ahangles.h

Trolltech公司发布的基于C++图形开发环境

/***************************************************************************/
/*                                                                         */
/*  ahangles.h                                                             */
/*                                                                         */
/*    A routine used to compute vector angles with limited accuracy        */
/*    and very high speed (specification).                                 */
/*                                                                         */
/*  Copyright 2000 Catharon Productions Inc.                               */
/*  Author: David Turner                                                   */
/*                                                                         */
/*  This file is part of the Catharon Typography Project and shall only    */
/*  be used, modified, and distributed under the terms of the Catharon     */
/*  Open Source License that should come with this file under the name     */
/*  `CatharonLicense.txt'.  By continuing to use, modify, or distribute    */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/*  Note that this license is compatible with the FreeType license.        */
/*                                                                         */
/***************************************************************************/


#ifndef AHANGLES_H
#define AHANGLES_H


#ifdef FT_FLAT_COMPILE

#include "ahtypes.h"

#else

#include <autohint/ahtypes.h>

#endif


#include <freetype/internal/ftobjs.h>


#ifdef __cplusplus
  extern "C" {
#endif


  /* PI expressed in ah_angles -- we don't really need an important */
  /* precision, so 256 should be enough                             */
#define AH_PI       256
#define AH_2PI      ( AH_PI * 2 )
#define AH_HALF_PI  ( AH_PI / 2 )
#define AH_2PIMASK  ( AH_2PI - 1 )

  /* the number of bits used to express an arc tangent; */
  /* see the structure of the lookup table              */
#define AH_ATAN_BITS  8

  extern
  const AH_Angle  ah_arctan[1L << AH_ATAN_BITS];


  FT_LOCAL
  AH_Angle  ah_angle( FT_Vector*  v );


#ifdef __cplusplus
  }
#endif


#endif /* AHANGLES_H */


/* END */