| 1 |
greg |
3.2 |
#ifndef lint
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| 2 |
greg |
3.6 |
static const char RCSid[] = "$Id: bsdf_t.c,v 3.5 2011/04/19 21:31:22 greg Exp $";
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| 3 |
greg |
3.2 |
#endif
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| 4 |
greg |
3.1 |
/*
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| 5 |
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* bsdf_t.c
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| 6 |
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*
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| 7 |
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* Definitions for variable-resolution BSDF trees
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| 8 |
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*
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| 9 |
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* Created by Greg Ward on 2/2/11.
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| 10 |
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*
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| 11 |
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*/
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| 12 |
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| 13 |
greg |
3.3 |
#include "rtio.h"
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| 14 |
greg |
3.1 |
#include <stdlib.h>
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| 15 |
greg |
3.3 |
#include <math.h>
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| 16 |
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#include <ctype.h>
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| 17 |
greg |
3.1 |
#include "ezxml.h"
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| 18 |
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#include "bsdf.h"
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| 19 |
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#include "bsdf_t.h"
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| 20 |
greg |
3.6 |
#include "hilbert.h"
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| 21 |
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| 22 |
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/* Callback function type for SDtraverseTre() */
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| 23 |
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typedef int SDtreCallback(float val, const double *cmin,
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| 24 |
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double csiz, void *cptr);
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| 25 |
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| 26 |
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/* reference width maximum (1.0) */
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| 27 |
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static const unsigned iwmax = (1<<(sizeof(unsigned)*4))-1;
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| 28 |
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| 29 |
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/* Struct used for our distribution-building callback */
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| 30 |
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typedef struct {
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int wmin; /* minimum square size so far */
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| 32 |
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int wmax; /* maximum square size */
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| 33 |
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int nic; /* number of input coordinates */
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| 34 |
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int alen; /* current array length */
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| 35 |
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int nall; /* number of allocated entries */
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| 36 |
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struct outdir_s {
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| 37 |
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unsigned hent; /* entering Hilbert index */
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| 38 |
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int wid; /* this square size */
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| 39 |
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float bsdf; /* BSDF for this square */
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| 40 |
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} *darr; /* output direction array */
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| 41 |
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} SDdistScaffold;
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| 42 |
greg |
3.1 |
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| 43 |
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/* Allocate a new scattering distribution node */
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| 44 |
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static SDNode *
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| 45 |
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SDnewNode(int nd, int lg)
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| 46 |
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{
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| 47 |
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SDNode *st;
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| 48 |
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| 49 |
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if (nd <= 0) {
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| 50 |
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strcpy(SDerrorDetail, "Zero dimension BSDF node request");
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| 51 |
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return NULL;
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| 52 |
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}
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| 53 |
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if (nd > SD_MAXDIM) {
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| 54 |
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sprintf(SDerrorDetail, "Illegal BSDF dimension (%d > %d)",
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nd, SD_MAXDIM);
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| 56 |
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return NULL;
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| 57 |
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}
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| 58 |
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if (lg < 0) {
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st = (SDNode *)malloc(sizeof(SDNode) +
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((1<<nd) - 1)*sizeof(st->u.t[0]));
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if (st != NULL)
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greg |
3.5 |
memset(st->u.t, 0, sizeof(st->u.t[0])<<nd);
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greg |
3.1 |
} else
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| 64 |
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st = (SDNode *)malloc(sizeof(SDNode) +
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((1 << nd*lg) - 1)*sizeof(st->u.v[0]));
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| 67 |
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if (st == NULL) {
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| 68 |
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if (lg < 0)
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sprintf(SDerrorDetail,
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| 70 |
greg |
3.6 |
"Cannot allocate %d branch BSDF tree", 1<<nd);
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| 71 |
greg |
3.1 |
else
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| 72 |
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sprintf(SDerrorDetail,
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| 73 |
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"Cannot allocate %d BSDF leaves", 1 << nd*lg);
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| 74 |
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return NULL;
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| 75 |
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}
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| 76 |
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st->ndim = nd;
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| 77 |
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st->log2GR = lg;
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| 78 |
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return st;
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| 79 |
