| 1 | /* | 
| 2 | ================================================================== | 
| 3 | In-core kd-tree for photon map | 
| 4 |  | 
| 5 | Roland Schregle (roland.schregle@{hslu.ch, gmail.com}) | 
| 6 | (c) Fraunhofer Institute for Solar Energy Systems, | 
| 7 | (c) Lucerne University of Applied Sciences and Arts, | 
| 8 | supported by the Swiss National Science Foundation (SNSF, #147053) | 
| 9 | ================================================================== | 
| 10 |  | 
| 11 | $Id: pmapkdt.h,v 1.2 2020/04/08 15:14:21 rschregle Exp $ | 
| 12 | */ | 
| 13 |  | 
| 14 |  | 
| 15 | #ifndef PMAPKDT_H | 
| 16 | #define PMAPKDT_H | 
| 17 |  | 
| 18 | /*   #include <stdio.h> | 
| 19 | #include "fvect.h" */ | 
| 20 | #include "pmapdata.h" | 
| 21 |  | 
| 22 | #ifdef __cplusplus | 
| 23 | extern "C" { | 
| 24 | #endif | 
| 25 |  | 
| 26 | /* Forward declarations to break dependency loop with pmapdata.h */ | 
| 27 | struct PhotonMap; | 
| 28 |  | 
| 29 | /* k-d tree as linear array of photons */ | 
| 30 | typedef struct { | 
| 31 | Photon   *nodes;  /* k-d tree as linear array */ | 
| 32 | } PhotonKdTree; | 
| 33 |  | 
| 34 | typedef  PhotonKdTree   PhotonStorage; | 
| 35 | typedef  Photon*        PhotonIdx; | 
| 36 |  | 
| 37 | /* Priority queue node for kd-tree lookups */ | 
| 38 | typedef struct { | 
| 39 | PhotonIdx   idx;        /* Pointer to photon */ | 
| 40 | float       dist2;      /* Photon's SQUARED distance to query point */ | 
| 41 | } kdT_SearchQueueNode; | 
| 42 |  | 
| 43 | typedef struct { | 
| 44 | kdT_SearchQueueNode  *node; | 
| 45 | unsigned             len, tail; | 
| 46 | } kdT_SearchQueue; | 
| 47 |  | 
| 48 | typedef  kdT_SearchQueueNode  PhotonSearchQueueNode; | 
| 49 | typedef  kdT_SearchQueue      PhotonSearchQueue; | 
| 50 |  | 
| 51 |  | 
| 52 |  | 
| 53 | void kdT_Null (PhotonKdTree *kdt); | 
| 54 | /* Initialise kd-tree prior to storing photons */ | 
| 55 |  | 
| 56 | void kdT_BuildPhotonMap (struct PhotonMap *pmap); | 
| 57 | /* Build a balanced kd-tree pmap -> store from photons in unsorted | 
| 58 | * heapfile pmap -> heap to guarantee logarithmic search times.  The heap | 
| 59 | * is destroyed on return.  */ | 
| 60 |  | 
| 61 | int kdT_SavePhotons (const struct PhotonMap *pmap, FILE *out); | 
| 62 | /* Save photons in kd-tree to file. Return -1 on error, else 0 */ | 
| 63 |  | 
| 64 | int kdT_LoadPhotons (struct PhotonMap *pmap, FILE *in); | 
| 65 | /* Load photons in kd-tree from file. Return -1 on error, else 0 */ | 
| 66 |  | 
| 67 | void kdT_InitFindPhotons (struct PhotonMap *pmap); | 
| 68 | /* Initialise NN search queue prior to calling kdT_FindPhotons() */ | 
| 69 |  | 
| 70 | int kdT_FindPhotons (struct PhotonMap* pmap, const FVECT pos, | 
| 71 | const FVECT norm); | 
| 72 | /* Locate pmap -> squeue.len nearest photons to pos with similar normal | 
| 73 | * (NULL for volume photons) and return in search queue pmap -> squeue, | 
| 74 | * starting with the further photon at pmap -> squeue.node. Return -1 | 
| 75 | * if none found, else 0. */ | 
| 76 |  | 
| 77 | int kdT_Find1Photon (struct PhotonMap* pmap, const FVECT pos, | 
| 78 | const FVECT norm, Photon *photon); | 
| 79 | /* Locate single nearest photon to pos with similar normal. Return -1 | 
| 80 | * if none found, else 0. */ | 
| 81 |  | 
| 82 | int kdT_GetPhoton (const struct PhotonMap *pmap, PhotonIdx idx, | 
| 83 | Photon *photon); | 
| 84 | /* Retrieve photon referenced by idx from kd-tree and return -1 on | 
| 85 | * error, else 0. */ | 
| 86 |  | 
| 87 | Photon *kdT_GetNearestPhoton (const PhotonSearchQueue *squeue, | 
| 88 | PhotonIdx idx); | 
| 89 | /* Retrieve photon from NN search queue after OOC_FindPhotons() */ | 
| 90 |  | 
| 91 | PhotonIdx kdT_FirstPhoton (const struct PhotonMap* pmap); | 
| 92 | /* Return pointer to first photon in kd-Tree */ | 
| 93 |  | 
| 94 | void kdT_Delete (PhotonKdTree *kdt); | 
| 95 | /* Self-destruct */ | 
| 96 |  | 
| 97 | #ifdef __cplusplus | 
| 98 | } | 
| 99 | #endif | 
| 100 |  | 
| 101 | #endif |