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/* |
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================================================================== |
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Photon map support routines for emission from light sources |
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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: pmapsrc.h,v 2.1 2015/02/24 19:39:27 greg Exp $ |
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*/ |
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#ifndef PMAPSRC_H |
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#define PMAPSRC_H |
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#include "ray.h" |
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#include "source.h" |
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/* Data structures for photon emission */ |
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typedef struct { |
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unsigned theta, phi; /* Direction indices */ |
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COLOR pdf; /* Probability of emission in this |
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direction per RGB */ |
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float cdf; /* Cumulative probability up to |
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this sample */ |
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} EmissionSample; |
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typedef struct { |
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unsigned numTheta, numPhi; /* Num divisions in theta & phi */ |
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RREAL cosThetaMax; /* cos(source aperture) */ |
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FVECT uh, vh, wh; /* Emission aperture axes at origin, |
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w is normal*/ |
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FVECT us, vs, ws; /* Source surface axes at origin, |
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w is normal */ |
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FVECT photonOrg; /* Current photon origin */ |
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EmissionSample *samples; /* PDF samples for photon emission |
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directions */ |
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unsigned long numPartitions; /* Number of surface partitions */ |
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RREAL partArea; /* Area covered by each partition */ |
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SRCREC *src, *port; /* Current source and port */ |
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unsigned long partitionCnt, /* Current surface partition */ |
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maxPartitions, /* Max allocated partitions */ |
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numSamples; /* Number of PDF samples */ |
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unsigned char* partitions; /* Source surface partitions */ |
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COLOR partFlux; /* Total flux emitted by partition */ |
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float cdf; /* Cumulative probability */ |
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} EmissionMap; |
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/* Photon port list for emission from geometry en lieu of light sources */ |
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extern SRCREC *photonPorts; |
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extern unsigned numPhotonPorts; |
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/* Dispatch tables for partitioning light source surfaces and generating |
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an origin for photon emission */ |
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extern void (*photonPartition []) (EmissionMap*); |
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extern void (*photonOrigin []) (EmissionMap*); |
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void getPhotonPorts (); |
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/* Find geometry declared as photon ports */ |
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void initPhotonEmissionFuncs (); |
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/* Init photonPartition[] and photonOrigin[] dispatch tables with source |
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specific emission routines */ |
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void initPhotonEmission (EmissionMap *emap, float numPdfSamples); |
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/* Initialize photon emission from partitioned light source emap -> src; |
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* this involves integrating the flux emitted from the current photon |
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* origin emap -> photonOrg and setting up a PDF to sample the emission |
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* distribution with numPdfSamples samples */ |
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void emitPhoton (const EmissionMap*, RAY* ray); |
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/* Emit photon from current source partition based on emission |
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distribution and return new photon ray */ |
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void multDirectPmap (RAY *r); |
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/* Factor irradiance from direct photons into r -> rcol; interface to |
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* direct() */ |
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void inscatterVolumePmap (RAY *r, COLOR inscatter); |
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/* Add inscattering from volume photon map; interface to srcscatter() */ |
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#endif |