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}
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| 81 |
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/* Free an SD tree */
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static void
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| 83 |
greg |
3.6 |
SDfreeTre(SDNode *st)
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greg |
3.1 |
{
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| 85 |
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int i;
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| 86 |
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| 87 |
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if (st == NULL)
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return;
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| 89 |
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for (i = (st->log2GR < 0) << st->ndim; i--; )
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| 90 |
greg |
3.5 |
SDfreeTre(st->u.t[i]);
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greg |
3.1 |
free((void *)st);
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| 92 |
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}
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| 93 |
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| 94 |
greg |
3.6 |
/* Free a variable-resolution BSDF */
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static void
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| 96 |
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SDFreeBTre(void *p)
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| 97 |
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{
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| 98 |
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SDTre *sdt = (SDTre *)p;
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| 99 |
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| 100 |
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if (sdt == NULL)
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| 101 |
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return;
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| 102 |
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SDfreeTre(sdt->st);
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| 103 |
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free(sdt);
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| 104 |
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}
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| 105 |
greg |
3.5 |
|
| 106 |
greg |
3.1 |
/* Add up N-dimensional hypercube array values over the given box */
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| 107 |
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static double
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| 108 |
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SDiterSum(const float *va, int nd, int siz, const int *imin, const int *imax)
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| 109 |
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{
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| 110 |
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double sum = .0;
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| 111 |
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unsigned skipsiz = 1;
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| 112 |
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int i;
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| 113 |
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| 114 |
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for (i = nd; --i > 0; )
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| 115 |
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skipsiz *= siz;
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| 116 |
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if (skipsiz == 1)
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| 117 |
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for (i = *imin; i < *imax; i++)
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| 118 |
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sum += va[i];
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| 119 |
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else
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| 120 |
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for (i = *imin; i < *imax; i++)
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| 121 |
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sum += SDiterSum(va + i*skipsiz,
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| 122 |
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nd-1, siz, imin+1, imax+1);
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| 123 |
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return sum;
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| 124 |
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}
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| 125 |
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| 126 |
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/* Average BSDF leaves over an orthotope defined by the unit hypercube */
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| 127 |
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static double
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| 128 |
greg |
3.6 |
SDavgTreBox(const SDNode *st, const double *bmin, const double *bmax)
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| 129 |
greg |
3.1 |
{
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| 130 |
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int imin[SD_MAXDIM], imax[SD_MAXDIM];
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| 131 |
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unsigned n;
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| 132 |
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int i;
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| 133 |
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| 134 |
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if (!st)
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| 135 |
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return .0;
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| 136 |
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/* check box limits */
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| 137 |
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for (i = st->ndim; i--; ) {
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| 138 |
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if (bmin[i] >= 1.)
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| 139 |
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return .0;
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| 140 |
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if (bmax[i] <= .0)
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| 141 |
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return .0;
|
| 142 |
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if (bmin[i] >= bmax[i])
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| 143 |
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return .0;
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| 144 |
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}
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| 145 |
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if (st->log2GR < 0) { /* iterate on subtree */
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| 146 |
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double sum = .0, wsum = 1e-20;
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| 147 |
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double sbmin[SD_MAXDIM], sbmax[SD_MAXDIM], w;
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| 148 |
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| 149 |
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for (n = 1 << st->ndim; n--; ) {
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| 150 |
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w = 1.;
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| 151 |
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for (i = st->ndim; i--; ) {
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| 152 |
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sbmin[i] = 2.*bmin[i];
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| 153 |
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sbmax[i] = 2.*bmax[i];
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| 154 |
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if (n & 1<<i) {
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| 155 |
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sbmin[i] -= 1.;
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| 156 |
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sbmax[i] -= 1.;
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| 157 |
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}
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| 158 |
