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path: root/src/3rdparty/freetype/src/autofit/afhints.h
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 ```1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 ``` ``````/***************************************************************************/ /* */ /* afhints.h */ /* */ /* Auto-fitter hinting routines (specification). */ /* */ /* Copyright 2003-2008, 2010-2012, 2014 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ /* modified, and distributed under the terms of the FreeType project */ /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ /* this file you indicate that you have read the license and */ /* understand and accept it fully. */ /* */ /***************************************************************************/ #ifndef __AFHINTS_H__ #define __AFHINTS_H__ #include "aftypes.h" #define xxAF_SORT_SEGMENTS FT_BEGIN_HEADER /* * The definition of outline glyph hints. These are shared by all * writing system analysis routines (until now). */ typedef enum AF_Dimension_ { AF_DIMENSION_HORZ = 0, /* x coordinates, */ /* i.e., vertical segments & edges */ AF_DIMENSION_VERT = 1, /* y coordinates, */ /* i.e., horizontal segments & edges */ AF_DIMENSION_MAX /* do not remove */ } AF_Dimension; /* hint directions -- the values are computed so that two vectors are */ /* in opposite directions iff `dir1 + dir2 == 0' */ typedef enum AF_Direction_ { AF_DIR_NONE = 4, AF_DIR_RIGHT = 1, AF_DIR_LEFT = -1, AF_DIR_UP = 2, AF_DIR_DOWN = -2 } AF_Direction; /* * The following explanations are mostly taken from the article * * Real-Time Grid Fitting of Typographic Outlines * * by David Turner and Werner Lemberg * * http://www.tug.org/TUGboat/Articles/tb24-3/lemberg.pdf * * with appropriate updates. * * * Segments * * `af_{cjk,latin,...}_hints_compute_segments' are the functions to * find segments in an outline. * * A segment is a series of at least two consecutive points that are * approximately aligned along a coordinate axis. The analysis to do * so is specific to a writing system. * * * Edges * * `af_{cjk,latin,...}_hints_compute_edges' are the functions to find * edges. * * As soon as segments are defined, the auto-hinter groups them into * edges. An edge corresponds to a single position on the main * dimension that collects one or more segments (allowing for a small * threshold). * * As an example, the `latin' writing system first tries to grid-fit * edges, then to align segments on the edges unless it detects that * they form a serif. * * * A H * | | * | | * | | * | | * C | | F * +------<-----+ +-----<------+ * | B G | * | | * | | * +--------------->------------------+ * D E * * * Stems * * Stems are detected by `af_{cjk,latin,...}_hint_edges'. * * Segments need to be `linked' to other ones in order to detect stems. * A stem is made of two segments that face each other in opposite * directions and that are sufficiently close to each other. Using * vocabulary from the TrueType specification, stem segments form a * `black distance'. * * In the above ASCII drawing, the horizontal segments are BC, DE, and * FG; the vertical segments are AB, CD, EF, and GH. * * Each segment has at most one `best' candidate to form a black * distance, or no candidate at all. Notice that two distinct segments * can have the same candidate, which frequently means a serif. * * A stem is recognized by the following condition: * * best segment_1 = segment_2 && best segment_2 = segment_1 * * The best candidate is stored in field `link' in structure * `AF_Segment'. * * In the above ASCII drawing, the best candidate for both AB and CD is * GH, while the best candidate for GH is AB. Similarly, the best * candidate for EF and GH is AB, while the best candidate for AB is * GH. * * The detection and handling of stems is dependent on the writing * system. * * * Serifs * * Serifs are detected by `af_{cjk,latin,...