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 )
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 )
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 )
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 )
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
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 )
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
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 )
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 )
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 )
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 )
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