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if (sbmin[i] < .0) sbmin[i] = .0;
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| 159 |
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if (sbmax[i] > 1.) sbmax[i] = 1.;
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| 160 |
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w *= sbmax[i] - sbmin[i];
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| 161 |
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}
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| 162 |
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if (w > 1e-10) {
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| 163 |
greg |
3.6 |
sum += w * SDavgTreBox(st->u.t[n], sbmin, sbmax);
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| 164 |
greg |
3.1 |
wsum += w;
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| 165 |
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}
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| 166 |
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}
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| 167 |
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return sum / wsum;
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| 168 |
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}
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| 169 |
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n = 1; /* iterate over leaves */
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| 170 |
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for (i = st->ndim; i--; ) {
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| 171 |
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imin[i] = (bmin[i] <= .0) ? 0
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| 172 |
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: (int)((1 << st->log2GR)*bmin[i]);
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| 173 |
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imax[i] = (bmax[i] >= 1.) ? (1 << st->log2GR)
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| 174 |
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: (int)((1 << st->log2GR)*bmax[i] + .999999);
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| 175 |
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n *= imax[i] - imin[i];
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| 176 |
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}
|
| 177 |
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if (!n)
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| 178 |
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return .0;
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| 179 |
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| 180 |
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return SDiterSum(st->u.v, st->ndim, 1 << st->log2GR, imin, imax) /
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| 181 |
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(double)n;
|
| 182 |
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}
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| 183 |
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| 184 |
greg |
3.6 |
/* Recursive call for SDtraverseTre() */
|
| 185 |
|
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static int
|
| 186 |
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SDdotravTre(const SDNode *st, const double *pos, int cmask,
|
| 187 |
|
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SDtreCallback *cf, void *cptr,
|
| 188 |
|
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const double *cmin, double csiz)
|
| 189 |
|
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{
|
| 190 |
|
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int rv, rval = 0;
|
| 191 |
|
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double bmin[SD_MAXDIM];
|
| 192 |
|
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int i, n;
|
| 193 |
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/* in branches? */
|
| 194 |
|
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if (st->log2GR < 0) {
|
| 195 |
|
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unsigned skipmask = 0;
|
| 196 |
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|
| 197 |
|
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csiz *= .5;
|
| 198 |
|
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for (i = st->ndim; i--; )
|
| 199 |
|
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if (1<<i & cmask)
|
| 200 |
|
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if (pos[i] < cmin[i] + csiz)
|
| 201 |
|
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for (n = 1 << st->ndim; n--; )
|
| 202 |
|
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if (n & 1<<i)
|
| 203 |
|
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skipmask |= 1<<n;
|
| 204 |
|
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else
|
| 205 |
|
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for (n = 1 << st->ndim; n--; )
|
| 206 |
|
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if (!(n & 1<<i))
|
| 207 |
|
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skipmask |= 1<<n;
|
| 208 |
|
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for (n = 1 << st->ndim; n--; ) {
|
| 209 |
|
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if (1<<n & skipmask)
|
| 210 |
|
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continue;
|
| 211 |
|
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for (i = st->ndim; i--; )
|
| 212 |
|
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if (1<<i & n)
|
| 213 |
|
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bmin[i] = cmin[i] + csiz;
|
| 214 |
|
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else
|
| 215 |
|
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bmin[i] = cmin[i];
|
| 216 |
|
|
|
| 217 |
|
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rval += rv = SDdotravTre(st->u.t[n], pos, cmask,
|
| 218 |
|
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cf, cptr, bmin, csiz);
|
| 219 |
|
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if (rv < 0)
|
| 220 |
|
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return rv;
|
| 221 |
|
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}
|
| 222 |
|
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} else { /* else traverse leaves */
|
| 223 |
|
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int clim[SD_MAXDIM][2];
|
| 224 |
|
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int cpos[SD_MAXDIM];
|
| 225 |
|
|
|
| 226 |
|
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if (st->log2GR == 0) /* short cut */
|
| 227 |
|
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return (*cf)(st->u.v[0], cmin, csiz, cptr);
|
| 228 |
|
|
|
| 229 |
|
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csiz /= (double)(1 << st->log2GR);
|
| 230 |
|
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/* assign coord. ranges */
|
| 231 |
|
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for (i = st->ndim; i--; )
|
| 232 |
|
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if (1<<i & cmask) {
|
| 233 |
|
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clim[i][0] = (pos[i] - cmin[i])/csiz;
|
| 234 |
|
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/* check overflow from f.p. error */
|
| 235 |
|
|
clim[i][0] -= clim[i][0] >> st->log2GR;
|
| 236 |
|
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clim[i][1] = clim[i][0] + 1;
|
| 237 |
|
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} else {
|
| 238 |
|
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clim[i][0] = 0;
|
| 239 |
|
|
clim[i][1] = 1 << st->log2GR;
|
| 240 |
|
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}
|
| 241 |
|
|
/* fill in unused dimensions */
|
| 242 |
|
|
for (i = SD_MAXDIM; i-- > st->ndim; ) {
|
| 243 |
|
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clim[i][0] = 0; clim[i][1] = 1;
|
| 244 |
|
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}
|
| 245 |
|
|
#if (SD_MAXDIM == 4)
|
| 246 |
|
|
bmin[0] = cmin[0] + csiz*clim[0][0];
|
| 247 |
|
|
for (cpos[0] = clim[0][0]; cpos[0] < clim[0][1]; cpos[0]++) {
|
| 248 |
|
|
bmin[1] = cmin[1] + csiz*clim[1][0];
|
| 249 |
|
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for (cpos[1] = clim[1][0]; cpos[1] < clim[1][1]; cpos[1]++) {
|
| 250 |
|
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bmin[2] = cmin[2] + csiz*clim[2][0];
|
| 251 |
|
|
for (cpos[2] = clim[2][0]; cpos[2] < clim[2][1]; cpos[2]++) {
|
| 252 |
|
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bmin[3] = cmin[3] + csiz*(cpos[3] = clim[3][0]);
|
| 253 |
|
|
n = cpos[0];
|
| 254 |
|
|
for (i = 1; i < st->ndim; i++)
|
| 255 |
|
|
n = (n << st->log2GR) + cpos[i];
|
| 256 |
|
|
for ( ; cpos[3] < clim[3][1]; cpos[3]++) {
|
| 257 |
|
|
rval += rv = (*cf)(st->u.v[n++], bmin, csiz, cptr);
|
| 258 |
|
|
if (rv < 0)
|
| 259 |
|
|
return rv;
|
| 260 |
|
|
bmin[3] += csiz;
|
| 261 |
|
|
}
|
| 262 |
|
|
bmin[2] += csiz;
|
| 263 |
|
|
}
|
| 264 |
|
|
bmin[1] += csiz;
|
| 265 |
|
|
}
|
| 266 |
|
|
bmin[0] += csiz;
|
| 267 |
|
|
}
|
| 268 |
|
|
#else
|
| 269 |
|
|
_!_ "broken code segment!"
