]>
Commit | Line | Data |
---|---|---|
cabec872 RR |
1 | /***************************************************************************/ |
2 | /* */ | |
3 | /* ahangles.h */ | |
4 | /* */ | |
5 | /* A routine used to compute vector angles with limited accuracy */ | |
6 | /* and very high speed (body). */ | |
7 | /* */ | |
8 | /* Copyright 2000 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 | #ifdef FT_FLAT_COMPILE | |
24 | ||
25 | #include "ahangles.h" | |
26 | ||
27 | #else | |
28 | ||
29 | #include <autohint/ahangles.h> | |
30 | ||
31 | #endif | |
32 | ||
33 | ||
34 | /* the following table has been automatically generated with */ | |
35 | /* the `mather.py' Python script */ | |
36 | ||
37 | const AH_Angle ah_arctan[1L << AH_ATAN_BITS] = | |
38 | { | |
39 | 0, 0, 1, 1, 1, 2, 2, 2, | |
40 | 3, 3, 3, 3, 4, 4, 4, 5, | |
41 | 5, 5, 6, 6, 6, 7, 7, 7, | |
42 | 8, 8, 8, 9, 9, 9, 10, 10, | |
43 | 10, 10, 11, 11, 11, 12, 12, 12, | |
44 | 13, 13, 13, 14, 14, 14, 14, 15, | |
45 | 15, 15, 16, 16, 16, 17, 17, 17, | |
46 | 18, 18, 18, 18, 19, 19, 19, 20, | |
47 | 20, 20, 21, 21, 21, 21, 22, 22, | |
48 | 22, 23, 23, 23, 24, 24, 24, 24, | |
49 | 25, 25, 25, 26, 26, 26, 26, 27, | |
50 | 27, 27, 28, 28, 28, 28, 29, 29, | |
51 | 29, 30, 30, 30, 30, 31, 31, 31, | |
52 | 31, 32, 32, 32, 33, 33, 33, 33, | |
53 | 34, 34, 34, 34, 35, 35, 35, 35, | |
54 | 36, 36, 36, 36, 37, 37, 37, 38, | |
55 | 38, 38, 38, 39, 39, 39, 39, 40, | |
56 | 40, 40, 40, 41, 41, 41, 41, 42, | |
57 | 42, 42, 42, 42, 43, 43, 43, 43, | |
58 | 44, 44, 44, 44, 45, 45, 45, 45, | |
59 | 46, 46, 46, 46, 46, 47, 47, 47, | |
60 | 47, 48, 48, 48, 48, 48, 49, 49, | |
61 | 49, 49, 50, 50, 50, 50, 50, 51, | |
62 | 51, 51, 51, 51, 52, 52, 52, 52, | |
63 | 52, 53, 53, 53, 53, 53, 54, 54, | |
64 | 54, 54, 54, 55, 55, 55, 55, 55, | |
65 | 56, 56, 56, 56, 56, 57, 57, 57, | |
66 | 57, 57, 57, 58, 58, 58, 58, 58, | |
67 | 59, 59, 59, 59, 59, 59, 60, 60, | |
68 | 60, 60, 60, 61, 61, 61, 61, 61, | |
69 | 61, 62, 62, 62, 62, 62, 62, 63, | |
70 | 63, 63, 63, 63, 63, 64, 64, 64 | |
71 | }; | |
72 | ||
73 | ||
74 | LOCAL_FUNC | |
75 | AH_Angle ah_angle( FT_Vector* v ) | |
76 | { | |
77 | FT_Pos dx, dy; | |
78 | AH_Angle angle; | |
79 | ||
80 | ||
81 | dx = v->x; | |
82 | dy = v->y; | |
83 | ||
84 | /* check trivial cases */ | |
85 | if ( dy == 0 ) | |
86 | { | |
87 | angle = 0; | |
88 | if ( dx < 0 ) | |
89 | angle = AH_PI; | |
90 | return angle; | |
91 | } | |
92 | else if ( dx == 0 ) | |
93 | { | |
94 | angle = AH_HALF_PI; | |
95 | if ( dy < 0 ) | |
96 | angle = -AH_HALF_PI; | |
97 | return angle; | |
98 | } | |
99 | ||
100 | angle = 0; | |
101 | if ( dx < 0 ) | |
102 | { | |
103 | dx = -v->x; | |
104 | dy = -v->y; | |
105 | angle = AH_PI; | |
106 | } | |
107 | ||
108 | if ( dy < 0 ) | |
109 | { | |
110 | FT_Pos tmp; | |
111 | ||
112 | ||
113 | tmp = dx; | |
114 | dx = -dy; | |
115 | dy = tmp; | |
116 | angle -= AH_HALF_PI; | |
117 | } | |
118 | ||
119 | if ( dx == 0 && dy == 0 ) | |
120 | return 0; | |
121 | ||
122 | if ( dx == dy ) | |
123 | angle += AH_PI / 4; | |
124 | else if ( dx > dy ) | |
125 | angle += ah_arctan[FT_DivFix( dy, dx ) >> ( 16 - AH_ATAN_BITS )]; | |
126 | else | |
127 | angle += AH_HALF_PI - | |
128 | ah_arctan[FT_DivFix( dx, dy ) >> ( 16 - AH_ATAN_BITS )]; | |
129 | ||
130 | if ( angle > AH_PI ) | |
131 | angle -= AH_2PI; | |
132 | ||
133 | return angle; | |
134 | } | |
135 | ||
136 | ||
137 | /* END */ |