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#ifndef lint |
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static const char RCSid[] = "$Id: bsdf_t.c,v 3.53 2021/12/15 01:38:50 greg Exp $"; |
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#endif |
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/* |
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* bsdf_t.c |
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* |
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* Definitions for variable-resolution BSDF trees |
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* |
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* Created by Greg Ward on 2/2/11. |
10 |
* |
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*/ |
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|
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#define _USE_MATH_DEFINES |
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#include "rtio.h" |
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#include <stdlib.h> |
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#include <math.h> |
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#include <ctype.h> |
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#include "ezxml.h" |
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#include "bsdf.h" |
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#include "bsdf_t.h" |
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#include "hilbert.h" |
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|
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/* Callback function type for SDtraverseTre() */ |
24 |
typedef int SDtreCallback(float val, const double *cmin, double csiz, |
25 |
void *cptr); |
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/* reference width maximum (1.0) */ |
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static const unsigned iwbits = sizeof(unsigned)*4; |
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static const unsigned iwmax = 1<<(sizeof(unsigned)*4); |
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/* maximum cumulative value */ |
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static const unsigned cumlmax = ~0; |
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/* constant z-vector */ |
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static const FVECT zvec = {.0, .0, 1.}; |
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/* quantization value */ |
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static double quantum = 1./256.; |
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/* our RGB primaries */ |
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static C_COLOR tt_RGB_prim[3]; |
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static float tt_RGB_coef[3]; |
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|
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static const double czero[SD_MAXDIM]; |
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|
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enum {tt_Y, tt_u, tt_v}; /* tree components (tt_Y==0) */ |
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|
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/* Struct used for our distribution-building callback */ |
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typedef struct { |
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short nic; /* number of input coordinates */ |
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short rev; /* reversing query */ |
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unsigned alen; /* current array length */ |
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unsigned nall; /* number of allocated entries */ |
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unsigned wmin; /* minimum square size so far */ |
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unsigned wmax; /* maximum square size */ |
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struct outdir_s { |
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unsigned hent; /* entering Hilbert index */ |
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int wid; /* this square size */ |
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float bsdf; /* BSDF for this square */ |
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} *darr; /* output direction array */ |
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} SDdistScaffold; |
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|
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/* Allocate a new scattering distribution node */ |
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static SDNode * |
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SDnewNode(int nd, int lg) |
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{ |
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SDNode *st; |
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|
64 |
if (nd <= 0) { |
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strcpy(SDerrorDetail, "Zero dimension BSDF node request"); |
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return NULL; |
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} |
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if (nd > SD_MAXDIM) { |
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sprintf(SDerrorDetail, "Illegal BSDF dimension (%d > %d)", |
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nd, SD_MAXDIM); |
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return NULL; |
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} |
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if (lg < 0) { |
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st = (SDNode *)malloc(sizeof(SDNode) + |
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sizeof(st->u.t[0])*((1<<nd) - 1)); |
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if (st == NULL) { |
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sprintf(SDerrorDetail, |
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"Cannot allocate %d branch BSDF tree", 1<<nd); |
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return NULL; |
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} |
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memset(st->u.t, 0, sizeof(st->u.t[0])<<nd); |
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} else { |
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st = (SDNode *)malloc(sizeof(SDNode) + |
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sizeof(st->u.v[0])*((1 << nd*lg) - 1)); |
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if (st == NULL) { |
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sprintf(SDerrorDetail, |
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"Cannot allocate %d BSDF leaves", 1 << nd*lg); |
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return NULL; |
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} |
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} |
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st->ndim = nd; |
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st->log2GR = lg; |
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return st; |
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} |
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|
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/* Free an SD tree */ |
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static void |
