW( Invalid_Argument );
328       goto Exit;
329     }
330 
331     *target = NULL;
332 
333     if ( !source || !source->clazz )
334     {
335       error = FT_THROW( Invalid_Argument );
336       goto Exit;
337     }
338 
339     clazz = source->clazz;
340     error = ft_new_glyph( source->library, clazz, &copy );
341     if ( error )
342       goto Exit;
343 
344     copy->advance = source->advance;
345     copy->format  = source->format;
346 
347     if ( clazz->glyph_copy )
348       error = clazz->glyph_copy( source, copy );
349 
350     if ( error )
351       FT_Done_Glyph( copy );
352     else
353       *target = copy;
354 
355   Exit:
356     return error;
357   }
358 
359 
360   /* documentation is in ftglyph.h */
361 
362   FT_EXPORT( FT_Error )
FT_New_Glyph(FT_Library library,FT_Glyph_Format format,FT_Glyph * aglyph)363   FT_New_Glyph( FT_Library       library,
364                 FT_Glyph_Format  format,
365                 FT_Glyph        *aglyph )
366   {
367     const FT_Glyph_Class*  clazz = NULL;
368 
369     if ( !library || !aglyph )
370       return FT_THROW( Invalid_Argument );
371 
372     /* if it is a bitmap, that's easy :-) */
373     if ( format == FT_GLYPH_FORMAT_BITMAP )
374       clazz = &ft_bitmap_glyph_class;
375 
376     /* if it is an outline */
377     else if ( format == FT_GLYPH_FORMAT_OUTLINE )
378       clazz = &ft_outline_glyph_class;
379 
380     else
381     {
382       /* try to find a renderer that supports the glyph image format */
383       FT_Renderer  render = FT_Lookup_Renderer( library, format, 0 );
384 
385 
386       if ( render )
387         clazz = &render->glyph_class;
388     }
389 
390     if ( !clazz )
391       return FT_THROW( Invalid_Glyph_Format );
392 
393     /* create FT_Glyph object */
394     return ft_new_glyph( library, clazz, aglyph );
395   }
396 
397 
398   /* documentation is in ftglyph.h */
399 
400   FT_EXPORT_DEF( FT_Error )
FT_Get_Glyph(FT_GlyphSlot slot,FT_Glyph * aglyph)401   FT_Get_Glyph( FT_GlyphSlot  slot,
402                 FT_Glyph     *aglyph )
403   {
404     FT_Error  error;
405     FT_Glyph  glyph;
406 
407 
408     if ( !slot )
409       return FT_THROW( Invalid_Slot_Handle );
410 
411     if ( !aglyph )
412       return FT_THROW( Invalid_Argument );
413 
414     /* create FT_Glyph object */
415     error = FT_New_Glyph( slot->library, slot->format, &glyph );
416     if ( error )
417       goto Exit;
418 
419     /* copy advance while converting 26.6 to 16.16 format */
420     if ( slot->advance.x >=  0x8000L * 64 ||
421          slot->advance.x <= -0x8000L * 64 )
422     {
423       FT_ERROR(( "FT_Get_Glyph: advance width too large\n" ));
424       error = FT_THROW( Invalid_Argument );
425       goto Exit2;
426     }
427     if ( slot->advance.y >=  0x8000L * 64 ||
428          slot->advance.y <= -0x8000L * 64 )
429     {
430       FT_ERROR(( "FT_Get_Glyph: advance height too large\n" ));
431       error = FT_THROW( Invalid_Argument );
432       goto Exit2;
433     }
434 
435     glyph->advance.x = slot->advance.x * 1024;
436     glyph->advance.y = slot->advance.y * 1024;
437 
438     /* now import the image from the glyph slot */
439     error = glyph->clazz->glyph_init( glyph, slot );
440 
441   Exit2:
442     /* if an error occurred, destroy the glyph */
443     if ( error )
444       FT_Done_Glyph( glyph );
445     else
446       *aglyph = glyph;
447 
448   Exit:
449     return error;
450   }
451 
452 
453   /* documentation is in ftglyph.h */
454 
455   FT_EXPORT_DEF( FT_Error )
FT_Glyph_Transform(FT_Glyph glyph,FT_Matrix * matrix,FT_Vector * delta)456   FT_Glyph_Transform( FT_Glyph    glyph,
457                       FT_Matrix*  matrix,
458                       FT_Vector*  delta )
459   {
460     FT_Error  error = FT_Err_Ok;
461 
462 
463     if ( !glyph || !glyph->clazz )
464       error = FT_THROW( Invalid_Argument );
465     else
466     {
467       const FT_Glyph_Class*  clazz = glyph->clazz;
468 
469 
470       if ( clazz->glyph_transform )
471       {
472         /* transform glyph image */
473         clazz->glyph_transform( glyph, matrix, delta );
474 
475         /* transform advance vector */
476         if ( matrix )
477           FT_Vector_Transform( &glyph->advance, matrix );
478       }
479       else
480         error = FT_THROW( Invalid_Glyph_Format );
481     }
482     return error;
483   }
484 
485 
486   /* documentation is in ftglyph.h */
487 
488   FT_EXPORT_DEF( void )
FT_Glyph_Get_CBox(FT_Glyph glyph,FT_UInt bbox_mode,FT_BBox * acbox)489   FT_Glyph_Get_CBox( FT_Glyph  glyph,
490                      FT_UInt   bbox_mode,
