libraries/freetype-2.0.5/include/ahangles.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ahangles.h                                                             */
   4 /*                                                                         */
   5 /*    A routine used to compute vector angles with limited accuracy        */
   6 /*    and very high speed (specification).                                 */
   7 /*                                                                         */
   8 /*  Copyright 2000-2001 Catharon Productions Inc.                          */
   9 /*  Author: David Turner                                                   */
  10 /*                                                                         */
  11 /*  This file is part of the Catharon Typography Project and shall only    */
  12 /*  be used, modified, and distributed under the terms of the Catharon     */
  13 /*  Open Source License that should come with this file under the name     */
  14 /*  `CatharonLicense.txt'.  By continuing to use, modify, or distribute    */
  15 /*  this file you indicate that you have read the license and              */
  16 /*  understand and accept it fully.                                        */
  17 /*                                                                         */
  18 /*  Note that this license is compatible with the FreeType license.        */
  19 /*                                                                         */
  20 /***************************************************************************/
  21
  22
  23 #ifndef __AHANGLES_H__
  24 #define __AHANGLES_H__
  25
  26
  27 #include <ft2build.h>
  28 #include FT_INTERNAL_OBJECTS_H
  29 #include "ahtypes.h"
  30
  31
  32 FT_BEGIN_HEADER
  33
  34
  35   /* PI expressed in ah_angles -- we don't really need an important */
  36   /* precision, so 256 should be enough                             */
  37 #define AH_PI       256
  38 #define AH_2PI      ( AH_PI * 2 )
  39 #define AH_HALF_PI  ( AH_PI / 2 )
  40 #define AH_2PIMASK  ( AH_2PI - 1 )
  41
  42   /* the number of bits used to express an arc tangent; */
  43   /* see the structure of the lookup table              */
  44 #define AH_ATAN_BITS  8
  45
  46   extern
  47   const AH_Angle  ah_arctan[1L << AH_ATAN_BITS];
  48
  49
  50   FT_LOCAL AH_Angle
  51   ah_angle( FT_Vector*  v );
  52
  53
  54 FT_END_HEADER
  55
  56 #endif /* __AHANGLES_H__ */
  57
  58
  59 /* END */