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1 | /***************************************************************************/ |
2 | /* */ | |
3 | /* ttdriver.c */ | |
4 | /* */ | |
5 | /* TrueType font driver implementation (body). */ | |
6 | /* */ | |
7 | /* Copyright 1996-2000 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 <freetype/internal/ftdebug.h> | |
20 | #include <freetype/internal/ftstream.h> | |
21 | #include <freetype/internal/sfnt.h> | |
22 | #include <freetype/ttnameid.h> | |
23 | ||
24 | ||
25 | #ifdef FT_FLAT_COMPILE | |
26 | ||
27 | #include "ttdriver.h" | |
28 | #include "ttgload.h" | |
29 | ||
30 | #else | |
31 | ||
32 | #include <truetype/ttdriver.h> | |
33 | #include <truetype/ttgload.h> | |
34 | ||
35 | #endif | |
36 | ||
37 | ||
38 | /*************************************************************************/ | |
39 | /* */ | |
40 | /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ | |
41 | /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ | |
42 | /* messages during execution. */ | |
43 | /* */ | |
44 | #undef FT_COMPONENT | |
45 | #define FT_COMPONENT trace_ttdriver | |
46 | ||
47 | ||
48 | /*************************************************************************/ | |
49 | /*************************************************************************/ | |
50 | /*************************************************************************/ | |
51 | /**** ****/ | |
52 | /**** ****/ | |
53 | /**** F A C E S ****/ | |
54 | /**** ****/ | |
55 | /**** ****/ | |
56 | /*************************************************************************/ | |
57 | /*************************************************************************/ | |
58 | /*************************************************************************/ | |
59 | ||
60 | ||
61 | #undef PAIR_TAG | |
62 | #define PAIR_TAG( left, right ) ( ( (FT_ULong)left << 16 ) | \ | |
63 | (FT_ULong)right ) | |
64 | ||
65 | ||
66 | /*************************************************************************/ | |
67 | /* */ | |
68 | /* <Function> */ | |
69 | /* Get_Kerning */ | |
70 | /* */ | |
71 | /* <Description> */ | |
72 | /* A driver method used to return the kerning vector between two */ | |
73 | /* glyphs of the same face. */ | |
74 | /* */ | |
75 | /* <Input> */ | |
76 | /* face :: A handle to the source face object. */ | |
77 | /* */ | |
78 | /* left_glyph :: The index of the left glyph in the kern pair. */ | |
79 | /* */ | |
80 | /* right_glyph :: The index of the right glyph in the kern pair. */ | |
81 | /* */ | |
82 | /* <Output> */ | |
83 | /* kerning :: The kerning vector. This is in font units for */ | |
84 | /* scalable formats, and in pixels for fixed-sizes */ | |
85 | /* formats. */ | |
86 | /* */ | |
87 | /* <Return> */ | |
88 | /* FreeType error code. 0 means success. */ | |
89 | /* */ | |
90 | /* <Note> */ | |
91 | /* Only horizontal layouts (left-to-right & right-to-left) are */ | |
92 | /* supported by this function. Other layouts, or more sophisticated */ | |
93 | /* kernings, are out of scope of this method (the basic driver */ | |
94 | /* interface is meant to be simple). */ | |
95 | /* */ | |
96 | /* They can be implemented by format-specific interfaces. */ | |
97 | /* */ | |
98 | static | |
99 | FT_Error Get_Kerning( TT_Face face, | |
100 | FT_UInt left_glyph, | |
101 | FT_UInt right_glyph, | |
102 | FT_Vector* kerning ) | |
103 | { | |
104 | TT_Kern_0_Pair* pair; | |
105 | ||
106 | ||
107 | if ( !face ) | |
