1 /****************************************************************************
2  *
3  * ftgloadr.c
4  *
5  *   The FreeType glyph loader (body).
6  *
7  * Copyright (C) 2002-2019 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 #include <ft2build.h>
20 #include FT_INTERNAL_DEBUG_H
21 #include FT_INTERNAL_GLYPH_LOADER_H
22 #include FT_INTERNAL_MEMORY_H
23 #include FT_INTERNAL_OBJECTS_H
24 
25 #undef  FT_COMPONENT
26 #define FT_COMPONENT  gloader
27 
28 
29   /*************************************************************************/
30   /*************************************************************************/
31   /*************************************************************************/
32   /*****                                                               *****/
33   /*****                                                               *****/
34   /*****                    G L Y P H   L O A D E R                    *****/
35   /*****                                                               *****/
36   /*****                                                               *****/
37   /*************************************************************************/
38   /*************************************************************************/
39   /*************************************************************************/
40 
41   /**************************************************************************
42    *
43    * The glyph loader is a simple object which is used to load a set of
44    * glyphs easily.  It is critical for the correct loading of composites.
45    *
46    * Ideally, one can see it as a stack of abstract `glyph' objects.
47    *
48    *   loader.base     Is really the bottom of the stack.  It describes a
49    *                   single glyph image made of the juxtaposition of
50    *                   several glyphs (those `in the stack').
51    *
52    *   loader.current  Describes the top of the stack, on which a new
53    *                   glyph can be loaded.
54    *
55    *   Rewind          Clears the stack.
56    *   Prepare         Set up `loader.current' for addition of a new glyph
57    *                   image.
58    *   Add             Add the `current' glyph image to the `base' one,
59    *                   and prepare for another one.
60    *
61    * The glyph loader is now a base object.  Each driver used to
62    * re-implement it in one way or the other, which wasted code and
63    * energy.
64    *
65    */
66 
67 
68   /* create a new glyph loader */
69   FT_BASE_DEF( FT_Error )
FT_GlyphLoader_New(FT_Memory memory,FT_GlyphLoader * aloader)70   FT_GlyphLoader_New( FT_Memory        memory,
71                       FT_GlyphLoader  *aloader )
72   {
73     FT_GlyphLoader  loader = NULL;
74     FT_Error        error;
75 
76 
77     if ( !FT_NEW( loader ) )
78     {
79       loader->memory = memory;
80       *aloader       = loader;
81     }
82     return error;
83   }
84 
85 
86   /* rewind the glyph loader - reset counters to 0 */
87   FT_BASE_DEF( void )
FT_GlyphLoader_Rewind(FT_GlyphLoader loader)88   FT_GlyphLoader_Rewind( FT_GlyphLoader  loader )
89   {
90     FT_GlyphLoad  base    = &loader->base;
91     FT_GlyphLoad  current = &loader->current;
92 
93 
94     base->outline.n_points   = 0;
95     base->outline.n_contours = 0;
96     base->num_subglyphs      = 0;
97 
98     *current = *base;
99   }
100 
101 
102   /* reset glyph loader, free all allocated tables, */
103   /* and start from zero                            */
104   FT_BASE_DEF( void )
FT_GlyphLoader_Reset(FT_GlyphLoader loader)105   FT_GlyphLoader_Reset( FT_GlyphLoader  loader )
106   {
107     FT_Memory  memory = loader->memory;
108 
109 
110     FT_FREE( loader->base.outline.points );
111     FT_FREE( loader->base.outline.tags );
112     FT_FREE( loader->base.outline.contours );
113     FT_FREE( loader->base.extra_points );
114     FT_FREE( loader->base.subglyphs );
115 
116     loader->base.extra_points2 = NULL;
117 
118     loader->max_points    = 0;
