pshints.h (9869B)
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 24 * submitted. If You institute patent litigation against any entity 25 * (including a cross-claim or counterclaim in a lawsuit) alleging that 26 * the Work or a contribution incorporated within the Work constitutes 27 * direct or contributory patent infringement, then any patent licenses 28 * granted to You under this License for that Work shall terminate as of 29 * the date such litigation is filed. 30 * 31 * By using, modifying, or distributing the Work you indicate that you 32 * have read and understood the terms and conditions of the 33 * FreeType Project License as well as those provided in this section, 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 */