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ftoutln.h
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00001 /***************************************************************************/ 00002 /* */ 00003 /* ftoutln.h */ 00004 /* */ 00005 /* Support for the FT_Outline type used to store glyph shapes of */ 00006 /* most scalable font formats (specification). */ 00007 /* */ 00008 /* Copyright 1996-2001, 2002, 2003, 2005, 2006, 2007, 2008, 2009, 2010 by */ 00009 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ 00010 /* */ 00011 /* This file is part of the FreeType project, and may only be used, */ 00012 /* modified, and distributed under the terms of the FreeType project */ 00013 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ 00014 /* this file you indicate that you have read the license and */ 00015 /* understand and accept it fully. */ 00016 /* */ 00017 /***************************************************************************/ 00018 00019 00020 #ifndef __FTOUTLN_H__ 00021 #define __FTOUTLN_H__ 00022 00023 00024 #include <ft2build.h> 00025 #include FT_FREETYPE_H 00026 00027 #ifdef FREETYPE_H 00028 #error "freetype.h of FreeType 1 has been loaded!" 00029 #error "Please fix the directory search order for header files" 00030 #error "so that freetype.h of FreeType 2 is found first." 00031 #endif 00032 00033 00034 FT_BEGIN_HEADER 00035 00036 00037 /*************************************************************************/ 00038 /* */ 00039 /* <Section> */ 00040 /* outline_processing */ 00041 /* */ 00042 /* <Title> */ 00043 /* Outline Processing */ 00044 /* */ 00045 /* <Abstract> */ 00046 /* Functions to create, transform, and render vectorial glyph images. */ 00047 /* */ 00048 /* <Description> */ 00049 /* This section contains routines used to create and destroy scalable */ 00050 /* glyph images known as `outlines'. These can also be measured, */ 00051 /* transformed, and converted into bitmaps and pixmaps. */ 00052 /* */ 00053 /* <Order> */ 00054 /* FT_Outline */ 00055 /* FT_OUTLINE_FLAGS */ 00056 /* FT_Outline_New */ 00057 /* FT_Outline_Done */ 00058 /* FT_Outline_Copy */ 00059 /* FT_Outline_Translate */ 00060 /* FT_Outline_Transform */ 00061 /* FT_Outline_Embolden */ 00062 /* FT_Outline_Reverse */ 00063 /* FT_Outline_Check */ 00064 /* */ 00065 /* FT_Outline_Get_CBox */ 00066 /* FT_Outline_Get_BBox */ 00067 /* */ 00068 /* FT_Outline_Get_Bitmap */ 00069 /* FT_Outline_Render */ 00070 /* */ 00071 /* FT_Outline_Decompose */ 00072 /* FT_Outline_Funcs */ 00073 /* FT_Outline_MoveTo_Func */ 00074 /* FT_Outline_LineTo_Func */ 00075 /* FT_Outline_ConicTo_Func */ 00076 /* FT_Outline_CubicTo_Func */ 00077 /* */ 00078 /*************************************************************************/ 00079 00080 00081 /*************************************************************************/ 00082 /* */ 00083 /* <Function> */ 00084 /* FT_Outline_Decompose */ 00085 /* */ 00086 /* <Description> */ 00087 /* Walk over an outline's structure to decompose it into individual */ 00088 /* segments and Bézier arcs. This function also emits `move to' */ 00089 /* operations to indicate the start of new contours in the outline. */ 00090 /* */ 00091 /* <Input> */ 00092 /* outline :: A pointer to the source target. */ 00093 /* */ 00094 /* func_interface :: A table of `emitters', i.e., function pointers */ 00095 /* called during decomposition to indicate path */ 00096 /* operations. */ 00097 /* */ 00098 /* <InOut> */ 00099 /* user :: A typeless pointer which is passed to each */ 00100 /* emitter during the decomposition. It can be */ 00101 /* used to store the state during the */ 00102 /* decomposition. */ 00103 /* */ 00104 /* <Return> */ 00105 /* FreeType error code. 0~means success. */ 00106 /* */ 00107 FT_EXPORT( FT_Error ) 00108 FT_Outline_Decompose( FT_Outline* outline, 00109 const FT_Outline_Funcs* func_interface, 00110 void* user ); 00111 00112 00113 /*************************************************************************/ 00114 /* */ 00115 /* <Function> */ 00116 /* FT_Outline_New */ 00117 /* */ 00118 /* <Description> */ 00119 /* Create a new outline of a given size. */ 00120 /* */ 00121 /* <Input> */ 00122 /* library :: A handle to the library object from where the */ 00123 /* outline is allocated. Note however that the new */ 00124 /* outline will *not* necessarily be *freed*, when */ 00125 /* destroying the library, by @FT_Done_FreeType. */ 00126 /* */ 00127 /* numPoints :: The maximal number of points within the outline. */ 00128 /* */ 00129 /* numContours :: The maximal number of contours within the outline. */ 00130 /* */ 00131 /* <Output> */ 00132 /* anoutline :: A handle to the new outline. */ 00133 /* */ 00134 /* <Return> */ 00135 /* FreeType error code. 0~means success. */ 00136 /* */ 00137 /* <Note> */ 00138 /* The reason why this function takes a `library' parameter is simply */ 00139 /* to use the library's memory allocator. */ 00140 /* */ 00141 FT_EXPORT( FT_Error ) 00142 FT_Outline_New( FT_Library library, 00143 FT_UInt numPoints, 00144 FT_Int numContours, 00145 FT_Outline *anoutline ); 00146 00147 00148 FT_EXPORT( FT_Error ) 00149 FT_Outline_New_Internal( FT_Memory memory, 00150 FT_UInt numPoints, 00151 FT_Int numContours, 00152 FT_Outline *anoutline ); 00153 00154 00155 /*************************************************************************/ 00156 /* */ 00157 /* <Function> */ 00158 /* FT_Outline_Done */ 00159 /* */ 00160 /* <Description> */ 00161 /* Destroy an outline created with @FT_Outline_New. */ 00162 /* */ 00163 /* <Input> */ 00164 /* library :: A handle of the library object used to allocate the */ 00165 /* outline. */ 00166 /* */ 00167 /* outline :: A pointer to the outline object to be discarded. */ 00168 /* */ 00169 /* <Return> */ 00170 /* FreeType error code. 0~means success. */ 00171 /* */ 00172 /* <Note> */ 00173 /* If the outline's `owner' field is not set, only the outline */ 00174 /* descriptor will be released. */ 00175 /* */ 00176 /* The reason why this function takes an `library' parameter is */ 00177 /* simply to use ft_mem_free(). */ 00178 /* */ 00179 FT_EXPORT( FT_Error ) 00180 FT_Outline_Done( FT_Library library, 00181 FT_Outline* outline ); 00182 00183 00184 FT_EXPORT( FT_Error ) 00185 FT_Outline_Done_Internal( FT_Memory memory, 00186 FT_Outline* outline ); 00187 00188 00189 /*************************************************************************/ 00190 /* */ 00191 /* <Function> */ 00192 /* FT_Outline_Check */ 00193 /* */ 00194 /* <Description> */ 00195 /* Check the contents of an outline descriptor. */ 00196 /* */ 00197 /* <Input> */ 00198 /* outline :: A handle to a source outline. */ 00199 /* */ 00200 /* <Return> */ 00201 /* FreeType error code. 0~means success. */ 00202 /* */ 00203 FT_EXPORT( FT_Error ) 00204 FT_Outline_Check( FT_Outline* outline ); 00205 00206 00207 /*************************************************************************/ 00208 /* */ 00209 /* <Function> */ 00210 /* FT_Outline_Get_CBox */ 00211 /* */ 00212 /* <Description> */ 00213 /* Return an outline's `control box'. The control box encloses all */ 00214 /* the outline's points, including Bézier control points. Though it */ 00215 /* coincides with the exact bounding box for most glyphs, it can be */ 00216 /* slightly larger in some situations (like when rotating an outline */ 00217 /* which contains