/* RCSid $Id: pmapcontrib.h,v 2.5 2016/05/17 17:39:47 rschregle Exp $ */

/* 
   =========================================================================
   Photon map routines for precomputed light source contributions; these
   routines interface to mkpmap and rcontrib.

   Roland Schregle (roland.schregle@{hslu.ch, gmail.com})
   (c) Lucerne University of Applied Sciences and Arts,
       supported by the Swiss National Science Foundation 
       (SNSF #147053, "Daylight Redirecting Components",
        SNSF #179067, "Light Fields for Spatio-Temporal Glare Assessment")
   =========================================================================
   
   $Id: pmapcontrib.h,v 2.5 2016/05/17 17:39:47 rschregle Exp $
*/



#ifndef _PMAPCONTRIB_H
   #define _PMAPCONTRIB_H

   #include "pmapdata.h"
   #include "wavelet2.h"
   #include "mrgbe.h"
   #ifndef MAXPROCESS
      #include "rcontrib.h"
   #endif
   
   #ifndef MAXMODLIST 
      /* Max number of contributing sources */
      #define MAXMODLIST 1024 
   #endif
   
   /* Filename templates for per-modifier contrib photon maps and wavelet
      coeffs; these are held in a separate subdirectory PMAP_CONTRIB_DIR */
   #define PMAP_CONTRIB_DIR         "%s.rc"
   #define PMAP_CONTRIB_FILE        "%s/%s.pm"
   #define PMAP_CONTRIB_WAVELETFILE "%s/%s.wvt"
   
   /* The following variables can be specified to override the orientation
      of the Shirley-Chiu mapping (see also disk2square.cal).
      We use the built-in functions in disk2square.c for efficiency and
      in order to not depend on an external function file. These variables
      merely mimic the function file interace.

      RHS            : right-hand-coordinate system (-1 for left-hand)
      rNx, rNy, rNz  : surface normal
      Ux, Uy, Uz     : up vector (defines phi = 0) */
   #define PMAP_CONTRIB_SCRHS       "RHS"
   #define PMAP_CONTRIB_SCNORMX     "rNx"
   #define PMAP_CONTRIB_SCNORMY     "rNy"
   #define PMAP_CONTRIB_SCNORMZ     "rNz"
   #define PMAP_CONTRIB_SCUPX       "Ux"
   #define PMAP_CONTRIB_SCUPY       "Uy"
   #define PMAP_CONTRIB_SCUPZ       "Uz"
   #define PMAP_CONTRIB_SCDEFAULTS  ( \
      "RHS=1; rNx=0; rNy=0; rNz=1; Ux=0; Uy=1; Uz=0;" \
   )
   
   /* Maximum Shirley-Chiu binning resolution l*/
   #define PMAP_CONTRIB_MAXBINRES      (mRGBE_DATABITS >> 1)
   
   /* Shirley-Chiu square dimensions and number of bins for resolution l */
   #define PMAP_CONTRIB_SCDIM(l)       (1 << (l))
   #define PMAP_CONTRIB_SCBINS(l)      (1 << ((l) << 1))



   typedef struct {
      WAVELET_COEFF  *coeff;
      unsigned       bin;
   } ThreshWaveletCoeff;
   
   typedef struct {
      char                 *waveletFname;
      FILE                 *waveletFile;
      WaveletMatrix        waveletMatrix, tWaveletMatrix;
      ThreshWaveletCoeff   *threshCoeffs;
      mRGBERange           mrgbeRange;
      mRGBE                *mrgbeCoeffs;
      unsigned             l, scDim, nCompressedBins;
      unsigned long        contribSize;
   } PreComputedContrib;



   MODCONT *addContribModifier(LUTAB *contribTab, unsigned *numContribs, 
      char *mod, char *binParm, int binCnt
   );
   /* Add light source modifier mod to contribution lookup table
      contribsTab, and update numContribs. Return initialised
      contribution data for this modifier. */


   void addContribModfile(LUTAB *contribTab, unsigned *numContribs, 
      char *modFile, char *binParm, int binCnt
   );
   /* Add light source modifiers from file modFile to contribution lookup
    * table contribTab, and update numContribs. */


   void initPmapContrib (LUTAB *contribTab);
   /* Set up photon map contributions (interface to rcmain.c) */


   PhotonContribSourceIdx newPhotonContribSource (PhotonMap *pmap, 
      const RAY *contribSrcRay, FILE *contribSrcHeap
   );
   /* Add contribution source ray for emitted contribution photon and save 
    * light source index and binned direction. The current contribution source
    * is stored in pmap -> lastContribSrc. If the previous contribution source
    * spawned photons (i.e. has srcIdx >= 0), it's appended to contribSrcHeap.
    * If contribSrcRay == NULL, the current contribution source is still 
    * flushed, but no new source is set. Returns updated contribution source
    * counter pmap -> numContribSrc. */


   PhotonContribSourceIdx buildContribSources (PhotonMap *pmap, 
      FILE **contribSrcHeap, char **contribSrcHeapFname, 
      PhotonContribSourceIdx *contribSrcOfs, unsigned numHeaps
   );
   /* Consolidate per-subprocess contribution sources heaps into array
    * pmap -> contribSrc. Returns offset for contribution source index 
    * linearisation in pmap -> numContribSrc. The heap files in 
    * contribSrcHeap are closed on return. */


   void preComputeContrib (PhotonMap *pmap);
   /* Precompute contributions for a random subset of (finalGather * 
      pmap -> numPhotons) photons, and init the per-modifier precomputed
      contribution photon maps in LUT pmap -> preCompContribTab, discarding
      the original photons. */


   void distribPhotonContrib (PhotonMap *pmap, LUTAB *contribTab, 
      unsigned numContribs, unsigned numProc
   );
   /* Emit photons with binned light source contributions, precompute their
      contributions and build photon map */

   int buildPreCompContribPmap (const LUENT *preCompContribNode, void *p);
   /* Build per-modifier precomputed photon map. Returns 0 on success.  */

   void saveContribPhotonMap (const PhotonMap *pmap, int argc, char **argv);
   /* Save contribution photon map and with its constituent per-modifier
      photon maps in pmap -> preCompContribTab */

   void getPreCompPhotonContrib (PhotonMap *pmap, RAY *ray, 
      COLOR totalContrib
   );
   /* Fetch and decode precomputed light source contributions from single 
      closest precomputed contribution photon at ray -> rop, and accumulate 
      them in pmap -> contribTab. Also returns total precomputed contribs. */

#endif