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1 | /***************************************************************************/ |
2 | /* */ | |
3 | /* ftautoh.h */ | |
4 | /* */ | |
5 | /* FreeType API for controlling the auto-hinter (specification only). */ | |
6 | /* */ | |
7 | /* Copyright 2012 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 | #ifndef __FTAUTOH_H__ | |
20 | #define __FTAUTOH_H__ | |
21 | ||
22 | #include <ft2build.h> | |
23 | #include FT_FREETYPE_H | |
24 | ||
25 | #ifdef FREETYPE_H | |
26 | #error "freetype.h of FreeType 1 has been loaded!" | |
27 | #error "Please fix the directory search order for header files" | |
28 | #error "so that freetype.h of FreeType 2 is found first." | |
29 | #endif | |
30 | ||
31 | ||
32 | FT_BEGIN_HEADER | |
33 | ||
34 | ||
35 | /************************************************************************** | |
36 | * | |
37 | * @section: | |
38 | * auto_hinter | |
39 | * | |
40 | * @title: | |
41 | * The auto-hinter | |
42 | * | |
43 | * @abstract: | |
44 | * Controlling the auto-hinting module. | |
45 | * | |
46 | * @description: | |
47 | * While FreeType's auto-hinter doesn't expose API functions by itself, | |
48 | * it is possible to control its behaviour with @FT_Property_Set and | |
49 | * @FT_Property_Get. The following lists the available properties | |
50 | * together with the necessary macros and structures. | |
51 | * | |
52 | * Note that the auto-hinter's module name is `autofitter' for | |
53 | * historical reasons. | |
54 | * | |
55 | */ | |
56 | ||
57 | ||
58 | /************************************************************************** | |
59 | * | |
60 | * @property: | |
61 | * glyph-to-script-map | |
62 | * | |
63 | * @description: | |
64 | * The auto-hinter provides various script modules to hint glyphs. | |
65 | * Examples of supported scripts are Latin or CJK. Before a glyph is | |
66 | * auto-hinted, the Unicode character map of the font gets examined, and | |
67 | * the script is then determined based on Unicode character ranges, see | |
68 | * below. | |
69 | * | |
70 | * OpenType fonts, however, often provide much more glyphs than | |
71 | * character codes (small caps, superscripts, ligatures, swashes, etc.), | |
72 | * to be controlled by so-called `features'. Handling OpenType features | |
73 | * can be quite complicated and thus needs a separate library on top of | |
74 | * FreeType. | |
75 | * | |
76 | * The mapping between glyph indices and scripts (in the auto-hinter | |
77 | * sense, see the @FT_AUTOHINTER_SCRIPT_XXX values) is stored as an | |
78 | * array with `num_glyphs' elements, as found in the font's @FT_Face | |
79 | * structure. The `glyph-to-script-map' property returns a pointer to | |
80 | * this array which can be modified as needed. Note that the | |
81 | * modification should happen before the first glyph gets processed by | |
82 | * the auto-hinter so that the global analysis of the font shapes | |
83 | * actually uses the modified mapping. | |
84 | * | |
85 | * The following example code demonstrates how to access it (omitting | |
86 | * the error handling). | |
87 | * | |
88 | * { | |
89 | * FT_Library library; | |
90 | * FT_Face face; | |
91 | * FT_Prop_GlyphToScriptMap prop; | |
92 | * | |
93 | * | |
94 | * FT_Init_FreeType( &library ); | |