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SDfreeTre(SDNode *st) |
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{ |
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int n; |
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|
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if (st == NULL) |
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return; |
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for (n = (st->log2GR < 0) << st->ndim; n--; ) |
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SDfreeTre(st->u.t[n]); |
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free(st); |
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} |
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|
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/* Free a variable-resolution BSDF */ |
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static void |
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SDFreeBTre(void *p) |
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{ |
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SDTre *sdt = (SDTre *)p; |
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|
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if (sdt == NULL) |
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return; |
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SDfreeTre(sdt->stc[tt_Y]); |
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SDfreeTre(sdt->stc[tt_u]); |
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SDfreeTre(sdt->stc[tt_v]); |
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free(sdt); |
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} |
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|
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/* Fill branch's worth of grid values from subtree */ |
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static void |
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fill_grid_branch(float *dptr, const float *sptr, int nd, int shft) |
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{ |
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unsigned n = 1 << (shft-1); |
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|
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if (!--nd) { /* end on the line */ |
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memcpy(dptr, sptr, sizeof(*dptr)*n); |
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return; |
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} |
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while (n--) /* recurse on each slice */ |
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fill_grid_branch(dptr + (n << shft*nd), |
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sptr + (n << (shft-1)*nd), nd, shft); |
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} |
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|
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/* Get pointer at appropriate offset for the given branch */ |
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static float * |
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grid_branch_start(SDNode *st, int n) |
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{ |
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unsigned skipsiz = 1 << (st->log2GR - 1); |
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float *vptr = st->u.v; |
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int i; |
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|
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for (i = st->ndim; i--; skipsiz <<= st->log2GR) |
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if (1<<i & n) |
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vptr += skipsiz; |
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return vptr; |
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} |
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|
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/* Simplify (consolidate) a tree by flattening uniform depth regions */ |
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static SDNode * |
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SDsimplifyTre(SDNode *st) |
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{ |
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int match, n; |
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|
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if (st == NULL) /* check for invalid tree */ |
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return NULL; |
160 |
if (st->log2GR >= 0) /* grid just returns unaltered */ |
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return st; |
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match = 1; /* check if grids below match */ |
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for (n = 0; n < 1<<st->ndim; n++) { |
164 |
if ((st->u.t[n] = SDsimplifyTre(st->u.t[n])) == NULL) |
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return NULL; /* propogate error up call stack */ |
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match &= (st->u.t[n]->log2GR == st->u.t[0]->log2GR); |
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} |
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if (match && (match = st->u.t[0]->log2GR) >= 0) { |
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SDNode *stn = SDnewNode(st->ndim, match + 1); |
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if (stn == NULL) /* out of memory? */ |
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return st; |
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/* transfer values to new grid */ |
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for (n = 1 << st->ndim; n--; ) |
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fill_grid_branch(grid_branch_start(stn, n), |
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st->u.t[n]->u.v, stn->ndim, stn->log2GR); |
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SDfreeTre(st); /* free old tree */ |
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st = stn; /* return new one */ |
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} |
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return st; |
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} |
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|
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/* Assign the given voxel in tree (produces no grid nodes) */ |
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static SDNode * |
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SDsetVoxel(SDNode *sroot, int nd, const double *tmin, const double tsiz, float val) |
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{ |
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double ctrk[SD_MAXDIM]; |
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double csiz = 1.; |
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SDNode *st; |
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int i, n; |
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/* check arguments */ |
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for (i = nd; i-- > 0; ) |
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if ((tmin[i] < .0) | (tmin[i] >= 1.-FTINY)) |
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break; |
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if ((i >= 0) | (nd <= 0) | (tsiz <= FTINY) | (tsiz > 1.+FTINY) | |
