1*4882a593Smuzhiyun #ifndef _FIXP_ARITH_H
2*4882a593Smuzhiyun #define _FIXP_ARITH_H
3*4882a593Smuzhiyun
4*4882a593Smuzhiyun /*
5*4882a593Smuzhiyun * Simplistic fixed-point arithmetics.
6*4882a593Smuzhiyun * Hmm, I'm probably duplicating some code :(
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * Copyright (c) 2002 Johann Deneux
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun /*
12*4882a593Smuzhiyun * This program is free software; you can redistribute it and/or modify
13*4882a593Smuzhiyun * it under the terms of the GNU General Public License as published by
14*4882a593Smuzhiyun * the Free Software Foundation; either version 2 of the License, or
15*4882a593Smuzhiyun * (at your option) any later version.
16*4882a593Smuzhiyun *
17*4882a593Smuzhiyun */
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun #include <linux/types.h>
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun static const s32 sin_table[] = {
22*4882a593Smuzhiyun 0x00000000, 0x023be165, 0x04779632, 0x06b2f1d2, 0x08edc7b6, 0x0b27eb5c,
23*4882a593Smuzhiyun 0x0d61304d, 0x0f996a26, 0x11d06c96, 0x14060b67, 0x163a1a7d, 0x186c6ddd,
24*4882a593Smuzhiyun 0x1a9cd9ac, 0x1ccb3236, 0x1ef74bf2, 0x2120fb82, 0x234815ba, 0x256c6f9e,
25*4882a593Smuzhiyun 0x278dde6e, 0x29ac379f, 0x2bc750e8, 0x2ddf003f, 0x2ff31bdd, 0x32037a44,
26*4882a593Smuzhiyun 0x340ff241, 0x36185aee, 0x381c8bb5, 0x3a1c5c56, 0x3c17a4e7, 0x3e0e3ddb,
27*4882a593Smuzhiyun 0x3fffffff, 0x41ecc483, 0x43d464fa, 0x45b6bb5d, 0x4793a20f, 0x496af3e1,
28*4882a593Smuzhiyun 0x4b3c8c11, 0x4d084650, 0x4ecdfec6, 0x508d9210, 0x5246dd48, 0x53f9be04,
29*4882a593Smuzhiyun 0x55a6125a, 0x574bb8e5, 0x58ea90c2, 0x5a827999, 0x5c135399, 0x5d9cff82,
30*4882a593Smuzhiyun 0x5f1f5ea0, 0x609a52d1, 0x620dbe8a, 0x637984d3, 0x64dd894f, 0x6639b039,
31*4882a593Smuzhiyun 0x678dde6d, 0x68d9f963, 0x6a1de735, 0x6b598ea1, 0x6c8cd70a, 0x6db7a879,
32*4882a593Smuzhiyun 0x6ed9eba0, 0x6ff389de, 0x71046d3c, 0x720c8074, 0x730baeec, 0x7401e4bf,
33*4882a593Smuzhiyun 0x74ef0ebb, 0x75d31a5f, 0x76adf5e5, 0x777f903b, 0x7847d908, 0x7906c0af,
34*4882a593Smuzhiyun 0x79bc384c, 0x7a6831b8, 0x7b0a9f8c, 0x7ba3751c, 0x7c32a67c, 0x7cb82884,
35*4882a593Smuzhiyun 0x7d33f0c8, 0x7da5f5a3, 0x7e0e2e31, 0x7e6c924f, 0x7ec11aa3, 0x7f0bc095,
36*4882a593Smuzhiyun 0x7f4c7e52, 0x7f834ecf, 0x7fb02dc4, 0x7fd317b3, 0x7fec09e1, 0x7ffb025e,
37*4882a593Smuzhiyun 0x7fffffff
38*4882a593Smuzhiyun };
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun /**
41*4882a593Smuzhiyun * __fixp_sin32() returns the sin of an angle in degrees
42*4882a593Smuzhiyun *
43*4882a593Smuzhiyun * @degrees: angle, in degrees, from 0 to 360.
44*4882a593Smuzhiyun *
45*4882a593Smuzhiyun * The returned value ranges from -0x7fffffff to +0x7fffffff.
46*4882a593Smuzhiyun */
__fixp_sin32(int degrees)47*4882a593Smuzhiyun static inline s32 __fixp_sin32(int degrees)
48*4882a593Smuzhiyun {
49*4882a593Smuzhiyun s32 ret;
50*4882a593Smuzhiyun bool negative = false;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun if (degrees > 180) {
53*4882a593Smuzhiyun negative = true;
54*4882a593Smuzhiyun degrees -= 180;
55*4882a593Smuzhiyun }
56*4882a593Smuzhiyun if (degrees > 90)
57*4882a593Smuzhiyun degrees = 180 - degrees;
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun ret = sin_table[degrees];
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun return negative ? -ret : ret;
62*4882a593Smuzhiyun }
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun /**
65*4882a593Smuzhiyun * fixp_sin32() returns the sin of an angle in degrees
66*4882a593Smuzhiyun *
67*4882a593Smuzhiyun * @degrees: angle, in degrees. The angle can be positive or negative
68*4882a593Smuzhiyun *
69*4882a593Smuzhiyun * The returned value ranges from -0x7fffffff to +0x7fffffff.
70*4882a593Smuzhiyun */
fixp_sin32(int degrees)71*4882a593Smuzhiyun static inline s32 fixp_sin32(int degrees)
72*4882a593Smuzhiyun {
73*4882a593Smuzhiyun degrees = (degrees % 360 + 360) % 360;
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun return __fixp_sin32(degrees);
76*4882a593Smuzhiyun }
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun /* cos(x) = sin(x + 90 degrees) */
79*4882a593Smuzhiyun #define fixp_cos32(v) fixp_sin32((v) + 90)
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun /*
82*4882a593Smuzhiyun * 16 bits variants
83*4882a593Smuzhiyun *
84*4882a593Smuzhiyun * The returned value ranges from -0x7fff to 0x7fff
85*4882a593Smuzhiyun */
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun #define fixp_sin16(v) (fixp_sin32(v) >> 16)
88*4882a593Smuzhiyun #define fixp_cos16(v) (fixp_cos32(v) >> 16)
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun #endif
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