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1 /* |
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2 Based on |
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3 JAVA REFERENCE IMPLEMENTATION OF IMPROVED NOISE |
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4 by KEN PERLIN (COPYRIGHT 2002) |
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5 */ |
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6 |
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7 #include <math.h> |
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8 |
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9 #include "noise.h" |
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10 |
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11 double fade(double t) |
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12 { |
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13 return t * t * t * (t * (t * 6 - 15) + 10); |
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14 } |
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15 |
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16 double lerp(double t, double a, double b) |
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17 { |
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18 return a + t * (b - a); |
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19 } |
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20 |
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21 double grad(unsigned char hash, double x, double y, double z) |
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22 { |
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23 unsigned char h = hash & 15; // CONVERT LO 4 BITS OF HASH CODE |
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24 double u = h<8 ? x : y, // INTO 12 GRADIENT DIRECTIONS. |
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25 v = h<4 ? y : h==12||h==14 ? x : z; |
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26 return ((h&1) == 0 ? u : -u) + ((h&2) == 0 ? v : -v); |
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27 } |
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28 |
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29 unsigned char p[512] = { 151,160,137,91,90,15, |
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30 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, |
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31 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, |
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32 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, |
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33 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, |
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34 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, |
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35 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, |
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36 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, |
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37 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, |
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38 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, |
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39 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, |
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40 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, |
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41 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180, |
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42 |
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43 151,160,137,91,90,15, |
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44 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, |
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45 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, |
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46 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, |
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47 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, |
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48 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, |
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49 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, |
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50 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, |
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51 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, |
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52 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, |
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53 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, |
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54 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, |
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55 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180 |
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56 }; |
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57 |
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58 |
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59 double perlin(double x, double y, double z) |
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60 { |
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61 int X = (int)floor(x) & 255, // FIND UNIT CUBE THAT |
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62 Y = (int)floor(y) & 255, // CONTAINS POINT. |
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63 Z = (int)floor(z) & 255; |
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64 x -= floor(x); // FIND RELATIVE X,Y,Z |
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65 y -= floor(y); // OF POINT IN CUBE. |
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66 z -= floor(z); |
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67 double u = fade(x), // COMPUTE FADE CURVES |
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68 v = fade(y), // FOR EACH OF X,Y,Z. |
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69 w = fade(z); |
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70 int A = p[X ]+Y, AA = p[A]+Z, AB = p[A+1]+Z, // HASH COORDINATES OF |
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71 B = p[X+1]+Y, BA = p[B]+Z, BB = p[B+1]+Z; // THE 8 CUBE CORNERS, |
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72 |
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73 return lerp(w, lerp(v, lerp(u, grad(p[AA ], x , y , z ), // AND ADD |
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74 grad(p[BA ], x-1, y , z )), // BLENDED |
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75 lerp(u, grad(p[AB ], x , y-1, z ), // RESULTS |
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76 grad(p[BB ], x-1, y-1, z ))),// FROM 8 |
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77 lerp(v, lerp(u, grad(p[AA+1], x , y , z-1 ), // CORNERS |
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78 grad(p[BA+1], x-1, y , z-1 )), // OF CUBE |
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79 lerp(u, grad(p[AB+1], x , y-1, z-1 ), |
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80 grad(p[BB+1], x-1, y-1, z-1 )))); |
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81 } |
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82 |
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83 |
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84 /* |
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85 // JAVA REFERENCE IMPLEMENTATION OF IMPROVED NOISE - COPYRIGHT 2002 KEN PERLIN. |
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86 |
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87 public final class ImprovedNoise { |
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88 static public double noise(double x, double y, double z) { |
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89 int X = (int)Math.floor(x) & 255, // FIND UNIT CUBE THAT |
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90 Y = (int)Math.floor(y) & 255, // CONTAINS POINT. |
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91 Z = (int)Math.floor(z) & 255; |
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92 x -= Math.floor(x); // FIND RELATIVE X,Y,Z |
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93 y -= Math.floor(y); // OF POINT IN CUBE. |
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94 z -= Math.floor(z); |
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95 double u = fade(x), // COMPUTE FADE CURVES |
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96 v = fade(y), // FOR EACH OF X,Y,Z. |
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97 w = fade(z); |
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98 int A = p[X ]+Y, AA = p[A]+Z, AB = p[A+1]+Z, // HASH COORDINATES OF |
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99 B = p[X+1]+Y, BA = p[B]+Z, BB = p[B+1]+Z; // THE 8 CUBE CORNERS, |
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100 |
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101 return lerp(w, lerp(v, lerp(u, grad(p[AA ], x , y , z ), // AND ADD |
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102 grad(p[BA ], x-1, y , z )), // BLENDED |
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103 lerp(u, grad(p[AB ], x , y-1, z ), // RESULTS |
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104 grad(p[BB ], x-1, y-1, z ))),// FROM 8 |
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105 lerp(v, lerp(u, grad(p[AA+1], x , y , z-1 ), // CORNERS |
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106 grad(p[BA+1], x-1, y , z-1 )), // OF CUBE |
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107 lerp(u, grad(p[AB+1], x , y-1, z-1 ), |
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108 grad(p[BB+1], x-1, y-1, z-1 )))); |
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109 } |
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110 static double fade(double t) { return t * t * t * (t * (t * 6 - 15) + 10); } |
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111 static double lerp(double t, double a, double b) { return a + t * (b - a); } |
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112 static double grad(int hash, double x, double y, double z) { |
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113 int h = hash & 15; // CONVERT LO 4 BITS OF HASH CODE |
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114 double u = h<8 ? x : y, // INTO 12 GRADIENT DIRECTIONS. |
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115 v = h<4 ? y : h==12||h==14 ? x : z; |
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116 return ((h&1) == 0 ? u : -u) + ((h&2) == 0 ? v : -v); |
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117 } |
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118 static final int p[] = new int[512], permutation[] = { 151,160,137,91,90,15, |
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119 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, |
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120 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, |
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121 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, |
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122 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, |
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123 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, |
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124 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, |
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125 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, |
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126 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, |
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127 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, |
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128 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, |
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129 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, |
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130 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180 |
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131 }; |
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132 static { for (int i=0; i < 256 ; i++) p[256+i] = p[i] = permutation[i]; } |
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133 } |
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134 */ |