1/***************************************************************************/
2/*                                                                         */
3/*  aftypes.h                                                              */
4/*                                                                         */
5/*    Auto-fitter types (specification only).                              */
6/*                                                                         */
7/*  Copyright 2003-2009, 2011 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  /*************************************************************************
20   *
21   *  The auto-fitter is a complete rewrite of the old auto-hinter.
22   *  Its main feature is the ability to differentiate between different
23   *  scripts in order to apply language-specific rules.
24   *
25   *  The code has also been compartmentized into several entities that
26   *  should make algorithmic experimentation easier than with the old
27   *  code.
28   *
29   *  Finally, we get rid of the Catharon license, since this code is
30   *  released under the FreeType one.
31   *
32   *************************************************************************/
33
34
35#ifndef __AFTYPES_H__
36#define __AFTYPES_H__
37
38#include <ft2build.h>
39
40#include FT_FREETYPE_H
41#include FT_OUTLINE_H
42#include FT_INTERNAL_OBJECTS_H
43#include FT_INTERNAL_DEBUG_H
44
45
46FT_BEGIN_HEADER
47
48  /*************************************************************************/
49  /*************************************************************************/
50  /*****                                                               *****/
51  /*****                    D E B U G G I N G                          *****/
52  /*****                                                               *****/
53  /*************************************************************************/
54  /*************************************************************************/
55
56#ifdef FT_DEBUG_AUTOFIT
57
58#include FT_CONFIG_STANDARD_LIBRARY_H
59
60extern int    _af_debug_disable_horz_hints;
61extern int    _af_debug_disable_vert_hints;
62extern int    _af_debug_disable_blue_hints;
63extern void*  _af_debug_hints;
64
65#endif /* FT_DEBUG_AUTOFIT */
66
67
68  /*************************************************************************/
69  /*************************************************************************/
70  /*****                                                               *****/
71  /*****                 U T I L I T Y   S T U F F                     *****/
72  /*****                                                               *****/
73  /*************************************************************************/
74  /*************************************************************************/
75
76  typedef struct  AF_WidthRec_
77  {
78    FT_Pos  org;  /* original position/width in font units              */
79    FT_Pos  cur;  /* current/scaled position/width in device sub-pixels */
80    FT_Pos  fit;  /* current/fitted position/width in device sub-pixels */
81
82  } AF_WidthRec, *AF_Width;
83
84
85  FT_LOCAL( void )
86  af_sort_pos( FT_UInt  count,
87               FT_Pos*  table );
88
89  FT_LOCAL( void )
90  af_sort_widths( FT_UInt   count,
91                  AF_Width  widths );
92
93
94  /*************************************************************************/
95  /*************************************************************************/
96  /*****                                                               *****/
97  /*****                   A N G L E   T Y P E S                       *****/
98  /*****                                                               *****/
99  /*************************************************************************/
100  /*************************************************************************/
101
102  /*
103   *  The auto-fitter doesn't need a very high angular accuracy;
104   *  this allows us to speed up some computations considerably with a
105   *  light Cordic algorithm (see afangles.c).
106   */
107
108  typedef FT_Int  AF_Angle;
109
110
111#define AF_ANGLE_PI   256
112#define AF_ANGLE_2PI  ( AF_ANGLE_PI * 2 )
113#define AF_ANGLE_PI2  ( AF_ANGLE_PI / 2 )
114#define AF_ANGLE_PI4  ( AF_ANGLE_PI / 4 )
115
116
117#if 0
118  /*
119   *  compute the angle of a given 2-D vector
120   */
121  FT_LOCAL( AF_Angle )
122  af_angle_atan( FT_Pos  dx,
123                 FT_Pos  dy );
124
125
126  /*
127   *  compute `angle2 - angle1'; the result is always within
128   *  the range [-AF_ANGLE_PI .. AF_ANGLE_PI - 1]
129   */
130  FT_LOCAL( AF_Angle )
131  af_angle_diff( AF_Angle  angle1,
132                 AF_Angle  angle2 );
133#endif /* 0 */
134
135
136#define AF_ANGLE_DIFF( result, angle1, angle2 ) \
137  FT_BEGIN_STMNT                                \
138    AF_Angle  _delta = (angle2) - (angle1);     \
139                                                \
140                                                \
141    _delta %= AF_ANGLE_2PI;                     \
142    if ( _delta < 0 )                           \
143      _delta += AF_ANGLE_2PI;                   \
144                                                \
145    if ( _delta > AF_ANGLE_PI )                 \
146      _delta -= AF_ANGLE_2PI;                   \
147                                                \
148    result = _delta;                            \
149  FT_END_STMNT
150
151
152  /*  opaque handle to glyph-specific hints -- see `afhints.h' for more
153   *  details
154   */
155  typedef struct AF_GlyphHintsRec_*  AF_GlyphHints;
156
157
158  /*************************************************************************/
159  /*************************************************************************/
160  /*****                                                               *****/
161  /*****                       S C A L E R S                           *****/
162  /*****                                                               *****/
163  /*************************************************************************/
164  /*************************************************************************/
165
166  /*
167   *  A scaler models the target pixel device that will receive the
168   *  auto-hinted glyph image.
