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1 | /***************************************************************************/ |
2 | /* */ | |
3 | /* ftadvanc.h */ | |
4 | /* */ | |
5 | /* Quick computation of advance widths (specification only). */ | |
6 | /* */ | |
7 | /* Copyright 2008 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 __FTADVANC_H__ | |
20 | #define __FTADVANC_H__ | |
21 | ||
22 | ||
23 | #include <ft2build.h> | |
24 | #include FT_FREETYPE_H | |
25 | ||
26 | #ifdef FREETYPE_H | |
27 | #error "freetype.h of FreeType 1 has been loaded!" | |
28 | #error "Please fix the directory search order for header files" | |
29 | #error "so that freetype.h of FreeType 2 is found first." | |
30 | #endif | |
31 | ||
32 | ||
33 | FT_BEGIN_HEADER | |
34 | ||
35 | ||
36 | /************************************************************************** | |
37 | * | |
38 | * @section: | |
39 | * quick_advance | |
40 | * | |
41 | * @title: | |
42 | * Quick retrieval of advance values | |
43 | * | |
44 | * @abstract: | |
45 | * Retrieve horizontal and vertical advance values without processing | |
46 | * glyph outlines, if possible. | |
47 | * | |
48 | * @description: | |
49 | * This section contains functions to quickly extract advance values | |
50 | * without handling glyph outlines, if possible. | |
51 | */ | |
52 | ||
53 | ||
54 | /*************************************************************************/ | |
55 | /* */ | |
56 | /* <Const> */ | |
57 | /* FT_ADVANCE_FLAG_FAST_ONLY */ | |
58 | /* */ | |
59 | /* <Description> */ | |
60 | /* A bit-flag to be OR-ed with the `flags' parameter of the */ | |
61 | /* @FT_Get_Advance and @FT_Get_Advances functions. */ | |
62 | /* */ | |
63 | /* If set, it indicates that you want these functions to fail if the */ | |
64 | /* corresponding hinting mode or font driver doesn't allow for very */ | |
65 | /* quick advance computation. */ | |
66 | /* */ | |
67 | /* Typically, glyphs which are either unscaled, unhinted, bitmapped, */ | |
68 | /* or light-hinted can have their advance width computed very */ | |
69 | /* quickly. */ | |
70 | /* */ | |
71 | /* Normal and bytecode hinted modes, which require loading, scaling, */ | |
72 | /* and hinting of the glyph outline, are extremely slow by */ | |
73 | /* comparison. */ | |
74 | /* */ | |
75 | #define FT_ADVANCE_FLAG_FAST_ONLY 0x20000000UL | |
76 | ||
77 | ||
78 | /*************************************************************************/ | |
79 | /* */ | |
80 | /* <Function> */ | |
81 | /* FT_Get_Advance */ | |
82 | /* */ | |
83 | /* <Description> */ | |
84 | /* Retrieve the advance value of a given glyph outline in an */ | |
85 | /* @FT_Face. By default, the unhinted advance is returned in font */ | |
86 | /* units. */ | |
87 | /* */ | |
88 | /* <Input> */ | |
89 | /* face :: The source @FT_Face handle. */ | |
90 | /* */ | |
91 | /* gindex :: The glyph index. */ | |
92 | /* */ | |
93 | /* load_flags :: A set of bit flags similar to those used when */ | |
94 | /* calling @FT_Load_Glyph, used to determine what kind */ | |
95 | /* of advances you need. */ | |
96 | /* <Output> */ | |
97 | /* padvance :: The advance value, in either font units or 16.16 */ | |
98 | /* format. */ | |
99 | /* */ | |
100 | /* If @FT_LOAD_VERTICAL_LAYOUT is set, this is the */ | |
101 | /* vertical advance corresponding to a vertical layout. */ | |
102 | /* Otherwise, it is the horizontal advance in a */ | |
103 | /* horizontal layout. */ | |
104 | /* */ | |
105 | /* <Return> */ | |
106 | /* FreeType error code. 0 means success. */ | |
107 | /* */ | |
108 | /* <Note> */ | |
109 | /* This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and */ | |
110 | /* if the corresponding font backend doesn't have a quick way to */ | |
111 | /* retrieve the advances. */ | |
112 | /* */ | |
113 | /* A scaled advance is returned in 16.16 format but isn't transformed */ | |
114 | /* by the affine transformation specified by @FT_Set_Transform. */ | |
115 | /* */ | |
116 | FT_EXPORT( FT_Error ) | |
117 | FT_Get_Advance( FT_Face face, | |
118 | FT_UInt gindex, | |
119 | FT_Int32 load_flags, | |
120 | FT_Fixed *padvance ); | |
121 | ||
122 | ||
123 | /*************************************************************************/ | |
124 | /* */ | |
125 | /* <Function> */ | |
126 | /* FT_Get_Advances */ | |
127 | /* */ | |
128 | /* <Description> */ | |
129 | /* Retrieve the advance values of several glyph outlines in an */ | |
130 | /* @FT_Face. By default, the unhinted advances are returned in font */ | |
131 | /* units. */ | |
132 | /* */ | |
133 | /* <Input> */ | |
134 | /* face :: The source @FT_Face handle. */ | |
135 | /* */ | |
136 | /* start :: The first glyph index. */ | |
137 | /* */ | |
138 | /* count :: The number of advance values you want to retrieve. */ | |
139 | /* */ | |
140 | /* load_flags :: A set of bit flags similar to those used when */ | |
141 | /* calling @FT_Load_Glyph. */ | |
142 | /* */ | |
143 | /* <Output> */ | |
144 | /* padvance :: The advances, in either font units or 16.16 format. */ | |
145 | /* This array must contain at least `count' elements. */ | |
146 | /* */ | |
147 | /* If @FT_LOAD_VERTICAL_LAYOUT is set, these are the */ | |
148 | /* vertical advances corresponding to a vertical layout. */ | |
149 | /* Otherwise, they are the horizontal advances in a */ | |
150 | /* horizontal layout. */ | |
151 | /* */ | |
152 | /* <Return> */ | |
153 | /* FreeType error code. 0 means success. */ | |
154 | /* */ | |
155 | /* <Note> */ | |
156 | /* This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and */ | |
157 | /* if the corresponding font backend doesn't have a quick way to */ | |
158 | /* retrieve the advances. */ | |
159 | /* */ | |
160 | /* Scaled advances are returned in 16.16 format but aren't */ | |
161 | /* transformed by the affine transformation specified by */ | |
162 | /* @FT_Set_Transform. */ | |
163 | /* */ | |
164 | FT_EXPORT( FT_Error ) | |
165 | FT_Get_Advances( FT_Face face, | |
166 | FT_UInt start, | |
167 | FT_UInt count, | |
168 | FT_Int32 load_flags, | |
169 | FT_Fixed *padvances ); | |
170 | ||
171 | /* */ | |
172 | ||
173 | ||
174 | FT_END_HEADER | |
175 | ||
176 | #endif /* __FTADVANC_H__ */ | |
177 | ||
178 | ||
179 | /* END */ |