1 /***************************************************************************/
2 /*                                                                         */
3 /*  aflatin.h                                                              */
4 /*                                                                         */
5 /*    Auto-fitter hinting routines for latin writing system                */
6 /*    (specification).                                                     */
7 /*                                                                         */
8 /*  Copyright 2003-2007, 2009, 2011-2013 by                                */
9 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
10 /*                                                                         */
11 /*  This file is part of the FreeType project, and may only be used,       */
12 /*  modified, and distributed under the terms of the FreeType project      */
13 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
14 /*  this file you indicate that you have read the license and              */
15 /*  understand and accept it fully.                                        */
16 /*                                                                         */
17 /***************************************************************************/
18 
19 
20 #ifndef __AFLATIN_H__
21 #define __AFLATIN_H__
22 
23 #include "afhints.h"
24 
25 
26 FT_BEGIN_HEADER
27 
28   /* the `latin' writing system */
29 
30   AF_DECLARE_WRITING_SYSTEM_CLASS( af_latin_writing_system_class )
31 
32 
33   /* constants are given with units_per_em == 2048 in mind */
34 #define AF_LATIN_CONSTANT( metrics, c )                                      \
35   ( ( (c) * (FT_Long)( (AF_LatinMetrics)(metrics) )->units_per_em ) / 2048 )
36 
37 
38   /*************************************************************************/
39   /*************************************************************************/
40   /*****                                                               *****/
41   /*****            L A T I N   G L O B A L   M E T R I C S            *****/
42   /*****                                                               *****/
43   /*************************************************************************/
44   /*************************************************************************/
45 
46 
47   /*
48    *  The following declarations could be embedded in the file `aflatin.c';
49    *  they have been made semi-public to allow alternate writing system
50    *  hinters to re-use some of them.
51    */
52 
53 
54 #define AF_LATIN_IS_TOP_BLUE( b ) \
55           ( (b)->properties & AF_BLUE_PROPERTY_LATIN_TOP )
56 #define AF_LATIN_IS_X_HEIGHT_BLUE( b ) \
57           ( (b)->properties & AF_BLUE_PROPERTY_LATIN_X_HEIGHT )
58 #define AF_LATIN_IS_LONG_BLUE( b ) \
59           ( (b)->properties & AF_BLUE_PROPERTY_LATIN_LONG )
60 
61 #define AF_LATIN_MAX_WIDTHS  16
62 
63 
64   enum
65   {
66     AF_LATIN_BLUE_ACTIVE     = 1 << 0,  /* set if zone height is <= 3/4px */
67     AF_LATIN_BLUE_TOP        = 1 << 1,  /* result of AF_LATIN_IS_TOP_BLUE */
68     AF_LATIN_BLUE_ADJUSTMENT = 1 << 2,  /* used for scale adjustment      */
69                                         /* optimization                   */
70     AF_LATIN_BLUE_FLAG_MAX
71   };
72 
73 
74   typedef struct  AF_LatinBlueRec_
75   {
76     AF_WidthRec  ref;
77     AF_WidthRec  shoot;
78     FT_UInt      flags;
79 
80   } AF_LatinBlueRec, *AF_LatinBlue;
81 
82 
83   typedef struct  AF_LatinAxisRec_
84   {
85     FT_Fixed         scale;
86     FT_Pos           delta;
87 
88     FT_UInt          width_count;                 /* number of used widths */
89     AF_WidthRec      widths[AF_LATIN_MAX_WIDTHS]; /* widths array          */
90     FT_Pos           edge_distance_threshold;   /* used for creating edges */
91     FT_Pos           standard_width;         /* the default stem thickness */
92     FT_Bool          extra_light;         /* is standard width very light? */
93 
94     /* ignored for horizontal metrics */
95     FT_UInt          blue_count;
96     AF_LatinBlueRec  blues[AF_BLUE_STRINGSET_MAX];
97 
98     FT_Fixed         org_scale;
99     FT_Pos           org_delta;
100 
101   } AF_LatinAxisRec, *AF_LatinAxis;
102 
103 
104   typedef struct  AF_LatinMetricsRec_
105   {
106     AF_StyleMetricsRec  root;
107     FT_UInt             units_per_em;
108     AF_LatinAxisRec     axis[AF_DIMENSION_MAX];
109 
110   } AF_LatinMetricsRec, *AF_LatinMetrics;
111 
112 
113   FT_LOCAL( FT_Error )
114   af_latin_metrics_init( AF_LatinMetrics  metrics,
115                          FT_Face          face );
116 
117   FT_LOCAL( void )
118   af_latin_metrics_scale( AF_LatinMetrics  metrics,
119                           AF_Scaler        scaler );
120 
121   FT_LOCAL( void )
122   af_latin_metrics_init_widths( AF_LatinMetrics  metrics,
123                                 FT_Face          face );
124 
125   FT_LOCAL( void )
126   af_latin_metrics_check_digits( AF_LatinMetrics  metrics,
127                                  FT_Face          face );
128 
129 
130   /*************************************************************************/
131   /*************************************************************************/
132   /*****                                                               *****/
133   /*****           L A T I N   G L Y P H   A N A L Y S I S             *****/
134   /*****                                                               *****/
135   /*************************************************************************/
136   /*************************************************************************/
137 
138   enum
139   {
140     AF_LATIN_HINTS_HORZ_SNAP   = 1 << 0, /* enable stem width snapping  */
141     AF_LATIN_HINTS_VERT_SNAP   = 1 << 1, /* enable stem height snapping */
142     AF_LATIN_HINTS_STEM_ADJUST = 1 << 2, /* enable stem width/height    */
143                                          /* adjustment                  */
144     AF_LATIN_HINTS_MONO        = 1 << 3  /* indicate monochrome         */
145                                          /* rendering                   */
146   };
147 
148 
149 #define AF_LATIN_HINTS_DO_HORZ_SNAP( h )             \
150   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_HORZ_SNAP )
151 
152 #define AF_LATIN_HINTS_DO_VERT_SNAP( h )             \
153   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_VERT_SNAP )
154 
155 #define AF_LATIN_HINTS_DO_STEM_ADJUST( h )             \
156   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_STEM_ADJUST )
157 
158 #define AF_LATIN_HINTS_DO_MONO( h )             \
159   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_MONO )
160 
161 
162   /*
163    *  The next functions shouldn't normally be exported.  However, other
164    *  writing systems might like to use these functions as-is.
165    */
166   FT_LOCAL( FT_Error )
167   af_latin_hints_compute_segments( AF_GlyphHints  hints,
168                                    AF_Dimension   dim );
169 
170   FT_LOCAL( void )
171   af_latin_hints_link_segments( AF_GlyphHints  hints,
172                                 AF_Dimension   dim );
173 
174   FT_LOCAL( FT_Error )
175   af_latin_hints_compute_edges( AF_GlyphHints  hints,
176                                 AF_Dimension   dim );
177 
178   FT_LOCAL( FT_Error )
179   af_latin_hints_detect_features( AF_GlyphHints  hints,
180                                   AF_Dimension   dim );
181 
182 /* */
183 
184 FT_END_HEADER
185 
186 #endif /* __AFLATIN_H__ */
187 
188 
189 /* END */
190