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0bf6c885 TW |
1 | package kaka.cakelight.util; |
2 | ||
3 | import java.util.Random; | |
4 | ||
5 | import static java.lang.Math.*; | |
6 | ||
7 | public class SimplexNoise3D { | |
8 | private final byte[] ptab = new byte[256]; | |
9 | private final double[][] gtab = { | |
10 | { 1, 1, 0}, {-1, 1, 0}, { 1, -1, 0}, {-1, -1, 0}, | |
11 | { 1, 0, 1}, {-1, 0, 1}, { 1, 0, -1}, {-1, 0, -1}, | |
12 | { 0, 1, 1}, { 0, -1, 1}, { 0, 1, -1}, { 0, -1, -1}, | |
13 | }; | |
14 | ||
15 | public SimplexNoise3D(Random rnd) { | |
16 | for(int i = 0; i < 256; i++) | |
17 | ptab[i] = (byte)i; | |
18 | for(int i = 0; i < 256; i++) { | |
19 | int r = rnd.nextInt(256); | |
20 | byte t = ptab[i]; ptab[i] = ptab[r]; ptab[r] = t; | |
21 | } | |
22 | } | |
23 | ||
24 | public SimplexNoise3D(long seed) { | |
25 | this(new Random(seed)); | |
26 | } | |
27 | ||
28 | public SimplexNoise3D() { | |
29 | this(new Random()); | |
30 | } | |
31 | ||
32 | public double get(double r, double x, double y, double z) { | |
33 | x /= r; y /= r; z /= r; | |
34 | ||
35 | double i, j, k; | |
36 | { | |
37 | double s = (x + y + z) / 3; | |
38 | i = floor(x + s); | |
39 | j = floor(y + s); | |
40 | k = floor(z + s); | |
41 | } | |
42 | ||
43 | double dx, dy, dz; | |
44 | { | |
45 | double s = (i + j + k) / 6; | |
46 | dx = x - (i - s); | |
47 | dy = y - (j - s); | |
48 | dz = z - (k - s); | |
49 | } | |
50 | ||
51 | int i1, j1, k1, i2, j2, k2; | |
52 | if((dx >= dy) && (dy >= dz)) { | |
53 | i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 1; k2 = 0; | |
54 | } else if((dx >= dz) && (dz >= dy)) { | |
55 | i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 0; k2 = 1; | |
56 | } else if((dz >= dx) && (dx >= dy)) { | |
57 | i1 = 0; j1 = 0; k1 = 1; i2 = 1; j2 = 0; k2 = 1; | |
58 | } else if((dz >= dy) && (dy >= dx)) { | |
59 | i1 = 0; j1 = 0; k1 = 1; i2 = 0; j2 = 1; k2 = 1; | |
60 | } else if((dy >= dz) && (dz >= dx)) { | |
61 | i1 = 0; j1 = 1; k1 = 0; i2 = 0; j2 = 1; k2 = 1; | |
62 | } else /* if((dy >= dx) && (dx >= dz)) */ { | |
63 | i1 = 0; j1 = 1; k1 = 0; i2 = 1; j2 = 1; k2 = 0; | |
64 | } | |
65 | ||
66 | double x1 = dx - i1 + (1.0 / 6.0), y1 = dy - j1 + (1.0 / 6.0), z1 = dz - k1 + (1.0 / 6.0); | |
67 | double x2 = dx - i2 + (1.0 / 3.0), y2 = dy - j2 + (1.0 / 3.0), z2 = dz - k2 + (1.0 / 3.0); | |
68 | double x3 = dx - 0.5, y3 = dy - 0.5, z3 = dz - 0.5; | |
69 | ||
70 | int ip = (int)i, jp = (int)j, kp = (int)k; | |
71 | double[] g0 = gtab[((int)ptab[(int)(ip + ptab[(int)(jp + ptab[(int)kp & 0xff]) & 0xff]) & 0xff] & 0xff) % 12]; | |
72 | double[] g1 = gtab[((int)ptab[(int)(ip + i1 + ptab[(int)(jp + j1 + ptab[(int)(kp + k1) & 0xff]) & 0xff]) & 0xff] & 0xff) % 12]; | |
73 | double[] g2 = gtab[((int)ptab[(int)(ip + i2 + ptab[(int)(jp + j2 + ptab[(int)(kp + k2) & 0xff]) & 0xff]) & 0xff] & 0xff) % 12]; | |
74 | double[] g3 = gtab[((int)ptab[(int)(ip + 1 + ptab[(int)(jp + 1 + ptab[(int)(kp + 1) & 0xff]) & 0xff]) & 0xff] & 0xff) % 12]; | |
75 | ||
76 | double n0 = 0.6 - (dx * dx) - (dy * dy) - (dz * dz); | |
77 | double n1 = 0.6 - (x1 * x1) - (y1 * y1) - (z1 * z1); | |
78 | double n2 = 0.6 - (x2 * x2) - (y2 * y2) - (z2 * z2); | |
79 | double n3 = 0.6 - (x3 * x3) - (y3 * y3) - (z3 * z3); | |
80 | ||
81 | double v = 0.0; | |
82 | if(n0 > 0) v += n0 * n0 * n0 * n0 * ((g0[0] * dx) + (g0[1] * dy) + (g0[2] * dz)); | |
83 | if(n1 > 0) v += n1 * n1 * n1 * n1 * ((g1[0] * x1) + (g1[1] * y1) + (g1[2] * z1)); | |
84 | if(n2 > 0) v += n2 * n2 * n2 * n2 * ((g2[0] * x2) + (g2[1] * y2) + (g2[2] * z2)); | |
85 | if(n3 > 0) v += n3 * n3 * n3 * n3 * ((g3[0] * x3) + (g3[1] * y3) + (g3[2] * z3)); | |
86 | ||
87 | return(min(max(v * 32, -1.0), 1.0)); | |
88 | } | |
89 | ||
90 | public double getr(double lo, double hi, double r, double x, double y, double z) { | |
91 | return((((get(r, x, y, z) * 0.5) + 0.5) * (hi - lo)) + lo); | |
92 | } | |
93 | ||
94 | public int geti(int lo, int hi, double r, double x, double y, double z) { | |
95 | return(min((int)(((get(r, x, y, z) * 0.5) + 0.5) * (hi - lo)), (int)((hi - lo) - 1)) + lo); | |
96 | } | |
97 | } |