1 /***************************************************************************/ 2 /* */ 3 /* ftoutln.h */ 4 /* */ 5 /* Support for the FT_Outline type used to store glyph shapes of */ 6 /* most scalable font formats (specification). */ 7 /* */ 8 /* Copyright 1996-2001, 2002, 2003, 2005, 2006, 2007, 2008, 2009, 2010 by */ 9 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ 10 /* */ 11 /* This file is part of the FreeType project, and may only be used, */ 12 /* modified, and distributed under the terms of the FreeType project */ 13 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ 14 /* this file you indicate that you have read the license and */ 15 /* understand and accept it fully. */ 16 /* */ 17 /***************************************************************************/ 18 19 20 #ifndef __FTOUTLN_H__ 21 #define __FTOUTLN_H__ 22 23 24 #include <ft2build.h> 25 #include FT_FREETYPE_H 26 27 #ifdef FREETYPE_H 28 #error "freetype.h of FreeType 1 has been loaded!" 29 #error "Please fix the directory search order for header files" 30 #error "so that freetype.h of FreeType 2 is found first." 31 #endif 32 33 34 FT_BEGIN_HEADER 35 36 37 /*************************************************************************/ 38 /* */ 39 /* <Section> */ 40 /* outline_processing */ 41 /* */ 42 /* <Title> */ 43 /* Outline Processing */ 44 /* */ 45 /* <Abstract> */ 46 /* Functions to create, transform, and render vectorial glyph images. */ 47 /* */ 48 /* <Description> */ 49 /* This section contains routines used to create and destroy scalable */ 50 /* glyph images known as `outlines'. These can also be measured, */ 51 /* transformed, and converted into bitmaps and pixmaps. */ 52 /* */ 53 /* <Order> */ 54 /* FT_Outline */ 55 /* FT_OUTLINE_FLAGS */ 56 /* FT_Outline_New */ 57 /* FT_Outline_Done */ 58 /* FT_Outline_Copy */ 59 /* FT_Outline_Translate */ 60 /* FT_Outline_Transform */ 61 /* FT_Outline_Embolden */ 62 /* FT_Outline_Reverse */ 63 /* FT_Outline_Check */ 64 /* */ 65 /* FT_Outline_Get_CBox */ 66 /* FT_Outline_Get_BBox */ 67 /* */ 68 /* FT_Outline_Get_Bitmap */ 69 /* FT_Outline_Render */ 70 /* */ 71 /* FT_Outline_Decompose */ 72 /* FT_Outline_Funcs */ 73 /* FT_Outline_MoveTo_Func */ 74 /* FT_Outline_LineTo_Func */ 75 /* FT_Outline_ConicTo_Func */ 76 /* FT_Outline_CubicTo_Func */ 77 /* */ 78 /*************************************************************************/ 79 80 81 /*************************************************************************/ 82 /* */ 83 /* <Function> */ 84 /* FT_Outline_Decompose */ 85 /* */ 86 /* <Description> */ 87 /* Walk over an outline's structure to decompose it into individual */ 88 /* segments and Bézier arcs. This function also emits `move to' */ 89 /* operations to indicate the start of new contours in the outline. */ 90 /* */ 91 /* <Input> */ 92 /* outline :: A pointer to the source target. */ 93 /* */ 94 /* func_interface :: A table of `emitters', i.e., function pointers */ 95 /* called during decomposition to indicate path */ 96 /* operations. */ 97 /* */ 98 /* <InOut> */ 99 /* user :: A typeless pointer which is passed to each */ 100 /* emitter during the decomposition. It can be */ 101 /* used to store the state during the */ 102 /* decomposition. */ 103 /* */ 104 /* <Return> */ 105 /* FreeType error code. 0~means success. */ 106 /* */ 107 FT_EXPORT( FT_Error ) 108 FT_Outline_Decompose( FT_Outline* outline, 109 const FT_Outline_Funcs* func_interface, 110 void* user ); 111 112 113 /*************************************************************************/ 114 /* */ 115 /* <Function> */ 116 /* FT_Outline_New */ 117 /* */ 118 /* <Description> */ 119 /* Create a new outline of a given size. */ 120 /* */ 121 /* <Input> */ 122 /* library :: A handle to the library object from where the */ 123 /* outline is allocated. Note however that the new */ 124 /* outline will *not* necessarily be *freed*, when */ 125 /* destroying the library, by @FT_Done_FreeType. */ 126 /* */ 127 /* numPoints :: The maximal number of points within the outline. */ 128 /* */ 129 /* numContours :: The maximal number of contours within the outline. */ 130 /* */ 131 /* <Output> */ 132 /* anoutline :: A handle to the new outline. */ 133 /* */ 134 /* <Return> */ 135 /* FreeType error code. 0~means