108 | return TT_Err_Invalid_Face_Handle; | |
109 | ||
110 | kerning->x = 0; | |
111 | kerning->y = 0; | |
112 | ||
113 | if ( face->kern_pairs ) | |
114 | { | |
115 | /* there are some kerning pairs in this font file! */ | |
116 | FT_ULong search_tag = PAIR_TAG( left_glyph, right_glyph ); | |
117 | FT_Long left, right; | |
118 | ||
119 | ||
120 | left = 0; | |
121 | right = face->num_kern_pairs - 1; | |
122 | ||
123 | while ( left <= right ) | |
124 | { | |
125 | FT_Int middle = left + ( ( right - left ) >> 1 ); | |
126 | FT_ULong cur_pair; | |
127 | ||
128 | ||
129 | pair = face->kern_pairs + middle; | |
130 | cur_pair = PAIR_TAG( pair->left, pair->right ); | |
131 | ||
132 | if ( cur_pair == search_tag ) | |
133 | goto Found; | |
134 | ||
135 | if ( cur_pair < search_tag ) | |
136 | left = middle + 1; | |
137 | else | |
138 | right = middle - 1; | |
139 | } | |
140 | } | |
141 | ||
142 | Exit: | |
143 | return TT_Err_Ok; | |
144 | ||
145 | Found: | |
146 | kerning->x = pair->value; | |
147 | goto Exit; | |
148 | } | |
149 | ||
150 | ||
151 | #undef PAIR_TAG | |
152 | ||
153 | ||
154 | /*************************************************************************/ | |
155 | /*************************************************************************/ | |
156 | /*************************************************************************/ | |
157 | /**** ****/ | |
158 | /**** ****/ | |
159 | /**** S I Z E S ****/ | |
160 | /**** ****/ | |
161 | /**** ****/ | |
162 | /*************************************************************************/ | |
163 | /*************************************************************************/ | |
164 | /*************************************************************************/ | |
165 | ||
166 | ||
167 | /*************************************************************************/ | |
168 | /* */ | |
169 | /* <Function> */ | |
170 | /* Set_Char_Sizes */ | |
171 | /* */ | |
172 | /* <Description> */ | |
173 | /* A driver method used to reset a size's character sizes (horizontal */ | |
174 | /* and vertical) expressed in fractional points. */ | |
175 | /* */ | |
176 | /* <Input> */ | |
177 | /* char_width :: The character width expressed in 26.6 */ | |
178 | /* fractional points. */ | |
179 | /* */ | |
180 | /* char_height :: The character height expressed in 26.6 */ | |
181 | /* fractional points. */ | |
182 | /* */ | |
183 | /* horz_resolution :: The horizontal resolution of the output device. */ | |
184 | /* */ | |
185 | /* vert_resolution :: The vertical resolution of the output device. */ | |
186 | /* */ | |
187 | /* <InOut> */ | |
188 | /* size :: A handle to the target size object. */ | |
189 | /* */ | |
190 | /* <Return> */ | |
191 | /* FreeType error code. 0 means success. */ | |
192 | /* */ | |
193 | static | |
194 | FT_Error Set_Char_Sizes( TT_Size size, | |
195 | FT_F26Dot6 char_width, | |
196 | FT_F26Dot6 char_height, | |
197 | FT_UInt horz_resolution, | |
198 | FT_UInt vert_resolution ) | |
199 | { | |
200 | FT_Size_Metrics* metrics = &size->root.metrics; | |
201 | TT_Face face = (TT_Face)size->root.face; | |
202 | FT_Long dim_x, dim_y; | |
203 | ||
204 | ||
205 | /* This bit flag, when set, indicates that the pixel size must be */ | |
206 | /* truncated to an integer. Nearly all TrueType fonts have this */ | |
207 | /* bit set, as hinting won't work really well otherwise. */ | |
208 | /* */ | |
209 | /* However, for those rare fonts who do not set it, we override */ | |