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(sroot != NULL && sroot->ndim != nd)) { |
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SDfreeTre(sroot); |
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return NULL; |
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} |
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if (tsiz >= 1.-FTINY) { /* special case when tree is a leaf */ |
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SDfreeTre(sroot); |
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if ((sroot = SDnewNode(nd, 0)) != NULL) |
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sroot->u.v[0] = val; |
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return sroot; |
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} |
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/* make sure we have branching root */ |
206 |
if (sroot != NULL && sroot->log2GR >= 0) { |
207 |
SDfreeTre(sroot); sroot = NULL; |
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} |
209 |
if (sroot == NULL && (sroot = SDnewNode(nd, -1)) == NULL) |
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return NULL; |
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st = sroot; /* climb/grow tree */ |
212 |
memset(ctrk, 0, sizeof(ctrk)); |
213 |
for ( ; ; ) { |
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csiz *= .5; /* find appropriate branch */ |
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n = 0; |
216 |
for (i = nd; i--; ) |
217 |
if (ctrk[i]+csiz <= tmin[i]+FTINY) { |
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ctrk[i] += csiz; |
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n |= 1 << i; |
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} |
221 |
/* reached desired voxel? */ |
222 |
if (csiz <= tsiz+FTINY) { |
223 |
SDfreeTre(st->u.t[n]); |
224 |
st = st->u.t[n] = SDnewNode(nd, 0); |
225 |
break; |
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} |
227 |
/* else grow tree as needed */ |
228 |
if (st->u.t[n] != NULL && st->u.t[n]->log2GR >= 0) { |
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SDfreeTre(st->u.t[n]); st->u.t[n] = NULL; |
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} |
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if (st->u.t[n] == NULL) |
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st->u.t[n] = SDnewNode(nd, -1); |
233 |
if ((st = st->u.t[n]) == NULL) |
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break; |
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} |
236 |
if (st == NULL) { |
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SDfreeTre(sroot); |
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return NULL; |
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} |
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st->u.v[0] = val; /* assign leaf and return root */ |
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return sroot; |
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} |
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|
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/* Find smallest leaf in tree */ |
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static double |
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SDsmallestLeaf(const SDNode *st) |
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{ |
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if (st->log2GR < 0) { /* tree branches */ |
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double lmin = 1.; |
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int n; |
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for (n = 1<<st->ndim; n--; ) { |
252 |
double lsiz = SDsmallestLeaf(st->u.t[n]); |
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if (lsiz < lmin) |
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lmin = lsiz; |
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} |
256 |
return .5*lmin; |
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} |
258 |
/* leaf grid width */ |
259 |
return 1. / (double)(1 << st->log2GR); |
260 |
} |
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|
262 |
/* Add up N-dimensional hypercube array values over the given box */ |
263 |
static double |
264 |
SDiterSum(const float *va, int nd, int shft, const int *imin, const int *imax) |
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{ |
266 |
const unsigned skipsiz = 1 << --nd*shft; |
267 |
double sum = .0; |
268 |
int i; |
269 |
|
270 |
va += *imin * skipsiz; |
271 |
|
272 |
if (skipsiz == 1) |
273 |
for (i = *imin; i < *imax; i++) |
274 |
sum += *va++; |
275 |
else |
276 |
for (i = *imin; i < *imax; i++, va += skipsiz) |
277 |
sum += SDiterSum(va, nd, shft, imin+1, imax+1); |
278 |
return sum; |
279 |
} |
280 |
|
281 |
/* Average BSDF leaves over an orthotope defined by the unit hypercube */ |
282 |
static double |
283 |
SDavgTreBox(const SDNode *st, const double *bmin, const double *bmax) |
284 |
{ |
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unsigned n; |
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int i; |
287 |
|
288 |
if (!st) |
289 |
return .0; |
290 |
/* check box limits */ |
291 |
for (i = st->ndim; i--; ) { |
292 |
if (bmin[i] >= 1.) |
293 |
return .0; |
294 |
if (bmax[i] <= 0) |
295 |
return .0; |
296 |
if (bmin[i] >= bmax[i]) |
297 |
return .0; |
298 |
} |
299 |
if (st->log2GR < 0) { /* iterate on subtree */ |
300 |
double sum = .0, wsum = 1e-20; |
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double sbmin[SD_MAXDIM], sbmax[SD_MAXDIM], w; |
302 |
for (n = 1 << st->ndim; n--; ) { |
303 |
w = 1.; |
304 |
for (i = st->ndim; i--; ) { |
305 |
sbmin[i] = 2.*bmin[i]; |
306 |
sbmax[i] = 2.*bmax[i]; |
307 |
if (n & 1<<i) { |
308 |
sbmin[i] -= 1.; |
309 |
sbmax[i] -= 1.; |
310 |
} |
311 |
if (sbmin[i] < .0) sbmin[i] = .0; |
312 |
if (sbmax[i] > 1.) sbmax[i] = 1.; |
313 |
if (sbmin[i] >= sbmax[i]) { |
314 |
w = .0; |
315 |
break; |
316 |
} |
317 |
w *= sbmax[i] - sbmin[i]; |
318 |
} |
319 |
if (w > 1e-10) { |
320 |
sum += w * SDavgTreBox(st->u.t[n], sbmin, sbmax); |
321 |
wsum += w; |
322 |
} |
323 |
} |
324 |
return sum / wsum; |
325 |
} else { /* iterate over leaves */ |
326 |
int imin[SD_MAXDIM], imax[SD_MAXDIM]; |
327 |
|
328 |
n = 1; |
329 |
for (i = st->ndim; i--; ) { |
330 |
imin[i] = (bmin[i] <= 0) ? 0 : |
331 |
(int)((1 << st->log2GR)*bmin[i]); |
332 |
imax[i] = (bmax[i] >= 1.) ? (1 << st->log2GR) : |
333 |
(int)((1 << st->log2GR)*bmax[i] + .999999); |
334 |
n *= imax[i] - imin[i]; |
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} |
336 |
if (n) |
337 |
return SDiterSum(st->u.v, st->ndim, |
338 |
st->log2GR, imin, imax) / (double)n; |
339 |
} |
340 |
return .0; |
341 |
} |
342 |
|
343 |
/* Recursive call for SDtraverseTre() */ |
344 |
static int |
345 |
SDdotravTre(const SDNode *st, const double *pos, int cmask, |
346 |
SDtreCallback *cf, void *cptr, |
347 |
const double *cmin, double csiz) |
348 |
{ |
349 |
int rv, rval = 0; |
350 |
double bmin[SD_MAXDIM]; |
351 |
int i, n; |
352 |
/* paranoia */ |
353 |
if (st == NULL) |
354 |
return 0; |
355 |
/* in branches? */ |
356 |
if (st->log2GR < 0) { |
357 |
unsigned skipmask = 0; |
358 |
csiz *= .5; |
359 |
for (i = st->ndim; i--; ) |
360 |
if (1<<i & cmask) { |
361 |
if (pos[i] < cmin[i] + csiz) |
362 |
for (n = 1 << st->ndim; n--; ) { |
363 |
if (n & 1<<i) |
364 |
skipmask |= 1<<n; |
365 |
} |
366 |
else |
367 |
for (n = 1 << st->ndim; n--; ) { |
368 |
if (!(n & 1<<i)) |
369 |
skipmask |= 1<<n; |
370 |
} |
371 |
} |
372 |
for (n = 1 << st->ndim; n--; ) { |
373 |
