| /***************************************************************************/ |
| /* */ |
| /* ahangles.h */ |
| /* */ |
| /* A routine used to compute vector angles with limited accuracy */ |
| /* and very high speed (body). */ |
| /* */ |
| /* Copyright 2000-2001 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; |
| } |
| |
| |
| /* END */ |