|
| 270 |
|
|
#endif
|
| 271 |
|
|
}
|
| 272 |
|
|
return rval;
|
| 273 |
|
|
}
|
| 274 |
|
|
|
| 275 |
|
|
/* Traverse a tree, visiting nodes in a slice that fits partial position */
|
| 276 |
|
|
static int
|
| 277 |
|
|
SDtraverseTre(const SDNode *st, const double *pos, int cmask,
|
| 278 |
|
|
SDtreCallback *cf, void *cptr)
|
| 279 |
|
|
{
|
| 280 |
|
|
static double czero[SD_MAXDIM];
|
| 281 |
|
|
int i;
|
| 282 |
|
|
/* check arguments */
|
| 283 |
|
|
if ((st == NULL) | (cf == NULL))
|
| 284 |
|
|
return -1;
|
| 285 |
|
|
for (i = st->ndim; i--; )
|
| 286 |
|
|
if (1<<i & cmask && (pos[i] < 0) | (pos[i] >= 1.))
|
| 287 |
|
|
return -1;
|
| 288 |
|
|
|
| 289 |
|
|
return SDdotravTre(st, pos, cmask, cf, cptr, czero, 1.);
|
| 290 |
|
|
}
|
| 291 |
greg |
3.5 |
|
| 292 |
|
|
/* Look up tree value at the given grid position */
|
| 293 |
|
|
static float
|
| 294 |
greg |
3.6 |
SDlookupTre(const SDNode *st, const double *pos, double *hcube)
|
| 295 |
greg |
3.5 |
{
|
| 296 |
|
|
double spos[SD_MAXDIM];
|
| 297 |
|
|
int i, n, t;
|
| 298 |
greg |
3.6 |
/* initialize voxel return */
|
| 299 |
|
|
if (hcube) {
|
| 300 |
|
|
hcube[i = st->ndim] = 1.;
|
| 301 |
|
|
while (i--)
|
| 302 |
|
|
hcube[i] = .0;
|
| 303 |
|
|
}
|
| 304 |
greg |
3.5 |
/* climb the tree */
|
| 305 |
|
|
while (st->log2GR < 0) {
|
| 306 |
|
|
n = 0; /* move to appropriate branch */
|
| 307 |
greg |
3.6 |
if (hcube) hcube[st->ndim] *= .5;
|
| 308 |
greg |
3.5 |
for (i = st->ndim; i--; ) {
|
| 309 |
|
|
spos[i] = 2.*pos[i];
|
| 310 |
|
|
t = (spos[i] >= 1.);
|
| 311 |
|
|
n |= t<<i;
|
| 312 |
|
|
spos[i] -= (double)t;
|
| 313 |
greg |
3.6 |
if (hcube) hcube[i] += (double)t * hcube[st->ndim];
|
| 314 |
greg |
3.5 |
}
|
| 315 |
|
|
st = st->u.t[n]; /* avoids tail recursion */
|
| 316 |
|
|
pos = spos;
|
| 317 |
|
|
}
|
| 318 |
greg |
3.6 |
if (st->log2GR == 0) /* short cut */
|
| 319 |
|
|
return st->u.v[0];
|
| 320 |
greg |
3.5 |
n = t = 0; /* find grid array index */
|
| 321 |
|
|
for (i = st->ndim; i--; ) {
|
| 322 |
|
|
n += (int)((1<<st->log2GR)*pos[i]) << t;
|
| 323 |
|
|
t += st->log2GR;
|
| 324 |
|
|
}
|
| 325 |
greg |
3.6 |
if (hcube) { /* compute final hypercube */
|
| 326 |
|
|
hcube[st->ndim] /= (double)(1<<st->log2GR);
|
| 327 |
|
|
for (i = st->ndim; i--; )
|
| 328 |
|
|
hcube[i] += floor((1<<st->log2GR)*pos[i])*hcube[st->ndim];
|
| 329 |
|
|
}
|
| 330 |
|
|
return st->u.v[n]; /* no interpolation */
|
| 331 |
|
|
}
|
| 332 |
|
|
|
| 333 |
|
|
/* Query BSDF value and sample hypercube for the given vectors */
|
| 334 |
|
|
static float
|
| 335 |
|
|
SDqueryTre(const SDTre *sdt, const FVECT outVec, const FVECT inVec, double *hc)
|
| 336 |
|
|
{
|
| 337 |
|
|
static const FVECT zvec = {.0, .0, 1.};
|
| 338 |
|
|
FVECT rOutVec;
|
| 339 |
|
|
double gridPos[4];
|
| 340 |
|
|
/* check transmission */
|
| 341 |
|
|
if (!sdt->isxmit ^ outVec[2] > 0 ^ inVec[2] > 0)
|
| 342 |
|
|
return -1.;
|
| 343 |
|
|
/* convert vector coordinates */
|
| 344 |
|
|
if (sdt->st->ndim == 3) {
|