success. */ 136 /* */ 137 /* <Note> */ 138 /* The reason why this function takes a `library' parameter is simply */ 139 /* to use the library's memory allocator. */ 140 /* */ 141 FT_EXPORT( FT_Error ) 142 FT_Outline_New( FT_Library library, 143 FT_UInt numPoints, 144 FT_Int numContours, 145 FT_Outline *anoutline ); 146 147 148 FT_EXPORT( FT_Error ) 149 FT_Outline_New_Internal( FT_Memory memory, 150 FT_UInt numPoints, 151 FT_Int numContours, 152 FT_Outline *anoutline ); 153 154 155 /*************************************************************************/ 156 /* */ 157 /* <Function> */ 158 /* FT_Outline_Done */ 159 /* */ 160 /* <Description> */ 161 /* Destroy an outline created with @FT_Outline_New. */ 162 /* */ 163 /* <Input> */ 164 /* library :: A handle of the library object used to allocate the */ 165 /* outline. */ 166 /* */ 167 /* outline :: A pointer to the outline object to be discarded. */ 168 /* */ 169 /* <Return> */ 170 /* FreeType error code. 0~means success. */ 171 /* */ 172 /* <Note> */ 173 /* If the outline's `owner' field is not set, only the outline */ 174 /* descriptor will be released. */ 175 /* */ 176 /* The reason why this function takes an `library' parameter is */ 177 /* simply to use ft_mem_free(). */ 178 /* */ 179 FT_EXPORT( FT_Error ) 180 FT_Outline_Done( FT_Library library, 181 FT_Outline* outline ); 182 183 184 FT_EXPORT( FT_Error ) 185 FT_Outline_Done_Internal( FT_Memory memory, 186 FT_Outline* outline ); 187 188 189 /*************************************************************************/ 190 /* */ 191 /* <Function> */ 192 /* FT_Outline_Check */ 193 /* */ 194 /* <Description> */ 195 /* Check the contents of an outline descriptor. */ 196 /* */ 197 /* <Input> */ 198 /* outline :: A handle to a source outline. */ 199 /* */ 200 /* <Return> */ 201 /* FreeType error code. 0~means success. */ 202 /* */ 203 FT_EXPORT( FT_Error ) 204 FT_Outline_Check( FT_Outline* outline ); 205 206 207 /*************************************************************************/ 208 /* */ 209 /* <Function> */ 210 /* FT_Outline_Get_CBox */ 211 /* */ 212 /* <Description> */ 213 /* Return an outline's `control box'. The control box encloses all */ 214 /* the outline's points, including Bézier control points. Though it */ 215 /* coincides with the exact bounding box for most glyphs, it can be */ 216 /* slightly larger in some situations (like when rotating an outline */ 217 /* which contains Bézier outside arcs). */ 218 /* */ 219 /* Computing the control box is very fast, while getting the bounding */ 220 /* box can take much more time as it needs to walk over all segments */ 221 /* and arcs in the outline. To get the latter, you can use the */ 222 /* `ftbbox' component which is dedicated to this single task. */ 223 /* */ 224 /* <Input> */ 225 /* outline :: A pointer to the source outline descriptor. */ 226 /* */ 227 /* <Output> */ 228 /* acbox :: The outline's control box. */ 229 /* */ 230 FT_EXPORT( void ) 231 FT_Outline_Get_CBox( const FT_Outline* outline, 232 FT_BBox *acbox ); 233 234 235 /*************************************************************************/ 236 /* */ 237 /* <Function> */ 238 /* FT_Outline_Translate */ 239 /* */ 240 /* <Description> */ 241 /* Apply a simple translation to the points of an outline. */ 242 /* */ 243 /* <InOut> */ 244 /* outline :: A pointer to the target outline descriptor. */ 245 /* */ 246 /* <Input> */ 247 /* xOffset :: The horizontal offset. */ 248 /* */ 249 /* yOffset :: The vertical offset. */ 250 /* */ 251 FT_EXPORT( void ) 252 FT_Outline_Translate( const FT_Outline* outline, 253 FT_Pos xOffset, 254 FT_Pos yOffset ); 255 256 257 /*************************************************************************/ 258 /* */ 259 /* <Function> */ 260 /* FT_Outline_Copy */ 261 /* */ 262 /* <Description> */ 263 /* Copy an outline into another one. Both objects must have the */ 264 /* same sizes (number of points & number of contours) when this */ 265 /* function is called. */ 266 /* */ 267 /* <Input> */ 268 /* source :: A handle to the source outline. */ 269 /* */ 270 /* <Output> */ 271 /* target :: A handle to the target outline. */ 272 /* */ 273 /* <Return> */ 274 /* FreeType error code. 0~means success. */ 275 /* */ 276 FT_EXPORT( FT_Error ) 