if (1<<n & skipmask) |
374 |
continue; |
375 |
for (i = st->ndim; i--; ) |
376 |
if (1<<i & n) |
377 |
bmin[i] = cmin[i] + csiz; |
378 |
else |
379 |
bmin[i] = cmin[i]; |
380 |
|
381 |
rval += rv = SDdotravTre(st->u.t[n], pos, cmask, |
382 |
cf, cptr, bmin, csiz); |
383 |
if (rv < 0) |
384 |
return rv; |
385 |
} |
386 |
} else { /* else traverse leaves */ |
387 |
int clim[SD_MAXDIM][2]; |
388 |
int cpos[SD_MAXDIM]; |
389 |
|
390 |
if (st->log2GR == 0) /* short cut */ |
391 |
return (*cf)(st->u.v[0], cmin, csiz, cptr); |
392 |
|
393 |
csiz /= (double)(1 << st->log2GR); |
394 |
/* assign coord. ranges */ |
395 |
for (i = st->ndim; i--; ) |
396 |
if (1<<i & cmask) { |
397 |
clim[i][0] = (pos[i] - cmin[i])/csiz; |
398 |
/* check overflow from f.p. error */ |
399 |
clim[i][0] -= clim[i][0] >> st->log2GR; |
400 |
clim[i][1] = clim[i][0] + 1; |
401 |
} else { |
402 |
clim[i][0] = 0; |
403 |
clim[i][1] = 1 << st->log2GR; |
404 |
} |
405 |
#if (SD_MAXDIM == 4) |
406 |
bmin[0] = cmin[0] + csiz*clim[0][0]; |
407 |
for (cpos[0] = clim[0][0]; cpos[0] < clim[0][1]; cpos[0]++) { |
408 |
bmin[1] = cmin[1] + csiz*clim[1][0]; |
409 |
for (cpos[1] = clim[1][0]; cpos[1] < clim[1][1]; cpos[1]++) { |
410 |
bmin[2] = cmin[2] + csiz*clim[2][0]; |
411 |
if (st->ndim == 3) { |
412 |
cpos[2] = clim[2][0]; |
413 |
n = cpos[0]; |
414 |
for (i = 1; i < 3; i++) |
415 |
n = (n << st->log2GR) + cpos[i]; |
416 |
for ( ; cpos[2] < clim[2][1]; cpos[2]++) { |
417 |
rval += rv = (*cf)(st->u.v[n++], bmin, csiz, cptr); |
418 |
if (rv < 0) |
419 |
return rv; |
420 |
bmin[2] += csiz; |
421 |
} |
422 |
} else { |
423 |
for (cpos[2] = clim[2][0]; cpos[2] < clim[2][1]; cpos[2]++) { |
424 |
bmin[3] = cmin[3] + csiz*(cpos[3] = clim[3][0]); |
425 |
n = cpos[0]; |
426 |
for (i = 1; i < 4; i++) |
427 |
n = (n << st->log2GR) + cpos[i]; |
428 |
for ( ; cpos[3] < clim[3][1]; cpos[3]++) { |
429 |
rval += rv = (*cf)(st->u.v[n++], bmin, csiz, cptr); |
430 |
if (rv < 0) |
431 |
return rv; |
432 |
bmin[3] += csiz; |
433 |
} |
434 |
bmin[2] += csiz; |
435 |
} |
436 |
} |
437 |
bmin[1] += csiz; |
438 |
} |
439 |
bmin[0] += csiz; |
440 |
} |
441 |
#else |
442 |
_!_ "broken code segment!" |
443 |
#endif |
444 |
} |
445 |
return rval; |
446 |
} |
447 |
|
448 |
/* Traverse a tree, visiting nodes in a slice that fits partial position */ |
449 |
static int |
450 |
SDtraverseTre(const SDNode *st, const double *pos, int cmask, |
451 |
SDtreCallback *cf, void *cptr) |
452 |
{ |
453 |
int i; |
454 |
/* check arguments */ |
455 |
if ((st == NULL) | (cf == NULL)) |
456 |
return -1; |
457 |
for (i = st->ndim; i--; ) |
458 |
if (1<<i & cmask && (pos[i] < 0) | (pos[i] >= 1.)) |
459 |
return -1; |
460 |
|
461 |
return SDdotravTre(st, pos, cmask, cf, cptr, czero, 1.); |
462 |
} |
463 |
|
464 |
/* Look up tree value at the given grid position */ |
465 |
static float |
466 |
SDlookupTre(const SDNode *st, const double *pos, double *hcube) |
467 |
{ |
468 |
double spos[SD_MAXDIM]; |
469 |
int i, n, t; |
470 |
/* initialize voxel return */ |
471 |
if (hcube) { |
472 |
hcube[i = st->ndim] = 1.; |
473 |
while (i--) |
474 |
hcube[i] = .0; |
475 |
} |
476 |
/* climb the tree */ |
477 |
while (st != NULL && st->log2GR < 0) { |
478 |
n = 0; /* move to appropriate branch */ |
479 |
if (hcube) hcube[st->ndim] *= .5; |
480 |
for (i = st->ndim; i--; ) { |
481 |
spos[i] = 2.*pos[i]; |
482 |
t = (spos[i] >= 1.); |
483 |
n |= t<<i; |
484 |
spos[i] -= (double)t; |
485 |
if (hcube) hcube[i] += (double)t * hcube[st->ndim]; |
486 |
} |
487 |
st = st->u.t[n]; /* avoids tail recursion */ |
488 |
pos = spos; |
489 |
} |
490 |
if (st == NULL) /* should never happen? */ |
491 |
return .0; |
492 |
if (st->log2GR == 0) /* short cut */ |
493 |
return st->u.v[0]; |
494 |
n = t = 0; /* find grid array index */ |
495 |
for (i = st->ndim; i--; ) { |
496 |
n += (int)((1<<st->log2GR)*pos[i]) << t; |
497 |
t += st->log2GR; |
498 |
} |
499 |
if (hcube) { /* compute final hypercube */ |
500 |
hcube[st->ndim] /= (double)(1<<st->log2GR); |
501 |
for (i = st->ndim; i--; ) |
502 |
hcube[i] += floor((1<<st->log2GR)*pos[i])*hcube[st->ndim]; |
503 |
} |
504 |
return st->u.v[n]; /* no interpolation */ |
505 |
} |
506 |
|
507 |
/* Convert CIE (Y,u',v') color to our RGB */ |
508 |
static void |
509 |
SDyuv2rgb(double yval, double uprime, double vprime, float rgb[3]) |
510 |
{ |
511 |
const double dfact = 1./(6.*uprime - 16.*vprime + 12.); |
512 |
C_COLOR cxy; |
513 |
|
514 |
c_cset(&cxy, 9.*uprime*dfact, 4.*vprime*dfact); |
515 |
c_toSharpRGB(&cxy, yval, rgb); |
516 |
} |
517 |
|
518 |
static double |
519 |
pfrac(double x) |
520 |
{ |
521 |
return( x - (int)x ); |
522 |
} |
523 |
|
524 |
/* Query BSDF value and sample hypercube for the given vectors */ |
525 |
static int |
526 |
SDqueryTre(const SDTre *sdt, float *coef, |
527 |
const FVECT inVec, const FVECT outVec, double *hc) |
528 |
{ |
529 |
const RREAL *vtmp; |
530 |
double hcube[SD_MAXDIM+1]; |
531 |
float yval; |
532 |
FVECT rOutVec; |
533 |
RREAL gridPos[4]; |
534 |
double d; |
535 |
int i; |
536 |
|
537 |
if (sdt->stc[tt_Y] == NULL) /* paranoia, I hope */ |
538 |
return 0; |
539 |
|
540 |
switch (sdt->sidef) { /* whose side are you on? */ |
541 |
case SD_FREFL: |
542 |
if ((outVec[2] < 0) | (inVec[2] < 0)) |
543 |
return 0; |
544 |
break; |
545 |
case SD_BREFL: |
546 |
if ((outVec[2] > 0) | (inVec[2] > 0)) |
547 |
return 0; |
548 |
break; |
549 |
case SD_FXMIT: |
550 |
if (outVec[2] > 0) { |
551 |
if (inVec[2] > 0) |
552 |
return 0; |
553 |
vtmp = outVec; outVec = inVec; inVec = vtmp; |
554 |
} else if (inVec[2] < 0) |
555 |
return 0; |
556 |
break; |
557 |
case SD_BXMIT: |
558 |
if (inVec[2] > 0) { |
559 |
if (outVec[2] > 0) |
560 |
return 0; |
561 |
vtmp = outVec; outVec = inVec; inVec = vtmp; |
562 |
} else if (outVec[2] < 0) |
563 |
return 0; |
564 |
break; |
565 |
default: |
566 |
return 0; |
567 |
} |
568 |
/* convert vector coordinates */ |
569 |
if (sdt->stc[tt_Y]->ndim == 3) { |
570 |
spinvector(rOutVec, outVec, zvec, -atan2(-inVec[1],-inVec[0])); |
571 |
gridPos[0] = (.5-FTINY) - |
572 |
.5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]); |
573 |
disk2square(gridPos+1, rOutVec[0], rOutVec[1]); |
574 |
} else if (sdt->stc[tt_Y]->ndim == 4) { |
575 |
disk2square(gridPos, -inVec[0], -inVec[1]); |
576 |
disk2square(gridPos+2, outVec[0], outVec[1]); |
577 |
} else |
578 |
return 0; /* should be internal error */ |
579 |
|
580 |
if (hc == NULL) hc = hcube; /* get BSDF value */ |
581 |
yval = SDlookupTre(sdt->stc[tt_Y], gridPos, hc); |
582 |
if (coef == NULL) /* just getting hypercube? */ |
583 |
return 1; |
584 |
d = 0; /* position-specific perturbation */ |
585 |
for (i = sdt->stc[tt_Y]->ndim; i--; ) |
586 |
d += pfrac((2<<i)/(hc[i]+.01687)) - .5; |
587 |
yval *= 1. + 1e-4*d; /* assumes tolerance is > 0.04% */ |
588 |
if (sdt->stc[tt_u] == NULL || sdt->stc[tt_v] == NULL) { |
589 |
*coef = yval; |
590 |
return 1; /* no color */ |
591 |
} |
592 |
/* else decode color */ |
593 |
SDyuv2rgb(yval, SDlookupTre(sdt->stc[tt_u], gridPos, NULL), |
594 |
SDlookupTre(sdt->stc[tt_v], gridPos, NULL), coef); |
595 |
coef[0] *= tt_RGB_coef[0]; |
596 |
coef[1] *= tt_RGB_coef[1]; |
597 |
coef[2] *= tt_RGB_coef[2]; |
598 |
return 3; |
599 |
} |
600 |
|
601 |
/* Compute non-diffuse component for variable-resolution BSDF */ |
602 |
static int |
603 |
SDgetTreBSDF(float coef[SDmaxCh], const FVECT outVec, |
604 |
const FVECT inVec, SDComponent *sdc) |
605 |
{ |
606 |
/* check arguments */ |
607 |
if ((coef == NULL) | (outVec == NULL) | (inVec == NULL) | (sdc == NULL) |
