1 /***************************************************************************/
2 /* */
3 /* pshalgo.h */
4 /* */
5 /* PostScript hinting algorithm (specification). */
6 /* */
7 /* Copyright 2001-2018 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
26
27 FT_BEGIN_HEADER
28
29
30 /* handle to Hint structure */
31 typedef struct PSH_HintRec_* PSH_Hint;
32
33
34 /* hint bit-flags */
35 #define PSH_HINT_GHOST PS_HINT_FLAG_GHOST
36 #define PSH_HINT_BOTTOM PS_HINT_FLAG_BOTTOM
37 #define PSH_HINT_ACTIVE 4U
38 #define PSH_HINT_FITTED 8U
39
40
41 #define psh_hint_is_active( x ) ( ( (x)->flags & PSH_HINT_ACTIVE ) != 0 )
42 #define psh_hint_is_ghost( x ) ( ( (x)->flags & PSH_HINT_GHOST ) != 0 )
43 #define psh_hint_is_fitted( x ) ( ( (x)->flags & PSH_HINT_FITTED ) != 0 )
44
45 #define psh_hint_activate( x ) (x)->flags |= PSH_HINT_ACTIVE
46 #define psh_hint_deactivate( x ) (x)->flags &= ~PSH_HINT_ACTIVE
47 #define psh_hint_set_fitted( x ) (x)->flags |= PSH_HINT_FITTED
48
49
50 /* hint structure */
51 typedef struct PSH_HintRec_
52 {
53 FT_Int org_pos;
54 FT_Int org_len;
55 FT_Pos cur_pos;
56 FT_Pos cur_len;
57 FT_UInt flags;
58 PSH_Hint parent;
59 FT_Int order;
60
61 } PSH_HintRec;
62
63
64 /* this is an interpolation zone used for strong points; */
65 /* weak points are interpolated according to their strong */
66 /* neighbours */
67 typedef struct PSH_ZoneRec_
68 {
69 FT_Fixed scale;
70 FT_Fixed delta;
71 FT_Pos min;
72 FT_Pos max;
73
74 } PSH_ZoneRec, *PSH_Zone;
75
76
77 typedef struct PSH_Hint_TableRec_
78 {
79 FT_UInt max_hints;
80 FT_UInt num_hints;
81 PSH_Hint hints;
82 PSH_Hint* sort;
83 PSH_Hint* sort_global;
84 FT_UInt num_zones;
85 PSH_ZoneRec* zones;
86 PSH_Zone zone;
87 PS_Mask_Table hint_masks;
88 PS_Mask_Table counter_masks;
89
90 } PSH_Hint_TableRec, *PSH_Hint_Table;
91
92
93 typedef struct PSH_PointRec_* PSH_Point;
94 typedef struct PSH_ContourRec_* PSH_Contour;
95
96 enum
97 {
98 PSH_DIR_NONE = 4,
99 PSH_DIR_UP = -1,
100 PSH_DIR_DOWN = 1,
101 PSH_DIR_LEFT = -2,
102 PSH_DIR_RIGHT = 2
103 };
104
105 #define PSH_DIR_HORIZONTAL 2
106 #define PSH_DIR_VERTICAL 1
107
108 #define PSH_DIR_COMPARE( d1, d2 ) ( (d1) == (d2) || (d1) == -(d2) )
109 #define PSH_DIR_IS_HORIZONTAL( d ) PSH_DIR_COMPARE( d, PSH_DIR_HORIZONTAL )
110 #define PSH_DIR_IS_VERTICAL( d ) PSH_DIR_COMPARE( d, PSH_DIR_VERTICAL )
111
112
113 /* the following bit-flags are computed once by the glyph */
114 /* analyzer, for both dimensions */
115 #define PSH_POINT_OFF 1U /* point is off the curve */
116 #define PSH_POINT_SMOOTH 2U /* point is smooth */
117 #define PSH_POINT_INFLEX 4U /* point is inflection */
118
119
120 #define psh_point_is_smooth( p ) ( (p)->flags & PSH_POINT_SMOOTH )
121 #define psh_point_is_off( p ) ( (p)->flags & PSH_POINT_OFF )
122 #define psh_point_is_inflex( p ) ( (p)->flags & PSH_POINT_INFLEX )
123
124 #define psh_point_set_smooth( p ) (p)->flags |= PSH_POINT_SMOOTH
125 #define psh_point_set_off( p ) (p)->flags |= PSH_POINT_OFF
126 #define psh_point_set_inflex( p ) (p)->flags |= PSH_POINT_INFLEX
127
128
129 /* the following bit-flags are re-computed for each dimension */