277 FT_Outline_Copy( const FT_Outline* source, 278 FT_Outline *target ); 279 280 281 /*************************************************************************/ 282 /* */ 283 /* <Function> */ 284 /* FT_Outline_Transform */ 285 /* */ 286 /* <Description> */ 287 /* Apply a simple 2x2 matrix to all of an outline's points. Useful */ 288 /* for applying rotations, slanting, flipping, etc. */ 289 /* */ 290 /* <InOut> */ 291 /* outline :: A pointer to the target outline descriptor. */ 292 /* */ 293 /* <Input> */ 294 /* matrix :: A pointer to the transformation matrix. */ 295 /* */ 296 /* <Note> */ 297 /* You can use @FT_Outline_Translate if you need to translate the */ 298 /* outline's points. */ 299 /* */ 300 FT_EXPORT( void ) 301 FT_Outline_Transform( const FT_Outline* outline, 302 const FT_Matrix* matrix ); 303 304 305 /*************************************************************************/ 306 /* */ 307 /* <Function> */ 308 /* FT_Outline_Embolden */ 309 /* */ 310 /* <Description> */ 311 /* Embolden an outline. The new outline will be at most 4~times */ 312 /* `strength' pixels wider and higher. You may think of the left and */ 313 /* bottom borders as unchanged. */ 314 /* */ 315 /* Negative `strength' values to reduce the outline thickness are */ 316 /* possible also. */ 317 /* */ 318 /* <InOut> */ 319 /* outline :: A handle to the target outline. */ 320 /* */ 321 /* <Input> */ 322 /* strength :: How strong the glyph is emboldened. Expressed in */ 323 /* 26.6 pixel format. */ 324 /* */ 325 /* <Return> */ 326 /* FreeType error code. 0~means success. */ 327 /* */ 328 /* <Note> */ 329 /* The used algorithm to increase or decrease the thickness of the */ 330 /* glyph doesn't change the number of points; this means that certain */ 331 /* situations like acute angles or intersections are sometimes */ 332 /* handled incorrectly. */ 333 /* */ 334 /* If you need `better' metrics values you should call */ 335 /* @FT_Outline_Get_CBox ot @FT_Outline_Get_BBox. */ 336 /* */ 337 /* Example call: */ 338 /* */ 339 /* { */ 340 /* FT_Load_Glyph( face, index, FT_LOAD_DEFAULT ); */ 341 /* if ( face->slot->format == FT_GLYPH_FORMAT_OUTLINE ) */ 342 /* FT_Outline_Embolden( &face->slot->outline, strength ); */ 343 /* } */ 344 /* */ 345 FT_EXPORT( FT_Error ) 346 FT_Outline_Embolden( FT_Outline* outline, 347 FT_Pos strength ); 348 349 350 /*************************************************************************/ 351 /* */ 352 /* <Function> */ 353 /* FT_Outline_Reverse */ 354 /* */ 355 /* <Description> */ 356 /* Reverse the drawing direction of an outline. This is used to */ 357 /* ensure consistent fill conventions for mirrored glyphs. */ 358 /* */ 359 /* <InOut> */ 360 /* outline :: A pointer to the target outline descriptor. */ 361 /* */ 362 /* <Note> */ 363 /* This function toggles the bit flag @FT_OUTLINE_REVERSE_FILL in */ 364 /* the outline's `flags' field. */ 365 /* */ 366 /* It shouldn't be used by a normal client application, unless it */ 367 /* knows what it is doing. */ 368 /* */ 369 FT_EXPORT( void ) 370 FT_Outline_Reverse( FT_Outline* outline ); 371 372 373 /*************************************************************************/ 374 /* */ 375 /* <Function> */ 376 /* FT_Outline_Get_Bitmap */ 377 /* */ 378 /* <Description> */ 379 /* Render an outline within a bitmap. The outline's image is simply */ 380 /* OR-ed to the target bitmap. */ 381 /* */ 382 /* <Input> */ 383 /* library :: A handle to a FreeType library object. */ 384 /* */ 385 /* outline :: A pointer to the source outline descriptor. */ 386 /* */ 387 /* <InOut> */ 388 /* abitmap :: A pointer to the target bitmap descriptor. */ 389 /* */ 390 /* <Return> */ 391 /* FreeType error code. 0~means success. */ 392 /* */ 393 /* <Note> */ 394 /* This function does NOT CREATE the bitmap, it only renders an */ 395 /* outline image within the one you pass to it! Consequently, the */ 396 /* various fields in `abitmap' should be set accordingly. */ 397 /* */ 398 /* It will use the raster corresponding to the default glyph format. */ 399 /* */ 400 /* The value of the `num_grays' field in `abitmap' is ignored. If */ 401 /* you select the gray-level rasterizer, and you want less than 256 */ 402 /* gray levels, you have to use @FT_Outline_Render