src/common/image.c

/* Copyright (c) 1994 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ 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 (v->vfore < -FTINY || v->vaft < -FTINY ||
                        (v->vaft > FTINY && v->vaft <= v->vfore))
                return("illegal fore/aft clipping plane");

        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 */
}


double
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] + v->vfore*v->vdir[0]
                                + x*v->hvec[0] + y*v->vvec[0];
                orig[1] = v->vp[1] + v->vfore*v->vdir[1]
                                + x*v->hvec[1] + y*v->vvec[1];
                orig[2] = v->vp[2] + v->vfore*v->vdir[2]
                                + x*v->hvec[2] + y*v->vvec[2];
                VCOPY(direc, v->vdir);
                return(v->vaft - v->vfore);
        case VT_PER:                    /* perspective view */
                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];
                orig[0] = v->vp[0] + v->vfore*direc[0];
                orig[1] = v->vp[1] + v->vfore*direc[1];
                orig[2] = v->vp[2] + v->vfore*direc[2];
                d = normalize(direc);
                return((v->vaft - v->vfore)*d);
        case VT_HEM:                    /* hemispherical fisheye */
                z = 1.0 - x*x*v->hn2 - y*y*v->vn2;
                if (z < 0.0)
                        return(-1.0);
                z = sqrt(z);
                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];
                orig[0] = v->vp[0] + v->vfore*direc[0];
                orig[1] = v->vp[1] + v->vfore*direc[1];
                orig[2] = v->vp[2] + v->vfore*direc[2];
                return(v->vaft - v->vfore);
        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(-1.0);
                d = sqrt(d);
                z = cos(PI*d);
                d = d <= FTINY ? PI : 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];
                orig[0] = v->vp[0] + v->vfore*direc[0];
                orig[1] = v->vp[1] + v->vfore*direc[1];
                orig[2] = v->vp[2] + v->vfore*direc[2];
                return(v->vaft - v->vfore);
        }
        return(-1.0);
}


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) - v->vfore;
                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;
                }
                if (d > FTINY) {
                        d = 1.0/d;
                        disp[0] *= d;
                        disp[1] *= d;
                        disp[2] *= d;
                }
                ip[2] *= (1.0 - v->vfore*d);
                break;
        case VT_HEM:                    /* hemispherical fisheye */
                d = normalize(disp);
                if (DOT(disp,v->vdir) < 0.0)
                        ip[2] = -d;
                else
                        ip[2] = d;
                ip[2] -= v->vfore;
                break;
        case VT_ANG:                    /* angular fisheye */
                ip[0] = 0.5 - v->hoff;
                ip[1] = 0.5 - v->voff;
                ip[2] = normalize(disp) - v->vfore;
                d = DOT(disp,v->vdir);
                if (d >= 1.0-FTINY)
                        return;
                if (d <= -(1.0-FTINY)) {
                        ip[0] += 180.0/v->horiz;
                        ip[1] += 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 'o':                       /* fore clipping plane */
                check(3,"f");
                v->vfore = atof(av[1]);
                return(1);
        case 'a':                       /* aft clipping plane */
                check(3,"f");
                v->vaft = 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, " -vo %.6g -va %.6g", vp->vfore, vp->vaft);
        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);
}
Revision:	2.7
Committed:	Tue Dec 20 20:15:04 1994 UTC (30 years, 10 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.6:	+46 -20 lines
Log Message:	added -vo and -va (fore and aft clipping plane) parameters
#	User	Rev	Content
1	greg	2.7	/* Copyright (c) 1994 Regents of the University of California */
2	greg	1.1
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* image.c - routines for image generation.
