/* RCSid $Id$ */

/* 
   ======================================================================
   Photon map density estimation routines
   
   Roland Schregle (roland.schregle@{hslu.ch, gmail.com})
   (c) Fraunhofer Institute for Solar Energy Systems,
       supported by the German Research Foundation 
       (DFG LU-204/10-2, "Fassadenintegrierte Regelsysteme" (FARESYS)) 
   (c) Lucerne University of Applied Sciences and Arts,
       supported by the Swiss National Science Foundation 
       (SNSF #147053, "Daylight Redirecting Components")
   (c) Tokyo University of Science,
       supported by the JSPS Grants-in-Aid for Scientific Research 
       (KAKENHI JP19KK0115, "Three-Dimensional Light Flow")
   ======================================================================
   
   $Id$
*/



#ifndef PMAPDENS_H
   #define PMAPDENS_H
   
   #include "pmap.h"

   /* Photon map lookup functions per type */
   void (*pmapLookup [NUM_PMAP_TYPES])(PhotonMap*, RAY*, COLOR);

   void photonDensity (PhotonMap *pmap, RAY *ray, COLOR irrad);
   /* Surface-bound photon density estimate for global and caustic photons. 
      Returns irradiance at ray -> rop. */
      
   void photonPreCompDensity (PhotonMap *pmap, RAY *r, COLOR irrad);
   /* Surface-bound photon density estimate for (single) precomputed photon. 
      Returns precomputed irradiance at ray -> rop. */

   void volumePhotonDensity (PhotonMap *pmap, RAY *ray, COLOR irrad);
   /* Volume photon density estimate using Henyey-Greenstein phase function. 
      Returns inscattered irradiance at ray -> rop. */

   #ifdef PMAP_PHOTONFLOW
      void volumePhotonSphIrrad (PhotonMap *pmap, RAY *ray, COLOR irrad);
      /* Evaluate spherical irradiance from volume photons inscattered at
      /* ray->rop, ignoring participating medium.  This evaluates the scalar
      /* irradiance of a physical light field represented by "photon flow". 
      /* The found photons in the search queue must originate from disparate
      /* paths for an unbiased solution.  This requires enabling the photon
      /* path ID filter callback in findPhotons() to remove duplicate paths.
       */
    #endif
#endif