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IMAGE.C
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C/C++ Source or Header
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1993-10-07
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/* Copyright (c) 1992 Regents of the University of California */
#ifndef lint
static char SCCSid[] = "@(#)image.c 2.5 9/8/92 LBL";
#endif
/*
* image.c - routines for image generation.
*
* 10/17/85
*/
#include "standard.h"
#include "view.h"
#include "resolu.h"
#include "paths.h"
VIEW stdview = STDVIEW; /* default view parameters */
char *
setview(v) /* set hvec and vvec, return message on error */
register VIEW *v;
{
static char ill_horiz[] = "illegal horizontal view size";
static char ill_vert[] = "illegal vertical view size";
if (normalize(v->vdir) == 0.0) /* normalize direction */
return("zero view direction");
if (normalize(v->vup) == 0.0) /* normalize view up */
return("zero view up vector");
fcross(v->hvec, v->vdir, v->vup); /* compute horiz dir */
if (normalize(v->hvec) == 0.0)
return("view up parallel to view direction");
fcross(v->vvec, v->hvec, v->vdir); /* compute vert dir */
if (v->horiz <= FTINY)
return(ill_horiz);
if (v->vert <= FTINY)
return(ill_vert);
switch (v->type) {
case VT_PAR: /* parallel view */
v->hn2 = v->horiz;
v->vn2 = v->vert;
break;
case VT_PER: /* perspective view */
if (v->horiz >= 180.0-FTINY)
return(ill_horiz);
if (v->vert >= 180.0-FTINY)
return(ill_vert);
v->hn2 = 2.0 * tan(v->horiz*(PI/180.0/2.0));
v->vn2 = 2.0 * tan(v->vert*(PI/180.0/2.0));
break;
case VT_ANG: /* angular fisheye */
if (v->horiz > 360.0+FTINY)
return(ill_horiz);
if (v->vert > 360.0+FTINY)
return(ill_vert);
v->hn2 = v->horiz / 90.0;
v->vn2 = v->vert / 90.0;
break;
case VT_HEM: /* hemispherical fisheye */
if (v->horiz > 180.0+FTINY)
return(ill_horiz);
if (v->vert > 180.0+FTINY)
return(ill_vert);
v->hn2 = 2.0 * sin(v->horiz*(PI/180.0/2.0));
v->vn2 = 2.0 * sin(v->vert*(PI/180.0/2.0));
break;
default:
return("unknown view type");
}
if (v->type != VT_ANG) {
v->hvec[0] *= v->hn2;
v->hvec[1] *= v->hn2;
v->hvec[2] *= v->hn2;
v->vvec[0] *= v->vn2;
v->vvec[1] *= v->vn2;
v->vvec[2] *= v->vn2;
}
v->hn2 *= v->hn2;
v->vn2 *= v->vn2;
return(NULL);
}
normaspect(va, ap, xp, yp) /* fix pixel aspect or resolution */
double va; /* view aspect ratio */
double *ap; /* pixel aspect in (or out if 0) */
int *xp, *yp; /* x and y resolution in (or out if *ap!=0) */
{
if (*ap <= FTINY)
*ap = va * *xp / *yp; /* compute pixel aspect */
else if (va * *xp > *ap * *yp)
*xp = *yp / va * *ap + .5; /* reduce x resolution */
else
*yp = *xp * va / *ap + .5; /* reduce y resolution */
}
viewray(orig, direc, v, x, y) /* compute ray origin and direction */
FVECT orig, direc;
register VIEW *v;
double x, y;
{
double d, z;
x += v->hoff - 0.5;
y += v->voff - 0.5;
switch(v->type) {
case VT_PAR: /* parallel view */
