1 /****************************************************************************
2 *
3 * pshints.h
4 *
5 * Adobe's code for handling CFF hints (body).
6 *
7 * Copyright 2007-2013 Adobe Systems Incorporated.
8 *
9 * This software, and all works of authorship, whether in source or
10 * object code form as indicated by the copyright notice(s) included
11 * herein (collectively, the "Work") is made available, and may only be
12 * used, modified, and distributed under the FreeType Project License,
13 * LICENSE.TXT. Additionally, subject to the terms and conditions of the
14 * FreeType Project License, each contributor to the Work hereby grants
15 * to any individual or legal entity exercising permissions granted by
16 * the FreeType Project License and this section (hereafter, "You" or
17 * "Your") a perpetual, worldwide, non-exclusive, no-charge,
18 * royalty-free, irrevocable (except as stated in this section) patent
19 * license to make, have made, use, offer to sell, sell, import, and
20 * otherwise transfer the Work, where such license applies only to those
21 * patent claims licensable by such contributor that are necessarily
22 * infringed by their contribution(s) alone or by combination of their
23 * contribution(s) with the Work to which such contribution(s) was
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32 * have read and understood the terms and conditions of the
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34 * and you accept them fully.
35 *
36 */
37
38
39 #ifndef PSHINT_H_
40 #define PSHINT_H_
41
42 FT_BEGIN_HEADER
43
44
45 enum
46 {
47 CF2_MAX_HINTS = 96 /* maximum # of hints */
48 };
49
50
51 /*
52 * A HintMask object stores a bit mask that specifies which hints in the
53 * charstring are active at a given time. Hints in CFF must be declared
54 * at the start, before any drawing operators, with horizontal hints
55 * preceding vertical hints. The HintMask is ordered the same way, with
56 * horizontal hints immediately followed by vertical hints. Clients are
57 * responsible for knowing how many of each type are present.
58 *
59 * The maximum total number of hints is 96, as specified by the CFF
60 * specification.
61 *
62 * A HintMask is built 0 or more times while interpreting a charstring, by
63 * the HintMask operator. There is only one HintMask, but it is built or
64 * rebuilt each time there is a hint substitution (HintMask operator) in
65 * the charstring. A default HintMask with all bits set is built if there
66 * has been no HintMask operator prior to the first drawing operator.
67 *
68 */
69
70 typedef struct CF2_HintMaskRec_
71 {
72 FT_Error* error;
73
74 FT_Bool isValid;
75 FT_Bool isNew;
76
77 size_t bitCount;
78 size_t byteCount;
79
80 FT_Byte mask[( CF2_MAX_HINTS + 7 ) / 8];
81
82 } CF2_HintMaskRec, *CF2_HintMask;
83
84
85 typedef struct CF2_StemHintRec_
86 {
87 FT_Bool used; /* DS positions are valid */
88
89 CF2_Fixed min; /* original character space value */
90 CF2_Fixed max;
91
92 CF2_Fixed minDS; /* DS position after first use */
93 CF2_Fixed maxDS;
94
95 } CF2_StemHintRec, *CF2_StemHint;
96
97
98 /*
99 * A HintMap object stores a piecewise linear function for mapping
100 * y-coordinates from character space to device space, providing
101 * appropriate pixel alignment to stem edges.
102 *
103 * The map is implemented as an array of `CF2_Hint' elements, each
104 * representing an edge. When edges are paired, as from stem hints, the
105 * bottom edge must immediately precede the top edge in the array.
106 * Element character space AND device space positions must both increase
107 * monotonically in the array. `CF2_Hint' elements are also used as
108 * parameters to `cf2_blues_capture'.
109 *
110 * The `cf2_hintmap_build' method must be called before any drawing
111 * operation (beginning with a Move operator) and at each hint
112 * substitution (HintMask operator).
113 *
114 * The `cf2_hintmap_map' method is called to transform y-coordinates at
115 * each drawing operation (move, line, curve).
116 *
117 */
118
119 /* TODO: make this a CF2_ArrStack and add a deep copy method */
120 enum
121 {
122 CF2_MAX_HINT_EDGES = CF2_MAX_HINTS * 2
123 };
124
125
126 typedef struct CF2_HintMapRec_
127 {
128 CF2_Font font;
129
130 /* initial map based on blue zones */
131 struct CF2_HintMapRec_* initialHintMap;
132
133 /* working storage for 2nd pass adjustHints */
134 CF2_ArrStack hintMoves;
135
136 FT_Bool isValid;
137 FT_Bool hinted;
138
139 CF2_Fixed scale;
140 CF2_UInt count;
141
142 /* start search from this index */
143 CF2_UInt lastIndex;
144
145 CF2_HintRec edge[CF2_MAX_HINT_EDGES]; /* 192 */
146
147 } CF2_HintMapRec, *CF2_HintMap;
148
149
150 FT_LOCAL( FT_Bool )
151 cf2_hint_isValid( const CF2_Hint hint );
152 FT_LOCAL( FT_Bool )
153 cf2_hint_isTop( const CF2_Hint hint );
154 FT_LOCAL( FT_Bool )
155 cf2_hint_isBottom( const CF2_Hint hint );
156 FT_LOCAL( void )
157 cf2_hint_lock( CF2_Hint hint );
158
159
160 FT_LOCAL( void )
161 cf2_hintmap_init( CF2_HintMap hintmap,
162 CF2_Font font,
163 CF2_HintMap initialMap,
164 CF2_ArrStack hintMoves,
165 CF2_Fixed scale );
166 FT_LOCAL( void )
167 cf2_hintmap_build( CF2_HintMap hintmap,
168 CF2_ArrStack hStemHintArray,
169 CF2_ArrStack vStemHintArray,
170 CF2_HintMask hintMask,
171 CF2_Fixed hintOrigin,
172 FT_Bool initialMap );
173
174
175 /*
176 * GlyphPath is a wrapper for drawing operations that scales the
177 * coordinates according to the render matrix and HintMap. It also tracks
178 * open paths to control ClosePath and to insert MoveTo for broken fonts.
