root/OpenSceneGraph/trunk/src/osgUtil/PerlinNoise.cpp @ 13041

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1/* OpenSceneGraph example, osgshaders.
2*
3*  Permission is hereby granted, free of charge, to any person obtaining a copy
4*  of this software and associated documentation files (the "Software"), to deal
5*  in the Software without restriction, including without limitation the rights
6*  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7*  copies of the Software, and to permit persons to whom the Software is
8*  furnished to do so, subject to the following conditions:
9*
10*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
11*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
12*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
13*  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
14*  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
15*  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
16*  THE SOFTWARE.
17*/
18
19/************************************************************************
20 *                                                                      *
21 *                   Copyright (C) 2002  3Dlabs Inc. Ltd.               *
22 *                                                                      *
23 ************************************************************************/
24
25/* Adapted from osgshaders example by Robert Osfield for use as part of osgUtil.*/
26
27#include <math.h>
28#include <stdlib.h>
29
30#include <osgUtil/PerlinNoise>
31
32using namespace osgUtil;
33
34/* Coherent noise function over 1, 2 or 3 dimensions */
35/* (copyright Ken Perlin) */
36
37#define N 0x1000
38#define NP 12   /* 2^N */
39#define NM 0xfff
40
41#define s_curve(t) ( t * t * (3. - 2. * t) )
42#define lerp(t, a, b) ( a + t * (b - a) )
43#define setup(i,b0,b1,r0,r1)\
44        t = vec[i] + N;\
45        b0 = ((int)t) & BM;\
46        b1 = (b0+1) & BM;\
47        r0 = t - (int)t;\
48        r1 = r0 - 1.;
49#define at2(rx,ry) ( rx * q[0] + ry * q[1] )
50#define at3(rx,ry,rz) ( rx * q[0] + ry * q[1] + rz * q[2] )
51
52
53PerlinNoise::PerlinNoise()
54{
55    SetNoiseFrequency(1);
56}
57
58void PerlinNoise::SetNoiseFrequency(int frequency)
59{
60        start = 1;
61        B = frequency;
62        BM = B-1;
63}
64
65double PerlinNoise::noise1(double arg)
66{
67   int bx0, bx1;
68   double rx0, rx1, sx, t, u, v, vec[1];
69
70   vec[0] = arg;
71   if (start) {
72      start = 0;
73      initNoise();
74   }
75
76   setup(0,bx0,bx1,rx0,rx1);
77
78   sx = s_curve(rx0);
79   u = rx0 * g1[ p[ bx0 ] ];
80   v = rx1 * g1[ p[ bx1 ] ];
81
82   return(lerp(sx, u, v));
83}
84
85double PerlinNoise::noise2(double vec[2])
86{
87   int bx0, bx1, by0, by1, b00, b10, b01, b11;
88   double rx0, rx1, ry0, ry1, *q, sx, sy, a, b, t, u, v;
89   int i, j;
90
91   if (start) {
92      start = 0;
93      initNoise();
94   }
95
96   setup(0, bx0,bx1, rx0,rx1);
97   setup(1, by0,by1, ry0,ry1);
98
99   i = p[ bx0 ];
100   j = p[ bx1 ];
101
102   b00 = p[ i + by0 ];
103   b10 = p[ j + by0 ];
104   b01 = p[ i + by1 ];
105   b11 = p[ j + by1 ];