| 345 |
|
|
spinvector(rOutVec, outVec, zvec, -atan2(inVec[1],inVec[0]));
|
| 346 |
|
|
gridPos[0] = .5 - .5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]);
|
| 347 |
|
|
SDdisk2square(gridPos+1, rOutVec[0], rOutVec[1]);
|
| 348 |
|
|
} else if (sdt->st->ndim == 4) {
|
| 349 |
|
|
SDdisk2square(gridPos, -inVec[0], -inVec[1]);
|
| 350 |
|
|
SDdisk2square(gridPos+2, outVec[0], outVec[1]);
|
| 351 |
|
|
} else
|
| 352 |
|
|
return -1.; /* should be internal error */
|
| 353 |
|
|
|
| 354 |
|
|
return SDlookupTre(sdt->st, gridPos, hc);
|
| 355 |
greg |
3.5 |
}
|
| 356 |
|
|
|
| 357 |
|
|
/* Compute non-diffuse component for variable-resolution BSDF */
|
| 358 |
|
|
static int
|
| 359 |
|
|
SDgetTreBSDF(float coef[SDmaxCh], const FVECT outVec,
|
| 360 |
greg |
3.6 |
const FVECT inVec, SDComponent *sdc)
|
| 361 |
greg |
3.5 |
{
|
| 362 |
greg |
3.6 |
/* check arguments */
|
| 363 |
|
|
if ((coef == NULL) | (outVec == NULL) | (inVec == NULL) | (sdc == NULL)
|
| 364 |
|
|
|| sdc->dist == NULL)
|
| 365 |
|
|
return 0;
|
| 366 |
greg |
3.5 |
/* get nearest BSDF value */
|
| 367 |
greg |
3.6 |
coef[0] = SDqueryTre((SDTre *)sdc->dist, outVec, inVec, NULL);
|
| 368 |
|
|
return (coef[0] >= 0); /* monochromatic for now */
|
| 369 |
|
|
}
|
| 370 |
|
|
|
| 371 |
|
|
/* Callback to build cumulative distribution using SDtraverseTre() */
|
| 372 |
|
|
static int
|
| 373 |
|
|
build_scaffold(float val, const double *cmin, double csiz, void *cptr)
|
| 374 |
|
|
{
|
| 375 |
|
|
SDdistScaffold *sp = (SDdistScaffold *)cptr;
|
| 376 |
|
|
int wid = csiz*(double)iwmax + .5;
|
| 377 |
|
|
bitmask_t bmin[2], bmax[2];
|
| 378 |
|
|
|
| 379 |
|
|
cmin += sp->nic; /* skip to output coords */
|
| 380 |
|
|
if (wid < sp->wmin) /* new minimum width? */
|
| 381 |
|
|
sp->wmin = wid;
|
| 382 |
|
|
if (wid > sp->wmax) /* new maximum? */
|
| 383 |
|
|
sp->wmax = wid;
|
| 384 |
|
|
if (sp->alen >= sp->nall) { /* need more space? */
|
| 385 |
|
|
struct outdir_s *ndarr;
|
| 386 |
|
|
sp->nall += 8192;
|
| 387 |
|
|
ndarr = (struct outdir_s *)realloc(sp->darr,
|
| 388 |
|
|
sizeof(struct outdir_s)*sp->nall);
|
| 389 |
|
|
if (ndarr == NULL)
|
| 390 |
|
|
return -1; /* abort build */
|
| 391 |
|
|
sp->darr = ndarr;
|
| 392 |
|
|
}
|
| 393 |
|
|
/* find Hilbert entry index */
|
| 394 |
|
|
bmin[0] = cmin[0]*(double)iwmax + .5;
|
| 395 |
|
|
bmin[1] = cmin[1]*(double)iwmax + .5;
|
| 396 |
|
|
bmax[0] = bmin[0] + wid;
|
| 397 |
|
|
bmax[1] = bmin[1] + wid;
|
| 398 |
|
|
hilbert_box_vtx(2, sizeof(bitmask_t), sizeof(unsigned)*4,
|
| 399 |
|
|
1, bmin, bmax);
|
| 400 |
|
|
sp->darr[sp->alen].hent = hilbert_c2i(2, sizeof(unsigned)*4, bmin);
|
| 401 |
|
|
sp->darr[sp->alen].wid = wid;
|
| 402 |
|
|
sp->darr[sp->alen].bsdf = val;
|
| 403 |
|
|
sp->alen++; /* on to the next entry */
|
| 404 |
|
|
return 0;
|
| 405 |
|
|
}
|
| 406 |
|
|
|
| 407 |
|
|
/* Scaffold comparison function for qsort -- ascending Hilbert index */
|
| 408 |
|
|
static int
|
| 409 |
|
|
sscmp(const void *p1, const void *p2)
