1 /***************************************************************************/
5 /* Quick computation of advance widths (specification only). */
7 /* Copyright 2008, 2013 by */
8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
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. */
16 /***************************************************************************/
19 #ifndef __FTADVANC_H__
20 #define __FTADVANC_H__
24 #include FT_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."
36 /**************************************************************************
42 * Quick retrieval of advance values
45 * Retrieve horizontal and vertical advance values without processing
46 * glyph outlines, if possible.
49 * This section contains functions to quickly extract advance values
50 * without handling glyph outlines, if possible.
54 /*************************************************************************/
57 /* FT_ADVANCE_FLAG_FAST_ONLY */
60 /* A bit-flag to be OR-ed with the `flags' parameter of the */
61 /* @FT_Get_Advance and @FT_Get_Advances functions. */
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. */
67 /* Typically, glyphs which are either unscaled, unhinted, bitmapped, */
68 /* or light-hinted can have their advance width computed very */
71 /* Normal and bytecode hinted modes, which require loading, scaling, */
72 /* and hinting of the glyph outline, are extremely slow by */
75 #define FT_ADVANCE_FLAG_FAST_ONLY 0x20000000UL
78 /*************************************************************************/
84 /* Retrieve the advance value of a given glyph outline in an */
88 /* face :: The source @FT_Face handle. */
90 /* gindex :: The glyph index. */
92 /* load_flags :: A set of bit flags similar to those used when */
93 /* calling @FT_Load_Glyph, used to determine what kind */
94 /* of advances you need. */
96 /* padvance :: The advance value. If scaling is performed (based on */
97 /* the value of `load_flags'), the advance value is in */
98 /* 16.16 format. Otherwise, it is in font units. */
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. */
106 /* FreeType error code. 0 means success. */
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. */
113 /* A scaled advance is returned in 16.16 format but isn't transformed */
114 /* by the affine transformation specified by @FT_Set_Transform. */
116 FT_EXPORT( FT_Error
)
117 FT_Get_Advance( FT_Face face
,
120 FT_Fixed
*padvance
);
123 /*************************************************************************/
126 /* FT_Get_Advances */
129 /* Retrieve the advance values of several glyph outlines in an */
133 /* face :: The source @FT_Face handle. */
135 /* start :: The first glyph index. */
137 /* count :: The number of advance values you want to retrieve. */
139 /* load_flags :: A set of bit flags similar to those used when */
140 /* calling @FT_Load_Glyph. */
143 /* padvance :: The advance values. This array, to be provided by the */
144 /* caller, must contain at least `count' elements. */
146 /* If scaling is performed (based on the value of */
147 /* `load_flags'), the advance values are in 16.16 format. */
148 /* Otherwise, they are in font units. */
150 /* If @FT_LOAD_VERTICAL_LAYOUT is set, these are the */
151 /* vertical advances corresponding to a vertical layout. */
152 /* Otherwise, they are the horizontal advances in a */
153 /* horizontal layout. */
156 /* FreeType error code. 0 means success. */
159 /* This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and */
160 /* if the corresponding font backend doesn't have a quick way to */
161 /* retrieve the advances. */
163 /* Scaled advances are returned in 16.16 format but aren't */
164 /* transformed by the affine transformation specified by */
165 /* @FT_Set_Transform. */
167 FT_EXPORT( FT_Error
)
168 FT_Get_Advances( FT_Face face
,
172 FT_Fixed
*padvances
);
179 #endif /* __FTADVANC_H__ */