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/* RCSid $Id: pmaprand.h,v 2.4 2015/08/18 18:45:55 greg Exp $ */ |
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/* |
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================================================================== |
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Random number generators for photon distribution |
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|
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Roland Schregle (roland.schregle@{hslu.ch, gmail.com}) |
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(c) Fraunhofer Institute for Solar Energy Systems, |
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(c) Lucerne University of Applied Sciences and Arts, |
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supported by the Swiss National Science Foundation (SNSF, #147053) |
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================================================================== |
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$Id: pmaprand.h,v 2.3 2015/05/08 13:20:23 rschregle Exp $ |
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*/ |
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#ifndef PMAPRAND_H |
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#define PMAPRAND_H |
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/* According to the analytical validation, skipping numbers in the sequence |
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introduces bias in scenes with high reflectance. We therefore use |
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erand48() with separate states for photon emission, scattering, and |
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russian roulette. The pmapSeed() and pmapRandom() macros can be |
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adapted to other (better?) RNGs. */ |
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#if defined(_WIN32) || defined(BSD) |
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/* Assume no erand48(), so use standard RNG without explicit multistate |
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control; the resulting sequences will be suboptimal */ |
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#include "random.h" |
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#define pmapSeed(seed, state) (srandom(seed)) |
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#define pmapRandom(state) (frandom()) |
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#else |
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#define pmapSeed(seed, state) (state [0] += seed, state [1] += seed, \ |
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state [2] += seed) |
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#define pmapRandom(state) erand48(state) |
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#endif |
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extern unsigned short partState [3], emitState [3], cntState [3], |
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mediumState [3], scatterState [3], rouletteState [3], |
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randSeed; |
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#endif |
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