|
| 410 |
|
|
{
|
| 411 |
|
|
return (int)((*(const struct outdir_s *)p1).hent -
|
| 412 |
|
|
(*(const struct outdir_s *)p2).hent);
|
| 413 |
|
|
}
|
| 414 |
|
|
|
| 415 |
|
|
/* Create a new cumulative distribution for the given input direction */
|
| 416 |
|
|
static SDTreCDst *
|
| 417 |
|
|
make_cdist(const SDTre *sdt, const double *pos)
|
| 418 |
|
|
{
|
| 419 |
|
|
const unsigned cumlmax = ~0;
|
| 420 |
|
|
SDdistScaffold myScaffold;
|
| 421 |
|
|
SDTreCDst *cd;
|
| 422 |
|
|
struct outdir_s *sp;
|
| 423 |
|
|
double scale, cursum;
|
| 424 |
|
|
int i;
|
| 425 |
|
|
/* initialize scaffold */
|
| 426 |
|
|
myScaffold.wmin = iwmax;
|
| 427 |
|
|
myScaffold.wmax = 0;
|
| 428 |
|
|
myScaffold.nic = sdt->st->ndim - 2;
|
| 429 |
|
|
myScaffold.alen = 0;
|
| 430 |
|
|
myScaffold.nall = 8192;
|
| 431 |
|
|
myScaffold.darr = (struct outdir_s *)malloc(sizeof(struct outdir_s) *
|
| 432 |
|
|
myScaffold.nall);
|
| 433 |
|
|
if (myScaffold.darr == NULL)
|
| 434 |
|
|
return NULL;
|
| 435 |
|
|
/* grow the distribution */
|
| 436 |
|
|
if (SDtraverseTre(sdt->st, pos, (1<<myScaffold.nic)-1,
|
| 437 |
|
|
&build_scaffold, &myScaffold) < 0) {
|
| 438 |
|
|
free(myScaffold.darr);
|
| 439 |
|
|
return NULL;
|
| 440 |
|
|
}
|
| 441 |
|
|
/* allocate result holder */
|
| 442 |
|
|
cd = (SDTreCDst *)malloc(sizeof(SDTreCDst) +
|
| 443 |
|
|
sizeof(cd->carr[0])*myScaffold.alen);
|
| 444 |
|
|
if (cd == NULL) {
|
| 445 |
|
|
free(myScaffold.darr);
|
| 446 |
|
|
return NULL;
|
| 447 |
|
|
}
|
| 448 |
|
|
/* sort the distribution */
|
| 449 |
|
|
qsort(myScaffold.darr, cd->calen = myScaffold.alen,
|
| 450 |
|
|
sizeof(struct outdir_s), &sscmp);
|
| 451 |
|
|
|
| 452 |
|
|
/* record input range */
|
| 453 |
|
|
scale = (double)myScaffold.wmin / iwmax;
|
| 454 |
|
|
for (i = myScaffold.nic; i--; ) {
|
| 455 |
|
|
cd->clim[i][0] = floor(pos[i]/scale + .5) * scale;
|
| 456 |
|
|
cd->clim[i][1] = cd->clim[i][0] + scale;
|
| 457 |
|
|
}
|
| 458 |
|
|
cd->max_psa = myScaffold.wmax / (double)iwmax;
|
| 459 |
|
|
cd->max_psa *= cd->max_psa * M_PI;
|
| 460 |
|
|
cd->isxmit = sdt->isxmit;
|
| 461 |
|
|
cd->cTotal = 1e-20; /* compute directional total */
|
| 462 |
|
|
sp = myScaffold.darr;
|
| 463 |
|
|
for (i = myScaffold.alen; i--; sp++)
|
| 464 |
|
|
cd->cTotal += sp->bsdf * (double)sp->wid * sp->wid;
|
| 465 |
|
|
cursum = .0; /* go back and get cumulative values */
|
| 466 |
|
|
scale = (double)cumlmax / cd->cTotal;
|
| 467 |
|
|
sp = myScaffold.darr;
|
| 468 |
|
|
for (i = 0; i < cd->calen; i++, sp++) {
|
| 469 |
|
|
cd->carr[i].cuml = scale*cursum + .5;
|
| 470 |
|
|
cursum += sp->bsdf * (double)sp->wid * sp->wid;
|
| 471 |
|
|
}
|
| 472 |
|
|
cd->carr[i].hndx = ~0; /* make final entry */
|
| 473 |
|
|
cd->carr[i].cuml = cumlmax;
|
| 474 |
|
|
cd->cTotal *= M_PI/(double)iwmax/iwmax;
|
| 475 |
|
|
/* all done, clean up and return */
|
| 476 |
|
|
free(myScaffold.darr);
|
| 477 |
|
|
return cd;
|
| 478 |
|
|
}
|
| 479 |
|
|
|
| 480 |
|
|