169   */
170
171  typedef enum  AF_ScalerFlags_
172  {
173    AF_SCALER_FLAG_NO_HORIZONTAL = 1,  /* disable horizontal hinting */
174    AF_SCALER_FLAG_NO_VERTICAL   = 2,  /* disable vertical hinting   */
175    AF_SCALER_FLAG_NO_ADVANCE    = 4   /* disable advance hinting    */
176
177  } AF_ScalerFlags;
178
179
180  typedef struct  AF_ScalerRec_
181  {
182    FT_Face         face;        /* source font face                        */
183    FT_Fixed        x_scale;     /* from font units to 1/64th device pixels */
184    FT_Fixed        y_scale;     /* from font units to 1/64th device pixels */
185    FT_Pos          x_delta;     /* in 1/64th device pixels                 */
186    FT_Pos          y_delta;     /* in 1/64th device pixels                 */
187    FT_Render_Mode  render_mode; /* monochrome, anti-aliased, LCD, etc.     */
188    FT_UInt32       flags;       /* additional control flags, see above     */
189
190  } AF_ScalerRec, *AF_Scaler;
191
192
193#define AF_SCALER_EQUAL_SCALES( a, b )      \
194          ( (a)->x_scale == (b)->x_scale && \
195            (a)->y_scale == (b)->y_scale && \
196            (a)->x_delta == (b)->x_delta && \
197            (a)->y_delta == (b)->y_delta )
198
199
200  /*************************************************************************/
201  /*************************************************************************/
202  /*****                                                               *****/
203  /*****                       S C R I P T S                           *****/
204  /*****                                                               *****/
205  /*************************************************************************/
206  /*************************************************************************/
207
208  /*
209   *  The list of known scripts.  Each different script corresponds to the
210   *  following information:
211   *
212   *   - A set of Unicode ranges to test whether the face supports the
213   *     script.
214   *
215   *   - A specific global analyzer that will compute global metrics
216   *     specific to the script.
217   *
218   *   - A specific glyph analyzer that will compute segments and
219   *     edges for each glyph covered by the script.
220   *
221   *   - A specific grid-fitting algorithm that will distort the
222   *     scaled glyph outline according to the results of the glyph
223   *     analyzer.
224   *
225   *  Note that a given analyzer and/or grid-fitting algorithm can be
226   *  used by more than one script.
227   */
228
229  typedef enum  AF_Script_
230  {
231    AF_SCRIPT_NONE  = 0,
232    AF_SCRIPT_LATIN = 1,
233    AF_SCRIPT_CJK   = 2,
234    AF_SCRIPT_INDIC = 3,
235#ifdef FT_OPTION_AUTOFIT2
236    AF_SCRIPT_LATIN2,
237#endif
238
239    /* add new scripts here.  Don't forget to update the list in */
240    /* `afglobal.c'.                                             */
241
242    AF_SCRIPT_MAX   /* do not remove */
243
244  } AF_Script;
245
246
247  typedef struct AF_ScriptClassRec_ const*  AF_ScriptClass;
248
249  typedef struct  AF_ScriptMetricsRec_
250  {
251    AF_ScriptClass  clazz;
252    AF_ScalerRec    scaler;
253    FT_Bool         digits_have_same_width;
254
255  } AF_ScriptMetricsRec, *AF_ScriptMetrics;
256
257
258  /*  This function parses an FT_Face to compute global metrics for
259   *  a specific script.
