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1 /***************************************************************************/
2 /*                                                                         */
3 /*  pshalgo.h                                                              */
4 /*                                                                         */
5 /*    PostScript hinting algorithm (specification).                        */
6 /*                                                                         */
7 /*  Copyright 2001, 2002, 2003, 2008 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 __PSHALGO_H__
20 #define __PSHALGO_H__
21 
22 
23 #include "pshrec.h"
24 #include "pshglob.h"
25 #include FT_TRIGONOMETRY_H
26 
27 
28 FT_BEGIN_HEADER
29 
30 
31   /* handle to Hint structure */
32   typedef struct PSH_HintRec_*  PSH_Hint;
33 
34   /* hint bit-flags */
35   typedef enum  PSH_Hint_Flags_
36   {
37     PSH_HINT_GHOST  = PS_HINT_FLAG_GHOST,
38     PSH_HINT_BOTTOM = PS_HINT_FLAG_BOTTOM,
39     PSH_HINT_ACTIVE = 4,
40     PSH_HINT_FITTED = 8
41 
42   } PSH_Hint_Flags;
43 
44 
45 #define psh_hint_is_active( x )  ( ( (x)->flags & PSH_HINT_ACTIVE ) != 0 )
46 #define psh_hint_is_ghost( x )   ( ( (x)->flags & PSH_HINT_GHOST  ) != 0 )
47 #define psh_hint_is_fitted( x )  ( ( (x)->flags & PSH_HINT_FITTED ) != 0 )
48 
49 #define psh_hint_activate( x )    (x)->flags |=  PSH_HINT_ACTIVE
50 #define psh_hint_deactivate( x )  (x)->flags &= ~PSH_HINT_ACTIVE
51 #define psh_hint_set_fitted( x )  (x)->flags |=  PSH_HINT_FITTED
52 
53   /* hint structure */
54   typedef struct  PSH_HintRec_
55   {
56     FT_Int    org_pos;
57     FT_Int    org_len;
58     FT_Pos    cur_pos;
59     FT_Pos    cur_len;
60     FT_UInt   flags;
61     PSH_Hint  parent;
62     FT_Int    order;
63 
64   } PSH_HintRec;
65 
66 
67   /* this is an interpolation zone used for strong points;  */
68   /* weak points are interpolated according to their strong */
69   /* neighbours                                             */
70   typedef struct  PSH_ZoneRec_
71   {
72     FT_Fixed  scale;
73     FT_Fixed  delta;
74     FT_Pos    min;
75     FT_Pos    max;
76 
77   } PSH_ZoneRec, *PSH_Zone;
78 
79 
80   typedef struct  PSH_Hint_TableRec_
81   {
82     FT_UInt        max_hints;
83     FT_UInt        num_hints;
84     PSH_Hint       hints;
85     PSH_Hint*      sort;
86     PSH_Hint*      sort_global;
87     FT_UInt        num_zones;
88     PSH_ZoneRec*   zones;
89     PSH_Zone       zone;
90     PS_Mask_Table  hint_masks;
91     PS_Mask_Table  counter_masks;
92 
93   } PSH_Hint_TableRec, *PSH_Hint_Table;
94 
95 
96   typedef struct PSH_PointRec_*    PSH_Point;
97   typedef struct PSH_ContourRec_*  PSH_Contour;
98 
99   enum
100   {
101     PSH_DIR_NONE  =  4,
102     PSH_DIR_UP    = -1,
103     PSH_DIR_DOWN  =  1,
104     PSH_DIR_LEFT  = -2,
105     PSH_DIR_RIGHT =  2
106   };
107 
108 #define PSH_DIR_HORIZONTAL  2
109 #define PSH_DIR_VERTICAL    1
110 
111 #define PSH_DIR_COMPARE( d1, d2 )   ( (d1) == (d2) || (d1) == -(d2) )
112 #define PSH_DIR_IS_HORIZONTAL( d )  PSH_DIR_COMPARE( d, PSH_DIR_HORIZONTAL )
113 #define PSH_DIR_IS_VERTICAL( d )    PSH_DIR_COMPARE( d, PSH_DIR_VERTICAL )
114 
115 
116  /* the following bit-flags are computed once by the glyph */
117  /* analyzer, for both dimensions                          */
118   enum
119   {
120     PSH_POINT_OFF    = 1,   /* point is off the curve */
121     PSH_POINT_SMOOTH = 2,   /* point is smooth        */
122     PSH_POINT_INFLEX = 4    /* point is inflection    */
123   };
124 
125 #define psh_point_is_smooth( p )  ( (p)->flags & PSH_POINT_SMOOTH )
126 #define psh_point_is_off( p )     ( (p)->flags & PSH_POINT_OFF    )
127 #define psh_point_is_inflex( p )  ( (p)->flags & PSH_POINT_INFLEX )
128 
129 #define psh_point_set_smooth( p )  (p)->flags |= PSH_POINT_SMOOTH
130 #define psh_point_set_off( p )     (p)->flags |= PSH_POINT_OFF
131 #define psh_point_set_inflex( p )  (p)->flags |= PSH_POINT_INFLEX
132 
133   /* the following bit-flags are re-computed for each dimension */
134   enum
135   {