608 |
|| sdc->dist == NULL) |
609 |
return 0; |
610 |
/* get nearest BSDF value */ |
611 |
return SDqueryTre((SDTre *)sdc->dist, coef, outVec, inVec, NULL); |
612 |
} |
613 |
|
614 |
/* Callback to build cumulative distribution using SDtraverseTre() */ |
615 |
static int |
616 |
build_scaffold(float val, const double *cmin, double csiz, void *cptr) |
617 |
{ |
618 |
SDdistScaffold *sp = (SDdistScaffold *)cptr; |
619 |
int wid = csiz*(double)iwmax + .5; |
620 |
double revcmin[2]; |
621 |
bitmask_t bmin[2], bmax[2]; |
622 |
|
623 |
if (sp->rev) { /* need to reverse sense? */ |
624 |
revcmin[0] = 1. - cmin[0] - csiz; |
625 |
revcmin[1] = 1. - cmin[1] - csiz; |
626 |
cmin = revcmin; |
627 |
} else { |
628 |
cmin += sp->nic; /* else skip to output coords */ |
629 |
} |
630 |
if (wid < sp->wmin) /* new minimum width? */ |
631 |
sp->wmin = wid; |
632 |
if (wid > sp->wmax) /* new maximum? */ |
633 |
sp->wmax = wid; |
634 |
if (sp->alen >= sp->nall) { /* need more space? */ |
635 |
struct outdir_s *ndarr; |
636 |
sp->nall = (int)(1.5*sp->nall) + 256; |
637 |
ndarr = (struct outdir_s *)realloc(sp->darr, |
638 |
sizeof(struct outdir_s)*sp->nall); |
639 |
if (ndarr == NULL) { |
640 |
sprintf(SDerrorDetail, |
641 |
"Cannot grow scaffold to %u entries", sp->nall); |
642 |
return -1; /* abort build */ |
643 |
} |
644 |
sp->darr = ndarr; |
645 |
} |
646 |
/* find Hilbert entry index */ |
647 |
bmin[0] = cmin[0]*(double)iwmax + .5; |
648 |
bmin[1] = cmin[1]*(double)iwmax + .5; |
649 |
bmax[0] = bmin[0] + wid-1; |
650 |
bmax[1] = bmin[1] + wid-1; |
651 |
hilbert_box_vtx(2, sizeof(bitmask_t), iwbits, 1, bmin, bmax); |
652 |
sp->darr[sp->alen].hent = hilbert_c2i(2, iwbits, bmin); |
653 |
sp->darr[sp->alen].wid = wid; |
654 |
sp->darr[sp->alen].bsdf = val; |
655 |
sp->alen++; /* on to the next entry */ |
656 |
return 0; |
657 |
} |
658 |
|
659 |
/* Scaffold comparison function for qsort -- ascending Hilbert index */ |
660 |
static int |
661 |
sscmp(const void *p1, const void *p2) |
662 |
{ |
663 |
unsigned h1 = (*(const struct outdir_s *)p1).hent; |
664 |
unsigned h2 = (*(const struct outdir_s *)p2).hent; |
665 |
|
666 |
if (h1 > h2) |
667 |
return 1; |
668 |
if (h1 < h2) |
669 |
return -1; |
670 |
return 0; |
671 |
} |
672 |
|
673 |
/* Create a new cumulative distribution for the given input direction */ |
674 |
static SDTreCDst * |
675 |
make_cdist(const SDTre *sdt, const double *invec, int rev) |
676 |
{ |
677 |
SDdistScaffold myScaffold; |
678 |
double pos[4]; |
679 |
int cmask; |
680 |
SDTreCDst *cd; |
681 |
struct outdir_s *sp; |
682 |
double scale, cursum; |
683 |
int i; |
684 |
/* initialize scaffold */ |
685 |
myScaffold.wmin = iwmax; |
686 |
myScaffold.wmax = 0; |
687 |
myScaffold.nic = sdt->stc[tt_Y]->ndim - 2; |
688 |
myScaffold.rev = rev; |
689 |
myScaffold.alen = 0; |
690 |
myScaffold.nall = 512; |
691 |
myScaffold.darr = (struct outdir_s *)malloc(sizeof(struct outdir_s) * |
692 |
myScaffold.nall); |
693 |
if (myScaffold.darr == NULL) |
694 |
return NULL; |
695 |
/* set up traversal */ |
696 |
cmask = (1<<myScaffold.nic) - 1; |
697 |
for (i = myScaffold.nic; i--; ) |
698 |
pos[i+2*rev] = invec[i]; |
699 |
cmask <<= 2*rev; |
700 |
/* grow the distribution */ |
701 |
if (SDtraverseTre(sdt->stc[tt_Y], pos, cmask, |
702 |
build_scaffold, &myScaffold) < 0) { |
703 |
free(myScaffold.darr); |
704 |
return NULL; |
705 |
} |
706 |
/* allocate result holder */ |
707 |
cd = (SDTreCDst *)malloc(sizeof(SDTreCDst) + |
708 |
sizeof(cd->carr[0])*myScaffold.alen); |
709 |
if (cd == NULL) { |
710 |
sprintf(SDerrorDetail, |
711 |
"Cannot allocate %u entry cumulative distribution", |
712 |
myScaffold.alen); |
713 |
free(myScaffold.darr); |
714 |
return NULL; |
715 |
} |
716 |
cd->isodist = (myScaffold.nic == 1); |
717 |
/* sort the distribution */ |
718 |
qsort(myScaffold.darr, cd->calen = myScaffold.alen, |
719 |
sizeof(struct outdir_s), sscmp); |
720 |
|
721 |
/* record input range */ |
722 |
scale = myScaffold.wmin / (double)iwmax; |
723 |
for (i = myScaffold.nic; i--; ) { |
724 |
cd->clim[i][0] = floor(pos[i+2*rev]/scale) * scale; |
725 |
cd->clim[i][1] = cd->clim[i][0] + scale; |
726 |
} |
727 |
if (cd->isodist) { /* avoid issue in SDqueryTreProjSA() */ |
728 |
cd->clim[1][0] = cd->clim[0][0]; |
729 |
cd->clim[1][1] = cd->clim[0][1]; |
730 |
} |
731 |
cd->max_psa = myScaffold.wmax / (double)iwmax; |
732 |
cd->max_psa *= cd->max_psa * M_PI; |
733 |
if (rev) |
734 |
cd->sidef = (sdt->sidef==SD_BXMIT) ? SD_FXMIT : SD_BXMIT; |
735 |
else |
736 |
cd->sidef = sdt->sidef; |
737 |
cd->cTotal = 1e-20; /* compute directional total */ |
738 |
sp = myScaffold.darr; |
739 |
for (i = myScaffold.alen; i--; sp++) |
740 |
cd->cTotal += sp->bsdf * (double)sp->wid * sp->wid; |
741 |
cursum = .0; /* go back and get cumulative values */ |
742 |
scale = (double)cumlmax / cd->cTotal; |
743 |
sp = myScaffold.darr; |
744 |
for (i = 0; i < cd->calen; i++, sp++) { |
745 |
cd->carr[i].hndx = sp->hent; |
746 |
cd->carr[i].cuml = scale*cursum + .5; |
747 |
cursum += sp->bsdf * (double)sp->wid * sp->wid; |
748 |
} |
749 |
cd->carr[i].hndx = ~0; /* make final entry */ |
750 |
cd->carr[i].cuml = cumlmax; |
751 |
cd->cTotal *= M_PI/(double)iwmax/iwmax; |
752 |
/* all done, clean up and return */ |
753 |
free(myScaffold.darr); |
754 |
return cd; |
755 |
} |
756 |
|
757 |
/* Find or allocate a cumulative distribution for the given incoming vector */ |
758 |
const SDCDst * |
759 |
SDgetTreCDist(const FVECT inVec, SDComponent *sdc) |
760 |
{ |
761 |
unsigned long cacheLeft = SDmaxCache; |
762 |
const SDTre *sdt; |
763 |
RREAL inCoord[2]; |
764 |
int i; |
765 |
int mode; |
766 |
SDTreCDst *cd, *cdlast, *cdlimit; |
767 |
/* check arguments */ |
768 |
if ((inVec == NULL) | (sdc == NULL) || |
769 |
(sdt = (SDTre *)sdc->dist) == NULL) |
770 |
return NULL; |
771 |
switch (mode = sdt->sidef) { /* check direction */ |
772 |
case SD_FREFL: |
773 |
if (inVec[2] < 0) |
774 |
return NULL; |
775 |
break; |
776 |
case SD_BREFL: |
777 |
if (inVec[2] > 0) |
778 |
return NULL; |
779 |
break; |
780 |
case SD_FXMIT: |
781 |
if (inVec[2] < 0) |
782 |
mode = SD_BXMIT; |
783 |
break; |
784 |
case SD_BXMIT: |
785 |
if (inVec[2] > 0) |
786 |
mode = SD_FXMIT; |
787 |
break; |
788 |
default: |
789 |
return NULL; |
790 |
} |
791 |
if (sdt->stc[tt_Y]->ndim == 3) { /* isotropic BSDF? */ |
792 |
if (mode != sdt->sidef) /* XXX unhandled reciprocity */ |
793 |
return &SDemptyCD; |
794 |
inCoord[0] = (.5-FTINY) - |
795 |
.5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]); |
796 |
} else if (sdt->stc[tt_Y]->ndim == 4) { |
797 |
if (mode != sdt->sidef) /* use reciprocity? */ |
798 |
disk2square(inCoord, inVec[0], inVec[1]); |
799 |
else |
800 |
disk2square(inCoord, -inVec[0], -inVec[1]); |
801 |
} else |
802 |
return NULL; /* should be internal error */ |
803 |
/* quantize to avoid f.p. errors */ |
804 |
for (i = sdt->stc[tt_Y]->ndim - 2; i--; ) |
805 |
inCoord[i] = floor(inCoord[i]/quantum)*quantum + .5*quantum; |
806 |
cdlast = cdlimit = NULL; /* check for direction in cache list */ |
807 |
/* PLACE MUTEX LOCK HERE FOR THREAD-SAFE */ |
808 |
for (cd = (SDTreCDst *)sdc->cdList; cd != NULL; |
809 |
cdlast = cd, cd = cd->next) { |
810 |
if (cacheLeft) { /* check cache size limit */ |
811 |
long csiz = sizeof(SDTreCDst) + |
812 |
sizeof(cd->carr[0])*cd->calen; |
813 |
if (cacheLeft > csiz) |
814 |
cacheLeft -= csiz; |
815 |
else { |
816 |
cdlimit = cdlast; |
817 |
cacheLeft = 0; |
818 |
} |
819 |
} |
820 |
if (cd->sidef != mode) |
821 |
continue; |