directly. */ 403 /* */ 404 FT_EXPORT( FT_Error ) 405 FT_Outline_Get_Bitmap( FT_Library library, 406 FT_Outline* outline, 407 const FT_Bitmap *abitmap ); 408 409 410 /*************************************************************************/ 411 /* */ 412 /* <Function> */ 413 /* FT_Outline_Render */ 414 /* */ 415 /* <Description> */ 416 /* Render an outline within a bitmap using the current scan-convert. */ 417 /* This function uses an @FT_Raster_Params structure as an argument, */ 418 /* allowing advanced features like direct composition, translucency, */ 419 /* etc. */ 420 /* */ 421 /* <Input> */ 422 /* library :: A handle to a FreeType library object. */ 423 /* */ 424 /* outline :: A pointer to the source outline descriptor. */ 425 /* */ 426 /* <InOut> */ 427 /* params :: A pointer to an @FT_Raster_Params structure used to */ 428 /* describe the rendering operation. */ 429 /* */ 430 /* <Return> */ 431 /* FreeType error code. 0~means success. */ 432 /* */ 433 /* <Note> */ 434 /* You should know what you are doing and how @FT_Raster_Params works */ 435 /* to use this function. */ 436 /* */ 437 /* The field `params.source' will be set to `outline' before the scan */ 438 /* converter is called, which means that the value you give to it is */ 439 /* actually ignored. */ 440 /* */ 441 /* The gray-level rasterizer always uses 256 gray levels. If you */ 442 /* want less gray levels, you have to provide your own span callback. */ 443 /* See the @FT_RASTER_FLAG_DIRECT value of the `flags' field in the */ 444 /* @FT_Raster_Params structure for more details. */ 445 /* */ 446 FT_EXPORT( FT_Error ) 447 FT_Outline_Render( FT_Library library, 448 FT_Outline* outline, 449 FT_Raster_Params* params ); 450 451 452 /************************************************************************** 453 * 454 * @enum: 455 * FT_Orientation 456 * 457 * @description: 458 * A list of values used to describe an outline's contour orientation. 459 * 460 * The TrueType and PostScript specifications use different conventions 461 * to determine whether outline contours should be filled or unfilled. 462 * 463 * @values: 464 * FT_ORIENTATION_TRUETYPE :: 465 * According to the TrueType specification, clockwise contours must 466 * be filled, and counter-clockwise ones must be unfilled. 467 * 468 * FT_ORIENTATION_POSTSCRIPT :: 469 * According to the PostScript specification, counter-clockwise contours 470 * must be filled, and clockwise ones must be unfilled. 471 * 472 * FT_ORIENTATION_FILL_RIGHT :: 473 * This is identical to @FT_ORIENTATION_TRUETYPE, but is used to 474 * remember that in TrueType, everything that is to the right of 475 * the drawing direction of a contour must be filled. 476 * 477 * FT_ORIENTATION_FILL_LEFT :: 478 * This is identical to @FT_ORIENTATION_POSTSCRIPT, but is used to 479 * remember that in PostScript, everything that is to the left of 480 * the drawing direction of a contour must be filled. 481 * 482 * FT_ORIENTATION_NONE :: 483 * The orientation cannot be determined. That is, different parts of 484 * the glyph have different orientation. 485 * 486 */ 487 typedef enum FT_Orientation_ 488 { 489 FT_ORIENTATION_TRUETYPE = 0, 490 FT_ORIENTATION_POSTSCRIPT = 1, 491 FT_ORIENTATION_FILL_RIGHT = FT_ORIENTATION_TRUETYPE, 492 FT_ORIENTATION_FILL_LEFT = FT_ORIENTATION_POSTSCRIPT, 493 FT_ORIENTATION_NONE 494 495 } FT_Orientation; 496 497 498 /************************************************************************** 499 * 500 * @function: 501 * FT_Outline_Get_Orientation 502 * 503 * @description: 504 * This function analyzes a glyph outline and tries to compute its 505 * fill orientation (see @FT_Orientation). This is done by computing 506 * the direction of each global horizontal and/or vertical extrema 507 * within the outline. 508 * 509 * Note that this will return @FT_ORIENTATION_TRUETYPE for empty 510 * outlines. 511 * 512 * @input: 513 * outline :: 514 * A handle to the source outline. 515 * 516 * @return: 517 * The orientation. 518 * 519 */ 520 FT_EXPORT( FT_Orientation ) 521 FT_Outline_Get_Orientation( FT_Outline* outline ); 522 523 524 /* */ 525 526 527 FT_END_HEADER 528 529 #endif /* __FTOUTLN_H__ */ 530 531 532 /* END */ 533 534 535 /* Local Variables: */ 536 /* coding: utf-8 */ 537 /* End: */ 538