XFA: merge patch from CL 817753002
[pdfium.git] / core / src / fxge / fx_freetype / fxft2.5.01 / include / freetype / ftadvanc.h
1 /***************************************************************************/
2 /*                                                                         */
3 /*  ftadvanc.h                                                             */
4 /*                                                                         */
5 /*    Quick computation of advance widths (specification only).            */
6 /*                                                                         */
7 /*  Copyright 2008, 2013 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 "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.                                                          */
86   /*                                                                       */
87   /* <Input>                                                               */
88   /*    face       :: The source @FT_Face handle.                          */
89   /*                                                                       */
90   /*    gindex     :: The glyph index.                                     */
91   /*                                                                       */
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.                                */
95   /* <Output>                                                              */
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.         */
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.                                                          */
131   /*                                                                       */
132   /* <Input>                                                               */
133   /*    face        :: The source @FT_Face handle.                         */
134   /*                                                                       */
135   /*    start       :: The first glyph index.                              */
136   /*                                                                       */
137   /*    count       :: The number of advance values you want to retrieve.  */
138   /*                                                                       */
139   /*    load_flags  :: A set of bit flags similar to those used when       */
140   /*                   calling @FT_Load_Glyph.                             */
141   /*                                                                       */
142   /* <Output>                                                              */
143   /*    padvance :: The advance values.  This array, to be provided by the */
144   /*                caller, must contain at least `count' elements.        */
145   /*                                                                       */
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.                     */
149   /*                                                                       */
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.                                     */
154   /*                                                                       */
155   /* <Return>                                                              */
156   /*    FreeType error code.  0 means success.                             */
157   /*                                                                       */
158   /* <Note>                                                                */
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.                                             */
162   /*                                                                       */
163   /*    Scaled advances are returned in 16.16 format but aren't            */
164   /*    transformed by the affine transformation specified by              */
165   /*    @FT_Set_Transform.                                                 */
166   /*                                                                       */
167   FT_EXPORT( FT_Error )
168   FT_Get_Advances( FT_Face    face,
169                    FT_UInt    start,
170                    FT_UInt    count,
171                    FT_Int32   load_flags,
172                    FT_Fixed  *padvances );
173
174 /* */
175
176
177 FT_END_HEADER
178
179 #endif /* __FTADVANC_H__ */
180
181
182 /* END */