Visualization Library 2.0.0-b5

A lightweight C++ OpenGL middleware for 2D/3D graphics

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ftautoh.h
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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 
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  */
243  {
246 
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  */
335  {
338 
340 
341 
342  /* */
343 
345 
346 #endif /* __FTAUTOH_H__ */
347 
348 
349 /* END */
struct FT_Prop_IncreaseXHeight_ FT_Prop_IncreaseXHeight
struct FT_Prop_GlyphToScriptMap_ FT_Prop_GlyphToScriptMap
#define FT_END_HEADER
Definition: ftheader.h:54
unsigned char FT_Byte
Definition: fttypes.h:150
#define FT_BEGIN_HEADER
Definition: ftheader.h:36
unsigned int FT_UInt
Definition: fttypes.h:227