freetype2/include/freetype/ftparams.h

205 lines
5.5 KiB
C

/****************************************************************************
*
* ftparams.h
*
* FreeType API for possible FT_Parameter tags (specification only).
*
* Copyright 2017-2018 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 FTPARAMS_H_
#define FTPARAMS_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:
* parameter_tags
*
* @title:
* Parameter Tags
*
* @abstract:
* Macros for driver property and font loading parameter tags.
*
* @description:
* This section contains macros for the @FT_Parameter structure that are
* used with various functions to activate some special functionality or
* different behaviour of various components of FreeType.
*
*/
/**************************************************************************
*
* @enum:
* FT_PARAM_TAG_IGNORE_TYPOGRAPHIC_FAMILY
*
* @description:
* A tag for @FT_Parameter to make @FT_Open_Face ignore typographic
* family names in the `name` table (introduced in OpenType version 1.4).
* Use this for backward compatibility with legacy systems that have a
* four-faces-per-family restriction.
*
* @since:
* 2.8
*
*/
#define FT_PARAM_TAG_IGNORE_TYPOGRAPHIC_FAMILY \
FT_MAKE_TAG( 'i', 'g', 'p', 'f' )
/* this constant is deprecated */
#define FT_PARAM_TAG_IGNORE_PREFERRED_FAMILY \
FT_PARAM_TAG_IGNORE_TYPOGRAPHIC_FAMILY
/**************************************************************************
*
* @enum:
* FT_PARAM_TAG_IGNORE_TYPOGRAPHIC_SUBFAMILY
*
* @description:
* A tag for @FT_Parameter to make @FT_Open_Face ignore typographic
* subfamily names in the `name` table (introduced in OpenType version
* 1.4). Use this for backward compatibility with legacy systems that
* have a four-faces-per-family restriction.
*
* @since:
* 2.8
*
*/
#define FT_PARAM_TAG_IGNORE_TYPOGRAPHIC_SUBFAMILY \
FT_MAKE_TAG( 'i', 'g', 'p', 's' )
/* this constant is deprecated */
#define FT_PARAM_TAG_IGNORE_PREFERRED_SUBFAMILY \
FT_PARAM_TAG_IGNORE_TYPOGRAPHIC_SUBFAMILY
/**************************************************************************
*
* @enum:
* FT_PARAM_TAG_INCREMENTAL
*
* @description:
* An @FT_Parameter tag to be used with @FT_Open_Face to indicate
* incremental glyph loading.
*
*/
#define FT_PARAM_TAG_INCREMENTAL \
FT_MAKE_TAG( 'i', 'n', 'c', 'r' )
/**************************************************************************
*
* @enum:
* FT_PARAM_TAG_LCD_FILTER_WEIGHTS
*
* @description:
* An @FT_Parameter tag to be used with @FT_Face_Properties. The
* corresponding argument specifies the five LCD filter weights for a
* given face (if using @FT_LOAD_TARGET_LCD, for example), overriding the
* global default values or the values set up with
* @FT_Library_SetLcdFilterWeights.
*
* @since:
* 2.8
*
*/
#define FT_PARAM_TAG_LCD_FILTER_WEIGHTS \
FT_MAKE_TAG( 'l', 'c', 'd', 'f' )
/**************************************************************************
*
* @enum:
* FT_PARAM_TAG_RANDOM_SEED
*
* @description:
* An @FT_Parameter tag to be used with @FT_Face_Properties. The
* corresponding 32bit signed integer argument overrides the font
* driver's random seed value with a face-specific one; see @random-seed.
*
* @since:
* 2.8
*
*/
#define FT_PARAM_TAG_RANDOM_SEED \
FT_MAKE_TAG( 's', 'e', 'e', 'd' )
/**************************************************************************
*
* @enum:
* FT_PARAM_TAG_STEM_DARKENING
*
* @description:
* An @FT_Parameter tag to be used with @FT_Face_Properties. The
* corresponding Boolean argument specifies whether to apply stem
* darkening, overriding the global default values or the values set up
* with @FT_Property_Set (see @no-stem-darkening).
*
* This is a passive setting that only takes effect if the font driver or
* autohinter honors it, which the CFF, Type~1, and CID drivers always
* do, but the autohinter only in 'light' hinting mode (as of version
* 2.9).
*
* @since:
* 2.8
*
*/
#define FT_PARAM_TAG_STEM_DARKENING \
FT_MAKE_TAG( 'd', 'a', 'r', 'k' )
/**************************************************************************
*
* @enum:
* FT_PARAM_TAG_UNPATENTED_HINTING
*
* @description:
* Deprecated, no effect.
*
* Previously: A constant used as the tag of an @FT_Parameter structure
* to indicate that unpatented methods only should be used by the
* TrueType bytecode interpreter for a typeface opened by @FT_Open_Face.
*
*/
#define FT_PARAM_TAG_UNPATENTED_HINTING \
FT_MAKE_TAG( 'u', 'n', 'p', 'a' )
/* */
FT_END_HEADER
#endif /* FTPARAMS_H_ */
/* END */