179 *
180 */
181 typedef struct CF2_GlyphPathRec_
182 {
183 /* TODO: gather some of these into a hinting context */
184
185 CF2_Font font; /* font instance */
186 CF2_OutlineCallbacks callbacks; /* outline consumer */
187
188
189 CF2_HintMapRec hintMap; /* current hint map */
190 CF2_HintMapRec firstHintMap; /* saved copy */
191 CF2_HintMapRec initialHintMap; /* based on all captured hints */
192
193 CF2_ArrStackRec hintMoves; /* list of hint moves for 2nd pass */
194
195 CF2_Fixed scaleX; /* matrix a */
196 CF2_Fixed scaleC; /* matrix c */
197 CF2_Fixed scaleY; /* matrix d */
198
199 FT_Vector fractionalTranslation; /* including deviceXScale */
200 #if 0
201 CF2_Fixed hShift; /* character space horizontal shift */
202 /* (for fauxing) */
203 #endif
204
205 FT_Bool pathIsOpen; /* true after MoveTo */
206 FT_Bool pathIsClosing; /* true when synthesizing closepath line */
207 FT_Bool darken; /* true if stem darkening */
208 FT_Bool moveIsPending; /* true between MoveTo and offset MoveTo */
209
210 /* references used to call `cf2_hintmap_build', if necessary */
211 CF2_ArrStack hStemHintArray;
212 CF2_ArrStack vStemHintArray;
213 CF2_HintMask hintMask; /* ptr to the current mask */
214 CF2_Fixed hintOriginY; /* copy of current origin */
215 const CF2_BluesRec* blues;
216
217 CF2_Fixed xOffset; /* character space offsets */
218 CF2_Fixed yOffset;
219
220 /* character space miter limit threshold */
221 CF2_Fixed miterLimit;
222 /* vertical/horizontal snap distance in character space */
223 CF2_Fixed snapThreshold;
224
225 FT_Vector offsetStart0; /* first and second points of first */
226 FT_Vector offsetStart1; /* element with offset applied */
227
228 /* current point, character space, before offset */
229 FT_Vector currentCS;
230 /* current point, device space */
231 FT_Vector currentDS;
232 /* start point of subpath, character space */
233 FT_Vector start;
234
235 /* the following members constitute the `queue' of one element */
236 FT_Bool elemIsQueued;
237 CF2_Int prevElemOp;
238
239 FT_Vector prevElemP0;
240 FT_Vector prevElemP1;
241 FT_Vector prevElemP2;
242 FT_Vector prevElemP3;
243
244 } CF2_GlyphPathRec, *CF2_GlyphPath;
245
246
247 FT_LOCAL( void )
248 cf2_glyphpath_init( CF2_GlyphPath glyphpath,
249 CF2_Font font,
250 CF2_OutlineCallbacks callbacks,
251 CF2_Fixed scaleY,
252 /* CF2_Fixed hShift, */
253 CF2_ArrStack hStemHintArray,
254 CF2_ArrStack vStemHintArray,
255 CF2_HintMask hintMask,
256 CF2_Fixed hintOrigin,
257 const CF2_Blues blues,
258 const FT_Vector* fractionalTranslation );
259 FT_LOCAL( void )
260 cf2_glyphpath_finalize( CF2_GlyphPath glyphpath );
261
262 FT_LOCAL( void )
263 cf2_glyphpath_moveTo( CF2_GlyphPath glyphpath,
264 CF2_Fixed x,
265 CF2_Fixed y );
266 FT_LOCAL( void )
267 cf2_glyphpath_lineTo( CF2_GlyphPath glyphpath,
268 CF2_Fixed x,
269 CF2_Fixed y );
270 FT_LOCAL( void )
271 cf2_glyphpath_curveTo( CF2_GlyphPath glyphpath,
272 CF2_Fixed x1,
273 CF2_Fixed y1,
274 CF2_Fixed x2,
275 CF2_Fixed y2,
276 CF2_Fixed x3,
277 CF2_Fixed y3 );
278 FT_LOCAL( void )
279 cf2_glyphpath_closeOpenPath( CF2_GlyphPath glyphpath );
280
281
282 FT_END_HEADER
283
284
285 #endif /* PSHINT_H_ */
286
287
288 /* END */