210 | /* the default computations performed by the base layer. I */ | |
211 | /* really don't know whether this is useful, but hey, that's the */ | |
212 | /* spec :-) */ | |
213 | /* */ | |
214 | if ( ( face->header.Flags & 8 ) == 0 ) | |
215 | { | |
216 | /* Compute pixel sizes in 26.6 units */ | |
217 | dim_x = ( char_width * horz_resolution ) / 72; | |
218 | dim_y = ( char_height * vert_resolution ) / 72; | |
219 | ||
220 | metrics->x_scale = FT_DivFix( dim_x, face->root.units_per_EM ); | |
221 | metrics->y_scale = FT_DivFix( dim_y, face->root.units_per_EM ); | |
222 | ||
223 | metrics->x_ppem = (FT_UShort)( dim_x >> 6 ); | |
224 | metrics->y_ppem = (FT_UShort)( dim_y >> 6 ); | |
225 | } | |
226 | ||
227 | size->ttmetrics.valid = FALSE; | |
228 | ||
229 | return TT_Reset_Size( size ); | |
230 | } | |
231 | ||
232 | ||
233 | /*************************************************************************/ | |
234 | /* */ | |
235 | /* <Function> */ | |
236 | /* Set_Pixel_Sizes */ | |
237 | /* */ | |
238 | /* <Description> */ | |
239 | /* A driver method used to reset a size's character sizes (horizontal */ | |
240 | /* and vertical) expressed in integer pixels. */ | |
241 | /* */ | |
242 | /* <Input> */ | |
243 | /* pixel_width :: The character width expressed in integer pixels. */ | |
244 | /* */ | |
245 | /* pixel_height :: The character height expressed in integer pixels. */ | |
246 | /* */ | |
247 | /* <InOut> */ | |
248 | /* size :: A handle to the target size object. */ | |
249 | /* */ | |
250 | /* <Return> */ | |
251 | /* FreeType error code. 0 means success. */ | |
252 | /* */ | |
253 | static | |
254 | FT_Error Set_Pixel_Sizes( TT_Size size, | |
255 | FT_UInt pixel_width, | |
256 | FT_UInt pixel_height ) | |
257 | { | |
258 | FT_UNUSED( pixel_width ); | |
259 | FT_UNUSED( pixel_height ); | |
260 | ||
261 | /* many things have been pre-computed by the base layer */ | |
262 | ||
263 | size->ttmetrics.valid = FALSE; | |
264 | ||
265 | return TT_Reset_Size( size ); | |
266 | } | |
267 | ||
268 | ||
269 | /*************************************************************************/ | |
270 | /* */ | |
271 | /* <Function> */ | |
272 | /* Load_Glyph */ | |
273 | /* */ | |
274 | /* <Description> */ | |
275 | /* A driver method used to load a glyph within a given glyph slot. */ | |
276 | /* */ | |
277 | /* <Input> */ | |
278 | /* slot :: A handle to the target slot object where the glyph */ | |
279 | /* will be loaded. */ | |
280 | /* */ | |
281 | /* size :: A handle to the source face size at which the glyph */ | |
282 | /* must be scaled, loaded, etc. */ | |
283 | /* */ | |
284 | /* glyph_index :: The index of the glyph in the font file. */ | |
285 | /* */ | |
286 | /* load_flags :: A flag indicating what to load for this glyph. The */ | |
287 | /* FTLOAD_??? constants can be used to control the */ | |
288 | /* glyph loading process (e.g., whether the outline */ | |
289 | /* should be scaled, whether to load bitmaps or not, */ | |
290 | /* whether to hint the outline, etc). */ | |
291 | /* */ | |
292 | /* <Return> */ | |
293 | /* FreeType error code. 0 means success. */ | |
294 | /* */ | |
295 | static | |
296 | FT_Error Load_Glyph( TT_GlyphSlot slot, | |
297 | TT_Size size, | |
298 | FT_UShort glyph_index, | |
299 | FT_UInt load_flags ) | |
300 | { | |
301 | FT_Error error; | |
302 | ||
303 | ||
304 | if ( !slot ) | |
305 | return TT_Err_Invalid_Glyph_Handle; | |
306 | ||
307 | /* check whether we want a scaled outline or bitmap */ | |
