static double
l_psize(char *nm) /* compute pixel size in steradians */
{
static unsigned long ltick[MAXINP];
static double psize[MAXINP];
FVECT dir0, org, dirx, diry;
RREAL locx[2], locy[2];
double d;
int fn;
register int i;
d = argument(1);
if (d <= -0.5 || d >= nfiles+0.5) {
errno = EDOM;
return(0.0);
}
if (d < 0.5)
return((double)nfiles);
fn = d - 0.5;
if (ltick[fn] != eclock) { /* need to compute? */
psize[fn] = 0.0;
if (input[fn].vw.type == 0)
errno = EDOM;
else if (input[fn].vw.type != VT_PAR &&
funvalue(vray[6], 1, &d) >= -FTINY) {
for (i = 0; i < 3; i++)
dir0[i] = funvalue(vray[3+i], 1, &d);
pix2loc(locx, &input[fn].rs, xscan+1, ymax-1-yscan);
pix2loc(locy, &input[fn].rs, xscan, ymax-yscan);
if (viewray(org, dirx, &input[fn].vw,
locx[0], locx[1]) >= -FTINY &&
viewray(org, diry, &input[fn].vw,
locy[0], locy[1]) >= -FTINY) {
/* approximate solid angle */
for (i = 0; i < 3; i++) {
dirx[i] -= dir0[i];
diry[i] -= dir0[i];
}
fcross(dir0, dirx, diry);
psize[fn] = VLEN(dir0);
}
}
ltick[fn] = eclock;
}
return(psize[fn]);
}
/* Interpolate and output a BSDF function using Klems basis */
static void
eval_function(char *funame)
{
ANGLE_BASIS *abp = get_basis(kbasis);
int assignD = (fundefined(funame) < 6);
FILE *ofp = open_component_file(CIE_Y);
double iovec[6];
double sum;
int i, j, n;
initurand(npsamps);
for (j = 0; j < abp->nangles; j++) { /* run through directions */
for (i = 0; i < abp->nangles; i++) {
sum = 0;
for (n = npsamps; n--; ) { /* average over patches */
if (output_orient > 0)
fo_getvec(iovec+3, j+(n+frandom())/npsamps, abp);
else
bo_getvec(iovec+3, j+(n+frandom())/npsamps, abp);
if (input_orient > 0)
fi_getvec(iovec, i+urand(n), abp);
else
bi_getvec(iovec, i+urand(n), abp);
if (assignD) {
varset("Dx", '=', -iovec[3]);
varset("Dy", '=', -iovec[4]);
varset("Dz", '=', -iovec[5]);
++eclock;
}
sum += funvalue(funame, 6, iovec);
}
fprintf(ofp, "\t%.3e\n", sum/npsamps);
}
fputc('\n', ofp);
prog_show((j+1.)/abp->nangles);
}
prog_done();
if (fclose(ofp)) {
fprintf(stderr, "%s: error writing Y output\n", progname);
exit(1);
}
}
/* Interpolate and output a BSDF function using Klems basis */
static void
eval_function(char *funame)
{
ANGLE_BASIS *abp = get_basis(kbasis);
int assignD = (fundefined(funame) < 6);
double iovec[6];
double sum;
int i, j, n;
initurand(npsamps);
data_prologue(); /* begin output */
for (j = 0; j < abp->nangles; j++) { /* run through directions */
for (i = 0; i < abp->nangles; i++) {
sum = 0;
for (n = npsamps; n--; ) { /* average over patches */
if (output_orient > 0)
fo_getvec(iovec+3, j+(n+frandom())/npsamps, abp);
else
bo_getvec(iovec+3, j+(n+frandom())/npsamps, abp);
if (input_orient > 0)
fi_getvec(iovec, i+urand(n), abp);
else
bi_getvec(iovec, i+urand(n), abp);
if (assignD) {
varset("Dx", '=', -iovec[3]);
varset("Dy", '=', -iovec[4]);
varset("Dz", '=', -iovec[5]);
++eclock;
}
sum += funvalue(funame, 6, iovec);
}
printf("\t%.3e\n", sum/npsamps);
}
putchar('\n');
}
data_epilogue(); /* finish output */
}
static void
dirbrdf( /* compute source contribution */
COLOR cval, /* returned coefficient */
void *nnp, /* material data */
FVECT ldir, /* light source direction */
double omega /* light source size */
)
{
BRDFDAT *np = nnp;
double ldot;
double dtmp;
COLOR ctmp;
FVECT ldx;
static double vldx[5], pt[MAXDIM];
char **sa;
int i;
#define lddx (vldx+1)
setcolor(cval, 0.0, 0.0, 0.0);
ldot = DOT(np->pnorm, ldir);
if (ldot <= FTINY && ldot >= -FTINY)
return; /* too close to grazing */
if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY)
return; /* wrong side */
if (ldot > 0.0) {
/*
* Compute and add diffuse reflected component to returned
* color. The diffuse reflected component will always be
* modified by the color of the material.