95 | * FT_New_Face( library, "foo.ttf", 0, &face ); | |
96 | * | |
97 | * prop.face = face; | |
98 | * | |
99 | * FT_Property_Get( library, "autofitter", | |
100 | * "glyph-to-script-map", &prop ); | |
101 | * | |
102 | * // adjust `prop.map' as needed right here | |
103 | * | |
104 | * FT_Load_Glyph( face, ..., FT_LOAD_FORCE_AUTOHINT ); | |
105 | * } | |
106 | * | |
107 | */ | |
108 | ||
109 | ||
110 | /************************************************************************** | |
111 | * | |
112 | * @enum: | |
113 | * FT_AUTOHINTER_SCRIPT_XXX | |
114 | * | |
115 | * @description: | |
116 | * A list of constants used for the @glyph-to-script-map property to | |
117 | * specify the script submodule the auto-hinter should use for hinting a | |
118 | * particular glyph. | |
119 | * | |
120 | * @values: | |
121 | * FT_AUTOHINTER_SCRIPT_NONE :: | |
122 | * Don't auto-hint this glyph. | |
123 | * | |
124 | * FT_AUTOHINTER_SCRIPT_LATIN :: | |
125 | * Apply the latin auto-hinter. For the auto-hinter, `latin' is a | |
126 | * very broad term, including Cyrillic and Greek also since characters | |
127 | * from those scripts share the same design constraints. | |
128 | * | |
129 | * By default, characters from the following Unicode ranges are | |
130 | * assigned to this submodule. | |
131 | * | |
132 | * { | |
133 | * U+0020 - U+007F // Basic Latin (no control characters) | |
134 | * U+00A0 - U+00FF // Latin-1 Supplement (no control characters) | |
135 | * U+0100 - U+017F // Latin Extended-A | |
136 | * U+0180 - U+024F // Latin Extended-B | |
137 | * U+0250 - U+02AF // IPA Extensions | |
138 | * U+02B0 - U+02FF // Spacing Modifier Letters | |
139 | * U+0300 - U+036F // Combining Diacritical Marks | |
140 | * U+0370 - U+03FF // Greek and Coptic | |
141 | * U+0400 - U+04FF // Cyrillic | |
142 | * U+0500 - U+052F // Cyrillic Supplement | |
143 | * U+1D00 - U+1D7F // Phonetic Extensions | |
144 | * U+1D80 - U+1DBF // Phonetic Extensions Supplement | |
145 | * U+1DC0 - U+1DFF // Combining Diacritical Marks Supplement | |
146 | * U+1E00 - U+1EFF // Latin Extended Additional | |
147 | * U+1F00 - U+1FFF // Greek Extended | |
148 | * U+2000 - U+206F // General Punctuation | |
149 | * U+2070 - U+209F // Superscripts and Subscripts | |
150 | * U+20A0 - U+20CF // Currency Symbols | |
151 | * U+2150 - U+218F // Number Forms | |
152 | * U+2460 - U+24FF // Enclosed Alphanumerics | |
153 | * U+2C60 - U+2C7F // Latin Extended-C | |
154 | * U+2DE0 - U+2DFF // Cyrillic Extended-A | |
155 | * U+2E00 - U+2E7F // Supplemental Punctuation | |
156 | * U+A640 - U+A69F // Cyrillic Extended-B | |
157 | * U+A720 - U+A7FF // Latin Extended-D | |
158 | * U+FB00 - U+FB06 // Alphab. Present. Forms (Latin Ligatures) | |
159 | * U+1D400 - U+1D7FF // Mathematical Alphanumeric Symbols | |
160 | * U+1F100 - U+1F1FF // Enclosed Alphanumeric Supplement | |
161 | * } | |
162 | * | |
163 | * FT_AUTOHINTER_SCRIPT_CJK :: | |
164 | * Apply the CJK auto-hinter, covering Chinese, Japanese, Korean, old | |
165 | * Vietnamese, and some other scripts. | |
166 | * | |
167 | * By default, characters from the following Unicode ranges are | |
168 | * assigned to this submodule. | |
169 | * | |
170 | * { | |
171 | * U+1100 - U+11FF // Hangul Jamo | |
172 | * U+2E80 - U+2EFF // CJK Radicals Supplement | |