}_hint_edges'. * * In comparison to a stem, a serif (as handled by the auto-hinter * module that takes care of the `latin' writing system) has * * best segment_1 = segment_2 && best segment_2 != segment_1 * * where segment_1 corresponds to the serif segment (CD and EF in the * above ASCII drawing). * * The best candidate is stored in field `serif' in structure * `AF_Segment' (and `link' is set to NULL). * * * Touched points * * A point is called `touched' if it has been processed somehow by the * auto-hinter. It basically means that it shouldn't be moved again * (or moved only under certain constraints to preserve the already * applied processing). * * * Flat and round segments * * Segments are `round' or `flat', depending on the series of points * that define them. A segment is round if the next and previous point * of an extremum (which can be either a single point or sequence of * points) are both conic or cubic control points. Otherwise, a * segment with an extremum is flat. * * * Strong Points * * Experience has shown that points not part of an edge need to be * interpolated linearly between their two closest edges, even if these * are not part of the contour of those particular points. Typical * candidates for this are * * - angle points (i.e., points where the `in' and `out' direction * differ greatly) * * - inflection points (i.e., where the `in' and `out' angles are the * same, but the curvature changes sign) [currently, such points * aren't handled specially in the auto-hinter] * * `af_glyph_hints_align_strong_points' is the function that takes * care of such situations; it is equivalent to the TrueType `IP' * hinting instruction. * * * Weak Points * * Other points in the outline must be interpolated using the * coordinates of their previous and next unfitted contour neighbours. * These are called `weak points' and are touched by the function * `af_glyph_hints_align_weak_points', equivalent to the TrueType `IUP' * hinting instruction. Typical candidates are control points and * points on the contour without a major direction. * * The major effect is to reduce possible distortion caused by * alignment of edges and strong points, thus weak points are processed * after strong points. */ /* point hint flags */ typedef enum AF_Flags_ { AF_FLAG_NONE = 0, /* point type flags */ AF_FLAG_CONIC = 1 << 0, AF_FLAG_CUBIC = 1 << 1, AF_FLAG_CONTROL = AF_FLAG_CONIC | AF_FLAG_CUBIC, /* point touch flags */ AF_FLAG_TOUCH_X = 1 << 2, AF_FLAG_TOUCH_Y = 1 << 3, /* candidates for weak interpolation have this flag set */ AF_FLAG_WEAK_INTERPOLATION = 1 << 4 } AF_Flags; /* edge hint flags */ typedef enum AF_Edge_Flags_ { AF_EDGE_NORMAL = 0, AF_EDGE_ROUND = 1 << 0, AF_EDGE_SERIF = 1 << 1, AF_EDGE_DONE = 1 << 2, AF_EDGE_NEUTRAL = 1 << 3 /* set if edge aligns to a neutral blue zone */ } AF_Edge_Flags; typedef struct AF_PointRec_* AF_Point; typedef struct AF_SegmentRec_* AF_Segment; typedef struct AF_EdgeRec_* AF_Edge; typedef struct AF_PointRec_ { FT_UShort flags; /* point flags used by hinter */ FT_Char in_dir; /* direction of inwards vector */ FT_Char out_dir; /* direction of outwards vector */ FT_Pos ox, oy; /* original, scaled position */ FT_Short fx, fy; /* original, unscaled position (in font units) */ FT_Pos x, y; /* current position */ FT_Pos u, v; /* current (x,y) or (y,x) depending on context */ AF_Point next; /* next point in contour */ AF_Point prev; /* previous point in contour */ } AF_PointRec; typedef struct AF_SegmentRec_ { FT_Byte flags; /* edge/segment flags for this segment */ FT_Char dir; /* segment direction */ FT_Short pos; /* position of segment */ FT_Short min_coord; /* minimum coordinate of segment */ FT_Short max_coord; /* maximum coordinate of segment */ FT_Short height; /* the hinted segment height */ AF_Edge edge; /* the segment's parent edge */ AF_Segment edge_next; /* link to next segment in parent edge */ AF_Segment link; /* (stem) link segment */ AF_Segment serif; /* primary segment for serifs */ FT_Pos num_linked; /* number of linked segments */ FT_Pos score; /* used during stem matching */ FT_Pos len; /* used during stem matching */ AF_Point first; /* first point in edge segment */ AF_Point last; /* last point in edge segment */ } AF_SegmentRec; typedef struct AF_EdgeRec_ { FT_Short fpos; /* original, unscaled position (in font units) */ FT_Pos opos; /* original, scaled position */ FT_Pos pos; /* current position */ FT_Byte flags; /* edge flags */ FT_Char dir; /* edge direction */ FT_Fixed scale; /* used to speed up interpolation between edges */ AF_Width blue_edge; /* non-NULL if this is a blue edge */ AF_Edge link; /* link edge */ AF_Edge serif; /* primary edge for serifs */ FT_Short num_linked; /* number of linked edges */ FT_Int score; /* used during stem matching */ AF_Segment first; /* first segment in edge */ AF_Segment last; /* last segment in edge */ } AF_EdgeRec; typedef struct AF_AxisHintsRec_ { FT_Int num_segments; /* number of used segments */ FT_Int max_segments; /* number of allocated segments */ AF_Segment segments; /* segments array */ #ifdef AF_SORT_SEGMENTS FT_Int mid_segments; #endif FT_Int num_edges; /* number of used edges */ FT_Int max_edges; /* number of allocated edges */ AF_Edge edges; /* edges array */ AF_Direction major_dir; /* either vertical or horizontal */ } AF_AxisHintsRec, *AF_AxisHints; typedef struct AF_GlyphHintsRec_ { FT_Memory memory; FT_Fixed x_scale; FT_Pos x_delta; FT_Fixed y_scale; FT_Pos y_delta; FT_Int max_points; /* number of allocated points */ FT_Int num_points; /* number of used points */ AF_Point points; /* points array */ FT_Int max_contours; /* number of allocated contours */ FT_Int num_contours; /* number of used contours */ AF_Point* contours; /* contours array */ AF_AxisHintsRec axis[AF_DIMENSION_MAX]; FT_UInt32 scaler_flags; /* copy of scaler flags */ FT_UInt32 other_flags; /* free for style-specific */ /* implementations */ AF_StyleMetrics metrics; FT_Pos xmin_delta; /* used for warping */ FT_Pos xmax_delta; } AF_GlyphHintsRec; #define AF_HINTS_TEST_SCALER( h, f ) ( (h)->scaler_flags & (f) ) #define AF_HINTS_TEST_OTHER( h, f ) ( (h)->other_flags & (f) ) #ifdef FT_DEBUG_AUTOFIT #define AF_HINTS_DO_HORIZONTAL( h ) \ ( !_af_debug_disable_horz_hints && \ !AF_HINTS_TEST_SCALER( h, AF_SCALER_FLAG_NO_HORIZONTAL ) ) #define AF_HINTS_DO_VERTICAL( h ) \ ( !_af_debug_disable_vert_hints && \ !AF_HINTS_TEST_SCALER( h, AF_SCALER_FLAG_NO_VERTICAL ) ) #define AF_HINTS_DO_ADVANCE( h ) \ !AF_HINTS_TEST_SCALER( h, AF_SCALER_FLAG_NO_ADVANCE ) #define AF_HINTS_DO_BLUES( h ) ( !_af_debug_disable_blue_hints ) #else /* !FT_DEBUG_AUTOFIT */ #define AF_HINTS_DO_HORIZONTAL( h ) \ !AF_HINTS_TEST_SCALER( h, AF_SCALER_FLAG_NO_HORIZONTAL ) #define AF_HINTS_DO_VERTICAL( h ) \ !AF_HINTS_TEST_SCALER( h, AF_SCALER_FLAG_NO_VERTICAL ) #define AF_HINTS_DO_ADVANCE( h ) \ !AF_HINTS_TEST_SCALER( h, AF_SCALER_FLAG_NO_ADVANCE ) #define AF_HINTS_DO_BLUES( h ) 1 #endif /* !FT_DEBUG_AUTOFIT */ FT_LOCAL( AF_Direction ) af_direction_compute( FT_Pos dx, FT_Pos dy ); FT_LOCAL( FT_Error ) af_axis_hints_new_segment( AF_AxisHints axis, FT_Memory memory, AF_Segment *asegment ); FT_LOCAL( FT_Error) af_axis_hints_new_edge( AF_AxisHints axis, FT_Int fpos, AF_Direction dir, FT_Memory memory, AF_Edge *edge ); FT_LOCAL( void ) af_glyph_hints_init( AF_GlyphHints hints, FT_Memory memory ); FT_LOCAL( void ) af_glyph_hints_rescale( AF_GlyphHints hints, AF_StyleMetrics metrics ); FT_LOCAL( FT_Error ) af_glyph_hints_reload( AF_GlyphHints hints, FT_Outline* outline ); FT_LOCAL( void ) af_glyph_hints_save( AF_GlyphHints hints, FT_Outline* outline ); FT_LOCAL( void ) af_glyph_hints_align_edge_points( AF_GlyphHints hints, AF_Dimension dim ); FT_LOCAL( void ) af_glyph_hints_align_strong_points( AF_GlyphHints hints, AF_Dimension dim ); FT_LOCAL( void ) af_glyph_hints_align_weak_points( AF_GlyphHints hints, AF_Dimension dim ); #ifdef AF_CONFIG_OPTION_USE_WARPER FT_LOCAL( void ) af_glyph_hints_scale_dim( AF_GlyphHints hints, AF_Dimension dim, FT_Fixed scale, FT_Pos delta ); #endif FT_LOCAL( void ) af_glyph_hints_done( AF_GlyphHints hints ); /* */ #define AF_SEGMENT_LEN( seg ) ( (seg)->max_coord - (seg)->min_coord ) #define AF_SEGMENT_DIST( seg1, seg2 ) ( ( (seg1)->pos > (seg2)->pos ) \ ? (seg1)->pos - (seg2)->pos \ : (seg2)->pos - (seg1)->pos ) FT_END_HEADER #endif /* __AFHINTS_H__ */ /* END */ ``````