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 /***************************************************************************/
23 #ifndef __AHANGLES_H__
24 #define __AHANGLES_H__
27 #include <ft2build.h>
28 #include FT_INTERNAL_OBJECTS_H
29 #include "ahtypes.h"
32 FT_BEGIN_HEADER
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 )
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
46 extern
47 const AH_Angle ah_arctan[1L << AH_ATAN_BITS];
50 FT_LOCAL AH_Angle
51 ah_angle( FT_Vector* v );
54 FT_END_HEADER
56 #endif /* __AHANGLES_H__ */
59 /* END */