9			*
10			* 10/17/85
11			*/
12
13			#include "standard.h"
14
15			#include "view.h"
16
17	greg	1.17	#include "resolu.h"
18
19	greg	2.4	#include "paths.h"
20
21	greg	1.5	VIEW stdview = STDVIEW; /* default view parameters */
22	greg	1.1
23
24			char *
25	greg	1.5	setview(v) /* set hvec and vvec, return message on error */
26			register VIEW *v;
27	greg	1.3	{
28	greg	1.12	static char ill_horiz[] = "illegal horizontal view size";
29			static char ill_vert[] = "illegal vertical view size";
30
31	greg	2.7	if (v->vfore < -FTINY \|\| v->vaft < -FTINY \|\|
32			(v->vaft > FTINY && v->vaft <= v->vfore))
33			return("illegal fore/aft clipping plane");
34
35	greg	1.1	if (normalize(v->vdir) == 0.0) /* normalize direction */
36			return("zero view direction");
37
38	greg	1.14	if (normalize(v->vup) == 0.0) /* normalize view up */
39			return("zero view up vector");
40
41	greg	1.5	fcross(v->hvec, v->vdir, v->vup); /* compute horiz dir */
42
43			if (normalize(v->hvec) == 0.0)
44	greg	1.14	return("view up parallel to view direction");
45	greg	1.1
46	greg	1.5	fcross(v->vvec, v->hvec, v->vdir); /* compute vert dir */
47
48	greg	1.12	if (v->horiz <= FTINY)
49			return(ill_horiz);
50			if (v->vert <= FTINY)
51			return(ill_vert);
52
53			switch (v->type) {
54			case VT_PAR: /* parallel view */
55	greg	1.5	v->hn2 = v->horiz;
56	greg	1.12	v->vn2 = v->vert;
57			break;
58			case VT_PER: /* perspective view */
59			if (v->horiz >= 180.0-FTINY)
60			return(ill_horiz);
61			if (v->vert >= 180.0-FTINY)
62			return(ill_vert);
63	greg	1.5	v->hn2 = 2.0 * tan(v->horiz*(PI/180.0/2.0));
64	greg	1.12	v->vn2 = 2.0 * tan(v->vert*(PI/180.0/2.0));
65			break;
66			case VT_ANG: /* angular fisheye */
67			if (v->horiz > 360.0+FTINY)
68			return(ill_horiz);
69			if (v->vert > 360.0+FTINY)
70			return(ill_vert);
71			v->hn2 = v->horiz / 90.0;
72			v->vn2 = v->vert / 90.0;
73			break;
74			case VT_HEM: /* hemispherical fisheye */
75			if (v->horiz > 180.0+FTINY)
76			return(ill_horiz);
77			if (v->vert > 180.0+FTINY)
78			return(ill_vert);
79			v->hn2 = 2.0 * sin(v->horiz*(PI/180.0/2.0));
80			v->vn2 = 2.0 * sin(v->vert*(PI/180.0/2.0));
81			break;
82			default:
83	greg	1.1	return("unknown view type");
84	greg	1.12	}
85	greg	1.13	if (v->type != VT_ANG) {
86	greg	1.12	v->hvec[0] *= v->hn2;
87			v->hvec[1] *= v->hn2;
88			v->hvec[2] *= v->hn2;
89			v->vvec[0] *= v->vn2;
90			v->vvec[1] *= v->vn2;
91			v->vvec[2] *= v->vn2;
92			}
93	greg	1.5	v->hn2 *= v->hn2;
94			v->vn2 *= v->vn2;
95	greg	1.1
96			return(NULL);
97			}
98
99
100	greg	1.7	normaspect(va, ap, xp, yp) /* fix pixel aspect or resolution */
101			double va; /* view aspect ratio */
102			double ap; / pixel aspect in (or out if 0) */
