diff options
Diffstat (limited to 'include/freetype/ftgasp.h')
| -rw-r--r-- | include/freetype/ftgasp.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/include/freetype/ftgasp.h b/include/freetype/ftgasp.h new file mode 100644 index 0000000..9a9b632 --- /dev/null +++ b/include/freetype/ftgasp.h @@ -0,0 +1,129 @@ +/***************************************************************************/ +/* */ +/* ftgasp.h */ +/* */ +/* Access of TrueType's `gasp' table (specification). */ +/* */ +/* Copyright 2007-2015 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 _FT_GASP_H_ +#define _FT_GASP_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 + + + /*************************************************************************** + * + * @section: + * gasp_table + * + * @title: + * Gasp Table + * + * @abstract: + * Retrieving TrueType `gasp' table entries. + * + * @description: + * The function @FT_Get_Gasp can be used to query a TrueType or OpenType + * font for specific entries in its `gasp' table, if any. This is + * mainly useful when implementing native TrueType hinting with the + * bytecode interpreter to duplicate the Windows text rendering results. + */ + + /************************************************************************* + * + * @enum: + * FT_GASP_XXX + * + * @description: + * A list of values and/or bit-flags returned by the @FT_Get_Gasp + * function. + * + * @values: + * FT_GASP_NO_TABLE :: + * This special value means that there is no GASP table in this face. + * It is up to the client to decide what to do. + * + * FT_GASP_DO_GRIDFIT :: + * Grid-fitting and hinting should be performed at the specified ppem. + * This *really* means TrueType bytecode interpretation. If this bit + * is not set, no hinting gets applied. + * + * FT_GASP_DO_GRAY :: + * Anti-aliased rendering should be performed at the specified ppem. + * If not set, do monochrome rendering. + * + * FT_GASP_SYMMETRIC_SMOOTHING :: + * If set, smoothing along multiple axes must be used with ClearType. + * + * FT_GASP_SYMMETRIC_GRIDFIT :: + * Grid-fitting must be used with ClearType's symmetric smoothing. + * + * @note: + * The bit-flags `FT_GASP_DO_GRIDFIT' and `FT_GASP_DO_GRAY' are to be + * used for standard font rasterization only. Independently of that, + * `FT_GASP_SYMMETRIC_SMOOTHING' and `FT_GASP_SYMMETRIC_GRIDFIT' are to + * be used if ClearType is enabled (and `FT_GASP_DO_GRIDFIT' and + * `FT_GASP_DO_GRAY' are consequently ignored). + * + * `ClearType' is Microsoft's implementation of LCD rendering, partly + * protected by patents. + * + * @since: + * 2.3.0 + */ +#define FT_GASP_NO_TABLE -1 +#define FT_GASP_DO_GRIDFIT 0x01 +#define FT_GASP_DO_GRAY 0x02 +#define FT_GASP_SYMMETRIC_SMOOTHING 0x08 +#define FT_GASP_SYMMETRIC_GRIDFIT 0x10 + + + /************************************************************************* + * + * @func: + * FT_Get_Gasp + * + * @description: + * Read the `gasp' table from a TrueType or OpenType font file and + * return the entry corresponding to a given character pixel size. + * + * @input: + * face :: The source face handle. + * ppem :: The vertical character pixel size. + * + * @return: + * Bit flags (see @FT_GASP_XXX), or @FT_GASP_NO_TABLE if there is no + * `gasp' table in the face. + * + * @since: + * 2.3.0 + */ + FT_EXPORT( FT_Int ) + FT_Get_Gasp( FT_Face face, + FT_UInt ppem ); + + /* */ + + +#endif /* _FT_GASP_H_ */ + + +/* END */ |