| 1 |
greg |
1.2 |
{ RCSid $Id$ } |
| 2 |
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{ 2-D Perlin Noise function } |
| 3 |
greg |
1.1 |
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| 4 |
greg |
1.2 |
frac(x):x-floor(x); |
| 5 |
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| 6 |
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hermite(p0,p1,r0,r1,t) : p0 * ((2*t-3)*t*t+1) + |
| 7 |
greg |
1.1 |
p1 * (-2*t+3)*t*t + |
| 8 |
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r0 * (((t-2)*t+1)*t) + |
| 9 |
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r1 * ((t-1)*t*t); |
| 10 |
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| 11 |
greg |
1.2 |
rand2a(x,y) : 1-2*rand(.69692*x+.35084*y); |
| 12 |
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rand2b(x,y) : 1-2*rand(.05393*x+.96196*y); |
| 13 |
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rand2c(x,y) : 1-2*rand(.04234*x+.46180*y); |
| 14 |
greg |
1.1 |
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| 15 |
greg |
1.2 |
noise_2(xl,xd,xu,yl,yd,yu) : |
| 16 |
greg |
1.1 |
hermite( |
| 17 |
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hermite(rand2c(xl,yl), |
| 18 |
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rand2c(xu,yl), |
| 19 |
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rand2a(xl,yl), |
| 20 |
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rand2a(xu,yl), |
| 21 |
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xd), |
| 22 |
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hermite(rand2c(xl,yu), |
| 23 |
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rand2c(xu,yu), |
| 24 |
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rand2a(xl,yu), |
| 25 |
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rand2a(xu,yu), |
| 26 |
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xd), |
| 27 |
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(1-xd)*rand2b(xl,yl)+ |
| 28 |
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xd*rand2b(xu,yl), |
| 29 |
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(1-xd)*rand2b(xl,yu)+ |
| 30 |
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xd*rand2b(xu,yu), |
| 31 |
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yd); |
| 32 |
greg |
1.2 |
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| 33 |
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noise2(x,y) : noise_2( floor(x),frac(x),ceil(x), |
| 34 |
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floor(y),frac(y),ceil(y) ); |
