ref: 9a7951d99b056957ba002a4e20ba7057d64faff5
dir: /include/freetype/ftcffdrv.h/
/***************************************************************************/ /* */ /* ftcffdrv.h */ /* */ /* FreeType API for controlling the CFF driver (specification only). */ /* */ /* Copyright 2013 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 __FTCFFDRV_H__ #define __FTCFFDRV_H__ #include <ft2build.h> #include FT_FREETYPE_H #ifdef FREETYPE_H #error "freetype.h of FreeType 1 has been loaded!" #error "Please fix the directory search order for header files" #error "so that freetype.h of FreeType 2 is found first." #endif FT_BEGIN_HEADER /************************************************************************** * * @section: * cff_driver * * @title: * The CFF driver * * @abstract: * Controlling the CFF driver module. * * @description: * While FreeType's CFF driver doesn't expose API functions by itself, * it is possible to control its behaviour with @FT_Property_Set and * @FT_Property_Get. The following lists the available properties * together with the necessary macros and structures. * * The CFF driver's module name is `cff'. * */ /************************************************************************** * * @property: * hinting-engine * * @description: * Thanks to Adobe, which contributed a new hinting (and parsing) * engine, an application can select between `freetype' and `adobe' if * compiled with CFF_CONFIG_OPTION_OLD_ENGINE. If this configuration * macro isn't defined, `hinting-engine' does nothing. * * The default engine is `freetype' if CFF_CONFIG_OPTION_OLD_ENGINE is * defined, and `adobe' otherwise. * * The following example code demonstrates how to select Adobe's hinting * engine (omitting the error handling). * * { * FT_Library library; * FT_UInt hinting_engine = FT_CFF_HINTING_ADOBE; * * * FT_Init_FreeType( &library ); * * FT_Property_Set( library, "cff", * "hinting-engine", &hinting_engine ); * } * * @note: * This property can be used with @FT_Property_Get also. * */ /************************************************************************** * * @enum: * FT_CFF_HINTING_XXX * * @description: * A list of constants used for the @hinting-engine property to select * the hinting engine for CFF fonts. * * @values: * FT_CFF_HINTING_FREETYPE :: * Use the old FreeType hinting engine. * * FT_CFF_HINTING_ADOBE :: * Use the hinting engine contributed by Adobe. * */ #define FT_CFF_HINTING_FREETYPE 0 #define FT_CFF_HINTING_ADOBE 1 /************************************************************************** * * @property: * no-stem-darkening * * @description: * By default, the Adobe CFF engine darkens stems at smaller sizes, * regardless of hinting, to enhance contrast. Setting this property, * stem darkening gets switched off. * * Note that stem darkening is never applied if @FT_LOAD_NO_SCALE is set. * * { * FT_Library library; * FT_Bool no_stem_darkening = TRUE; * * * FT_Init_FreeType( &library ); * * FT_Property_Set( library, "cff", * "no-stem-darkening", &no_stem_darkening ); * } * * @note: * This property can be used with @FT_Property_Get also. * */ /************************************************************************** * * @property: * darkening-parameters * * @description: * By default, the Adobe CFF engine darkens stems as follows (if the * `no-stem-darkening' property isn't set): * * { * stem width <= 0.5px: darkening amount = 0.4px * stem width = 1px: darkening amount = 0.275px * stem width = 1.667px: darkening amount = 0.275px * stem width >= 2.333px: darkening amount = 0px * } * * and piecewise linear in-between. Using the `darkening-parameters' * property, these four control points can be changed, as the following * example demonstrates. * * { * FT_Library library; * FT_Int darken_params[8] = { 500, 300, // x1, y1 * 1000, 200, // x2, y2 * 1500, 100, // x3, y3 * 2000, 0 }; // x4, y4 * * * FT_Init_FreeType( &library ); * * FT_Property_Set( library, "cff", * "darkening-parameters", darken_params ); * } * * The x~values give the stem width, and the y~values the darkening * amount. The unit is 1000th of pixels. All coordinate values must be * positive; the x~values must be monotonically increasing, and the * y~values smaller than or equal to 500 (corresponding to half a * pixel). * * @note: * This property can be used with @FT_Property_Get also. * */ /* */ FT_END_HEADER #endif /* __FTCFFDRV_H__ */ /* END */