/
vpsin.go
80 lines (66 loc) · 1.83 KB
/
vpsin.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
// Vapor is a toolkit designed to support Liquid War 7.
// Copyright (C) 2015, 2016 Christian Mauduit <ufoot@ufoot.org>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
// Vapor homepage: https://github.com/ufoot/vapor
// Contact author: ufoot@ufoot.org
package vpmath
import (
"github.com/ufoot/vapor/go/vpnumber"
)
// X32Sin is a lookup table based implementation of the sinus
// function, working with fixed point numbers on 32 bits.
func X32Sin(x vpnumber.X32) vpnumber.X32 {
var i int
var s vpnumber.X32 = 1
x = X32RadMod(x)
if x > X32ConstPi {
x -= X32ConstPi
s = -1
}
if x > X32ConstPi2 {
x = X32ConstPi - x
}
i = (int(x) * x32TableSize) / int(X32ConstPi2)
switch {
case i < 0:
i = 0
case i > x32TableSize:
i = x32TableSize
}
return x32SinTable[i] * s
}
// X64Sin is a lookup table based implementation of the sinus
// function, working with fixed point numbers on 64 bits.
func X64Sin(x vpnumber.X64) vpnumber.X64 {
var i int
var s vpnumber.X64 = 1
x = X64RadMod(x)
if x > X64ConstPi {
x -= X64ConstPi
s = -1
}
if x > X64ConstPi2 {
x = X64ConstPi - x
}
i = (int(x) * x64TableSize) / int(X64ConstPi2)
switch {
case i < 0:
i = 0
case i > x64TableSize:
i = x64TableSize
}
return x64SinTable[i] * s
}