freetype2/include/freetype/ftpfr.h

181 lines
4.8 KiB
C

/****************************************************************************
*
* ftpfr.h
*
* FreeType API for accessing PFR-specific data (specification only).
*
* Copyright (C) 2002-2019 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 FTPFR_H_
#define FTPFR_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:
* pfr_fonts
*
* @title:
* PFR Fonts
*
* @abstract:
* PFR/TrueDoc-specific API.
*
* @description:
* This section contains the declaration of PFR-specific functions.
*
*/
/**************************************************************************
*
* @function:
* FT_Get_PFR_Metrics
*
* @description:
* Return the outline and metrics resolutions of a given PFR face.
*
* @input:
* face ::
* Handle to the input face. It can be a non-PFR face.
*
* @output:
* aoutline_resolution ::
* Outline resolution. This is equivalent to `face->units_per_EM` for
* non-PFR fonts. Optional (parameter can be `NULL`).
*
* ametrics_resolution ::
* Metrics resolution. This is equivalent to `outline_resolution` for
* non-PFR fonts. Optional (parameter can be `NULL`).
*
* ametrics_x_scale ::
* A 16.16 fixed-point number used to scale distance expressed in
* metrics units to device subpixels. This is equivalent to
* `face->size->x_scale`, but for metrics only. Optional (parameter
* can be `NULL`).
*
* ametrics_y_scale ::
* Same as `ametrics_x_scale` but for the vertical direction.
* optional (parameter can be `NULL`).
*
* @return:
* FreeType error code. 0~means success.
*
* @note:
* If the input face is not a PFR, this function will return an error.
* However, in all cases, it will return valid values.
*/
FT_EXPORT( FT_Error )
FT_Get_PFR_Metrics( FT_Face face,
FT_UInt *aoutline_resolution,
FT_UInt *ametrics_resolution,
FT_Fixed *ametrics_x_scale,
FT_Fixed *ametrics_y_scale );
/**************************************************************************
*
* @function:
* FT_Get_PFR_Kerning
*
* @description:
* Return the kerning pair corresponding to two glyphs in a PFR face.
* The distance is expressed in metrics units, unlike the result of
* @FT_Get_Kerning.
*
* @input:
* face ::
* A handle to the input face.
*
* left ::
* Index of the left glyph.
*
* right ::
* Index of the right glyph.
*
* @output:
* avector ::
* A kerning vector.
*
* @return:
* FreeType error code. 0~means success.
*
* @note:
* This function always return distances in original PFR metrics units.
* This is unlike @FT_Get_Kerning with the @FT_KERNING_UNSCALED mode,
* which always returns distances converted to outline units.
*
* You can use the value of the `x_scale` and `y_scale` parameters
* returned by @FT_Get_PFR_Metrics to scale these to device subpixels.
*/
FT_EXPORT( FT_Error )
FT_Get_PFR_Kerning( FT_Face face,
FT_UInt left,
FT_UInt right,
FT_Vector *avector );
/**************************************************************************
*
* @function:
* FT_Get_PFR_Advance
*
* @description:
* Return a given glyph advance, expressed in original metrics units,
* from a PFR font.
*
* @input:
* face ::
* A handle to the input face.
*
* gindex ::
* The glyph index.
*
* @output:
* aadvance ::
* The glyph advance in metrics units.
*
* @return:
* FreeType error code. 0~means success.
*
* @note:
* You can use the `x_scale` or `y_scale` results of @FT_Get_PFR_Metrics
* to convert the advance to device subpixels (i.e., 1/64th of pixels).
*/
FT_EXPORT( FT_Error )
FT_Get_PFR_Advance( FT_Face face,
FT_UInt gindex,
FT_Pos *aadvance );
/* */
FT_END_HEADER
#endif /* FTPFR_H_ */
/* END */