103			int xp, yp; /* x and y resolution in (or out if ap!=0) /
104	greg	1.6	{
105			if (*ap <= FTINY)
106	greg	1.7	ap = va xp / yp; /* compute pixel aspect */
107	greg	1.6	else if (va * xp > ap * *yp)
108	greg	1.10	xp = yp / va * ap + .5; / reduce x resolution */
109	greg	1.6	else
110	greg	1.10	yp = xp * va / ap + .5; / reduce y resolution */
111	greg	1.6	}
112
113
114	greg	2.7	double
115	greg	1.5	viewray(orig, direc, v, x, y) /* compute ray origin and direction */
116	greg	1.1	FVECT orig, direc;
117			register VIEW *v;
118			double x, y;
119			{
120	greg	1.12	double d, z;
121
122	greg	1.5	x += v->hoff - 0.5;
123			y += v->voff - 0.5;
124	greg	1.1
125	greg	1.12	switch(v->type) {
126			case VT_PAR: /* parallel view */
127	greg	2.7	orig[0] = v->vp[0] + v->vfore*v->vdir[0]
128			+ xv->hvec[0] + yv->vvec[0];
129			orig[1] = v->vp[1] + v->vfore*v->vdir[1]
130			+ xv->hvec[1] + yv->vvec[1];
131			orig[2] = v->vp[2] + v->vfore*v->vdir[2]
132			+ xv->hvec[2] + yv->vvec[2];
133	greg	1.1	VCOPY(direc, v->vdir);
134	greg	2.7	return(v->vaft - v->vfore);
135	greg	1.12	case VT_PER: /* perspective view */
136	greg	1.5	direc[0] = v->vdir[0] + xv->hvec[0] + yv->vvec[0];
137			direc[1] = v->vdir[1] + xv->hvec[1] + yv->vvec[1];
138			direc[2] = v->vdir[2] + xv->hvec[2] + yv->vvec[2];
139	greg	2.7	orig[0] = v->vp[0] + v->vfore*direc[0];
140			orig[1] = v->vp[1] + v->vfore*direc[1];
141			orig[2] = v->vp[2] + v->vfore*direc[2];
142			d = normalize(direc);
143			return((v->vaft - v->vfore)*d);
144	greg	1.12	case VT_HEM: /* hemispherical fisheye */
145	greg	1.13	z = 1.0 - xxv->hn2 - yyv->vn2;
146	greg	1.12	if (z < 0.0)
147	greg	2.7	return(-1.0);
148	greg	1.12	z = sqrt(z);
149			direc[0] = zv->vdir[0] + xv->hvec[0] + y*v->vvec[0];
150			direc[1] = zv->vdir[1] + xv->hvec[1] + y*v->vvec[1];
151			direc[2] = zv->vdir[2] + xv->hvec[2] + y*v->vvec[2];
152	greg	2.7	orig[0] = v->vp[0] + v->vfore*direc[0];
153			orig[1] = v->vp[1] + v->vfore*direc[1];
154			orig[2] = v->vp[2] + v->vfore*direc[2];
155			return(v->vaft - v->vfore);
156	greg	1.12	case VT_ANG: /* angular fisheye */
157			x *= v->horiz/180.0;
158			y *= v->vert/180.0;
159			d = xx + yy;
160			if (d > 1.0)
161	greg	2.7	return(-1.0);
162	greg	1.12	d = sqrt(d);
163			z = cos(PI*d);
164	greg	2.6	d = d <= FTINY ? PI : sqrt(1 - z*z)/d;
165	greg	1.12	x *= d;
166			y *= d;
167			direc[0] = zv->vdir[0] + xv->hvec[0] + y*v->vvec[0];
168			direc[1] = zv->vdir[1] + xv->hvec[1] + y*v->vvec[1];
169			direc[2] = zv->vdir[2] + xv->hvec[2] + y*v->vvec[2];
170	greg	2.7	orig[0] = v->vp[0] + v->vfore*direc[0];
171			orig[1] = v->vp[1] + v->vfore*direc[1];
172			orig[2] = v->vp[2] + v->vfore*direc[2];
173			return(v->vaft - v->vfore);