orig[0] = v->vp[0] + x*v->hvec[0] + y*v->vvec[0];
orig[1] = v->vp[1] + x*v->hvec[1] + y*v->vvec[1];
orig[2] = v->vp[2] + x*v->hvec[2] + y*v->vvec[2];
VCOPY(direc, v->vdir);
return(0);
case VT_PER: /* perspective view */
VCOPY(orig, v->vp);
direc[0] = v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
direc[1] = v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
direc[2] = v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
normalize(direc);
return(0);
case VT_HEM: /* hemispherical fisheye */
z = 1.0 - x*x*v->hn2 - y*y*v->vn2;
if (z < 0.0)
return(-1);
z = sqrt(z);
VCOPY(orig, v->vp);
direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
return(0);
case VT_ANG: /* angular fisheye */
x *= v->horiz/180.0;
y *= v->vert/180.0;
d = x*x + y*y;
if (d > 1.0)
return(-1);
VCOPY(orig, v->vp);
if (d <= FTINY) {
VCOPY(direc, v->vdir);
return(0);
}
d = sqrt(d);
z = cos(PI*d);
d = sqrt(1 - z*z)/d;
x *= d;
y *= d;
direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
return(0);
}
return(-1);
}
viewloc(ip, v, p) /* find image location for point */
FVECT ip;
register VIEW *v;
FVECT p;
{
double d;
FVECT disp;
disp[0] = p[0] - v->vp[0];
disp[1] = p[1] - v->vp[1];
disp[2] = p[2] - v->vp[2];
switch (v->type) {
case VT_PAR: /* parallel view */
ip[2] = DOT(disp,v->vdir);
break;
case VT_PER: /* perspective view */
d = DOT(disp,v->vdir);
ip[2] = sqrt(DOT(disp,disp));
if (d < 0.0) { /* fold pyramid */
ip[2] = -ip[2];
d = -d;
} else if (d > FTINY) {
d = 1.0/d;
disp[0] *= d;
disp[1] *= d;
disp[2] *= d;
}
break;
case VT_HEM: /* hemispherical fisheye */
d = normalize(disp);
if (DOT(disp,v->vdir) < 0.0)
ip[2] = -d;
else
ip[2] = d;
break;
case VT_ANG: /* angular fisheye */
ip[0] = 0.5 - v->hoff;
ip[1] = 0.5 - v->voff;
ip[2] = normalize(disp);
d = DOT(disp,v->vdir);
if (d >= 1.0-FTINY)
return;
if (d <= -(1.0-FTINY)) {
ip[1] += 180.0/v->horiz;
ip[2] += 180.0/v->vert;
return;
}
d = acos(d)/PI / sqrt(1.0 - d*d);
ip[0] += DOT(disp,v->hvec)*d*180.0/v->horiz;
ip[1] += DOT(disp,v->vvec)*d*180.0/v->vert;
return;
}
ip[0] = DOT(disp,v->hvec)/v->hn2 + 0.5 - v->hoff;
ip[1] = DOT(disp,v->vvec)/v->vn2 + 0.5 - v->voff;
}
pix2loc(loc, rp, px, py) /* compute image location from pixel pos. */
FLOAT loc[2];
register RESOLU *rp;
int px, py;
{
register int x, y;
if (rp->or & YMAJOR) {
x = px;
y = py;
} else {
x = py;
y = px;
}
if (rp->or & XDECR)
x = rp->xr-1 - x;
if (rp->or & YDECR)
y = rp->yr-1 - y;
loc[0] = (x+.5)/rp->xr;
loc[1] = (y+.5)/rp->yr;
}
loc2pix(pp, rp, lx, ly) /* compute pixel pos. from image location */
int pp[2];
register RESOLU *rp;
double lx, ly;
{
register int x, y;
x = lx * rp->xr;
y = ly * rp->yr;
if (rp->or & XDECR)
x = rp->xr-1 - x;
if (rp->or & YDECR)
y = rp->yr-1 - y;
if (rp->or & YMAJOR) {
pp[0] = x;
pp[1] = y;
} else {
pp[0] = y;
pp[1] = x;
}
}
int
getviewopt(v, ac, av) /* process view argument */
register VIEW *v;
int ac;
register char *av[];