106
107   sx = s_curve(rx0);
108   sy = s_curve(ry0);
109
110   q = g2[ b00 ] ; u = at2(rx0,ry0);
111   q = g2[ b10 ] ; v = at2(rx1,ry0);
112   a = lerp(sx, u, v);
113
114   q = g2[ b01 ] ; u = at2(rx0,ry1);
115   q = g2[ b11 ] ; v = at2(rx1,ry1);
116   b = lerp(sx, u, v);
117
118   return lerp(sy, a, b);
119}
120
121double PerlinNoise::noise3(double vec[3])
122{
123   int bx0, bx1, by0, by1, bz0, bz1, b00, b10, b01, b11;
124   double rx0, rx1, ry0, ry1, rz0, rz1, *q, sy, sz, a, b, c, d, t, u, v;
125   int i, j;
126
127   if (start) {
128      start = 0;
129      initNoise();
130   }
131
132   setup(0, bx0,bx1, rx0,rx1);
133   setup(1, by0,by1, ry0,ry1);
134   setup(2, bz0,bz1, rz0,rz1);
135
136   i = p[ bx0 ];
137   j = p[ bx1 ];
138
139   b00 = p[ i + by0 ];
140   b10 = p[ j + by0 ];
141   b01 = p[ i + by1 ];
142   b11 = p[ j + by1 ];
143
144   t  = s_curve(rx0);
145   sy = s_curve(ry0);
146   sz = s_curve(rz0);
147
148   q = g3[ b00 + bz0 ] ; u = at3(rx0,ry0,rz0);
149   q = g3[ b10 + bz0 ] ; v = at3(rx1,ry0,rz0);
150   a = lerp(t, u, v);
151
152   q = g3[ b01 + bz0 ] ; u = at3(rx0,ry1,rz0);
153   q = g3[ b11 + bz0 ] ; v = at3(rx1,ry1,rz0);
154   b = lerp(t, u, v);
155
156   c = lerp(sy, a, b);
157
158   q = g3[ b00 + bz1 ] ; u = at3(rx0,ry0,rz1);
159   q = g3[ b10 + bz1 ] ; v = at3(rx1,ry0,rz1);
160   a = lerp(t, u, v);
161
162   q = g3[ b01 + bz1 ] ; u = at3(rx0,ry1,rz1);
163   q = g3[ b11 + bz1 ] ; v = at3(rx1,ry1,rz1);
164   b = lerp(t, u, v);
165
166   d = lerp(sy, a, b);
167
168   //fprintf(stderr, "%f\n", lerp(sz, c, d));
169
170   return lerp(sz, c, d);
171}
172
173void PerlinNoise::normalize2(double v[2])
174{
175   double s;
176
177   s = sqrt(v[0] * v[0] + v[1] * v[1]);
178   v[0] = v[0] / s;
179   v[1] = v[1] / s;
180}
181
182void PerlinNoise::normalize3(double v[3])
183{
184   double s;
185
186   s = sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
187   v[0] = v[0] / s;
188   v[1] = v[1] / s;
189   v[2] = v[2] / s;
190}
191
192void PerlinNoise::initNoise(void)
193{
194   int i, j, k;
195
196   srand(30757);
197   for (i = 0 ; i < B ; i++) {
198      p[i] = i;
199      g1[i] = (double)((rand() % (B + B)) - B) / B;
200
201      for (j = 0 ; j < 2 ; j++)
202         g2[i][j] = (double)((rand() % (B + B)) - B) / B;
203      normalize2(g2[i]);
204
205      for (j = 0 ; j < 3 ; j++)
206         g3[i][j] = (double)((rand() % (B + B)) - B) / B;
207      normalize3(g3[i]);
208   }
209
210   while (--i) {
211      k = p[i];
212      p[i] = p[j = rand() % B];
213      p[j] = k;
214   }
215
216   for (i = 0 ; i < B + 2 ; i++) {
217      p[B + i] = p[i];
218      g1[B + i] = g1[i];
219      for (j = 0 ; j < 2 ; j++)
220         g2[B + i][j] = g2[i][j];
221      for (j = 0 ; j < 3 ; j++)
222         g3[B + i][j] = g3[i][j];
223   }
224}
225
226/* --- My harmonic summing functions - PDB --------------------------*/
227
228/*
229   In what follows "alpha" is the weight when the sum is formed.
230   Typically it is 2, As this approaches 1 the function is noisier.
231   "beta" is the harmonic scaling/spacing, typically 2.
