freetype2/freetype/ftsynth.h

0001 /****************************************************************************
0002  *
0003  * ftsynth.h
0004  *
0005  *   FreeType synthesizing code for emboldening and slanting
0006  *   (specification).
0007  *
0008  * Copyright (C) 2000-2023 by
0009  * David Turner, Robert Wilhelm, and Werner Lemberg.
0010  *
0011  * This file is part of the FreeType project, and may only be used,
0012  * modified, and distributed under the terms of the FreeType project
0013  * license, LICENSE.TXT.  By continuing to use, modify, or distribute
0014  * this file you indicate that you have read the license and
0015  * understand and accept it fully.
0016  *
0017  */
0018
0019
0020   /*************************************************************************/
0021   /*************************************************************************/
0022   /*************************************************************************/
0023   /*************************************************************************/
0024   /*************************************************************************/
0025   /*********                                                       *********/
0026   /*********        WARNING, THIS IS ALPHA CODE!  THIS API         *********/
0027   /*********    IS DUE TO CHANGE UNTIL STRICTLY NOTIFIED BY THE    *********/
0028   /*********            FREETYPE DEVELOPMENT TEAM                  *********/
0029   /*********                                                       *********/
0030   /*************************************************************************/
0031   /*************************************************************************/
0032   /*************************************************************************/
0033   /*************************************************************************/
0034   /*************************************************************************/
0035
0036
0037   /* Main reason for not lifting the functions in this module to a  */
0038   /* 'standard' API is that the used parameters for emboldening and */
0039   /* slanting are not configurable.  Consider the functions as a    */
0040   /* code resource that should be copied into the application and   */
0041   /* adapted to the particular needs.                               */
0042
0043
0044 #ifndef FTSYNTH_H_
0045 #define FTSYNTH_H_
0046
0047
0048 #include <freetype/freetype.h>
0049
0050 #ifdef FREETYPE_H
0051 #error "freetype.h of FreeType 1 has been loaded!"
0052 #error "Please fix the directory search order for header files"
0053 #error "so that freetype.h of FreeType 2 is found first."
0054 #endif
0055
0056
0057 FT_BEGIN_HEADER
0058
0059   /* Embolden a glyph by a 'reasonable' value (which is highly a matter of */
0060   /* taste).  This function is actually a convenience function, providing  */
0061   /* a wrapper for @FT_Outline_Embolden and @FT_Bitmap_Embolden.           */
0062   /*                                                                       */
0063   /* For emboldened outlines the height, width, and advance metrics are    */
0064   /* increased by the strength of the emboldening -- this even affects     */
0065   /* mono-width fonts!                                                     */
0066   /*                                                                       */
0067   /* You can also call @FT_Outline_Get_CBox to get precise values.         */
0068   FT_EXPORT( void )
0069   FT_GlyphSlot_Embolden( FT_GlyphSlot  slot );
0070
0071   /* Precisely adjust the glyph weight either horizontally or vertically.  */
0072   /* The `xdelta` and `ydelta` values are fractions of the face Em size    */
0073   /* (in fixed-point format).  Considering that a regular face would have  */
0074   /* stem widths on the order of 0.1 Em, a delta of 0.05 (0x0CCC) should   */
0075   /* be very noticeable.  To increase or decrease the weight, use positive */
0076   /* or negative values, respectively.                                     */
0077   FT_EXPORT( void )
0078   FT_GlyphSlot_AdjustWeight( FT_GlyphSlot  slot,
0079                              FT_Fixed      xdelta,
0080                              FT_Fixed      ydelta );
0081
0082
0083   /* Slant an outline glyph to the right by about 12 degrees.              */
0084   FT_EXPORT( void )
0085   FT_GlyphSlot_Oblique( FT_GlyphSlot  slot );
0086
0087   /* Slant an outline glyph by a given sine of an angle.  You can apply    */
0088   /* slant along either x- or y-axis by choosing a corresponding non-zero  */
0089   /* argument.  If both slants are non-zero, some affine transformation    */
0090   /* will result.                                                          */
0091   FT_EXPORT( void )
0092   FT_GlyphSlot_Slant( FT_GlyphSlot  slot,
0093                       FT_Fixed      xslant,
0094                       FT_Fixed      yslant );
0095
0096   /* */
0097
0098
0099 FT_END_HEADER
0100
0101 #endif /* FTSYNTH_H_ */
0102
0103
0104 /* END */