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#ifndef lint |
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static const char RCSid[] = "$Id$"; |
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#endif |
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/* |
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* Binary space partitioning curve for multidimensional sampling. |
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* |
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* Written by Christophe Schlick |
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*/ |
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|
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#include "copyright.h" |
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|
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#include "random.h" |
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|
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void |
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multisamp(t, n, r) /* convert 1-dimensional sample to N dimensions */ |
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double t[]; /* returned N-dimensional vector */ |
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register int n; /* number of dimensions */ |
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double r; /* 1-dimensional sample [0,1) */ |
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{ |
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int j; |
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register int i, k; |
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int ti[8]; |
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double s; |
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|
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i = n; |
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while (i-- > 0) |
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ti[i] = 0; |
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j = 8; |
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while (j--) { |
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k = s = r*(1<<n); |
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r = s - k; |
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i = n; |
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while (i-- > 0) |
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ti[i] += ti[i] + ((k>>i) & 1); |
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} |
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i = n; |
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while (i-- > 0) |
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t[i] = 1./256. * (ti[i] + frandom()); |
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} |