119     loader->max_contours  = 0;
120     loader->max_subglyphs = 0;
121 
122     FT_GlyphLoader_Rewind( loader );
123   }
124 
125 
126   /* delete a glyph loader */
127   FT_BASE_DEF( void )
FT_GlyphLoader_Done(FT_GlyphLoader loader)128   FT_GlyphLoader_Done( FT_GlyphLoader  loader )
129   {
130     if ( loader )
131     {
132       FT_Memory  memory = loader->memory;
133 
134 
135       FT_GlyphLoader_Reset( loader );
136       FT_FREE( loader );
137     }
138   }
139 
140 
141   /* re-adjust the `current' outline fields */
142   static void
FT_GlyphLoader_Adjust_Points(FT_GlyphLoader loader)143   FT_GlyphLoader_Adjust_Points( FT_GlyphLoader  loader )
144   {
145     FT_Outline*  base    = &loader->base.outline;
146     FT_Outline*  current = &loader->current.outline;
147 
148 
149     current->points   = base->points   + base->n_points;
150     current->tags     = base->tags     + base->n_points;
151     current->contours = base->contours + base->n_contours;
152 
153     /* handle extra points table - if any */
154     if ( loader->use_extra )
155     {
156       loader->current.extra_points  = loader->base.extra_points +
157                                       base->n_points;
158 
159       loader->current.extra_points2 = loader->base.extra_points2 +
160                                       base->n_points;
161     }
162   }
163 
164 
165   FT_BASE_DEF( FT_Error )
FT_GlyphLoader_CreateExtra(FT_GlyphLoader loader)166   FT_GlyphLoader_CreateExtra( FT_GlyphLoader  loader )
167   {
168     FT_Error   error;
169     FT_Memory  memory = loader->memory;
170 
171 
172     if ( !FT_NEW_ARRAY( loader->base.extra_points, 2 * loader->max_points ) )
173     {
174       loader->use_extra          = 1;
175       loader->base.extra_points2 = loader->base.extra_points +
176                                    loader->max_points;
177 
178       FT_GlyphLoader_Adjust_Points( loader );
179     }
180     return error;
181   }
182 
183 
184   /* re-adjust the `current' subglyphs field */
185   static void
FT_GlyphLoader_Adjust_Subglyphs(FT_GlyphLoader loader)186   FT_GlyphLoader_Adjust_Subglyphs( FT_GlyphLoader  loader )
187   {
188     FT_GlyphLoad  base    = &loader->base;
189     FT_GlyphLoad  current = &loader->current;
190 
191 
192     current->subglyphs = base->subglyphs + base->num_subglyphs;
193   }
194 
195 
196   /* Ensure that we can add `n_points' and `n_contours' to our glyph.      */
197   /* This function reallocates its outline tables if necessary.  Note that */
198   /* it DOESN'T change the number of points within the loader!             */
199   /*                                                                       */
200   FT_BASE_DEF( FT_Error )
FT_GlyphLoader_CheckPoints(FT_GlyphLoader loader,FT_UInt n_points,FT_UInt n_contours)201   FT_GlyphLoader_CheckPoints( FT_GlyphLoader  loader,
202                               FT_UInt         n_points,
203                               FT_UInt         n_contours )
204   {
205     FT_Memory    memory  = loader->memory;
206     FT_Error     error   = FT_Err_Ok;
207     FT_Outline*  base    = &loader->base.outline;
208     FT_Outline*  current = &loader->current.outline;
209     FT_Bool      adjust  = 0;
210 
211     FT_UInt      new_max, old_max;
212 
213 
214     /* check points & tags */
215     new_max = (FT_UInt)base->n_points + (FT_UInt)current->n_points +
216               n_points;
217     old_max = loader->max_points;
218 
219     if ( new_max > old_max )
220     {
221       new_max = FT_PAD_CEIL( new_max, 8 );
222 
223       if ( new_max > FT_OUTLINE_POINTS_MAX )
224         return FT_THROW( Array_Too_Large );
225 
226       if ( FT_RENEW_ARRAY( base->points, old_max, new_max ) ||
227            FT_RENEW_ARRAY( base->tags,   old_max, new_max ) )
228         goto Exit;
229 
230       if ( loader->use_extra )
231       {
232         if ( FT_RENEW_ARRAY( loader->base.extra_points,
233                              old_max * 2, new_max * 2 ) )
234           goto Exit;
235 
236         FT_ARRAY_MOVE( loader->base.extra_points + new_max,
