Fork of Poseidon providing Bukkit #1060 to older Beta versions (b1.0-b1.7.3)
keii.dev
1package org.bukkit.craftbukkit;
2
3/**
4 * Credits for this class goes to user aioobe on stackoverflow.com
5 * Source: http://stackoverflow.com/questions/4454630/j2me-calculate-the-the-distance-between-2-latitude-and-longitude
6 */
7public class TrigMath {
8
9 static final double sq2p1 = 2.414213562373095048802e0;
10 static final double sq2m1 = .414213562373095048802e0;
11 static final double p4 = .161536412982230228262e2;
12 static final double p3 = .26842548195503973794141e3;
13 static final double p2 = .11530293515404850115428136e4;
14 static final double p1 = .178040631643319697105464587e4;
15 static final double p0 = .89678597403663861959987488e3;
16 static final double q4 = .5895697050844462222791e2;
17 static final double q3 = .536265374031215315104235e3;
18 static final double q2 = .16667838148816337184521798e4;
19 static final double q1 = .207933497444540981287275926e4;
20 static final double q0 = .89678597403663861962481162e3;
21 static final double PIO2 = 1.5707963267948966135E0;
22
23 private static double mxatan(double arg) {
24 double argsq = arg * arg, value;
25
26 value = ((((p4 * argsq + p3) * argsq + p2) * argsq + p1) * argsq + p0);
27 value = value / (((((argsq + q4) * argsq + q3) * argsq + q2) * argsq + q1) * argsq + q0);
28 return value * arg;
29 }
30
31 private static double msatan(double arg) {
32 return arg < sq2m1 ? mxatan(arg) : arg > sq2p1 ? PIO2 - mxatan(1 / arg) : PIO2 / 2 + mxatan((arg - 1) / (arg + 1));
33 }
34
35 public static double atan(double arg) {
36 return arg > 0 ? msatan(arg) : -msatan(-arg);
37 }
38
39 public static double atan2(double arg1, double arg2) {
40 if (arg1 + arg2 == arg1) return arg1 >= 0 ? PIO2 : -PIO2;
41 arg1 = atan(arg1 / arg2);
42 return arg2 < 0 ? arg1 <= 0 ? arg1 + Math.PI : arg1 - Math.PI : arg1;
43 }
44}