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/* |
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================================================================== |
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Photon map data structures and kd-tree handling |
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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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|
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$Id: pmapdata.h,v 4.21 2015/07/29 18:02:35 taschreg Exp taschreg $ |
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*/ |
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|
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#ifndef PMAPDATA_H |
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#define PMAPDATA_H |
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|
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#include "ray.h" |
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#include "pmaptype.h" |
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#include "lookup.h" |
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|
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/* Define PMAP_FLOAT_FLUX to store photon flux as floats instead of |
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* compact RGBE, which was found to improve accuracy in analytical |
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* validation. */ |
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#ifdef PMAP_FLOAT_FLUX |
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#define setPhotonFlux(p,f) copycolor((p) -> flux, f) |
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#define getPhotonFlux(p,f) copycolor(f, (p) -> flux) |
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#else |
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#define setPhotonFlux(p,f) setcolr((p)->flux, (f)[0], (f)[1], (f)[2]) |
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#define getPhotonFlux(p,f) colr_color(f, (p) -> flux) |
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#endif |
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/* Primary photon ray for light source contributions */ |
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typedef struct { |
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int32 srcIdx; /* Index of emitting light source */ |
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int32 dir; /* Encoded ray direction */ |
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float pos [3]; /* Hit point */ |
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} PhotonPrimary; |
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|
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#define photonSrcIdx(pm, p) ((pm) -> primary [(p) -> primary].srcIdx) |
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|
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typedef struct { |
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float pos [3]; /* Photon position */ |
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signed char norm [3]; /* Surface normal at pos (incident |
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direction for volume photons) */ |
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char flags; /* Bit 0-1: kd-tree discriminator axis, |
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Bit 2: caustic photon */ |
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#ifdef PMAP_FLOAT_FLUX |
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COLOR flux; |
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#else |
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COLR flux; /* Photon flux */ |
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#endif |
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|
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uint32 primary; /* Index to primary ray */ |
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} Photon; |
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|
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/* Photon flag bitmasks and manipulation macros */ |
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#define PMAP_DISCR_BIT 3 |
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#define PMAP_CAUST_BIT 4 |
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#define photonDiscr(p) ((p).flags & PMAP_DISCR_BIT) |
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#define setPhotonDiscr(p, d) ((p).flags = ((p).flags & ~PMAP_DISCR_BIT) | \ |
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((d) & PMAP_DISCR_BIT)) |
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|
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/* Photon map type tests */ |
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#define isGlobalPmap(p) ((p) -> type == PMAP_TYPE_GLOBAL) |
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#define isCausticPmap(p) ((p) -> type == PMAP_TYPE_CAUSTIC) |
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#define isContribPmap(p) ((p) -> type == PMAP_TYPE_CONTRIB) |
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#define isVolumePmap(p) ((p) -> type == PMAP_TYPE_VOLUME) |
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/* Queue node for photon lookups */ |
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typedef struct { |
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Photon *photon; |
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float dist; |
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} PhotonSQNode; |
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|
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/* Bias compensation history node */ |
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typedef struct { |
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COLOR irrad; |
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float weight; |
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} PhotonBCNode; |
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struct PhotonMap; /* Forward declarations */ |
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typedef struct PhotonMap { |
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PhotonMapType type; /* See pmaptype.h */ |
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char *fileName; /* Photon map file */ |
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Photon *heap; /* Photon k-d tree as linear array */ |
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PhotonSQNode *squeue; /* Search queue */ |
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PhotonBCNode *biasCompHist; /* Bias compensation history */ |
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char lookupFlags; /* Flags passed to findPhotons() */ |
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unsigned long distribTarget, /* Num stored specified by user */ |
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heapSize, |
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heapSizeInc, |
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heapEnd, /* Num actually stored in heap */ |
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numDensity, /* Num density estimates */ |
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totalGathered, /* Total photons gathered */ |
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numLookups, /* Counters for short photon lookups */ |
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numShortLookups; |
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unsigned minGather, /* Specified min/max photons per */ |
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maxGather, /* density estimate */ |
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squeueSize, |
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squeueEnd, |
