123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128 |
- /***************************************************************************/
- /* */
- /* ftgasp.h */
- /* */
- /* Access of TrueType's `gasp' table (specification). */
- /* */
- /* Copyright 2007, 2008, 2011 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 */
|