1/***************************************************************************/
2/*                                                                         */
3/*  aflatin.h                                                              */
4/*                                                                         */
5/*    Auto-fitter hinting routines for latin writing system                */
6/*    (specification).                                                     */
7/*                                                                         */
8/*  Copyright 2003-2007, 2009, 2011-2014 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
26FT_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_NEUTRAL_BLUE( b ) \
57          ( (b)->properties & AF_BLUE_PROPERTY_LATIN_NEUTRAL )
58#define AF_LATIN_IS_X_HEIGHT_BLUE( b ) \
59          ( (b)->properties & AF_BLUE_PROPERTY_LATIN_X_HEIGHT )
60#define AF_LATIN_IS_LONG_BLUE( b ) \
61          ( (b)->properties & AF_BLUE_PROPERTY_LATIN_LONG )
62
63#define AF_LATIN_MAX_WIDTHS  16
64
65
66  enum
67  {
68    AF_LATIN_BLUE_ACTIVE     = 1 << 0, /* set if zone height is <= 3/4px   */
69    AF_LATIN_BLUE_TOP        = 1 << 1, /* set if we have a top blue zone   */
70    AF_LATIN_BLUE_NEUTRAL    = 1 << 2, /* set if we have neutral blue zone */
71    AF_LATIN_BLUE_ADJUSTMENT = 1 << 3, /* used for scale adjustment        */
72                                       /* optimization                     */
73    AF_LATIN_BLUE_FLAG_MAX
74  };
75
76
77  typedef struct  AF_LatinBlueRec_
78  {
79    AF_WidthRec  ref;
80    AF_WidthRec  shoot;
81    FT_UInt      flags;
82
83  } AF_LatinBlueRec, *AF_LatinBlue;
84
85
86  typedef struct  AF_LatinAxisRec_
87  {
88    FT_Fixed         scale;
89    FT_Pos           delta;
90
91    FT_UInt          width_count;                 /* number of used widths */
92    AF_WidthRec      widths[AF_LATIN_MAX_WIDTHS]; /* widths array          */
93    FT_Pos           edge_distance_threshold;   /* used for creating edges */
94    FT_Pos           standard_width;         /* the default stem thickness */
95    FT_Bool          extra_light;         /* is standard width very light? */
96
97    /* ignored for horizontal metrics */
98    FT_UInt          blue_count;
99    AF_LatinBlueRec  blues[AF_BLUE_STRINGSET_MAX];
100
101    FT_Fixed         org_scale;
102    FT_Pos           org_delta;
103
104  } AF_LatinAxisRec, *AF_LatinAxis;
105
106
107  typedef struct  AF_LatinMetricsRec_
108  {
109    AF_StyleMetricsRec  root;
110    FT_UInt             units_per_em;
111    AF_LatinAxisRec     axis[AF_DIMENSION_MAX];
112
113  } AF_LatinMetricsRec, *AF_LatinMetrics;
114
115
116  FT_LOCAL( FT_Error )
117  af_latin_metrics_init( AF_LatinMetrics  metrics,
118                         FT_Face          face );
119
120  FT_LOCAL( void )
121  af_latin_metrics_scale( AF_LatinMetrics  metrics,
122                          AF_Scaler        scaler );
123
124  FT_LOCAL( void )
125  af_latin_metrics_init_widths( AF_LatinMetrics  metrics,
126                                FT_Face          face );
127
128  FT_LOCAL( void )
129  af_latin_metrics_check_digits( AF_LatinMetrics  metrics,
130                                 FT_Face          face );
131
132
133  /*************************************************************************/
134  /*************************************************************************/
135  /*****                                                               *****/
136  /*****           L A T I N   G L Y P H   A N A L Y S I S             *****/
137  /*****                                                               *****/
138  /*************************************************************************/
139  /*************************************************************************/
140
141  enum
142  {
143    AF_LATIN_HINTS_HORZ_SNAP   = 1 << 0, /* enable stem width snapping  */
144    AF_LATIN_HINTS_VERT_SNAP   = 1 << 1, /* enable stem height snapping */
145    AF_LATIN_HINTS_STEM_ADJUST = 1 << 2, /* enable stem width/height    */
146                                         /* adjustment                  */
147    AF_LATIN_HINTS_MONO        = 1 << 3  /* indicate monochrome         */
148                                         /* rendering                   */
149  };
150
151
152#define AF_LATIN_HINTS_DO_HORZ_SNAP( h )             \
153  AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_HORZ_SNAP )
154
155#define AF_LATIN_HINTS_DO_VERT_SNAP( h )             \
156  AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_VERT_SNAP )
157
158#define AF_LATIN_HINTS_DO_STEM_ADJUST( h )             \
159  AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_STEM_ADJUST )
160
161#define AF_LATIN_HINTS_DO_MONO( h )             \
162  AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_MONO )
163
164
165  /*
166   *  The next functions shouldn't normally be exported.  However, other
167   *  writing systems might like to use these functions as-is.
168   */
169  FT_LOCAL( FT_Error )
170  af_latin_hints_compute_segments( AF_GlyphHints  hints,
171                                   AF_Dimension   dim );
172
173  FT_LOCAL( void )
174  af_latin_hints_link_segments( AF_GlyphHints  hints,
175                                FT_UInt        width_count,
176                                AF_WidthRec*   widths,
177                                AF_Dimension   dim );
178
179  FT_LOCAL( FT_Error )
180  af_latin_hints_compute_edges( AF_GlyphHints  hints,
181                                AF_Dimension   dim );
182
183  FT_LOCAL( FT_Error )
184  af_latin_hints_detect_features( AF_GlyphHints  hints,
185                                  FT_UInt        width_count,
186                                  AF_WidthRec*   widths,
187                                  AF_Dimension   dim );
188
189/* */
190
191FT_END_HEADER
192
193#endif /* __AFLATIN_H__ */
194
195
196/* END */
197