*/
copycolor(ctmp, np->rdiff);
dtmp = ldot * omega / PI;
scalecolor(ctmp, dtmp);
addcolor(cval, ctmp);
} else {
/*
* Diffuse transmitted component.
*/
copycolor(ctmp, np->tdiff);
dtmp = -ldot * omega / PI;
scalecolor(ctmp, dtmp);
addcolor(cval, ctmp);
}
if (ldot > 0.0 ? np->rspec <= FTINY : np->tspec <= FTINY)
return; /* diffuse only */
/* set up function */
setbrdfunc(np);
sa = np->mp->oargs.sarg;
errno = 0;
/* transform light vector */
multv3(ldx, ldir, funcxf.xfm);
for (i = 0; i < 3; i++)
lddx[i] = ldx[i]/funcxf.sca;
lddx[3] = omega;
/* compute BRTDF */
if (np->mp->otype == MAT_BRTDF) {
if (sa[6][0] == '0') /* special case */
colval(ctmp,RED) = 0.0;
else
colval(ctmp,RED) = funvalue(sa[6], 4, lddx);
if (sa[7][0] == '0')
colval(ctmp,GRN) = 0.0;
else if (!strcmp(sa[7],sa[6]))
colval(ctmp,GRN) = colval(ctmp,RED);
else
colval(ctmp,GRN) = funvalue(sa[7], 4, lddx);
if (!strcmp(sa[8],sa[6]))
colval(ctmp,BLU) = colval(ctmp,RED);
else if (!strcmp(sa[8],sa[7]))
colval(ctmp,BLU) = colval(ctmp,GRN);
else
colval(ctmp,BLU) = funvalue(sa[8], 4, lddx);
dtmp = bright(ctmp);
} else if (np->dp == NULL) {
dtmp = funvalue(sa[0], 4, lddx);
setcolor(ctmp, dtmp, dtmp, dtmp);
} else {
for (i = 0; i < np->dp->nd; i++)
pt[i] = funvalue(sa[3+i], 4, lddx);
vldx[0] = datavalue(np->dp, pt);
dtmp = funvalue(sa[0], 5, vldx);
setcolor(ctmp, dtmp, dtmp, dtmp);
}
if ((errno == EDOM) | (errno == ERANGE)) {
objerror(np->mp, WARNING, "compute error");
return;
}
if (dtmp <= FTINY)
return;
if (ldot > 0.0) {
/*
* Compute reflected non-diffuse component.
*/
if ((np->mp->otype == MAT_MFUNC) | (np->mp->otype == MAT_MDATA))
multcolor(ctmp, np->mcolor);
dtmp = ldot * omega * np->rspec;
scalecolor(ctmp, dtmp);
addcolor(cval, ctmp);
} else {
/*
* Compute transmitted non-diffuse component.
*/
if ((np->mp->otype == MAT_TFUNC) | (np->mp->otype == MAT_TDATA))
multcolor(ctmp, np->mcolor);
dtmp = -ldot * omega * np->tspec;
scalecolor(ctmp, dtmp);
addcolor(cval, ctmp);
}
#undef lddx
}