308 | if ( !size ) | |
309 | load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING; | |
310 | ||
311 | if ( load_flags & FT_LOAD_NO_SCALE ) | |
312 | size = NULL; | |
313 | ||
314 | /* reset the size object if necessary */ | |
315 | if ( size ) | |
316 | { | |
317 | /* these two object must have the same parent */ | |
318 | if ( size->root.face != slot->face ) | |
319 | return TT_Err_Invalid_Face_Handle; | |
320 | ||
321 | if ( !size->ttmetrics.valid ) | |
322 | { | |
323 | if ( FT_SET_ERROR( TT_Reset_Size( size ) ) ) | |
324 | return error; | |
325 | } | |
326 | } | |
327 | ||
328 | /* now load the glyph outline if necessary */ | |
329 | error = TT_Load_Glyph( size, slot, glyph_index, load_flags ); | |
330 | ||
331 | /* force drop-out mode to 2 - irrelevant now */ | |
332 | /* slot->outline.dropout_mode = 2; */ | |
333 | ||
334 | return error; | |
335 | } | |
336 | ||
337 | ||
338 | /*************************************************************************/ | |
339 | /*************************************************************************/ | |
340 | /*************************************************************************/ | |
341 | /**** ****/ | |
342 | /**** ****/ | |
343 | /**** C H A R A C T E R M A P P I N G S ****/ | |
344 | /**** ****/ | |
345 | /**** ****/ | |
346 | /*************************************************************************/ | |
347 | /*************************************************************************/ | |
348 | /*************************************************************************/ | |
349 | ||
350 | /*************************************************************************/ | |
351 | /* */ | |
352 | /* <Function> */ | |
353 | /* Get_Char_Index */ | |
354 | /* */ | |
355 | /* <Description> */ | |
356 | /* Uses a charmap to return a given character code's glyph index. */ | |
357 | /* */ | |
358 | /* <Input> */ | |
359 | /* charmap :: A handle to the source charmap object. */ | |
360 | /* charcode :: The character code. */ | |
361 | /* */ | |
362 | /* <Return> */ | |
363 | /* Glyph index. 0 means `undefined character code'. */ | |
364 | /* */ | |
365 | static | |
366 | FT_UInt Get_Char_Index( TT_CharMap charmap, | |
367 | FT_Long charcode ) | |
368 | { | |
369 | FT_Error error; | |
370 | TT_Face face; | |
371 | TT_CMapTable* cmap; | |
372 | ||
373 | ||
374 | cmap = &charmap->cmap; | |
375 | face = (TT_Face)charmap->root.face; | |
376 | ||
377 | /* Load table if needed */ | |
378 | if ( !cmap->loaded ) | |
379 | { | |
380 | SFNT_Interface* sfnt = (SFNT_Interface*)face->sfnt; | |
381 | ||
382 | ||
383 | error = sfnt->load_charmap( face, cmap, face->root.stream ); | |
384 | if ( error ) | |
385 | return 0; | |
386 | ||
387 | cmap->loaded = TRUE; | |
388 | } | |
389 | ||
390 | if ( cmap->get_index ) | |
391 | return cmap->get_index( cmap, charcode ); | |
392 | else | |
393 | return 0; | |
394 | } | |
395 | ||
396 | ||
397 | /*************************************************************************/ | |
398 | /*************************************************************************/ | |
399 | /*************************************************************************/ | |
400 | /**** ****/ | |
401 | /**** ****/ | |
402 | /**** D R I V E R I N T E R F A C E ****/ | |
403 | /**** ****/ | |
404 | /**** ****/ | |
405 | /*************************************************************************/ | |
406 | /*************************************************************************/ | |