/* Find or allocate a cumulative distribution for the given incoming vector */
|
| 481 |
|
|
const SDCDst *
|
| 482 |
|
|
SDgetTreCDist(const FVECT inVec, SDComponent *sdc)
|
| 483 |
|
|
{
|
| 484 |
|
|
const SDTre *sdt;
|
| 485 |
|
|
double inCoord[2];
|
| 486 |
|
|
int vflags;
|
| 487 |
|
|
int i;
|
| 488 |
|
|
SDTreCDst *cd, *cdlast;
|
| 489 |
|
|
/* check arguments */
|
| 490 |
|
|
if ((inVec == NULL) | (sdc == NULL) ||
|
| 491 |
|
|
(sdt = (SDTre *)sdc->dist) == NULL)
|
| 492 |
|
|
return NULL;
|
| 493 |
|
|
if (sdt->st->ndim == 3) /* isotropic BSDF? */
|
| 494 |
|
|
inCoord[0] = .5 - .5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]);
|
| 495 |
|
|
else if (sdt->st->ndim == 4)
|
| 496 |
|
|
SDdisk2square(inCoord, -inVec[0], -inVec[1]);
|
| 497 |
|
|
else
|
| 498 |
|
|
return NULL; /* should be internal error */
|
| 499 |
|
|
cdlast = NULL; /* check for direction in cache list */
|
| 500 |
|
|
for (cd = (SDTreCDst *)sdc->cdList; cd != NULL;
|
| 501 |
|
|
cdlast = cd, cd = (SDTreCDst *)cd->next) {
|
| 502 |
|
|
for (i = sdt->st->ndim - 2; i--; )
|
| 503 |
|
|
if ((cd->clim[i][0] > inCoord[i]) |
|
| 504 |
|
|
(inCoord[i] >= cd->clim[i][1]))
|
| 505 |
|
|
break;
|
| 506 |
|
|
if (i < 0)
|
| 507 |
|
|
break; /* means we have a match */
|
| 508 |
|
|
}
|
| 509 |
|
|
if (cd == NULL) /* need to create new entry? */
|
| 510 |
|
|
cdlast = cd = make_cdist(sdt, inCoord);
|
| 511 |
|
|
if (cdlast != NULL) { /* move entry to head of cache list */
|
| 512 |
|
|
cdlast->next = cd->next;
|
| 513 |
|
|
cd->next = sdc->cdList;
|
| 514 |
|
|
sdc->cdList = (SDCDst *)cd;
|
| 515 |
|
|
}
|
| 516 |
|
|
return (SDCDst *)cd; /* ready to go */
|
| 517 |
|
|
}
|
| 518 |
|
|
|
| 519 |
|
|
/* Query solid angle for vector(s) */
|
| 520 |
|
|
static SDError
|
| 521 |
|
|
SDqueryTreProjSA(double *psa, const FVECT v1, const RREAL *v2,
|
| 522 |
|
|
int qflags, SDComponent *sdc)
|
| 523 |
|
|
{
|
| 524 |
|
|
double myPSA[2];
|
| 525 |
|
|
/* check arguments */
|
| 526 |
|
|
if ((psa == NULL) | (v1 == NULL) | (sdc == NULL) ||
|
| 527 |
|
|
sdc->dist == NULL)
|
| 528 |
|
|
return SDEargument;
|
| 529 |
|
|
/* get projected solid angle(s) */
|
| 530 |
|
|
if (v2 != NULL) {
|
| 531 |
|
|
const SDTre *sdt = (SDTre *)sdc->dist;
|
| 532 |
|
|
double hcube[SD_MAXDIM];
|
| 533 |
|
|
if (SDqueryTre(sdt, v1, v2, hcube) < 0) {
|
| 534 |
|
|
if (qflags == SDqueryVal)
|
| 535 |
|
|
*psa = M_PI;
|
| 536 |
|
|
return SDEnone;
|
| 537 |
|
|
}
|
| 538 |
|
|
myPSA[0] = hcube[sdt->st->ndim];
|
| 539 |
|
|
myPSA[1] = myPSA[0] *= myPSA[0] * M_PI;
|
| 540 |
|
|
} else {
|
| 541 |
|
|
const SDTreCDst *cd = (const SDTreCDst *)SDgetTreCDist(v1, sdc);
|
| 542 |
|
|
if (cd == NULL)
|
| 543 |
|
|
return SDEmemory;
|
| 544 |
|
|
myPSA[0] = M_PI * (cd->clim[0][1] - cd->clim[0][0]) *
|
| 545 |
|
|
(cd->clim[1][1] - cd->clim[1][0]);
|
| 546 |
|
|
myPSA[1] = cd->max_psa;
|
| 547 |
|
|
}
|
| 548 |
|
|
switch (qflags) { /* record based on flag settings */
|
| 549 |
|
|
case SDqueryVal:
|
| 550 |
|
|
*psa = myPSA[0];
|
| 551 |
|
|
break;
|