173 | * U+2F00 - U+2FDF // Kangxi Radicals | |
174 | * U+2FF0 - U+2FFF // Ideographic Description Characters | |
175 | * U+3000 - U+303F // CJK Symbols and Punctuation | |
176 | * U+3040 - U+309F // Hiragana | |
177 | * U+30A0 - U+30FF // Katakana | |
178 | * U+3100 - U+312F // Bopomofo | |
179 | * U+3130 - U+318F // Hangul Compatibility Jamo | |
180 | * U+3190 - U+319F // Kanbun | |
181 | * U+31A0 - U+31BF // Bopomofo Extended | |
182 | * U+31C0 - U+31EF // CJK Strokes | |
183 | * U+31F0 - U+31FF // Katakana Phonetic Extensions | |
184 | * U+3200 - U+32FF // Enclosed CJK Letters and Months | |
185 | * U+3300 - U+33FF // CJK Compatibility | |
186 | * U+3400 - U+4DBF // CJK Unified Ideographs Extension A | |
187 | * U+4DC0 - U+4DFF // Yijing Hexagram Symbols | |
188 | * U+4E00 - U+9FFF // CJK Unified Ideographs | |
189 | * U+A960 - U+A97F // Hangul Jamo Extended-A | |
190 | * U+AC00 - U+D7AF // Hangul Syllables | |
191 | * U+D7B0 - U+D7FF // Hangul Jamo Extended-B | |
192 | * U+F900 - U+FAFF // CJK Compatibility Ideographs | |
193 | * U+FE10 - U+FE1F // Vertical forms | |
194 | * U+FE30 - U+FE4F // CJK Compatibility Forms | |
195 | * U+FF00 - U+FFEF // Halfwidth and Fullwidth Forms | |
196 | * U+1B000 - U+1B0FF // Kana Supplement | |
197 | * U+1D300 - U+1D35F // Tai Xuan Hing Symbols | |
198 | * U+1F200 - U+1F2FF // Enclosed Ideographic Supplement | |
199 | * U+20000 - U+2A6DF // CJK Unified Ideographs Extension B | |
200 | * U+2A700 - U+2B73F // CJK Unified Ideographs Extension C | |
201 | * U+2B740 - U+2B81F // CJK Unified Ideographs Extension D | |
202 | * U+2F800 - U+2FA1F // CJK Compatibility Ideographs Supplement | |
203 | * } | |
204 | * | |
205 | * FT_AUTOHINTER_SCRIPT_INDIC :: | |
206 | * Apply the indic auto-hinter, covering all major scripts from the | |
207 | * Indian sub-continent and some other related scripts like Thai, Lao, | |
208 | * or Tibetan. | |
209 | * | |
210 | * By default, characters from the following Unicode ranges are | |
211 | * assigned to this submodule. | |
212 | * | |
213 | * { | |
214 | * U+0900 - U+0DFF // Indic Range | |
215 | * U+0F00 - U+0FFF // Tibetan | |
216 | * U+1900 - U+194F // Limbu | |
217 | * U+1B80 - U+1BBF // Sundanese | |
218 | * U+1C80 - U+1CDF // Meetei Mayak | |
219 | * U+A800 - U+A82F // Syloti Nagri | |
220 | * U+11800 - U+118DF // Sharada | |
221 | * } | |
222 | * | |
223 | * Note that currently Indic support is rudimentary only, missing blue | |
224 | * zone support. | |
225 | * | |
226 | */ | |
227 | #define FT_AUTOHINTER_SCRIPT_NONE 0 | |
228 | #define FT_AUTOHINTER_SCRIPT_LATIN 1 | |
229 | #define FT_AUTOHINTER_SCRIPT_CJK 2 | |
230 | #define FT_AUTOHINTER_SCRIPT_INDIC 3 | |
231 | ||
232 | ||
233 | /************************************************************************** | |
234 | * | |
235 | * @struct: | |
236 | * FT_Prop_GlyphToScriptMap | |
237 | * | |
238 | * @description: | |
239 | * The data exchange structure for the @glyph-to-script-map property. | |
240 | * | |
241 | */ | |
242 | typedef struct FT_Prop_GlyphToScriptMap_ | |
243 | { | |
244 | FT_Face face; | |
245 | FT_Byte* map; | |
246 | ||
247 | } FT_Prop_GlyphToScriptMap; | |
248 | ||
249 | ||
250 | /************************************************************************** | |
251 | * | |
252 | * @property: | |