Bézier outside arcs). */ 00218 /* */ 00219 /* Computing the control box is very fast, while getting the bounding */ 00220 /* box can take much more time as it needs to walk over all segments */ 00221 /* and arcs in the outline. To get the latter, you can use the */ 00222 /* `ftbbox' component which is dedicated to this single task. */ 00223 /* */ 00224 /* <Input> */ 00225 /* outline :: A pointer to the source outline descriptor. */ 00226 /* */ 00227 /* <Output> */ 00228 /* acbox :: The outline's control box. */ 00229 /* */ 00230 FT_EXPORT( void ) 00231 FT_Outline_Get_CBox( const FT_Outline* outline, 00232 FT_BBox *acbox ); 00233 00234 00235 /*************************************************************************/ 00236 /* */ 00237 /* <Function> */ 00238 /* FT_Outline_Translate */ 00239 /* */ 00240 /* <Description> */ 00241 /* Apply a simple translation to the points of an outline. */ 00242 /* */ 00243 /* <InOut> */ 00244 /* outline :: A pointer to the target outline descriptor. */ 00245 /* */ 00246 /* <Input> */ 00247 /* xOffset :: The horizontal offset. */ 00248 /* */ 00249 /* yOffset :: The vertical offset. */ 00250 /* */ 00251 FT_EXPORT( void ) 00252 FT_Outline_Translate( const FT_Outline* outline, 00253 FT_Pos xOffset, 00254 FT_Pos yOffset ); 00255 00256 00257 /*************************************************************************/ 00258 /* */ 00259 /* <Function> */ 00260 /* FT_Outline_Copy */ 00261 /* */ 00262 /* <Description> */ 00263 /* Copy an outline into another one. Both objects must have the */ 00264 /* same sizes (number of points & number of contours) when this */ 00265 /* function is called. */ 00266 /* */ 00267 /* <Input> */ 00268 /* source :: A handle to the source outline. */ 00269 /* */ 00270 /* <Output> */ 00271 /* target :: A handle to the target outline. */ 00272 /* */ 00273 /* <Return> */ 00274 /* FreeType error code. 0~means success. */ 00275 /* */ 00276 FT_EXPORT( FT_Error ) 00277 FT_Outline_Copy( const FT_Outline* source, 00278 FT_Outline *target ); 00279 00280 00281 /*************************************************************************/ 00282 /* */ 00283 /* <Function> */ 00284 /* FT_Outline_Transform */ 00285 /* */ 00286 /* <Description> */ 00287 /* Apply a simple 2x2 matrix to all of an outline's points. Useful */ 00288 /* for applying rotations, slanting, flipping, etc. */ 00289 /* */ 00290 /* <InOut> */ 00291 /* outline :: A pointer to the target outline descriptor. */ 00292 /* */ 00293 /* <Input> */ 00294 /* matrix :: A pointer to the transformation matrix. */ 00295 /* */ 00296 /* <Note> */ 00297 /* You can use @FT_Outline_Translate if you need to translate the */ 00298 /* outline's points. */ 00299 /* */ 00300 FT_EXPORT( void ) 00301 FT_Outline_Transform( const FT_Outline* outline, 00302 const FT_Matrix* matrix ); 00303 00304 00305 /*************************************************************************/ 00306 /* */ 00307 /* <Function> */ 00308 /* FT_Outline_Embolden */ 00309 /* */ 00310 /* <Description> */ 00311 /* Embolden an outline. The new outline will be at most 4~times */ 00312 /* `strength' pixels wider and higher. You may think of the left and */ 00313 /* bottom borders as unchanged. */ 00314 /* */ 00315 /* Negative `strength' values to reduce the outline thickness are */ 00316 /* possible also. */ 00317 /* */ 00318 /* <InOut> */ 00319 /* outline :: A handle to the target outline. */ 00320 /* */ 00321 /* <Input> */ 00322 /* strength :: How strong the glyph is emboldened. Expressed in */ 00323 /* 26.6 pixel format. */ 00324 /* */ 00325 /* <Return> */ 00326 /* FreeType error code. 0~means success. */ 00327 /* */ 00328 /* <Note> */ 00329 /* The used algorithm