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#ifndef lint |
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static const char RCSid[] = "$Id: pmcontrib2.c,v 2.3 2017/08/14 21:12:10 rschregle Exp $"; |
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#endif |
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|
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/* |
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====================================================================== |
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Photon map support for using light source contributions |
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|
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Roland Schregle (roland.schregle@{hslu.ch, gmail.com}) |
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(c) Lucerne University of Applied Sciences and Arts, |
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supported by the Swiss National Science Foundation (SNSF, #147053) |
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====================================================================== |
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|
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$Id: pmcontrib2.c,v 2.3 2017/08/14 21:12:10 rschregle Exp $ |
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*/ |
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|
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|
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#include "pmapcontrib.h" |
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#include "pmapmat.h" |
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#include "pmapsrc.h" |
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#include "pmaprand.h" |
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#include "pmapio.h" |
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#include "pmapdiag.h" |
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#include "rcontrib.h" |
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#include "otypes.h" |
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|
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|
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|
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static void setPmapContribParams (PhotonMap *pmap, LUTAB *srcContrib) |
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/* Set parameters for light source contributions */ |
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{ |
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/* Set light source modifier list and appropriate callback to extract |
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* their contributions from the photon map */ |
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if (pmap) { |
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pmap -> srcContrib = srcContrib; |
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pmap -> lookup = photonContrib; |
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/* Ensure we get all requested photon contribs during lookups */ |
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pmap -> gatherTolerance = 1.0; |
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} |
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} |
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|
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|
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|
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static void checkPmapContribs (const PhotonMap *pmap, LUTAB *srcContrib) |
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/* Check modifiers for light source contributions */ |
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{ |
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const PhotonPrimary *primary = pmap -> primaries; |
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PhotonPrimaryIdx i, found = 0; |
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OBJREC *srcMod; |
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|
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/* Make sure at least one of the modifiers is actually in the pmap, |
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* otherwise findPhotons() winds up in an infinite loop! */ |
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for (i = pmap -> numPrimary; i; --i, ++primary) { |
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if (primary -> srcIdx < 0 || primary -> srcIdx >= nsources) |
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error(INTERNAL, "invalid light source index in photon map"); |
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|
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srcMod = findmaterial(source [primary -> srcIdx].so); |
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if ((MODCONT*)lu_find(srcContrib, srcMod -> oname) -> data) |
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++found; |
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} |
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|
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if (!found) |
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error(USER, "modifiers not in photon map"); |
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} |
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|
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|
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|
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void initPmapContrib (LUTAB *srcContrib, unsigned numSrcContrib) |
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{ |
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unsigned t; |
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|
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for (t = 0; t < NUM_PMAP_TYPES; t++) |
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if (photonMaps [t] && t != PMAP_TYPE_CONTRIB) { |
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sprintf(errmsg, "%s photon map does not support contributions", |
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pmapName [t]); |
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error(USER, errmsg); |
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} |
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|
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/* Get params */ |
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setPmapContribParams(contribPmap, srcContrib); |
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|
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if (contribPhotonMapping) { |
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if (contribPmap -> maxGather < numSrcContrib) { |
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#if 0 |
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/* Adjust density estimate bandwidth if lower than modifier |
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* count, otherwise contributions are missing */ |
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error(WARNING, "contrib density estimate bandwidth too low, " |
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"adjusting to modifier count"); |
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contribPmap -> maxGather = numSrcContrib; |
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#else |
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/* Warn if density estimate bandwidth is lower than modifier |
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* count, since some contributions will be missing */ |
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error(WARNING, "photon density estimate bandwidth too low," |
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" contributions may be underestimated"); |
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#endif |
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} |
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|
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/* Sanity check */ |
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checkPmapContribs(contribPmap, srcContrib); |
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} |
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} |
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|
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|
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|
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void photonContrib (PhotonMap *pmap, RAY *ray, COLOR irrad) |
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/* Sum up light source contributions from photons in pmap->srcContrib */ |
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{ |
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unsigned i; |
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PhotonSearchQueueNode *sqn; |
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float r2, invArea; |
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RREAL rayCoeff [3]; |
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Photon *photon; |
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static char warnPos = 1, warnDir = 1; |
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|
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setcolor(irrad, 0, 0, 0); |
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|
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if (!pmap -> maxGather) |
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return; |
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|
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/* Ignore sources */ |
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if (ray -> ro && islight(objptr(ray -> ro -> omod) -> otype)) |
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return; |
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|
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/* Get cumulative path coefficient up to photon lookup point */ |