136     PSH_POINT_STRONG   = 16,   /* point is strong                           */
137     PSH_POINT_FITTED   = 32,   /* point is already fitted                   */
138     PSH_POINT_EXTREMUM = 64,   /* point is local extremum                   */
139     PSH_POINT_POSITIVE = 128,  /* extremum has positive contour flow        */
140     PSH_POINT_NEGATIVE = 256,  /* extremum has negative contour flow        */
141     PSH_POINT_EDGE_MIN = 512,  /* point is aligned to left/bottom stem edge */
142     PSH_POINT_EDGE_MAX = 1024  /* point is aligned to top/right stem edge   */
143   };
144 
145 #define psh_point_is_strong( p )    ( (p)->flags2 & PSH_POINT_STRONG )
146 #define psh_point_is_fitted( p )    ( (p)->flags2 & PSH_POINT_FITTED )
147 #define psh_point_is_extremum( p )  ( (p)->flags2 & PSH_POINT_EXTREMUM )
148 #define psh_point_is_positive( p )  ( (p)->flags2 & PSH_POINT_POSITIVE )
149 #define psh_point_is_negative( p )  ( (p)->flags2 & PSH_POINT_NEGATIVE )
150 #define psh_point_is_edge_min( p )  ( (p)->flags2 & PSH_POINT_EDGE_MIN )
151 #define psh_point_is_edge_max( p )  ( (p)->flags2 & PSH_POINT_EDGE_MAX )
152 
153 #define psh_point_set_strong( p )    (p)->flags2 |= PSH_POINT_STRONG
154 #define psh_point_set_fitted( p )    (p)->flags2 |= PSH_POINT_FITTED
155 #define psh_point_set_extremum( p )  (p)->flags2 |= PSH_POINT_EXTREMUM
156 #define psh_point_set_positive( p )  (p)->flags2 |= PSH_POINT_POSITIVE
157 #define psh_point_set_negative( p )  (p)->flags2 |= PSH_POINT_NEGATIVE
158 #define psh_point_set_edge_min( p )  (p)->flags2 |= PSH_POINT_EDGE_MIN
159 #define psh_point_set_edge_max( p )  (p)->flags2 |= PSH_POINT_EDGE_MAX
160 
161 
162   typedef struct  PSH_PointRec_
163   {
164     PSH_Point    prev;
165     PSH_Point    next;
166     PSH_Contour  contour;
167     FT_UInt      flags;
168     FT_UInt      flags2;
169     FT_Char      dir_in;
170     FT_Char      dir_out;
171     FT_Angle     angle_in;
172     FT_Angle     angle_out;
173     PSH_Hint     hint;
174     FT_Pos       org_u;
175     FT_Pos       org_v;
176     FT_Pos       cur_u;
177 #ifdef DEBUG_HINTER
178     FT_Pos       org_x;
179     FT_Pos       cur_x;
180     FT_Pos       org_y;
181     FT_Pos       cur_y;
182     FT_UInt      flags_x;
183     FT_UInt      flags_y;
184 #endif
185 
186   } PSH_PointRec;
187 
188 
189 #define PSH_POINT_EQUAL_ORG( a, b )  ( (a)->org_u == (b)->org_u && \
190                                        (a)->org_v == (b)->org_v )
191 
192 #define PSH_POINT_ANGLE( a, b )  FT_Atan2( (b)->org_u - (a)->org_u,  \
193                                            (b)->org_v - (a)->org_v )
194 
195   typedef struct  PSH_ContourRec_
196   {
197     PSH_Point  start;
198     FT_UInt    count;
199 
200   } PSH_ContourRec;
201 
202 
203   typedef struct  PSH_GlyphRec_
204   {
205     FT_UInt            num_points;
206     FT_UInt            num_contours;
207 
208     PSH_Point          points;
209     PSH_Contour        contours;
210 
211     FT_Memory          memory;
212     FT_Outline*        outline;
213     PSH_Globals        globals;
214     PSH_Hint_TableRec  hint_tables[2];
215 
216     FT_Bool            vertical;
217     FT_Int             major_dir;
218     FT_Int             minor_dir;
219 
220     FT_Bool            do_horz_hints;
221     FT_Bool            do_vert_hints;
222     FT_Bool            do_horz_snapping;
223     FT_Bool            do_vert_snapping;
224     FT_Bool            do_stem_adjust;
225 
226   } PSH_GlyphRec, *PSH_Glyph;
227 
228 
229 #ifdef DEBUG_HINTER
230   extern PSH_Hint_Table  ps_debug_hint_table;
231 
232   typedef void
233   (*PSH_HintFunc)( PSH_Hint  hint,
234                    FT_Bool   vertical );
235 
236   extern PSH_HintFunc    ps_debug_hint_func;
237 
238   extern PSH_Glyph       ps_debug_glyph;
239 #endif
240 
241 
242   extern FT_Error
243   ps_hints_apply( PS_Hints        ps_hints,
244                   FT_Outline*     outline,
245                   PSH_Globals     globals,
246                   FT_Render_Mode  hint_mode );
247 
248 
249 FT_END_HEADER
250 
251 
252 #endif /* __PSHALGO_H__ */
253 
254 
255 /* END */
256