ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
dir: /libfreetype/ahangles.c/
/***************************************************************************/ /* */ /* ahangles.h */ /* */ /* A routine used to compute vector angles with limited accuracy */ /* and very high speed (body). */ /* */ /* Copyright 2000-2001, 2002 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. */ /* */ /***************************************************************************/ #include <ft2build.h> #include "ahangles.h" /* the following table has been automatically generated with */ /* the `mather.py' Python script */ const AH_Angle ah_arctan[1L << AH_ATAN_BITS] = { 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 18, 19, 19, 19, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 24, 24, 25, 25, 25, 26, 26, 26, 26, 27, 27, 27, 28, 28, 28, 28, 29, 29, 29, 30, 30, 30, 30, 31, 31, 31, 31, 32, 32, 32, 33, 33, 33, 33, 34, 34, 34, 34, 35, 35, 35, 35, 36, 36, 36, 36, 37, 37, 37, 38, 38, 38, 38, 39, 39, 39, 39, 40, 40, 40, 40, 41, 41, 41, 41, 42, 42, 42, 42, 42, 43, 43, 43, 43, 44, 44, 44, 44, 45, 45, 45, 45, 46, 46, 46, 46, 46, 47, 47, 47, 47, 48, 48, 48, 48, 48, 49, 49, 49, 49, 50, 50, 50, 50, 50, 51, 51, 51, 51, 51, 52, 52, 52, 52, 52, 53, 53, 53, 53, 53, 54, 54, 54, 54, 54, 55, 55, 55, 55, 55, 56, 56, 56, 56, 56, 57, 57, 57, 57, 57, 57, 58, 58, 58, 58, 58, 59, 59, 59, 59, 59, 59, 60, 60, 60, 60, 60, 61, 61, 61, 61, 61, 61, 62, 62, 62, 62, 62, 62, 63, 63, 63, 63, 63, 63, 64, 64, 64 }; FT_LOCAL_DEF( AH_Angle ) ah_angle( FT_Vector* v ) { FT_Pos dx, dy; AH_Angle angle; dx = v->x; dy = v->y; /* check trivial cases */ if ( dy == 0 ) { angle = 0; if ( dx < 0 ) angle = AH_PI; return angle; } else if ( dx == 0 ) { angle = AH_HALF_PI; if ( dy < 0 ) angle = -AH_HALF_PI; return angle; } angle = 0; if ( dx < 0 ) { dx = -v->x; dy = -v->y; angle = AH_PI; } if ( dy < 0 ) { FT_Pos tmp; tmp = dx; dx = -dy; dy = tmp; angle -= AH_HALF_PI; } if ( dx == 0 && dy == 0 ) return 0; if ( dx == dy ) angle += AH_PI / 4; else if ( dx > dy ) angle += ah_arctan[FT_DivFix( dy, dx ) >> ( 16 - AH_ATAN_BITS )]; else angle += AH_HALF_PI - ah_arctan[FT_DivFix( dx, dy ) >> ( 16 - AH_ATAN_BITS )]; if ( angle > AH_PI ) angle -= AH_2PI; return angle; } FT_LOCAL_DEF( AH_Angle ) ah_angle_diff( AH_Angle angle1, AH_Angle angle2 ) { AH_Angle delta; delta = ( angle2 - angle1 ); if ( delta < 0 ) delta += AH_2PI; if ( delta > AH_PI ) delta -= AH_2PI; return delta; } /* END */