174	greg	1.1	}
175	greg	2.7	return(-1.0);
176	greg	1.1	}
177
178
179	greg	1.17	viewloc(ip, v, p) /* find image location for point */
180			FVECT ip;
181	greg	1.3	register VIEW *v;
182			FVECT p;
183			{
184			double d;
185			FVECT disp;
186	greg	1.5
187	greg	1.3	disp[0] = p[0] - v->vp[0];
188			disp[1] = p[1] - v->vp[1];
189			disp[2] = p[2] - v->vp[2];
190
191	greg	1.12	switch (v->type) {
192			case VT_PAR: /* parallel view */
193	greg	2.7	ip[2] = DOT(disp,v->vdir) - v->vfore;
194	greg	1.13	break;
195	greg	1.12	case VT_PER: /* perspective view */
196	greg	1.11	d = DOT(disp,v->vdir);
197	greg	1.17	ip[2] = sqrt(DOT(disp,disp));
198			if (d < 0.0) { /* fold pyramid */
199			ip[2] = -ip[2];
200	greg	1.11	d = -d;
201	greg	2.7	}
202			if (d > FTINY) {
203	greg	1.11	d = 1.0/d;
204			disp[0] *= d;
205			disp[1] *= d;
206			disp[2] *= d;
207			}
208	greg	2.7	ip[2] = (1.0 - v->vfored);
209	greg	1.13	break;
210	greg	1.12	case VT_HEM: /* hemispherical fisheye */
211			d = normalize(disp);
212	greg	1.17	if (DOT(disp,v->vdir) < 0.0)
213			ip[2] = -d;
214			else
215			ip[2] = d;
216	greg	2.7	ip[2] -= v->vfore;
217	greg	1.13	break;
218	greg	1.12	case VT_ANG: /* angular fisheye */
219	greg	1.17	ip[0] = 0.5 - v->hoff;
220			ip[1] = 0.5 - v->voff;
221	greg	2.7	ip[2] = normalize(disp) - v->vfore;
222	greg	1.12	d = DOT(disp,v->vdir);
223			if (d >= 1.0-FTINY)
224			return;
225			if (d <= -(1.0-FTINY)) {
226	greg	2.7	ip[0] += 180.0/v->horiz;
227			ip[1] += 180.0/v->vert;
228	greg	1.12	return;
229			}
230			d = acos(d)/PI / sqrt(1.0 - d*d);
231	greg	1.17	ip[0] += DOT(disp,v->hvec)d180.0/v->horiz;
232			ip[1] += DOT(disp,v->vvec)d180.0/v->vert;
233	greg	1.12	return;
234	greg	1.3	}
235	greg	1.17	ip[0] = DOT(disp,v->hvec)/v->hn2 + 0.5 - v->hoff;
236			ip[1] = DOT(disp,v->vvec)/v->vn2 + 0.5 - v->voff;
237	greg	1.3	}
238
239
240	greg	1.17	pix2loc(loc, rp, px, py) /* compute image location from pixel pos. */
241			FLOAT loc[2];
242			register RESOLU *rp;
243			int px, py;
244			{
245			register int x, y;
246
247			if (rp->or & YMAJOR) {
248			x = px;
249			y = py;
250			} else {
251			x = py;
252			y = px;
253			}
254			if (rp->or & XDECR)
255			x = rp->xr-1 - x;
256			if (rp->or & YDECR)
257			y = rp->yr-1 - y;
258			loc[0] = (x+.5)/rp->xr;
259			loc[1] = (y+.5)/rp->yr;
260			}
261
262
263			loc2pix(pp, rp, lx, ly) /* compute pixel pos. from image location */
264			int pp[2];
265			register RESOLU *rp;
266			double lx, ly;
267			{
268			register int x, y;
269
270			x = lx * rp->xr;
271			y = ly * rp->yr;
272			if (rp->or & XDECR)
273			x = rp->xr-1 - x;
274			if (rp->or & YDECR)
275			y = rp->yr-1 - y;
276			if (rp->or & YMAJOR) {
277			pp[0] = x;
278			pp[1] = y;