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raycontrib(rayCoeff, ray, PRIMARY); |
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|
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/* Lookup photons */ |
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pmap -> squeue.tail = 0; |
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findPhotons(pmap, ray); |
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|
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/* Need at least 2 photons */ |
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if (pmap -> squeue.tail < 2) { |
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#ifdef PMAP_NONEFOUND |
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sprintf(errmsg, "no photons found on %s at (%.3f, %.3f, %.3f)", |
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ray -> ro ? ray -> ro -> oname : "<null>", |
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ray -> rop [0], ray -> rop [1], ray -> rop [2]); |
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error(WARNING, errmsg); |
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#endif |
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|
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return; |
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} |
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|
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/* Average radius^2 between furthest two photons to improve accuracy and |
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* get inverse search area 1 / (PI * r^2), with extra normalisation |
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* factor 1 / PI for ambient calculation */ |
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sqn = pmap -> squeue.node + 1; |
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r2 = max(sqn -> dist2, (sqn + 1) -> dist2); |
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r2 = 0.25 * (pmap -> maxDist2 + r2 + 2 * sqrt(pmap -> maxDist2 * r2)); |
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invArea = 1 / (PI * PI * r2); |
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|
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/* Skip the extra photon */ |
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for (i = 1 ; i < pmap -> squeue.tail; i++, sqn++) { |
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COLOR flux; |
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|
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/* Get photon's contribution to density estimate */ |
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photon = getNearestPhoton(&pmap -> squeue, sqn -> idx); |
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getPhotonFlux(photon, flux); |
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scalecolor(flux, invArea); |
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#ifdef PMAP_EPANECHNIKOV |
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/* Apply Epanechnikov kernel to photon flux based on photon distance */ |
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scalecolor(flux, 2 * (1 - sqn -> dist2 / r2)); |
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#endif |
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addcolor(irrad, flux); |
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|
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if (pmap -> srcContrib) { |
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const PhotonPrimary *primary = pmap -> primaries + |
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photon -> primary; |
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const SRCREC *sp = &source [primary -> srcIdx]; |
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OBJREC *srcMod = findmaterial(sp -> so); |
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MODCONT *srcContrib = (MODCONT*)lu_find(pmap -> srcContrib, |
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srcMod -> oname) -> data; |
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double srcBinReal; |
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int srcBin; |
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RAY srcRay; |
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|
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if (!srcContrib) |
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continue; |
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|
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/* Photon's emitting light source has modifier whose contributions |
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* are sought */ |
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if (srcContrib -> binv -> type != NUM) { |
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/* Use intersection function to set shadow ray parameters if |
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* it's not simply a constant */ |
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rayorigin(&srcRay, SHADOW, NULL, NULL); |
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srcRay.rsrc = primary -> srcIdx; |
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#ifdef PMAP_PRIMARYPOS |
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VCOPY(srcRay.rorg, primary -> pos); |
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#else |
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/* No primary hitpoints; set dummy ray origin and warn once */ |
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srcRay.rorg [0] = srcRay.rorg [1] = srcRay.rorg [2] = 0; |
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if (warnPos) { |
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error(WARNING, |
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"no photon primary hitpoints for bin evaluation; " |
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"using dummy (0,0,0)! Recompile with -DPMAP_CBDM."); |
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warnPos = 0; |
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} |
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#endif |
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#ifdef PMAP_PRIMARYDIR |
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decodedir(srcRay.rdir, primary -> dir); |
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#else |
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/* No primary incident direction; set dummy and warn once */ |
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if (warnDir) { |
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error(WARNING, |
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"no photon primary directions for bin evaluation; " |
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"using dummy (0,0,0)! Recompile with -DPMAP_CBDM."); |
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warnDir = 0; |
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} |
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srcRay.rdir [0] = srcRay.rdir [1] = srcRay.rdir [2] = 0; |
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#endif |
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|
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if (!(sp->sflags & SDISTANT |
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? sourcehit(&srcRay) |
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: (*ofun[sp -> so -> otype].funp)(sp -> so, &srcRay))) |
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continue; /* XXX shouldn't happen! */ |
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|
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worldfunc(RCCONTEXT, &srcRay); |
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set_eparams((char *)srcContrib -> params); |
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} |
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|
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if ((srcBinReal = evalue(srcContrib -> binv)) < -.5) |
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continue; /* silently ignore negative bins */ |
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|
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if ((srcBin = srcBinReal + .5) >= srcContrib -> nbins) { |
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error(WARNING, "bad bin number (ignored)"); |
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continue; |
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} |
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|
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if (!contrib) { |
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/* Ray coefficient mode; normalise by light source radiance |
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* after applying distrib pattern */ |
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int j; |
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|
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raytexture(ray, srcMod -> omod); |
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setcolor(ray -> rcol, srcMod -> oargs.farg [0], |
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srcMod -> oargs.farg [1], srcMod -> oargs.farg [2]); |
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multcolor(ray -> rcol, ray -> pcol); |
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for (j = 0; j < 3; j++) |
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flux [j] = ray -> rcol [j] ? flux [j] / ray -> rcol [j] : 0; |
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} |
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|
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multcolor(flux, rayCoeff); |
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addcolor(srcContrib -> cbin [srcBin], flux); |
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} |
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} |
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|
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return; |
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} |
