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[reactos.git] / lib / 3rdparty / freetype / src / base / ftadvanc.c
1 /***************************************************************************/
2 /* */
3 /* ftadvanc.c */
4 /* */
5 /* Quick computation of advance widths (body). */
6 /* */
7 /* Copyright 2008, 2009 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 #include <ft2build.h>
20 #include FT_ADVANCES_H
21 #include FT_INTERNAL_OBJECTS_H
22
23
24 static FT_Error
25 _ft_face_scale_advances( FT_Face face,
26 FT_Fixed* advances,
27 FT_UInt count,
28 FT_Int32 flags )
29 {
30 FT_Fixed scale;
31 FT_UInt nn;
32
33
34 if ( flags & FT_LOAD_NO_SCALE )
35 return FT_Err_Ok;
36
37 if ( face->size == NULL )
38 return FT_Err_Invalid_Size_Handle;
39
40 if ( flags & FT_LOAD_VERTICAL_LAYOUT )
41 scale = face->size->metrics.y_scale;
42 else
43 scale = face->size->metrics.x_scale;
44
45 /* this must be the same scaling as to get linear{Hori,Vert}Advance */
46 /* (see `FT_Load_Glyph' implementation in src/base/ftobjs.c) */
47
48 for ( nn = 0; nn < count; nn++ )
49 advances[nn] = FT_MulDiv( advances[nn], scale, 64 );
50
51 return FT_Err_Ok;
52 }
53
54
55 /* at the moment, we can perform fast advance retrieval only in */
56 /* the following cases: */
57 /* */
58 /* - unscaled load */
59 /* - unhinted load */
60 /* - light-hinted load */
61
62 #define LOAD_ADVANCE_FAST_CHECK( flags ) \
63 ( flags & ( FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING ) || \
64 FT_LOAD_TARGET_MODE( flags ) == FT_RENDER_MODE_LIGHT )
65
66
67 /* documentation is in ftadvanc.h */
68
69 FT_EXPORT_DEF( FT_Error )
70 FT_Get_Advance( FT_Face face,
71 FT_UInt gindex,
72 FT_Int32 flags,
73 FT_Fixed *padvance )
74 {
75 FT_Face_GetAdvancesFunc func;
76
77
78 if ( !face )
79 return FT_Err_Invalid_Face_Handle;
80
81 if ( gindex >= (FT_UInt)face->num_glyphs )
82 return FT_Err_Invalid_Glyph_Index;
83
84 func = face->driver->clazz->get_advances;
85 if ( func && LOAD_ADVANCE_FAST_CHECK( flags ) )
86 {
87 FT_Error error;
88
89
90 error = func( face, gindex, 1, flags, padvance );
91 if ( !error )
92 return _ft_face_scale_advances( face, padvance, 1, flags );
93
94 if ( error != FT_ERROR_BASE( FT_Err_Unimplemented_Feature ) )
95 return error;
96 }
97
98 return FT_Get_Advances( face, gindex, 1, flags, padvance );
99 }
100
101
102 /* documentation is in ftadvanc.h */
103
104 FT_EXPORT_DEF( FT_Error )
105 FT_Get_Advances( FT_Face face,
106 FT_UInt start,
107 FT_UInt count,
108 FT_Int32 flags,
109 FT_Fixed *padvances )
110 {
111 FT_Face_GetAdvancesFunc func;
112 FT_UInt num, end, nn;
113 FT_Error error = FT_Err_Ok;
114
115
116 if ( !face )
117 return FT_Err_Invalid_Face_Handle;
118
119 num = (FT_UInt)face->num_glyphs;
120 end = start + count;
121 if ( start >= num || end < start || end > num )
122 return FT_Err_Invalid_Glyph_Index;
123
124 if ( count == 0 )
125 return FT_Err_Ok;
126
127 func = face->driver->clazz->get_advances;
128 if ( func && LOAD_ADVANCE_FAST_CHECK( flags ) )
129 {
130 error = func( face, start, count, flags, padvances );
131 if ( !error )
132 goto Exit;
133
134 if ( error != FT_ERROR_BASE( FT_Err_Unimplemented_Feature ) )
135 return error;
136 }
137
138 error = FT_Err_Ok;
139
140 if ( flags & FT_ADVANCE_FLAG_FAST_ONLY )
141 return FT_Err_Unimplemented_Feature;
142
143 flags |= (FT_UInt32)FT_LOAD_ADVANCE_ONLY;
144 for ( nn = 0; nn < count; nn++ )
145 {
146 error = FT_Load_Glyph( face, start + nn, flags );
147 if ( error )
148 break;
149
150 padvances[nn] = ( flags & FT_LOAD_VERTICAL_LAYOUT )
151 ? face->glyph->advance.y
152 : face->glyph->advance.x;
153 }
154
155 if ( error )
156 return error;
157
158 Exit:
159 return _ft_face_scale_advances( face, padvances, count, flags );
160 }
161
162
163 /* END */