407 | /*************************************************************************/ | |
408 | ||
409 | ||
410 | static | |
411 | FT_Module_Interface tt_get_interface( TT_Driver driver, | |
412 | const char* interface ) | |
413 | { | |
414 | FT_Module sfntd = FT_Get_Module( driver->root.root.library, | |
415 | "sfnt" ); | |
416 | SFNT_Interface* sfnt; | |
417 | ||
418 | ||
419 | /* only return the default interface from the SFNT module */ | |
420 | if ( sfntd ) | |
421 | { | |
422 | sfnt = (SFNT_Interface*)( sfntd->clazz->module_interface ); | |
423 | if ( sfnt ) | |
424 | return sfnt->get_interface( FT_MODULE( driver ), interface ); | |
425 | } | |
426 | ||
427 | return 0; | |
428 | } | |
429 | ||
430 | ||
431 | /* The FT_DriverInterface structure is defined in ftdriver.h. */ | |
432 | ||
433 | const FT_Driver_Class tt_driver_class = | |
434 | { | |
435 | { | |
436 | ft_module_font_driver | | |
437 | ft_module_driver_scalable | | |
438 | #ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER | |
439 | ft_module_driver_has_hinter, | |
440 | #else | |
441 | 0, | |
442 | #endif | |
443 | ||
444 | sizeof ( TT_DriverRec ), | |
445 | ||
446 | "truetype", /* driver name */ | |
447 | 0x10000L, /* driver version == 1.0 */ | |
448 | 0x20000L, /* driver requires FreeType 2.0 or above */ | |
449 | ||
450 | (void*)0, /* driver specific interface */ | |
451 | ||
452 | (FT_Module_Constructor)TT_Init_Driver, | |
453 | (FT_Module_Destructor) TT_Done_Driver, | |
454 | (FT_Module_Requester) tt_get_interface, | |
455 | }, | |
456 | ||
457 | sizeof ( TT_FaceRec ), | |
458 | sizeof ( TT_SizeRec ), | |
459 | sizeof ( FT_GlyphSlotRec ), | |
460 | ||
461 | ||
462 | (FTDriver_initFace) TT_Init_Face, | |
463 | (FTDriver_doneFace) TT_Done_Face, | |
464 | (FTDriver_initSize) TT_Init_Size, | |
465 | (FTDriver_doneSize) TT_Done_Size, | |
466 | (FTDriver_initGlyphSlot)0, | |
467 | (FTDriver_doneGlyphSlot)0, | |
468 | ||
469 | (FTDriver_setCharSizes) Set_Char_Sizes, | |
470 | (FTDriver_setPixelSizes)Set_Pixel_Sizes, | |
471 | (FTDriver_loadGlyph) Load_Glyph, | |
472 | (FTDriver_getCharIndex) Get_Char_Index, | |
473 | ||
474 | (FTDriver_getKerning) Get_Kerning, | |
475 | (FTDriver_attachFile) 0, | |
476 | (FTDriver_getAdvances) 0 | |
477 | }; | |
478 | ||
479 | ||
480 | #ifdef FT_CONFIG_OPTION_DYNAMIC_DRIVERS | |
481 | ||
482 | ||
483 | /*************************************************************************/ | |
484 | /* */ | |
485 | /* <Function> */ | |
486 | /* getDriverInterface */ | |
487 | /* */ | |
488 | /* <Description> */ | |
489 | /* This function is used when compiling the TrueType driver as a */ | |
490 | /* shared library (`.DLL' or `.so'). It will be used by the */ | |
491 | /* high-level library of FreeType to retrieve the address of the */ | |
492 | /* driver's generic interface. */ | |
493 | /* */ | |
494 | /* It shouldn't be implemented in a static build, as each driver must */ | |
495 | /* have the same function as an exported entry point. */ | |
496 | /* */ | |
497 | /* <Return> */ | |
498 | /* The address of the TrueType's driver generic interface. The */ | |
499 | /* format-specific interface can then be retrieved through the method */ | |
500 | /* interface->get_format_interface. */ | |
501 | /* */ | |
502 | EXPORT_FUNC( const FT_Driver_Class* ) getDriverClass( void ) | |
503 | { | |
504 | return &tt_driver_class; | |
505 | } | |
506 | ||
507 | ||
508 | #endif /* CONFIG_OPTION_DYNAMIC_DRIVERS */ | |
509 | ||
510 | ||
511 | /* END */ |