1 /*
2 Copyright (c) 2010-2011, Intel Corporation
3 All rights reserved.
4
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions are
7 met:
8
9 * Redistributions of source code must retain the above copyright
10 notice, this list of conditions and the following disclaimer.
11
12 * Redistributions in binary form must reproduce the above copyright
13 notice, this list of conditions and the following disclaimer in the
14 documentation and/or other materials provided with the distribution.
15
16 * Neither the name of Intel Corporation nor the names of its
17 contributors may be used to endorse or promote products derived from
18 this software without specific prior written permission.
19
20
21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
22 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
24 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
25 OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
28 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <math.h>
35
36 #define NOISE_PERM_SIZE 256
37
38 static int NoisePerm[2 * NOISE_PERM_SIZE] = {
39 151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225, 140, 36, 103, 30, 69, 142, 8,
40 99, 37, 240, 21, 10, 23, 190, 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35,
41 11, 32, 57, 177, 33, 88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175, 74, 165, 71, 134, 139,
42 48, 27, 166, 77, 146, 158, 231, 83, 111, 229, 122, 60, 211, 133, 230, 220, 105, 92, 41, 55, 46, 245, 40,
43 244, 102, 143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 18, 169, 200, 196, 135,
44 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 226, 250, 124, 123, 5, 202, 38, 147,
45 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42, 223, 183, 170, 213, 119,
46 248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9, 129, 22, 39, 253, 19, 98, 108, 110,
47 79, 113, 224, 232, 178, 185, 112, 104, 218, 246, 97, 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162,
48 241, 81, 51, 145, 235, 249, 14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157, 184, 84, 204, 176, 115, 121,
49 50, 45, 127, 4, 150, 254, 138, 236, 205, 93, 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215,
50 61, 156, 180, 151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225, 140, 36, 103, 30,
51 69, 142, 8, 99, 37, 240, 21, 10, 23, 190, 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219,
52 203, 117, 35, 11, 32, 57, 177, 33, 88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175, 74, 165,
53 71, 134, 139, 48, 27, 166, 77, 146, 158, 231, 83, 111, 229, 122, 60, 211, 133, 230, 220, 105, 92, 41, 55,
54 46, 245, 40, 244, 102, 143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 18, 169,
55 200, 196, 135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 226, 250, 124, 123, 5,
56 202, 38, 147, 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42, 223, 183,
57 170, 213, 119, 248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9, 129, 22, 39, 253, 19,
58 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104, 218, 246, 97, 228, 251, 34, 242, 193, 238, 210, 144, 12,
59 191, 179, 162, 241, 81, 51, 145, 235, 249, 14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157, 184, 84, 204,
60 176, 115, 121, 50, 45, 127, 4, 150, 254, 138, 236, 205, 93, 222, 114, 67, 29, 24, 72, 243, 141, 128, 195,
61 78, 66, 215, 61, 156, 180};
62
Clamp(float v,float low,float high)63 inline float Clamp(float v, float low, float high) { return v < low ? low : ((v > high) ? high : v); }
64
SmoothStep(float low,float high,float value)65 inline float SmoothStep(float low, float high, float value) {
66 float v = Clamp((value - low) / (high - low), 0.f, 1.f);
67 return v * v * (-2.f * v + 3.f);
68 }
69
Floor2Int(float val)70 inline int Floor2Int(float val) { return (int)floorf(val); }
71
Grad(int x,int y,int z,float dx,float dy,float dz)72 inline float Grad(int x, int y, int z, float dx, float dy, float dz) {
73 int h = NoisePerm[NoisePerm[NoisePerm[x] + y] + z];
74 h &= 15;
75 float u = h < 8 || h == 12 || h == 13 ? dx : dy;
76 float v = h < 4 || h == 12 || h == 13 ? dy : dz;
77 return ((h & 1) ? -u : u) + ((h & 2) ? -v : v);
78 }
79
NoiseWeight(float t)80 inline float NoiseWeight(float t) {
81 float t3 = t * t * t;
82 float t4 = t3 * t;
83 return 6.f * t4 * t - 15.f * t4 + 10.f * t3;
84 }
85
Lerp(float t,float low,float high)86 inline float Lerp(float t, float low, float high) { return (1.f - t) * low + t * high; }
87
Noise(float x,float y,float z)88 static float Noise(float x, float y, float z) {
89 // Compute noise cell coordinates and offsets
90 int ix = Floor2Int(x), iy = Floor2Int(y), iz = Floor2Int(z);
91 float dx = x - ix, dy = y - iy, dz = z - iz;
92
93 // Compute gradient weights
94 ix &= (NOISE_PERM_SIZE - 1);
95 iy &= (NOISE_PERM_SIZE - 1);
96 iz &= (NOISE_PERM_SIZE - 1);
97 float w000 = Grad(ix, iy, iz, dx, dy, dz);
98 float w100 = Grad(ix + 1, iy, iz, dx - 1, dy, dz);
99 float w010 = Grad(ix, iy + 1, iz, dx, dy - 1, dz);
100 float w110 = Grad(ix + 1, iy + 1, iz, dx - 1, dy - 1, dz);
101 float w001 = Grad(ix, iy, iz + 1, dx, dy, dz - 1);
102 float w101 = Grad(ix + 1, iy, iz + 1, dx - 1, dy, dz - 1);
103 float w011 = Grad(ix, iy + 1, iz + 1, dx, dy - 1, dz - 1);
104 float w111 = Grad(ix + 1, iy + 1, iz + 1, dx - 1, dy - 1, dz - 1);
105
106 // Compute trilinear interpolation of weights
107 float wx = NoiseWeight(dx), wy = NoiseWeight(dy), wz = NoiseWeight(dz);
108 float x00 = Lerp(wx, w000, w100);
109 float x10 = Lerp(wx, w010, w110);
110 float x01 = Lerp(wx, w001, w101);
111 float x11 = Lerp(wx, w011, w111);
112 float y0 = Lerp(wy, x00, x10);
113 float y1 = Lerp(wy, x01, x11);
114 return Lerp(wz, y0, y1);
115 }
116
Turbulence(float x,float y,float z,int octaves)117 static float Turbulence(float x, float y, float z, int octaves) {
118 float omega = 0.6;
119
120 float sum = 0., lambda = 1., o = 1.;
121 for (int i = 0; i < octaves; ++i) {
122 sum += fabsf(o * Noise(lambda * x, lambda * y, lambda * z));
123 lambda *= 1.99f;
124 o *= omega;
125 }
126 return sum * 0.5f;
127 }
128
noise_serial(float x0,float y0,float x1,float y1,int width,int height,float output[])129 void noise_serial(float x0, float y0, float x1, float y1, int width, int height, float output[]) {
130 float dx = (x1 - x0) / width;
131 float dy = (y1 - y0) / height;
132
133 for (int j = 0; j < height; j++) {
134 for (int i = 0; i < width; ++i) {
135 float x = x0 + i * dx;
136 float y = y0 + j * dy;
137
138 int index = (j * width + i);
139 output[index] = Turbulence(x, y, 0.6f, 8);
140 }
141 }
142 }
143