130 #define PSH_POINT_STRONG 16U /* point is strong */
131 #define PSH_POINT_FITTED 32U /* point is already fitted */
132 #define PSH_POINT_EXTREMUM 64U /* point is local extremum */
133 #define PSH_POINT_POSITIVE 128U /* extremum has positive contour flow */
134 #define PSH_POINT_NEGATIVE 256U /* extremum has negative contour flow */
135 #define PSH_POINT_EDGE_MIN 512U /* point is aligned to left/bottom stem edge */
136 #define PSH_POINT_EDGE_MAX 1024U /* point is aligned to top/right stem edge */
137
138
139 #define psh_point_is_strong( p ) ( (p)->flags2 & PSH_POINT_STRONG )
140 #define psh_point_is_fitted( p ) ( (p)->flags2 & PSH_POINT_FITTED )
141 #define psh_point_is_extremum( p ) ( (p)->flags2 & PSH_POINT_EXTREMUM )
142 #define psh_point_is_positive( p ) ( (p)->flags2 & PSH_POINT_POSITIVE )
143 #define psh_point_is_negative( p ) ( (p)->flags2 & PSH_POINT_NEGATIVE )
144 #define psh_point_is_edge_min( p ) ( (p)->flags2 & PSH_POINT_EDGE_MIN )
145 #define psh_point_is_edge_max( p ) ( (p)->flags2 & PSH_POINT_EDGE_MAX )
146
147 #define psh_point_set_strong( p ) (p)->flags2 |= PSH_POINT_STRONG
148 #define psh_point_set_fitted( p ) (p)->flags2 |= PSH_POINT_FITTED
149 #define psh_point_set_extremum( p ) (p)->flags2 |= PSH_POINT_EXTREMUM
150 #define psh_point_set_positive( p ) (p)->flags2 |= PSH_POINT_POSITIVE
151 #define psh_point_set_negative( p ) (p)->flags2 |= PSH_POINT_NEGATIVE
152 #define psh_point_set_edge_min( p ) (p)->flags2 |= PSH_POINT_EDGE_MIN
153 #define psh_point_set_edge_max( p ) (p)->flags2 |= PSH_POINT_EDGE_MAX
154
155
156 typedef struct PSH_PointRec_
157 {
158 PSH_Point prev;
159 PSH_Point next;
160 PSH_Contour contour;
161 FT_UInt flags;
162 FT_UInt flags2;
163 FT_Char dir_in;
164 FT_Char dir_out;
165 PSH_Hint hint;
166 FT_Pos org_u;
167 FT_Pos org_v;
168 FT_Pos cur_u;
169 #ifdef DEBUG_HINTER
170 FT_Pos org_x;
171 FT_Pos cur_x;
172 FT_Pos org_y;
173 FT_Pos cur_y;
174 FT_UInt flags_x;
175 FT_UInt flags_y;
176 #endif
177
178 } PSH_PointRec;
179
180
181 typedef struct PSH_ContourRec_
182 {
183 PSH_Point start;
184 FT_UInt count;
185
186 } PSH_ContourRec;
187
188
189 typedef struct PSH_GlyphRec_
190 {
191 FT_UInt num_points;
192 FT_UInt num_contours;
193
194 PSH_Point points;
195 PSH_Contour contours;
196
197 FT_Memory memory;
198 FT_Outline* outline;
199 PSH_Globals globals;
200 PSH_Hint_TableRec hint_tables[2];
201
202 FT_Bool vertical;
203 FT_Int major_dir;
204 FT_Int minor_dir;
205
206 FT_Bool do_horz_hints;
207 FT_Bool do_vert_hints;
208 FT_Bool do_horz_snapping;
209 FT_Bool do_vert_snapping;
210 FT_Bool do_stem_adjust;
211
212 } PSH_GlyphRec, *PSH_Glyph;
213
214
215 #ifdef DEBUG_HINTER
216 extern PSH_Hint_Table ps_debug_hint_table;
217
218 typedef void
219 (*PSH_HintFunc)( PSH_Hint hint,
220 FT_Bool vertical );
221
222 extern PSH_HintFunc ps_debug_hint_func;
223
224 extern PSH_Glyph ps_debug_glyph;
225 #endif
226
227
228 extern FT_Error
229 ps_hints_apply( PS_Hints ps_hints,
230 FT_Outline* outline,
231 PSH_Globals globals,
232 FT_Render_Mode hint_mode );
233
234
235 FT_END_HEADER
236
237
238 #endif /* PSHALGO_H_ */
239
240
241 /* END */