237                        loader->base.extra_points + old_max,
238                        old_max );
239 
240         loader->base.extra_points2 = loader->base.extra_points + new_max;
241       }
242 
243       adjust = 1;
244       loader->max_points = new_max;
245     }
246 
247     /* check contours */
248     old_max = loader->max_contours;
249     new_max = (FT_UInt)base->n_contours + (FT_UInt)current->n_contours +
250               n_contours;
251     if ( new_max > old_max )
252     {
253       new_max = FT_PAD_CEIL( new_max, 4 );
254 
255       if ( new_max > FT_OUTLINE_CONTOURS_MAX )
256         return FT_THROW( Array_Too_Large );
257 
258       if ( FT_RENEW_ARRAY( base->contours, old_max, new_max ) )
259         goto Exit;
260 
261       adjust = 1;
262       loader->max_contours = new_max;
263     }
264 
265     if ( adjust )
266       FT_GlyphLoader_Adjust_Points( loader );
267 
268   Exit:
269     if ( error )
270       FT_GlyphLoader_Reset( loader );
271 
272     return error;
273   }
274 
275 
276   /* Ensure that we can add `n_subglyphs' to our glyph. this function */
277   /* reallocates its subglyphs table if necessary.  Note that it DOES */
278   /* NOT change the number of subglyphs within the loader!            */
279   /*                                                                  */
280   FT_BASE_DEF( FT_Error )
FT_GlyphLoader_CheckSubGlyphs(FT_GlyphLoader loader,FT_UInt n_subs)281   FT_GlyphLoader_CheckSubGlyphs( FT_GlyphLoader  loader,
282                                  FT_UInt         n_subs )
283   {
284     FT_Memory     memory = loader->memory;
285     FT_Error      error  = FT_Err_Ok;
286     FT_UInt       new_max, old_max;
287 
288     FT_GlyphLoad  base    = &loader->base;
289     FT_GlyphLoad  current = &loader->current;
290 
291 
292     new_max = base->num_subglyphs + current->num_subglyphs + n_subs;
293     old_max = loader->max_subglyphs;
294     if ( new_max > old_max )
295     {
296       new_max = FT_PAD_CEIL( new_max, 2 );
297       if ( FT_RENEW_ARRAY( base->subglyphs, old_max, new_max ) )
298         goto Exit;
299 
300       loader->max_subglyphs = new_max;
301 
302       FT_GlyphLoader_Adjust_Subglyphs( loader );
303     }
304 
305   Exit:
306     return error;
307   }
308 
309 
310   /* prepare loader for the addition of a new glyph on top of the base one */
311   FT_BASE_DEF( void )
FT_GlyphLoader_Prepare(FT_GlyphLoader loader)312   FT_GlyphLoader_Prepare( FT_GlyphLoader  loader )
313   {
314     FT_GlyphLoad  current = &loader->current;
315 
316 
317     current->outline.n_points   = 0;
318     current->outline.n_contours = 0;
319     current->num_subglyphs      = 0;
320 
321     FT_GlyphLoader_Adjust_Points   ( loader );
322     FT_GlyphLoader_Adjust_Subglyphs( loader );
323   }
324 
325 
326   /* add current glyph to the base image -- and prepare for another */
327   FT_BASE_DEF( void )
FT_GlyphLoader_Add(FT_GlyphLoader loader)328   FT_GlyphLoader_Add( FT_GlyphLoader  loader )
329   {
330     FT_GlyphLoad  base;
331     FT_GlyphLoad  current;
332 
333     FT_Int        n_curr_contours;
334     FT_Int        n_base_points;
335     FT_Int        n;
336 
337 
338     if ( !loader )
339       return;
340 
341     base    = &loader->base;
342     current = &loader->current;
343 
344     n_curr_contours = current->outline.n_contours;
345     n_base_points   = base->outline.n_points;
346 
347     base->outline.n_points =
348       (short)( base->outline.n_points + current->outline.n_points );
349     base->outline.n_contours =
350       (short)( base->outline.n_contours + current->outline.n_contours );
351 
352     base->num_subglyphs += current->num_subglyphs;
353 
354     /* adjust contours count in newest outline */
355     for ( n = 0; n < n_curr_contours; n++ )
356       current->outline.contours[n] =
357         (short)( current->outline.contours[n] + n_base_points );
358 
359     /* prepare for another new glyph image */
360     FT_GlyphLoader_Prepare( loader );
361   }
362 
363 
364 /* END */
365