fttrigon.h

一个类似windows

/***************************************************************************/
/*                                                                         */
/*  fttrigon.h                                                             */
/*                                                                         */
/*    FreeType trigonometric functions (specification).                    */
/*                                                                         */
/*  Copyright 2001, 2003 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 __FTTRIGON_H__
#define __FTTRIGON_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:                                                             */
  /*   computations                                                        */
  /*                                                                       */
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* @type:                                                                */
  /*    FT_Angle                                                           */
  /*                                                                       */
  /* @description:                                                         */
  /*    This type is used to model angle values in FreeType.  Note that    */
  /*    the angle is a 16.16 fixed float value expressed in degrees.       */
  /*                                                                       */
  typedef FT_Fixed  FT_Angle;


  /*************************************************************************/
  /*                                                                       */
  /* @macro:                                                               */
  /*    FT_ANGLE_PI                                                        */
  /*                                                                       */
  /* @description:                                                         */
  /*   The angle pi expressed in @FT_Angle units.                          */
  /*                                                                       */
#define FT_ANGLE_PI  ( 180L << 16 )


  /*************************************************************************/
  /*                                                                       */
  /* @macro:                                                               */
  /*    FT_ANGLE_2PI                                                       */
  /*                                                                       */
  /* @description:                                                         */
  /*    The angle 2*pi expressed in @FT_Angle units.                       */
  /*                                                                       */
#define FT_ANGLE_2PI  ( FT_ANGLE_PI * 2 )


  /*************************************************************************/
  /*                                                                       */
  /* @macro:                                                               */
  /*    FT_ANGLE_PI2                                                       */
  /*                                                                       */
  /* @description:                                                         */
  /*    The angle pi/2 expressed in @FT_Angle units.                       */
  /*                                                                       */
#define FT_ANGLE_PI2  ( FT_ANGLE_PI / 2 )


  /*************************************************************************/
  /*                                                                       */
  /* @macro:                                                               */
  /*    FT_ANGLE_PI4                                                       */
  /*                                                                       */
  /* @description:                                                         */
  /*    The angle pi/4 expressed in @FT_Angle units.                       */
  /*                                                                       */
#define FT_ANGLE_PI4  ( FT_ANGLE_PI / 4 )


  /*************************************************************************/
  /*                                                                       */
  /* @function:                                                            */
  /*    FT_Sin                                                             */
  /*                                                                       */
  /* @description:                                                         */
  /*    Return the sinus of a given angle in fixed point format.           */
  /*                                                                       */
  /* @input:                                                               */
  /*    angle :: The input angle.                                          */
  /*                                                                       */
  /* @return:                                                              */
  /*    The sinus value.                                                   */
  /*                                                                       */
  /* @note:                                                                */
  /*    If you need both the sinus and cosinus for a given angle, use the  */
  /*    function @FT_Vector_Unit.                                          */
  /*                                                                       */
  FT_EXPORT( FT_Fixed )
  FT_Sin( FT_Angle  angle );


  /*************************************************************************/
  /*                                                                       */
  /* @function:                                                            */
  /*    FT_Cos                                                             */
  /*                                                                       */
  /* @description:                                                         */
  /*    Return the cosinus of a given angle in fixed point format.         */
  /*                                                                       */
  /* @input:                                                               */
  /*    angle :: The input angle.                                          */
  /*                                                                       */
  /* @return:                                                              */
  /*    The cosinus value.                                                 */
  /*                                                                       */
  /* @note:                                                                */
  /*    If you need both the sinus and cosinus for a given angle, use the  */
  /*    function @FT_Vector_Unit.                                          */
  /*                                                                       */
  FT_EXPORT( FT_Fixed )
  FT_Cos( FT_Angle  angle );


  /*************************************************************************/
  /*                                                                       */
  /* @function:                                                            */
  /*    FT_Tan                                                             */
  /*                                                                       */
  /* @description:                                                         */
  /*    Return the tangent of a given angle in fixed point format.         */
  /*                                                                       */
  /* @input:                                                               */
  /*    angle :: The input angle.                                          */
  /*                                                                       */
  /* @return:                                                              */
  /*    The tangent value.                                                 */
  /*                                                                       */
  FT_EXPORT( FT_Fixed )
  FT_Tan( FT_Angle  angle );