253 | * fallback-script | |
254 | * | |
255 | * @description: | |
256 | * If no auto-hinter script module can be assigned to a glyph, a | |
257 | * fallback script gets assigned to it (see also the | |
258 | * @glyph-to-script-map property). By default, this is | |
259 | * @FT_AUTOHINTER_SCRIPT_CJK. Using the `fallback-script' property, | |
260 | * this fallback value can be changed. | |
261 | * | |
262 | * { | |
263 | * FT_Library library; | |
264 | * FT_UInt fallback_script = FT_AUTOHINTER_SCRIPT_NONE; | |
265 | * | |
266 | * | |
267 | * FT_Init_FreeType( &library ); | |
268 | * | |
269 | * FT_Property_Set( library, "autofitter", | |
270 | * "fallback-script", &fallback_script ); | |
271 | * } | |
272 | * | |
273 | * @note: | |
274 | * This property can be used with @FT_Property_Get also. | |
275 | * | |
276 | * It's important to use the right timing for changing this value: The | |
277 | * creation of the glyph-to-script map which eventually uses the | |
278 | * fallback script value gets triggered either by setting or reading a | |
279 | * face-specific property like @glyph-to-script-map, or by auto-hinting | |
280 | * any glyph from that face. In particular, if you have already created | |
281 | * an @FT_Face structure but not loaded any glyph (using the | |
282 | * auto-hinter), a change of the fallback glyph will affect this face. | |
283 | * | |
284 | */ | |
285 | ||
286 | ||
287 | /************************************************************************** | |
288 | * | |
289 | * @property: | |
290 | * increase-x-height | |
291 | * | |
292 | * @description: | |
293 | * For ppem values in the range 6~<= ppem <= `increase-x-height', round | |
294 | * up the font's x~height much more often than normally. If the value | |
295 | * is set to~0, which is the default, this feature is switched off. Use | |
296 | * this property to improve the legibility of small font sizes if | |
297 | * necessary. | |
298 | * | |
299 | * { | |
300 | * FT_Library library; | |
301 | * FT_Face face; | |
302 | * FT_Prop_IncreaseXHeight prop; | |
303 | * | |
304 | * | |
305 | * FT_Init_FreeType( &library ); | |
306 | * FT_New_Face( library, "foo.ttf", 0, &face ); | |
307 | * FT_Set_Char_Size( face, 10 * 64, 0, 72, 0 ); | |
308 | * | |
309 | * prop.face = face; | |
310 | * prop.limit = 14; | |
311 | * | |
312 | * FT_Property_Set( library, "autofitter", | |
313 | * "increase-x-height", &prop ); | |
314 | * } | |
315 | * | |
316 | * @note: | |
317 | * This property can be used with @FT_Property_Get also. | |
318 | * | |
319 | * Set this value right after calling @FT_Set_Char_Size, but before | |
320 | * loading any glyph (using the auto-hinter). | |
321 | * | |
322 | */ | |
323 | ||
324 | ||
325 | /************************************************************************** | |
326 | * | |
327 | * @struct: | |
328 | * FT_Prop_IncreaseXHeight | |
329 | * | |
330 | * @description: | |
331 | * The data exchange structure for the @increase-x-height property. | |
332 | * | |
333 | */ | |
334 | typedef struct FT_Prop_IncreaseXHeight_ | |
335 | { | |
336 | FT_Face face; | |
337 | FT_UInt limit; | |
338 | ||
339 | } FT_Prop_IncreaseXHeight; | |
340 | ||
341 | ||
342 | /* */ | |
343 | ||
344 | FT_END_HEADER | |
345 | ||
346 | #endif /* __FTAUTOH_H__ */ | |
347 | ||
348 | ||
349 | /* END */ |