to increase or decrease the thickness of the */ 00330 /* glyph doesn't change the number of points; this means that certain */ 00331 /* situations like acute angles or intersections are sometimes */ 00332 /* handled incorrectly. */ 00333 /* */ 00334 /* If you need `better' metrics values you should call */ 00335 /* @FT_Outline_Get_CBox ot @FT_Outline_Get_BBox. */ 00336 /* */ 00337 /* Example call: */ 00338 /* */ 00339 /* { */ 00340 /* FT_Load_Glyph( face, index, FT_LOAD_DEFAULT ); */ 00341 /* if ( face->slot->format == FT_GLYPH_FORMAT_OUTLINE ) */ 00342 /* FT_Outline_Embolden( &face->slot->outline, strength ); */ 00343 /* } */ 00344 /* */ 00345 FT_EXPORT( FT_Error ) 00346 FT_Outline_Embolden( FT_Outline* outline, 00347 FT_Pos strength ); 00348 00349 00350 /*************************************************************************/ 00351 /* */ 00352 /* <Function> */ 00353 /* FT_Outline_Reverse */ 00354 /* */ 00355 /* <Description> */ 00356 /* Reverse the drawing direction of an outline. This is used to */ 00357 /* ensure consistent fill conventions for mirrored glyphs. */ 00358 /* */ 00359 /* <InOut> */ 00360 /* outline :: A pointer to the target outline descriptor. */ 00361 /* */ 00362 /* <Note> */ 00363 /* This function toggles the bit flag @FT_OUTLINE_REVERSE_FILL in */ 00364 /* the outline's `flags' field. */ 00365 /* */ 00366 /* It shouldn't be used by a normal client application, unless it */ 00367 /* knows what it is doing. */ 00368 /* */ 00369 FT_EXPORT( void ) 00370 FT_Outline_Reverse( FT_Outline* outline ); 00371 00372 00373 /*************************************************************************/ 00374 /* */ 00375 /* <Function> */ 00376 /* FT_Outline_Get_Bitmap */ 00377 /* */ 00378 /* <Description> */ 00379 /* Render an outline within a bitmap. The outline's image is simply */ 00380 /* OR-ed to the target bitmap. */ 00381 /* */ 00382 /* <Input> */ 00383 /* library :: A handle to a FreeType library object. */ 00384 /* */ 00385 /* outline :: A pointer to the source outline descriptor. */ 00386 /* */ 00387 /* <InOut> */ 00388 /* abitmap :: A pointer to the target bitmap descriptor. */ 00389 /* */ 00390 /* <Return> */ 00391 /* FreeType error code. 0~means success. */ 00392 /* */ 00393 /* <Note> */ 00394 /* This function does NOT CREATE the bitmap, it only renders an */ 00395 /* outline image within the one you pass to it! Consequently, the */ 00396 /* various fields in `abitmap' should be set accordingly. */ 00397 /* */ 00398 /* It will use the raster corresponding to the default glyph format. */ 00399 /* */ 00400 /* The value of the `num_grays' field in `abitmap' is ignored. If */ 00401 /* you select the gray-level rasterizer, and you want less than 256 */ 00402 /* gray levels, you have to use @FT_Outline_Render directly. */ 00403 /* */ 00404 FT_EXPORT( FT_Error ) 00405 FT_Outline_Get_Bitmap( FT_Library library, 00406 FT_Outline* outline, 00407 const FT_Bitmap *abitmap ); 00408 00409 00410 /*************************************************************************/ 00411 /* */ 00412 /* <Function> */ 00413 /* FT_Outline_Render */ 00414 /* */ 00415 /* <Description> */ 00416 /* Render an outline within a bitmap using the current scan-convert. */ 00417 /* This function uses an @FT_Raster_Params structure as an argument, */ 00418 /* allowing advanced features like direct composition, translucency, */ 00419 /* etc. */ 00420 /* */ 00421 /* <Input> */ 00422 /* library :: A handle to a FreeType library object. */ 00423 /* */ 00424 /* outline :: A pointer to the source outline descriptor. */ 00425 /* */ 00426 /* <InOut> */ 00427 /* params :: A pointer to an @FT_Raster_Params structure used to */ 00428 /* describe