822 |
for (i = sdt->stc[tt_Y]->ndim - 2; i--; ) |
823 |
if ((cd->clim[i][0] > inCoord[i]) | |
824 |
(inCoord[i] >= cd->clim[i][1])) |
825 |
break; |
826 |
if (i < 0) |
827 |
break; /* means we have a match */ |
828 |
} |
829 |
if (cd == NULL) { /* need to create new entry? */ |
830 |
if (cdlimit != NULL) /* exceeded cache size limit? */ |
831 |
while ((cd = cdlimit->next) != NULL) { |
832 |
cdlimit->next = cd->next; |
833 |
free(cd); |
834 |
} |
835 |
cdlast = cd = make_cdist(sdt, inCoord, mode != sdt->sidef); |
836 |
} |
837 |
if (cdlast != NULL) { /* move entry to head of cache list */ |
838 |
cdlast->next = cd->next; |
839 |
cd->next = (SDTreCDst *)sdc->cdList; |
840 |
sdc->cdList = (SDCDst *)cd; |
841 |
} |
842 |
/* END MUTEX LOCK */ |
843 |
return (SDCDst *)cd; /* ready to go */ |
844 |
} |
845 |
|
846 |
/* Query solid angle for vector(s) */ |
847 |
static SDError |
848 |
SDqueryTreProjSA(double *psa, const FVECT v1, const RREAL *v2, |
849 |
int qflags, SDComponent *sdc) |
850 |
{ |
851 |
double myPSA[2]; |
852 |
/* check arguments */ |
853 |
if ((psa == NULL) | (v1 == NULL) | (sdc == NULL) || |
854 |
sdc->dist == NULL) |
855 |
return SDEargument; |
856 |
/* get projected solid angle(s) */ |
857 |
if (v2 != NULL) { |
858 |
const SDTre *sdt = (SDTre *)sdc->dist; |
859 |
double hcube[SD_MAXDIM+1]; |
860 |
if (!SDqueryTre(sdt, NULL, v1, v2, hcube)) { |
861 |
strcpy(SDerrorDetail, "Bad call to SDqueryTreProjSA"); |
862 |
return SDEinternal; |
863 |
} |
864 |
myPSA[0] = hcube[sdt->stc[tt_Y]->ndim]; |
865 |
myPSA[1] = myPSA[0] *= myPSA[0] * M_PI; |
866 |
} else { |
867 |
const SDTreCDst *cd = (const SDTreCDst *)SDgetTreCDist(v1, sdc); |
868 |
if (cd == NULL) |
869 |
myPSA[0] = myPSA[1] = 0; |
870 |
else { |
871 |
myPSA[0] = M_PI * (cd->clim[0][1] - cd->clim[0][0]) * |
872 |
(cd->clim[1][1] - cd->clim[1][0]); |
873 |
myPSA[1] = cd->max_psa; |
874 |
} |
875 |
} |
876 |
switch (qflags) { /* record based on flag settings */ |
877 |
case SDqueryVal: |
878 |
*psa = myPSA[0]; |
879 |
break; |
880 |
case SDqueryMax: |
881 |
if (myPSA[1] > *psa) |
882 |
*psa = myPSA[1]; |
883 |
break; |
884 |
case SDqueryMin+SDqueryMax: |
885 |
if (myPSA[1] > psa[1]) |
886 |
psa[1] = myPSA[1]; |
887 |
/* fall through */ |
888 |
case SDqueryMin: |
889 |
if ((myPSA[0] > 0) & (myPSA[0] < psa[0])) |
890 |
psa[0] = myPSA[0]; |
891 |
break; |
892 |
} |
893 |
return SDEnone; |
894 |
} |
895 |
|
896 |
/* Sample cumulative distribution */ |
897 |
static SDError |
898 |
SDsampTreCDist(FVECT ioVec, double randX, const SDCDst *cdp) |
899 |
{ |
900 |
const unsigned nBitsC = 4*sizeof(bitmask_t); |
901 |
const unsigned nExtraBits = 8*(sizeof(bitmask_t)-sizeof(unsigned)); |
902 |
const SDTreCDst *cd = (const SDTreCDst *)cdp; |
903 |
const unsigned target = randX*cumlmax; |
904 |
bitmask_t hndx, hcoord[2]; |
905 |
FVECT gpos; |
906 |
double rotangle; |
907 |
int i, iupper, ilower; |
908 |
/* check arguments */ |
909 |
if ((ioVec == NULL) | (cd == NULL)) |
910 |
return SDEargument; |
911 |
if (!cd->sidef) |
912 |
return SDEnone; /* XXX should never happen */ |
913 |
if (ioVec[2] > 0) { |
914 |
if ((cd->sidef != SD_FREFL) & (cd->sidef != SD_FXMIT)) |
915 |
return SDEargument; |
916 |
} else if ((cd->sidef != SD_BREFL) & (cd->sidef != SD_BXMIT)) |
917 |
return SDEargument; |
918 |
/* binary search to find position */ |
919 |
ilower = 0; iupper = cd->calen; |
920 |
while ((i = (iupper + ilower) >> 1) != ilower) |
921 |
if (target >= cd->carr[i].cuml) |
922 |
ilower = i; |
923 |
else |
924 |
iupper = i; |
925 |
/* localize random position */ |
926 |
randX = (randX*cumlmax - cd->carr[ilower].cuml) / |
927 |
(double)(cd->carr[iupper].cuml - cd->carr[ilower].cuml); |
928 |
/* index in longer Hilbert curve */ |
929 |
hndx = (randX*cd->carr[iupper].hndx + (1.-randX)*cd->carr[ilower].hndx) |
930 |
* (double)((bitmask_t)1 << nExtraBits); |
931 |
/* convert Hilbert index to vector */ |
932 |
hilbert_i2c(2, nBitsC, hndx, hcoord); |
933 |
for (i = 2; i--; ) |
934 |
gpos[i] = ((double)hcoord[i] + rand()*(1./(RAND_MAX+.5))) / |
935 |
(double)((bitmask_t)1 << nBitsC); |
936 |
square2disk(gpos, gpos[0], gpos[1]); |
937 |
/* compute Z-coordinate */ |
938 |
gpos[2] = 1. - gpos[0]*gpos[0] - gpos[1]*gpos[1]; |
939 |
gpos[2] = sqrt(gpos[2]*(gpos[2]>0)); |
940 |
/* emit from back? */ |
941 |
if ((cd->sidef == SD_BREFL) | (cd->sidef == SD_FXMIT)) |
942 |
gpos[2] = -gpos[2]; |
943 |
if (cd->isodist) { /* rotate isotropic sample */ |
944 |
rotangle = atan2(-ioVec[1],-ioVec[0]); |
945 |
spinvector(ioVec, gpos, zvec, rotangle); |
946 |
} else |
947 |
VCOPY(ioVec, gpos); |
948 |
return SDEnone; |
949 |
} |
950 |
|
951 |
/* Advance pointer to the next non-white character in the string (or nul) */ |
952 |
static int |
953 |
next_token(char **spp) |
954 |
{ |
955 |
while (isspace(**spp)) |
956 |
++*spp; |
957 |
return **spp; |
958 |
} |
959 |
|
960 |
/* Advance pointer past matching token (or any token if c==0) */ |
961 |
#define eat_token(spp,c) ((next_token(spp)==(c)) ^ !(c) ? *(*(spp))++ : 0) |
962 |
|
963 |
/* Count words from this point in string to '}' */ |
964 |
static int |
965 |
count_values(char *cp) |
966 |
{ |
967 |
int n = 0; |
968 |
|
969 |
while (next_token(&cp) != '}' && *cp) { |
970 |
while (!isspace(*cp) & (*cp != ',') & (*cp != '}')) |
971 |
if (!*++cp) |
972 |
break; |
973 |
++n; |
974 |
eat_token(&cp, ','); |
975 |
} |
976 |
return n; |
977 |
} |
978 |
|
979 |
/* Load an array of real numbers, returning total */ |
980 |
static int |
981 |
load_values(char **spp, float *va, int n) |
982 |
{ |
983 |
float *v = va; |
984 |
char *svnext; |
985 |
|
986 |
while (n-- > 0 && (svnext = fskip(*spp)) != NULL) { |
987 |
if ((*v++ = atof(*spp)) < 0) |
988 |
v[-1] = 0; |
989 |
*spp = svnext; |
990 |
eat_token(spp, ','); |
991 |
} |
992 |
return v - va; |
993 |
} |
994 |
|
995 |
/* Load BSDF tree data */ |
996 |
static SDNode * |
997 |
load_tree_data(char **spp, int nd) |
998 |
{ |
999 |
SDNode *st; |
1000 |
int n; |
1001 |
|
1002 |
if (!eat_token(spp, '{')) { |
1003 |
strcpy(SDerrorDetail, "Missing '{' in tensor tree"); |
1004 |
return NULL; |
1005 |
} |
1006 |
if (next_token(spp) == '{') { /* tree branches */ |
1007 |
st = SDnewNode(nd, -1); |
1008 |
if (st == NULL) |
1009 |
return NULL; |
1010 |
for (n = 0; n < 1<<nd; n++) |
1011 |
if ((st->u.t[n] = load_tree_data(spp, nd)) == NULL) { |
1012 |
SDfreeTre(st); |
1013 |
return NULL; |
1014 |
} |
1015 |
} else { /* else load value grid */ |
1016 |
int bsiz; |
1017 |
n = count_values(*spp); /* see how big the grid is */ |
1018 |
for (bsiz = 0; bsiz < 8*sizeof(size_t); bsiz += nd) |
1019 |
if (1<<bsiz == n) |
1020 |
break; |
1021 |
if (bsiz >= 8*sizeof(size_t)) { |
1022 |
strcpy(SDerrorDetail, "Illegal value count in tensor tree"); |
1023 |
return NULL; |
1024 |
} |
1025 |
st = SDnewNode(nd, bsiz/nd); |
1026 |
if (st == NULL) |
1027 |
return NULL; |
1028 |
if (load_values(spp, st->u.v, n) != n) { |
1029 |
strcpy(SDerrorDetail, "Real format error in tensor tree"); |
1030 |
SDfreeTre(st); |
1031 |
return NULL; |
1032 |
} |
1033 |
} |
1034 |
if (!eat_token(spp, '}')) { |
1035 |
strcpy(SDerrorDetail, "Missing '}' in tensor tree"); |
1036 |
SDfreeTre(st); |
1037 |
return NULL; |
1038 |
} |
1039 |
eat_token(spp, ','); |
1040 |
return st; |
1041 |
} |
1042 |
|
1043 |
/* Compute min. proj. solid angle and max. direct hemispherical scattering */ |
1044 |
static SDError |
1045 |
get_extrema(SDSpectralDF *df) |
1046 |
{ |
1047 |
SDNode *st = (*(SDTre *)df->comp[0].dist).stc[tt_Y]; |
1048 |