232*/
233
234double PerlinNoise::PerlinNoise1D(double x,double alpha,double beta,int n)
235{
236   int i;
237   double val,sum = 0;
238   double p,scale = 1;
239
240   p = x;
241   for (i=0;i<n;i++) {
242      val = noise1(p);
243      sum += val / scale;
244      scale *= alpha;
245      p *= beta;
246   }
247   return(sum);
248}
249
250double PerlinNoise::PerlinNoise2D(double x,double y,double alpha,double beta,int n)
251{
252   int i;
253   double val,sum = 0;
254   double p[2],scale = 1;
255
256   p[0] = x;
257   p[1] = y;
258   for (i=0;i<n;i++) {
259      val = noise2(p);
260      sum += val / scale;
261      scale *= alpha;
262      p[0] *= beta;
263      p[1] *= beta;
264   }
265   return(sum);
266}
267
268double PerlinNoise::PerlinNoise3D(double x,double y,double z,double alpha,double beta,int n)
269{
270   int i;
271   double val,sum = 0;
272   double p[3],scale = 1;
273
274   p[0] = x;
275   p[1] = y;
276   p[2] = z;
277   for (i=0;i<n;i++) {
278      val = noise3(p);
279      sum += val / scale;
280      scale *= alpha;
281      p[0] *= beta;
282      p[1] *= beta;
283      p[2] *= beta;
284   }
285   return(sum);
286}
287
288osg::Image* PerlinNoise::create3DNoiseImage(int texSize)
289{
290    osg::Image* image = new osg::Image;
291    image->setImage(texSize, texSize, texSize,
292            4, GL_RGBA, GL_UNSIGNED_BYTE,
293            new unsigned char[4 * texSize * texSize * texSize],
294            osg::Image::USE_NEW_DELETE);
295
296    const int startFrequency = 4;
297    const int numOctaves = 4;
298
299    int f, i, j, k, inc;
300    double ni[3];
301    double inci, incj, inck;
302    int frequency = startFrequency;
303    GLubyte *ptr;
304    double amp = 0.5;
305
306    osg::notify(osg::INFO) << "creating 3D noise texture... ";
307
308    for (f = 0, inc = 0; f < numOctaves; ++f, frequency *= 2, ++inc, amp *= 0.5)
309    {
310        SetNoiseFrequency(frequency);
311        ptr = image->data();
312        ni[0] = ni[1] = ni[2] = 0;
313
314        inci = 1.0 / (texSize / frequency);
315        for (i = 0; i < texSize; ++i, ni[0] += inci)
316        {
317            incj = 1.0 / (texSize / frequency);
318            for (j = 0; j < texSize; ++j, ni[1] += incj)
319            {
320                inck = 1.0 / (texSize / frequency);
321                for (k = 0; k < texSize; ++k, ni[2] += inck, ptr += 4)
322                {
323                    *(ptr+inc) = (GLubyte) (((noise3(ni) + 1.0) * amp) * 128.0);
324                }
325            }
326        }
327    }
328
329    osg::notify(osg::INFO) << "DONE" << std::endl;
330    return image;
331}
332
333osg::Texture3D* PerlinNoise::create3DNoiseTexture(int texSize )
334{
335    osg::Texture3D* noiseTexture = new osg::Texture3D;
336    noiseTexture->setFilter(osg::Texture3D::MIN_FILTER, osg::Texture3D::LINEAR);
337    noiseTexture->setFilter(osg::Texture3D::MAG_FILTER, osg::Texture3D::LINEAR);
338    noiseTexture->setWrap(osg::Texture3D::WRAP_S, osg::Texture3D::REPEAT);
339    noiseTexture->setWrap(osg::Texture3D::WRAP_T, osg::Texture3D::REPEAT);
340    noiseTexture->setWrap(osg::Texture3D::WRAP_R, osg::Texture3D::REPEAT);
341    noiseTexture->setImage( create3DNoiseImage(texSize) );
342    return noiseTexture;
343}
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