| 552 |
|
|
case SDqueryMax:
|
| 553 |
|
|
if (myPSA[1] > *psa)
|
| 554 |
|
|
*psa = myPSA[1];
|
| 555 |
|
|
break;
|
| 556 |
|
|
case SDqueryMin+SDqueryMax:
|
| 557 |
|
|
if (myPSA[1] > psa[1])
|
| 558 |
|
|
psa[1] = myPSA[1];
|
| 559 |
|
|
/* fall through */
|
| 560 |
|
|
case SDqueryMin:
|
| 561 |
|
|
if (myPSA[0] < psa[0])
|
| 562 |
|
|
psa[0] = myPSA[0];
|
| 563 |
|
|
break;
|
| 564 |
|
|
}
|
| 565 |
|
|
return SDEnone;
|
| 566 |
|
|
}
|
| 567 |
|
|
|
| 568 |
|
|
/* Sample cumulative distribution */
|
| 569 |
|
|
static SDError
|
| 570 |
|
|
SDsampTreCDist(FVECT ioVec, double randX, const SDCDst *cdp)
|
| 571 |
|
|
{
|
| 572 |
|
|
const unsigned nBitsC = 4*sizeof(bitmask_t);
|
| 573 |
|
|
const unsigned nExtraBits = 8*(sizeof(bitmask_t)-sizeof(unsigned));
|
| 574 |
|
|
const unsigned maxval = ~0;
|
| 575 |
|
|
const SDTreCDst *cd = (const SDTreCDst *)cdp;
|
| 576 |
|
|
const unsigned target = randX*maxval;
|
| 577 |
|
|
bitmask_t hndx, hcoord[2];
|
| 578 |
|
|
double gpos[3];
|
| 579 |
|
|
int i, iupper, ilower;
|
| 580 |
|
|
/* check arguments */
|
| 581 |
|
|
if ((ioVec == NULL) | (cd == NULL))
|
| 582 |
|
|
return SDEargument;
|
| 583 |
|
|
/* binary search to find position */
|
| 584 |
|
|
ilower = 0; iupper = cd->calen;
|
| 585 |
|
|
while ((i = (iupper + ilower) >> 1) != ilower)
|
| 586 |
|
|
if ((long)target >= (long)cd->carr[i].cuml)
|
| 587 |
|
|
ilower = i;
|
| 588 |
|
|
else
|
| 589 |
|
|
iupper = i;
|
| 590 |
|
|
/* localize random position */
|
| 591 |
|
|
randX = (randX*maxval - cd->carr[ilower].cuml) /
|
| 592 |
|
|
(double)(cd->carr[iupper].cuml - cd->carr[ilower].cuml);
|
| 593 |
|
|
/* index in longer Hilbert curve */
|
| 594 |
|
|
hndx = (randX*cd->carr[iupper].hndx + (1.-randX)*cd->carr[ilower].hndx)
|
| 595 |
|
|
* (double)((bitmask_t)1 << nExtraBits);
|
| 596 |
|
|
/* convert Hilbert index to vector */
|
| 597 |
|
|
hilbert_i2c(2, nBitsC, hndx, hcoord);
|
| 598 |
|
|
for (i = 2; i--; )
|
| 599 |
|
|
gpos[i] = ((double)hcoord[i] + rand()*(1./(RAND_MAX+.5))) /
|
| 600 |
|
|
(double)((bitmask_t)1 << nBitsC);
|
| 601 |
|
|
SDsquare2disk(gpos, gpos[0], gpos[1]);
|
| 602 |
|
|
gpos[2] = 1. - gpos[0]*gpos[0] - gpos[1]*gpos[1];
|
| 603 |
|
|
if (gpos[2] > 0) /* paranoia, I hope */
|
| 604 |
|
|
gpos[2] = sqrt(gpos[2]);
|
| 605 |
|
|
if (ioVec[2] > 0 ^ !cd->isxmit)
|
| 606 |
|
|
gpos[2] = -gpos[2];
|
| 607 |
|
|
VCOPY(ioVec, gpos);
|
| 608 |
|
|
return SDEnone;
|
| 609 |
greg |
3.5 |
}
|
| 610 |
|
|
|
| 611 |
greg |
3.1 |
/* Load a variable-resolution BSDF tree from an open XML file */
|
| 612 |
|
|
SDError
|
| 613 |
greg |
3.4 |
SDloadTre(SDData *sd, ezxml_t wtl)
|
| 614 |
greg |
3.1 |
{
|
| 615 |
|
|
return SDEsupport;
|
| 616 |
|
|
}
|
| 617 |
|
|
|
| 618 |
|
|
/* Variable resolution BSDF methods */
|
| 619 |
greg |
3.5 |
SDFunc SDhandleTre = {
|
| 620 |
|
|
&SDgetTreBSDF,
|
| 621 |
greg |
3.6 |
&SDqueryTreProjSA,
|
| 622 |
|
|
&SDgetTreCDist,
|
| 623 |
|
|
&SDsampTreCDist,
|
| 624 |
|
|
&SDFreeBTre,
|
| 625 |
greg |
3.1 |
};
|
