void
compavg( /* recompute averages */
PNODE *p
)
{
int i, navg;
if (p->kid == NULL)
return;
setcolor(p->v, .0, .0, .0);
navg = 0;
for (i = 0; i < 4; i++) {
if (p->kid[i].xmin >= p->kid[i].xmax) continue;
if (p->kid[i].ymin >= p->kid[i].ymax) continue;
compavg(p->kid+i);
addcolor(p->v, p->kid[i].v);
navg++;
}
if (navg > 1)
scalecolor(p->v, 1./navg);
}
void
getexposure( /* get new exposure */
char *s
)
{
char buf[128];
char *cp;
int x, y;
PNODE *p = &ptrunk;
int adapt = 0;
double e = 1.0;
for (cp = s; isspace(*cp); cp++)
;
if (*cp == '@') {
adapt++;
while (isspace(*++cp))
;
}
if (*cp == '\0') { /* normalize to point */
if (dev->getcur == NULL)
return;
(*dev->comout)("Pick point for exposure\n");
if ((*dev->getcur)(&x, &y) == ABORT)
return;
p = findrect(x, y, &ptrunk, -1);
} else {
if (*cp == '=') { /* absolute setting */
p = NULL;
e = 1.0/exposure;
for (cp++; isspace(*cp); cp++)
;
if (*cp == '\0') { /* interactive */
sprintf(buf, "exposure (%f): ", exposure);
(*dev->comout)(buf);
(*dev->comin)(buf, NULL);
for (cp = buf; isspace(*cp); cp++)
;
if (*cp == '\0')
return;
}
}
if (*cp == '+' || *cp == '-') /* f-stops */
e *= pow(2.0, atof(cp));
else /* multiplier */
e *= atof(cp);
}
if (p != NULL) { /* relative setting */
compavg(p);
if (bright(p->v) < 1e-15) {
error(COMMAND, "cannot normalize to zero");
return;
}
if (adapt)
e *= 106./pow(1.219+pow(luminance(p->v)/exposure,.4),2.5)/exposure;
else
e *= 0.5 / bright(p->v);
}
if (e <= FTINY || fabs(1.0 - e) <= FTINY)
return;
scalepict(&ptrunk, e);
exposure *= e;
redraw();
}