{
#define check(c,l) if ((av[0][c]&&av[0][c]!=' ') || \
badarg(ac-1,av+1,l)) return(-1)
if (ac <= 0 || av[0][0] != '-' || av[0][1] != 'v')
return(-1);
switch (av[0][2]) {
case 't': /* type */
if (!av[0][3] || av[0][3]==' ')
return(-1);
check(4,"");
v->type = av[0][3];
return(0);
case 'p': /* point */
check(3,"fff");
v->vp[0] = atof(av[1]);
v->vp[1] = atof(av[2]);
v->vp[2] = atof(av[3]);
return(3);
case 'd': /* direction */
check(3,"fff");
v->vdir[0] = atof(av[1]);
v->vdir[1] = atof(av[2]);
v->vdir[2] = atof(av[3]);
return(3);
case 'u': /* up */
check(3,"fff");
v->vup[0] = atof(av[1]);
v->vup[1] = atof(av[2]);
v->vup[2] = atof(av[3]);
return(3);
case 'h': /* horizontal size */
check(3,"f");
v->horiz = atof(av[1]);
return(1);
case 'v': /* vertical size */
check(3,"f");
v->vert = atof(av[1]);
return(1);
case 's': /* shift */
check(3,"f");
v->hoff = atof(av[1]);
return(1);
case 'l': /* lift */
check(3,"f");
v->voff = atof(av[1]);
return(1);
default:
return(-1);
}
#undef check
}
int
sscanview(vp, s) /* get view parameters from string */
VIEW *vp;
register char *s;
{
int ac;
char *av[4];
int na;
int nvopts = 0;
if (*s != '-')
s = sskip(s);
while (*s) {
ac = 0;
do {
av[ac++] = s;
while (*s && *s != ' ')
s++;
while (*s == ' ')
s++;
} while (*s && ac < 4);
if ((na = getviewopt(vp, ac, av)) >= 0) {
if (na+1 < ac)
s = av[na+1];
nvopts++;
} else if (ac > 1)
s = av[1];
}
return(nvopts);
}
fprintview(vp, fp) /* write out view parameters */
register VIEW *vp;
FILE *fp;
{
fprintf(fp, " -vt%c", vp->type);
fprintf(fp, " -vp %.6g %.6g %.6g", vp->vp[0], vp->vp[1], vp->vp[2]);
fprintf(fp, " -vd %.6g %.6g %.6g", vp->vdir[0], vp->vdir[1], vp->vdir[2]);
fprintf(fp, " -vu %.6g %.6g %.6g", vp->vup[0], vp->vup[1], vp->vup[2]);
fprintf(fp, " -vh %.6g -vv %.6g", vp->horiz, vp->vert);
fprintf(fp, " -vs %.6g -vl %.6g", vp->hoff, vp->voff);
}
int
isview(s) /* is this a view string? */
char *s;
{
static char *altname[]={NULL,VIEWSTR,"rpict","rview","pinterp",NULL};
extern char *progname;
register char *cp;
register char **an;
/* add program name to list */
if (altname[0] == NULL) {
for (cp = progname; *cp; cp++)
;
while (cp > progname && !ISDIRSEP(cp[-1]))
cp--;
altname[0] = cp;
}
/* skip leading path */
cp = s;
while (*cp && *cp != ' ')
cp++;
while (cp > s && !ISDIRSEP(cp[-1]))
cp--;
for (an = altname; *an != NULL; an++)
if (!strncmp(*an, cp, strlen(*an)))
return(1);
return(0);
}
struct myview {
VIEW *hv;
int ok;
};
static
gethview(s, v) /* get view from header */
char *s;
register struct myview *v;
{
if (isview(s) && sscanview(v->hv, s) > 0)
v->ok++;
}
int
viewfile(fname, vp, rp) /* get view from file */
char *fname;
VIEW *vp;
RESOLU *rp;
{
struct myview mvs;
FILE *fp;
if ((fp = fopen(fname, "r")) == NULL)
return(-1);
mvs.hv = vp;
mvs.ok = 0;
getheader(fp, gethview, &mvs);
if (rp != NULL && !fgetsresolu(rp, fp))
mvs.ok = 0;
fclose(fp);
return(mvs.ok);
}