double stepWidth, dhemi, bmin[4], bmax[4]; |
1049 |
|
1050 |
stepWidth = SDsmallestLeaf(st); |
1051 |
if (quantum > stepWidth) /* adjust quantization factor */ |
1052 |
quantum = stepWidth; |
1053 |
df->minProjSA = M_PI*stepWidth*stepWidth; |
1054 |
if (stepWidth < .03125) |
1055 |
stepWidth = .03125; /* 1/32 resolution good enough */ |
1056 |
df->maxHemi = .0; |
1057 |
if (st->ndim == 3) { /* isotropic BSDF */ |
1058 |
bmin[1] = bmin[2] = .0; |
1059 |
bmax[1] = bmax[2] = 1.; |
1060 |
for (bmin[0] = .0; bmin[0] < .5-FTINY; bmin[0] += stepWidth) { |
1061 |
bmax[0] = bmin[0] + stepWidth; |
1062 |
dhemi = SDavgTreBox(st, bmin, bmax); |
1063 |
if (dhemi > df->maxHemi) |
1064 |
df->maxHemi = dhemi; |
1065 |
} |
1066 |
} else if (st->ndim == 4) { /* anisotropic BSDF */ |
1067 |
bmin[2] = bmin[3] = .0; |
1068 |
bmax[2] = bmax[3] = 1.; |
1069 |
for (bmin[0] = .0; bmin[0] < 1.-FTINY; bmin[0] += stepWidth) { |
1070 |
bmax[0] = bmin[0] + stepWidth; |
1071 |
for (bmin[1] = .0; bmin[1] < 1.-FTINY; bmin[1] += stepWidth) { |
1072 |
bmax[1] = bmin[1] + stepWidth; |
1073 |
dhemi = SDavgTreBox(st, bmin, bmax); |
1074 |
if (dhemi > df->maxHemi) |
1075 |
df->maxHemi = dhemi; |
1076 |
} |
1077 |
} |
1078 |
} else |
1079 |
return SDEinternal; |
1080 |
/* correct hemispherical value */ |
1081 |
df->maxHemi *= M_PI; |
1082 |
return SDEnone; |
1083 |
} |
1084 |
|
1085 |
/* Load BSDF distribution for this wavelength */ |
1086 |
static SDError |
1087 |
load_bsdf_data(SDData *sd, ezxml_t wdb, int ct, int ndim) |
1088 |
{ |
1089 |
SDSpectralDF *df; |
1090 |
SDTre *sdt; |
1091 |
char *sdata; |
1092 |
/* allocate BSDF component */ |
1093 |
sdata = ezxml_txt(ezxml_child(wdb, "WavelengthDataDirection")); |
1094 |
if (!sdata) |
1095 |
return SDEnone; |
1096 |
/* |
1097 |
* Remember that front and back are reversed from WINDOW 6 orientations |
1098 |
*/ |
1099 |
if (!strcasecmp(sdata, "Transmission Front")) { |
1100 |
if (sd->tb == NULL && (sd->tb = SDnewSpectralDF(1)) == NULL) |
1101 |
return SDEmemory; |
1102 |
df = sd->tb; |
1103 |
} else if (!strcasecmp(sdata, "Transmission Back")) { |
1104 |
if (sd->tf == NULL && (sd->tf = SDnewSpectralDF(1)) == NULL) |
1105 |
return SDEmemory; |
1106 |
df = sd->tf; |
1107 |
} else if (!strcasecmp(sdata, "Reflection Front")) { |
1108 |
if (sd->rb == NULL && (sd->rb = SDnewSpectralDF(1)) == NULL) |
1109 |
return SDEmemory; |
1110 |
df = sd->rb; |
1111 |
} else if (!strcasecmp(sdata, "Reflection Back")) { |
1112 |
if (sd->rf == NULL && (sd->rf = SDnewSpectralDF(1)) == NULL) |
1113 |
return SDEmemory; |
1114 |
df = sd->rf; |
1115 |
} else |
1116 |
return SDEnone; |
1117 |
/* get angle bases */ |
1118 |
sdata = ezxml_txt(ezxml_child(wdb,"AngleBasis")); |
1119 |
if (!sdata || strcasecmp(sdata, "LBNL/Shirley-Chiu")) { |
1120 |
sprintf(SDerrorDetail, "%s angle basis for BSDF '%s'", |
1121 |
!sdata ? "Missing" : "Unsupported", sd->name); |
1122 |
return !sdata ? SDEformat : SDEsupport; |
1123 |
} |
1124 |
if (df->comp[0].dist == NULL) { /* need to allocate BSDF tree? */ |
1125 |
sdt = (SDTre *)malloc(sizeof(SDTre)); |
1126 |
if (sdt == NULL) |
1127 |
return SDEmemory; |
1128 |
if (df == sd->rf) |
1129 |
sdt->sidef = SD_FREFL; |
1130 |
else if (df == sd->rb) |
1131 |
sdt->sidef = SD_BREFL; |
1132 |
else if (df == sd->tf) |
1133 |
sdt->sidef = SD_FXMIT; |
1134 |
else /* df == sd->tb */ |
1135 |
sdt->sidef = SD_BXMIT; |
1136 |
sdt->stc[tt_Y] = sdt->stc[tt_u] = sdt->stc[tt_v] = NULL; |
1137 |
df->comp[0].dist = sdt; |
1138 |
df->comp[0].func = &SDhandleTre; |
1139 |
} else { |
1140 |
sdt = (SDTre *)df->comp[0].dist; |
1141 |
if (sdt->stc[ct] != NULL) { |
1142 |
SDfreeTre(sdt->stc[ct]); |
1143 |
sdt->stc[ct] = NULL; |
1144 |
} |
1145 |
} |
1146 |
/* read BSDF data */ |
1147 |
sdata = ezxml_txt(ezxml_child(wdb, "ScatteringData")); |
1148 |
if (!sdata || !next_token(&sdata)) { |
1149 |
sprintf(SDerrorDetail, "Missing BSDF ScatteringData in '%s'", |
1150 |
sd->name); |
1151 |
return SDEformat; |
1152 |
} |
1153 |
sdt->stc[ct] = load_tree_data(&sdata, ndim); |
1154 |
if (sdt->stc[ct] == NULL) |
1155 |
return SDEformat; |
1156 |
if (next_token(&sdata)) { /* check for unconsumed characters */ |
1157 |
sprintf(SDerrorDetail, |
1158 |
"Extra characters at end of ScatteringData in '%s'", |
1159 |
sd->name); |
1160 |
return SDEformat; |
1161 |
} |
1162 |
/* flatten branches where possible */ |
1163 |
sdt->stc[ct] = SDsimplifyTre(sdt->stc[ct]); |
1164 |
if (sdt->stc[ct] == NULL) |
1165 |
return SDEinternal; |
1166 |
/* compute global quantities for Y */ |
1167 |
return (ct == tt_Y) ? get_extrema(df) : SDEnone; |
1168 |
} |
1169 |
|
1170 |
/* Find minimum value in tree */ |
1171 |
static float |
1172 |
SDgetTreMin(const SDNode *st) |
1173 |
{ |
1174 |
float vmin = FHUGE; |
1175 |
int n; |
1176 |
|
1177 |
if (st->log2GR < 0) { |
1178 |
for (n = 1<<st->ndim; n--; ) { |
1179 |
float v = SDgetTreMin(st->u.t[n]); |
1180 |
if (v < vmin) |
1181 |
vmin = v; |
1182 |
} |
1183 |
} else { |
1184 |
for (n = 1<<(st->ndim*st->log2GR); n--; ) |
1185 |
if (st->u.v[n] < vmin) |
1186 |
vmin = st->u.v[n]; |
1187 |
} |
1188 |
return vmin; |
1189 |
} |
1190 |
|
1191 |
/* Subtract the given value from all tree nodes */ |
1192 |
static void |
1193 |
SDsubtractTreVal(SDNode *st, float val) |
1194 |
{ |
1195 |
int n; |
1196 |
|
1197 |
if (st->log2GR < 0) { |
1198 |
for (n = 1<<st->ndim; n--; ) |
1199 |
SDsubtractTreVal(st->u.t[n], val); |
1200 |
} else { |
1201 |
for (n = 1<<(st->ndim*st->log2GR); n--; ) |
1202 |
if ((st->u.v[n] -= val) < 0) |
1203 |
st->u.v[n] = .0f; |
1204 |
} |
1205 |
} |
1206 |
|
1207 |
/* Subtract minimum Y value from BSDF */ |
1208 |
static double |
1209 |
subtract_min_Y(SDNode *st) |
1210 |
{ |
1211 |
const float vmaxmin = 1.5/M_PI; |
1212 |
float vmin; |
1213 |
/* be sure to skip unused portion */ |
1214 |
if (st->ndim == 3) { |
1215 |
int n; |
1216 |
vmin = vmaxmin; |
1217 |
if (st->log2GR < 0) { |
1218 |
for (n = 0; n < 8; n += 2) { |
1219 |
float v = SDgetTreMin(st->u.t[n]); |
1220 |
if (v < vmin) |
1221 |
vmin = v; |
1222 |
} |
1223 |
} else if (st->log2GR) { |
1224 |
for (n = 1 << (3*st->log2GR - 1); n--; ) |
1225 |
if (st->u.v[n] < vmin) |
1226 |
vmin = st->u.v[n]; |
1227 |
} else |
1228 |
vmin = st->u.v[0]; |
1229 |
} else /* anisotropic covers entire tree */ |
1230 |
vmin = SDgetTreMin(st); |
1231 |
|
1232 |
if ((vmin >= vmaxmin) | (vmin <= .01/M_PI)) |
1233 |
return .0; /* not worth bothering about */ |
1234 |
|
1235 |
SDsubtractTreVal(st, vmin); |
1236 |
|
1237 |
return M_PI * vmin; /* return hemispherical value */ |
1238 |
} |
1239 |
|
1240 |
/* Struct used in callback to find RGB extrema */ |
1241 |
typedef struct { |
1242 |
SDNode **stc; /* original Y, u' & v' trees */ |
1243 |
float rgb[3]; /* RGB value */ |
1244 |
SDNode *new_stu, *new_stv; /* replacement u' & v' trees */ |
1245 |
} SDextRGBs; |
1246 |
|
1247 |
/* Callback to find minimum RGB from Y value plus CIE (u',v') trees */ |
1248 |
static int |
1249 |
get_min_RGB(float yval, const double *cmin, double csiz, void *cptr) |
1250 |
{ |
1251 |
SDextRGBs *mp = (SDextRGBs *)cptr; |
1252 |
double cmax[SD_MAXDIM]; |
1253 |
float rgb[3]; |
1254 |
|
1255 |
if (mp->stc[tt_Y]->ndim == 3) { |
1256 |
if (cmin[0] + .5*csiz >= .5) |
1257 |
return 0; /* ignore dead half of isotropic */ |
1258 |
} else |
1259 |
cmax[3] = cmin[3] + csiz; |
1260 |
cmax[0] = cmin[0] + csiz; |
1261 |
cmax[1] = cmin[1] + csiz; |
1262 |
cmax[2] = cmin[2] + csiz; |
1263 |
/* average RGB color over voxel */ |
1264 |
SDyuv2rgb(yval, SDavgTreBox(mp->stc[tt_u], cmin, cmax), |
1265 |