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minGathered, /* Min/max photons actually gathered */ |
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maxGathered, /* per density estimate */ |
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shortLookupPct; /* Percentage of short lookups (for |
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statistics output */ |
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|
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/* NOTE: All distances are SQUARED */ |
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float maxDist, /* Max search radius during NN search */ |
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maxDist0, /* Initial value for above */ |
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maxDistLimit, /* Hard limit for above */ |
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CoGdist, /* Avg distance to centre of gravity */ |
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maxPos [3], minPos [3], /* Max & min photon positions */ |
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distribRatio, /* Probability of photon storage */ |
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gatherTolerance, /* Fractional deviation from minGather/ |
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maxGather for short lookup */ |
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minError, maxError, /* Min/max/rms density estimate error */ |
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rmsError; |
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|
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FVECT CoG; /* Centre of gravity (avg photon pos) */ |
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COLOR photonFlux; /* Average photon flux */ |
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unsigned short randState [3]; /* Local RNG state */ |
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void (*lookup)(struct PhotonMap*, RAY*, COLOR); |
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/* Callback for type-specific photon |
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* lookup (usually density estimate) */ |
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|
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PhotonPrimary *primary; /* Primary photon rays & associated |
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counters */ |
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unsigned primarySize, primaryEnd; |
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|
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LUTAB *srcContrib; /* lookup table for source contribs */ |
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} PhotonMap; |
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/* Photon maps by type (see PhotonMapType) */ |
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extern PhotonMap *photonMaps []; |
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|
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/* Macros for specific photon map types */ |
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#define globalPmap (photonMaps [PMAP_TYPE_GLOBAL]) |
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#define preCompPmap (photonMaps [PMAP_TYPE_PRECOMP]) |
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#define causticPmap (photonMaps [PMAP_TYPE_CAUSTIC]) |
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#define volumePmap (photonMaps [PMAP_TYPE_VOLUME]) |
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#define directPmap (photonMaps [PMAP_TYPE_DIRECT]) |
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#define contribPmap (photonMaps [PMAP_TYPE_CONTRIB]) |
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void initPhotonMap (PhotonMap *pmap, PhotonMapType t); |
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/* Initialise empty photon map of specified type */ |
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const PhotonPrimary* addPhotonPrimary (PhotonMap *pmap, const RAY *ray); |
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/* Add primary ray for emitted photon and save light source index, origin |
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* on source, and emitted direction; used by contrib photons */ |
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const Photon* addPhoton (PhotonMap *pmap, const RAY *ray); |
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/* Create new photon with ray's direction, intersection point, and flux, |
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and add to photon map subject to acceptance probability pmap -> |
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distribRatio for global density control; if the photon is rejected, |
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NULL is returned. The flux is scaled by ray -> rweight and |
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1 / pmap -> distribRatio. */ |
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void balancePhotons (PhotonMap *pmap, double *photonFlux); |
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/* Build a balanced kd-tree as heap to guarantee logarithmic search |
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* times. This must be called prior to performing photon search with |
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* findPhotons(). |
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* PhotonFlux is the flux scaling factor per photon averaged over RGB. In |
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* the case of a contribution photon map, this is an array with a |
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* separate factor specific to each light source due to non-uniform |
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* photon emission; Otherwise it is referenced as a scalar value. Flux is |
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* not scaled if photonFlux == NULL. */ |
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void buildHeap (Photon *heap, unsigned long *heapIdx, |
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unsigned long *heapXdi, const float min [3], |
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const float max [3], unsigned long left, |
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unsigned long right, unsigned long root); |
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/* Recursive part of balancePhotons(..); builds heap from subarray |
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* defined by indices left and right. */ |
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void findPhotons (PhotonMap* pmap, const RAY *ray); |
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/* Find pmap -> squeueSize closest photons to ray -> rop with similar |
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normal. For volume photons ray -> rorg is used and the normal is |
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ignored (being the incident direction in this case). Found photons |
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are placed in pmap -> squeue, with pmap -> squeueEnd being the number |
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actually found. */ |
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Photon *find1Photon (PhotonMap *pmap, const RAY *ray); |
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/* Finds single closest photon to ray -> rop with similar normal. |
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Returns NULL if none found. */ |
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void deletePhotons (PhotonMap*); |
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/* Free dem mammaries... */ |
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|
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#endif |