the rendering operation. */ 00429 /* */ 00430 /* <Return> */ 00431 /* FreeType error code. 0~means success. */ 00432 /* */ 00433 /* <Note> */ 00434 /* You should know what you are doing and how @FT_Raster_Params works */ 00435 /* to use this function. */ 00436 /* */ 00437 /* The field `params.source' will be set to `outline' before the scan */ 00438 /* converter is called, which means that the value you give to it is */ 00439 /* actually ignored. */ 00440 /* */ 00441 /* The gray-level rasterizer always uses 256 gray levels. If you */ 00442 /* want less gray levels, you have to provide your own span callback. */ 00443 /* See the @FT_RASTER_FLAG_DIRECT value of the `flags' field in the */ 00444 /* @FT_Raster_Params structure for more details. */ 00445 /* */ 00446 FT_EXPORT( FT_Error ) 00447 FT_Outline_Render( FT_Library library, 00448 FT_Outline* outline, 00449 FT_Raster_Params* params ); 00450 00451 00452 /************************************************************************** 00453 * 00454 * @enum: 00455 * FT_Orientation 00456 * 00457 * @description: 00458 * A list of values used to describe an outline's contour orientation. 00459 * 00460 * The TrueType and PostScript specifications use different conventions 00461 * to determine whether outline contours should be filled or unfilled. 00462 * 00463 * @values: 00464 * FT_ORIENTATION_TRUETYPE :: 00465 * According to the TrueType specification, clockwise contours must 00466 * be filled, and counter-clockwise ones must be unfilled. 00467 * 00468 * FT_ORIENTATION_POSTSCRIPT :: 00469 * According to the PostScript specification, counter-clockwise contours 00470 * must be filled, and clockwise ones must be unfilled. 00471 * 00472 * FT_ORIENTATION_FILL_RIGHT :: 00473 * This is identical to @FT_ORIENTATION_TRUETYPE, but is used to 00474 * remember that in TrueType, everything that is to the right of 00475 * the drawing direction of a contour must be filled. 00476 * 00477 * FT_ORIENTATION_FILL_LEFT :: 00478 * This is identical to @FT_ORIENTATION_POSTSCRIPT, but is used to 00479 * remember that in PostScript, everything that is to the left of 00480 * the drawing direction of a contour must be filled. 00481 * 00482 * FT_ORIENTATION_NONE :: 00483 * The orientation cannot be determined. That is, different parts of 00484 * the glyph have different orientation. 00485 * 00486 */ 00487 typedef enum FT_Orientation_ 00488 { 00489 FT_ORIENTATION_TRUETYPE = 0, 00490 FT_ORIENTATION_POSTSCRIPT = 1, 00491 FT_ORIENTATION_FILL_RIGHT = FT_ORIENTATION_TRUETYPE, 00492 FT_ORIENTATION_FILL_LEFT = FT_ORIENTATION_POSTSCRIPT, 00493 FT_ORIENTATION_NONE 00494 00495 } FT_Orientation; 00496 00497 00498 /************************************************************************** 00499 * 00500 * @function: 00501 * FT_Outline_Get_Orientation 00502 * 00503 * @description: 00504 * This function analyzes a glyph outline and tries to compute its 00505 * fill orientation (see @FT_Orientation). This is done by computing 00506 * the direction of each global horizontal and/or vertical extrema 00507 * within the outline. 00508 * 00509 * Note that this will return @FT_ORIENTATION_TRUETYPE for empty 00510 * outlines. 00511 * 00512 * @input: 00513 * outline :: 00514 * A handle to the source outline. 00515 * 00516 * @return: 00517 * The orientation. 00518 * 00519 */ 00520 FT_EXPORT( FT_Orientation ) 00521 FT_Outline_Get_Orientation( FT_Outline* outline ); 00522 00523 00524 /* */ 00525 00526 00527 FT_END_HEADER 00528 00529 #endif /* __FTOUTLN_H__ */ 00530 00531 00532 /* END */ 00533 00534 00535 /* Local Variables: */ 00536 /* coding: utf-8 */ 00537 /* End: */
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