SDavgTreBox(mp->stc[tt_v], cmin, cmax), rgb); |
1266 |
/* track smallest components */ |
1267 |
if (rgb[0] < mp->rgb[0]) mp->rgb[0] = rgb[0]; |
1268 |
if (rgb[1] < mp->rgb[1]) mp->rgb[1] = rgb[1]; |
1269 |
if (rgb[2] < mp->rgb[2]) mp->rgb[2] = rgb[2]; |
1270 |
return 0; |
1271 |
} |
1272 |
|
1273 |
/* Callback to build adjusted u' tree */ |
1274 |
static int |
1275 |
adjust_utree(float uprime, const double *cmin, double csiz, void *cptr) |
1276 |
{ |
1277 |
SDextRGBs *mp = (SDextRGBs *)cptr; |
1278 |
double cmax[SD_MAXDIM]; |
1279 |
double yval; |
1280 |
float rgb[3]; |
1281 |
C_COLOR clr; |
1282 |
|
1283 |
if (mp->stc[tt_Y]->ndim == 3) { |
1284 |
if (cmin[0] + .5*csiz >= .5) |
1285 |
return 0; /* ignore dead half of isotropic */ |
1286 |
} else |
1287 |
cmax[3] = cmin[3] + csiz; |
1288 |
cmax[0] = cmin[0] + csiz; |
1289 |
cmax[1] = cmin[1] + csiz; |
1290 |
cmax[2] = cmin[2] + csiz; |
1291 |
/* average RGB color over voxel */ |
1292 |
SDyuv2rgb(yval=SDavgTreBox(mp->stc[tt_Y], cmin, cmax), uprime, |
1293 |
SDavgTreBox(mp->stc[tt_v], cmin, cmax), rgb); |
1294 |
/* subtract minimum (& clamp) */ |
1295 |
if ((rgb[0] -= mp->rgb[0]) < 1e-5*yval) rgb[0] = 1e-5*yval; |
1296 |
if ((rgb[1] -= mp->rgb[1]) < 1e-5*yval) rgb[1] = 1e-5*yval; |
1297 |
if ((rgb[2] -= mp->rgb[2]) < 1e-5*yval) rgb[2] = 1e-5*yval; |
1298 |
c_fromSharpRGB(rgb, &clr); /* compute new u' for adj. RGB */ |
1299 |
uprime = 4.*clr.cx/(-2.*clr.cx + 12.*clr.cy + 3.); |
1300 |
/* assign in new u' tree */ |
1301 |
mp->new_stu = SDsetVoxel(mp->new_stu, mp->stc[tt_Y]->ndim, |
1302 |
cmin, csiz, uprime); |
1303 |
return -(mp->new_stu == NULL); |
1304 |
} |
1305 |
|
1306 |
/* Callback to build adjusted v' tree */ |
1307 |
static int |
1308 |
adjust_vtree(float vprime, const double *cmin, double csiz, void *cptr) |
1309 |
{ |
1310 |
SDextRGBs *mp = (SDextRGBs *)cptr; |
1311 |
double cmax[SD_MAXDIM]; |
1312 |
double yval; |
1313 |
float rgb[3]; |
1314 |
C_COLOR clr; |
1315 |
|
1316 |
if (mp->stc[tt_Y]->ndim == 3) { |
1317 |
if (cmin[0] + .5*csiz >= .5) |
1318 |
return 0; /* ignore dead half of isotropic */ |
1319 |
} else |
1320 |
cmax[3] = cmin[3] + csiz; |
1321 |
cmax[0] = cmin[0] + csiz; |
1322 |
cmax[1] = cmin[1] + csiz; |
1323 |
cmax[2] = cmin[2] + csiz; |
1324 |
/* average RGB color over voxel */ |
1325 |
SDyuv2rgb(yval=SDavgTreBox(mp->stc[tt_Y], cmin, cmax), |
1326 |
SDavgTreBox(mp->stc[tt_u], cmin, cmax), |
1327 |
vprime, rgb); |
1328 |
/* subtract minimum (& clamp) */ |
1329 |
if ((rgb[0] -= mp->rgb[0]) < 1e-5*yval) rgb[0] = 1e-5*yval; |
1330 |
if ((rgb[1] -= mp->rgb[1]) < 1e-5*yval) rgb[1] = 1e-5*yval; |
1331 |
if ((rgb[2] -= mp->rgb[2]) < 1e-5*yval) rgb[2] = 1e-5*yval; |
1332 |
c_fromSharpRGB(rgb, &clr); /* compute new v' for adj. RGB */ |
1333 |
vprime = 9.*clr.cy/(-2.*clr.cx + 12.*clr.cy + 3.); |
1334 |
/* assign in new v' tree */ |
1335 |
mp->new_stv = SDsetVoxel(mp->new_stv, mp->stc[tt_Y]->ndim, |
1336 |
cmin, csiz, vprime); |
1337 |
return -(mp->new_stv == NULL); |
1338 |
} |
1339 |
|
1340 |
/* Subtract minimum (diffuse) color and return luminance & CIE (x,y) */ |
1341 |
static double |
1342 |
subtract_min_RGB(C_COLOR *cs, SDNode *stc[]) |
1343 |
{ |
1344 |
SDextRGBs my_min; |
1345 |
double ymin; |
1346 |
|
1347 |
my_min.stc = stc; |
1348 |
my_min.rgb[0] = my_min.rgb[1] = my_min.rgb[2] = FHUGE; |
1349 |
my_min.new_stu = my_min.new_stv = NULL; |
1350 |
/* get minimum RGB value */ |
1351 |
SDtraverseTre(stc[tt_Y], NULL, 0, get_min_RGB, &my_min); |
1352 |
/* convert to C_COLOR */ |
1353 |
ymin = c_fromSharpRGB(my_min.rgb, cs); |
1354 |
if ((ymin >= .5*FHUGE) | (ymin <= .01/M_PI)) |
1355 |
return .0; /* close to zero or no tree */ |
1356 |
/* adjust u' & v' trees */ |
1357 |
SDtraverseTre(stc[tt_u], NULL, 0, adjust_utree, &my_min); |
1358 |
SDtraverseTre(stc[tt_v], NULL, 0, adjust_vtree, &my_min); |
1359 |
SDfreeTre(stc[tt_u]); SDfreeTre(stc[tt_v]); |
1360 |
stc[tt_u] = SDsimplifyTre(my_min.new_stu); |
1361 |
stc[tt_v] = SDsimplifyTre(my_min.new_stv); |
1362 |
/* subtract Y & return hemispherical */ |
1363 |
SDsubtractTreVal(stc[tt_Y], ymin); |
1364 |
|
1365 |
return M_PI * ymin; |
1366 |
} |
1367 |
|
1368 |
/* Extract and separate diffuse portion of BSDF */ |
1369 |
static void |
1370 |
extract_diffuse(SDValue *dv, SDSpectralDF *df) |
1371 |
{ |
1372 |
int n; |
1373 |
SDTre *sdt; |
1374 |
|
1375 |
if (df == NULL || df->ncomp <= 0) { |
1376 |
dv->spec = c_dfcolor; |
1377 |
dv->cieY = .0; |
1378 |
return; |
1379 |
} |
1380 |
sdt = (SDTre *)df->comp[0].dist; |
1381 |
/* subtract minimum color/grayscale */ |
1382 |
if (sdt->stc[tt_u] != NULL && sdt->stc[tt_v] != NULL) { |
1383 |
int i = 3*(tt_RGB_coef[1] < .001); |
1384 |
while (i--) { /* initialize on first call */ |
1385 |
float rgb[3]; |
1386 |
rgb[0] = rgb[1] = rgb[2] = .0f; rgb[i] = 1.f; |
1387 |
tt_RGB_coef[i] = c_fromSharpRGB(rgb, &tt_RGB_prim[i]); |
1388 |
} |
1389 |
memcpy(df->comp[0].cspec, tt_RGB_prim, sizeof(tt_RGB_prim)); |
1390 |
dv->cieY = subtract_min_RGB(&dv->spec, sdt->stc); |
1391 |
} else { |
1392 |
df->comp[0].cspec[0] = dv->spec = c_dfcolor; |
1393 |
dv->cieY = subtract_min_Y(sdt->stc[tt_Y]); |
1394 |
} |
1395 |
df->maxHemi -= dv->cieY; /* adjust maximum hemispherical */ |
1396 |
|
1397 |
c_ccvt(&dv->spec, C_CSXY); /* make sure (x,y) is set */ |
1398 |
} |
1399 |
|
1400 |
/* Load a variable-resolution BSDF tree from an open XML file */ |
1401 |
SDError |
1402 |
SDloadTre(SDData *sd, ezxml_t wtl) |
1403 |
{ |
1404 |
SDError ec; |
1405 |
ezxml_t wld, wdb; |
1406 |
int rank; |
1407 |
char *txt; |
1408 |
/* basic checks and tensor rank */ |
1409 |
txt = ezxml_txt(ezxml_child(ezxml_child(wtl, |
1410 |
"DataDefinition"), "IncidentDataStructure")); |
1411 |
if (txt == NULL || !*txt) { |
1412 |
sprintf(SDerrorDetail, |
1413 |
"BSDF \"%s\": missing IncidentDataStructure", |
1414 |
sd->name); |
1415 |
return SDEformat; |
1416 |
} |
1417 |
if (!strcasecmp(txt, "TensorTree3")) |
1418 |
rank = 3; |
1419 |
else if (!strcasecmp(txt, "TensorTree4")) |
1420 |
rank = 4; |
1421 |
else { |
1422 |
sprintf(SDerrorDetail, |
1423 |
"BSDF \"%s\": unsupported IncidentDataStructure", |
1424 |
sd->name); |
1425 |
return SDEsupport; |
1426 |
} |
1427 |
/* load BSDF components */ |
1428 |
for (wld = ezxml_child(wtl, "WavelengthData"); |
1429 |
wld != NULL; wld = wld->next) { |
1430 |
const char *cnm = ezxml_txt(ezxml_child(wld,"Wavelength")); |
1431 |
int ct = -1; |
1432 |
if (!strcasecmp(cnm, "Visible")) |
1433 |
ct = tt_Y; |
1434 |
else if (!strcasecmp(cnm, "CIE-u")) |
1435 |
ct = tt_u; |
1436 |
else if (!strcasecmp(cnm, "CIE-v")) |
1437 |
ct = tt_v; |
1438 |
else |
1439 |
continue; |
1440 |
for (wdb = ezxml_child(wld, "WavelengthDataBlock"); |
1441 |
wdb != NULL; wdb = wdb->next) |
1442 |
if ((ec = load_bsdf_data(sd, wdb, ct, rank)) != SDEnone) |
1443 |
return ec; |
1444 |
} |
1445 |
/* separate diffuse components */ |
1446 |
extract_diffuse(&sd->rLambFront, sd->rf); |
1447 |
extract_diffuse(&sd->rLambBack, sd->rb); |
1448 |
extract_diffuse(&sd->tLambFront, sd->tf); |
1449 |
if (sd->tb != NULL) { |
1450 |
extract_diffuse(&sd->tLambBack, sd->tb); |
1451 |
if (sd->tf == NULL) |
1452 |
sd->tLambFront = sd->tLambBack; |
1453 |
} else if (sd->tf != NULL) |
1454 |
sd->tLambBack = sd->tLambFront; |
1455 |
/* return success */ |
1456 |
return SDEnone; |
1457 |
} |
1458 |
|
1459 |
/* Variable resolution BSDF methods */ |
1460 |
const SDFunc SDhandleTre = { |
1461 |
&SDgetTreBSDF, |
1462 |
&SDqueryTreProjSA, |
1463 |
&SDgetTreCDist, |
1464 |
&SDsampTreCDist, |
1465 |
&SDFreeBTre, |
1466 |
}; |