260   */
261  typedef FT_Error
262  (*AF_Script_InitMetricsFunc)( AF_ScriptMetrics  metrics,
263                                FT_Face           face );
264
265  typedef void
266  (*AF_Script_ScaleMetricsFunc)( AF_ScriptMetrics  metrics,
267                                 AF_Scaler         scaler );
268
269  typedef void
270  (*AF_Script_DoneMetricsFunc)( AF_ScriptMetrics  metrics );
271
272
273  typedef FT_Error
274  (*AF_Script_InitHintsFunc)( AF_GlyphHints     hints,
275                              AF_ScriptMetrics  metrics );
276
277  typedef void
278  (*AF_Script_ApplyHintsFunc)( AF_GlyphHints     hints,
279                               FT_Outline*       outline,
280                               AF_ScriptMetrics  metrics );
281
282
283  typedef struct  AF_Script_UniRangeRec_
284  {
285    FT_UInt32  first;
286    FT_UInt32  last;
287
288  } AF_Script_UniRangeRec;
289
290#define AF_UNIRANGE_REC( a, b ) { (FT_UInt32)(a), (FT_UInt32)(b) }
291
292  typedef const AF_Script_UniRangeRec  *AF_Script_UniRange;
293
294
295  typedef struct  AF_ScriptClassRec_
296  {
297    AF_Script                   script;
298    AF_Script_UniRange          script_uni_ranges; /* last must be { 0, 0 } */
299
300    FT_Offset                   script_metrics_size;
301    AF_Script_InitMetricsFunc   script_metrics_init;
302    AF_Script_ScaleMetricsFunc  script_metrics_scale;
303    AF_Script_DoneMetricsFunc   script_metrics_done;
304
305    AF_Script_InitHintsFunc     script_hints_init;
306    AF_Script_ApplyHintsFunc    script_hints_apply;
307
308  } AF_ScriptClassRec;
309
310
311  /* Declare and define vtables for classes */
312#ifndef FT_CONFIG_OPTION_PIC
313
314#define AF_DECLARE_SCRIPT_CLASS( script_class ) \
315  FT_CALLBACK_TABLE const AF_ScriptClassRec     \
316  script_class;
317
318#define AF_DEFINE_SCRIPT_CLASS( script_class, script_, ranges, m_size,     \
319                                m_init, m_scale, m_done, h_init, h_apply ) \
320  FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec                            \
321  script_class =                                                           \
322  {                                                                        \
323    script_,                                                               \
324    ranges,                                                                \
325                                                                           \
326    m_size,                                                                \
327                                                                           \
328    m_init,                                                                \
329    m_scale,                                                               \
330    m_done,                                                                \
331                                                                           \
332    h_init,                                                                \
333    h_apply                                                                \
334  };
335
336#else /* FT_CONFIG_OPTION_PIC */
337
338#define AF_DECLARE_SCRIPT_CLASS( script_class )          \
339  FT_LOCAL( void )                                       \
340  FT_Init_Class_##script_class( AF_ScriptClassRec* ac );
341
342#define AF_DEFINE_SCRIPT_CLASS( script_class, script_, ranges, m_size,     \
343                                m_init, m_scale, m_done, h_init, h_apply ) \
344  FT_LOCAL_DEF( void )                                                     \
345  FT_Init_Class_##script_class( AF_ScriptClassRec* ac )                    \
346  {                                                                        \
347    ac->script               = script_;                                    \
348    ac->script_uni_ranges    = ranges;                                     \
349                                                                           \
350    ac->script_metrics_size  = m_size;                                     \
351                                                                           \
352    ac->script_metrics_init  = m_init;                                     \
353    ac->script_metrics_scale = m_scale;                                    \
354    ac->script_metrics_done  = m_done;                                     \
355                                                                           \
356    ac->script_hints_init    = h_init;                                     \
357    ac->script_hints_apply   = h_apply;                                    \
358  }
359
360#endif /* FT_CONFIG_OPTION_PIC */
361
362
363/* */
364
365FT_END_HEADER
366
367#endif /* __AFTYPES_H__ */
368
369
370/* END */
371