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FreeType on OpenGL ES (iPhone)

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24 Nov 2010CPOL4 min read 86.9K   3K   27  
Faster, smarter and better looking fonts rendered with OpenGL ES
/***************************************************************************/
/*                                                                         */
/*  ftpfr.h                                                                */
/*                                                                         */
/*    FreeType API for accessing PFR-specific data (specification only).   */
/*                                                                         */
/*  Copyright 2002, 2003, 2004, 2006, 2008, 2009 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 sub-pixels.  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 sub-pixels.
  */
  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 sub-pixels (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 */

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This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer Astronautz
Spain Spain
After working in the software industry for many years, I've started my own games company that specialises in strategy games for mobile platforms.

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