491                      FT_BBox  *acbox )
492   {
493     const FT_Glyph_Class*  clazz;
494 
495 
496     if ( !acbox )
497       return;
498 
499     acbox->xMin = acbox->yMin = acbox->xMax = acbox->yMax = 0;
500 
501     if ( !glyph || !glyph->clazz )
502       return;
503 
504     clazz = glyph->clazz;
505     if ( !clazz->glyph_bbox )
506       return;
507 
508     /* retrieve bbox in 26.6 coordinates */
509     clazz->glyph_bbox( glyph, acbox );
510 
511     /* perform grid fitting if needed */
512     if ( bbox_mode == FT_GLYPH_BBOX_GRIDFIT ||
513          bbox_mode == FT_GLYPH_BBOX_PIXELS  )
514     {
515       acbox->xMin = FT_PIX_FLOOR( acbox->xMin );
516       acbox->yMin = FT_PIX_FLOOR( acbox->yMin );
517       acbox->xMax = FT_PIX_CEIL_LONG( acbox->xMax );
518       acbox->yMax = FT_PIX_CEIL_LONG( acbox->yMax );
519     }
520 
521     /* convert to integer pixels if needed */
522     if ( bbox_mode == FT_GLYPH_BBOX_TRUNCATE ||
523          bbox_mode == FT_GLYPH_BBOX_PIXELS   )
524     {
525       acbox->xMin >>= 6;
526       acbox->yMin >>= 6;
527       acbox->xMax >>= 6;
528       acbox->yMax >>= 6;
529     }
530   }
531 
532 
533   /* documentation is in ftglyph.h */
534 
535   FT_EXPORT_DEF( FT_Error )
FT_Glyph_To_Bitmap(FT_Glyph * the_glyph,FT_Render_Mode render_mode,FT_Vector * origin,FT_Bool destroy)536   FT_Glyph_To_Bitmap( FT_Glyph*       the_glyph,
537                       FT_Render_Mode  render_mode,
538                       FT_Vector*      origin,
539                       FT_Bool         destroy )
540   {
541     FT_GlyphSlotRec           dummy;
542     FT_GlyphSlot_InternalRec  dummy_internal;
543     FT_Error                  error = FT_Err_Ok;
544     FT_Glyph                  b, glyph;
545     FT_BitmapGlyph            bitmap = NULL;
546     const FT_Glyph_Class*     clazz;
547 
548     FT_Library                library;
549 
550 
551     /* check argument */
552     if ( !the_glyph )
553       goto Bad;
554     glyph = *the_glyph;
555     if ( !glyph )
556       goto Bad;
557 
558     clazz   = glyph->clazz;
559     library = glyph->library;
560     if ( !library || !clazz )
561       goto Bad;
562 
563     /* when called with a bitmap glyph, do nothing and return successfully */
564     if ( clazz == &ft_bitmap_glyph_class )
565       goto Exit;
566 
567     if ( !clazz->glyph_prepare )
568       goto Bad;
569 
570     /* we render the glyph into a glyph bitmap using a `dummy' glyph slot */
571     /* then calling FT_Render_Glyph_Internal()                            */
572 
573     FT_ZERO( &dummy );
574     FT_ZERO( &dummy_internal );
575     dummy.internal = &dummy_internal;
576     dummy.library  = library;
577     dummy.format   = clazz->glyph_format;
578 
579     /* create result bitmap glyph */
580     error = ft_new_glyph( library, &ft_bitmap_glyph_class, &b );
581     if ( error )
582       goto Exit;
583     bitmap = (FT_BitmapGlyph)b;
584 
585 #if 1
586     /* if `origin' is set, translate the glyph image */
587     if ( origin )
588       FT_Glyph_Transform( glyph, 0, origin );
589 #else
590     FT_UNUSED( origin );
591 #endif
592 
593     /* prepare dummy slot for rendering */
594     error = clazz->glyph_prepare( glyph, &dummy );
595     if ( !error )
596       error = FT_Render_Glyph_Internal( glyph->library, &dummy, render_mode );
597 
598 #if 1
599     if ( !destroy && origin )
600     {
601       FT_Vector  v;
602 
603 
604       v.x = -origin->x;
605       v.y = -origin->y;
606       FT_Glyph_Transform( glyph, 0, &v );
607     }
608 #endif
609 
610     if ( error )
611       goto Exit;
612 
613     /* in case of success, copy the bitmap to the glyph bitmap */
614     error = ft_bitmap_glyph_init( (FT_Glyph)bitmap, &dummy );
615     if ( error )
616       goto Exit;
617 
618     /* copy advance */
619     bitmap->root.advance = glyph->advance;
620 
621     if ( destroy )
622       FT_Done_Glyph( glyph );
623 
624     *the_glyph = FT_GLYPH( bitmap );
625 
626   Exit:
627     if ( error && bitmap )
628       FT_Done_Glyph( FT_GLYPH( bitmap ) );
629 
630     return error;
631 
632   Bad:
633     error = FT_THROW( Invalid_Argument );
634     goto Exit;
635   }
636 
637 
638   /* documentation is in ftglyph.h */
639 
640   FT_EXPORT_DEF( void )
FT_Done_Glyph(FT_Glyph glyph)641   FT_Done_Glyph( FT_Glyph  glyph )
642   {
643     if ( glyph )
644     {
645       FT_Memory              memory = glyph->library->memory;
646       const FT_Glyph_Class*  clazz  = glyph->clazz;
647 
648 
649       if ( clazz->glyph_done )
650         clazz->glyph_done( glyph );
651 
652       FT_FREE( glyph );
653     }
654   }
655 
656 
657 /* END */
658