279			} else {
280			pp[0] = y;
281			pp[1] = x;
282			}
283			}
284
285
286	greg	1.5	int
287			getviewopt(v, ac, av) /* process view argument */
288			register VIEW *v;
289			int ac;
290			register char *av[];
291			{
292	greg	1.16	#define check(c,l) if ((av[0][c]&&av[0][c]!=' ') \|\| \
293			badarg(ac-1,av+1,l)) return(-1)
294	greg	1.5
295	greg	1.9	if (ac <= 0 \|\| av[0][0] != '-' \|\| av[0][1] != 'v')
296	greg	1.5	return(-1);
297			switch (av[0][2]) {
298			case 't': /* type */
299			if (!av[0][3] \|\| av[0][3]==' ')
300			return(-1);
301	greg	1.16	check(4,"");
302	greg	1.5	v->type = av[0][3];
303			return(0);
304			case 'p': /* point */
305	greg	1.16	check(3,"fff");
306	greg	1.5	v->vp[0] = atof(av[1]);
307			v->vp[1] = atof(av[2]);
308			v->vp[2] = atof(av[3]);
309			return(3);
310			case 'd': /* direction */
311	greg	1.16	check(3,"fff");
312	greg	1.5	v->vdir[0] = atof(av[1]);
313			v->vdir[1] = atof(av[2]);
314			v->vdir[2] = atof(av[3]);
315			return(3);
316			case 'u': /* up */
317	greg	1.16	check(3,"fff");
318	greg	1.5	v->vup[0] = atof(av[1]);
319			v->vup[1] = atof(av[2]);
320			v->vup[2] = atof(av[3]);
321			return(3);
322			case 'h': /* horizontal size */
323	greg	1.16	check(3,"f");
324	greg	1.5	v->horiz = atof(av[1]);
325			return(1);
326			case 'v': /* vertical size */
327	greg	1.16	check(3,"f");
328	greg	1.5	v->vert = atof(av[1]);
329			return(1);
330	greg	2.7	case 'o': /* fore clipping plane */
331			check(3,"f");
332			v->vfore = atof(av[1]);
333			return(1);
334			case 'a': /* aft clipping plane */
335			check(3,"f");
336			v->vaft = atof(av[1]);
337			return(1);
338	greg	1.5	case 's': /* shift */
339	greg	1.16	check(3,"f");
340	greg	1.5	v->hoff = atof(av[1]);
341			return(1);
342			case 'l': /* lift */
343	greg	1.16	check(3,"f");
344	greg	1.5	v->voff = atof(av[1]);
345			return(1);
346			default:
347			return(-1);
348			}
349			#undef check
350			}
351
352
353			int
354			sscanview(vp, s) /* get view parameters from string */
355			VIEW *vp;
356	greg	1.1	register char *s;
357			{
358	greg	1.5	int ac;
359			char *av[4];
360			int na;
361			int nvopts = 0;
362
363	greg	2.3	if (*s != '-')
364			s = sskip(s);
365	greg	1.9	while (*s) {
366	greg	1.5	ac = 0;
367			do {
368			av[ac++] = s;
369			while (s && s != ' ')
370			s++;
371			while (*s == ' ')
372			s++;
373			} while (*s && ac < 4);
374			if ((na = getviewopt(vp, ac, av)) >= 0) {
375			if (na+1 < ac)
376			s = av[na+1];
377			nvopts++;
378	greg	1.9	} else if (ac > 1)
379			s = av[1];
380			}
381	greg	1.5	return(nvopts);
382	greg	1.1	}
383
384
385			fprintview(vp, fp) /* write out view parameters */
386			register VIEW *vp;
387			FILE *fp;
388			{
389			fprintf(fp, " -vt%c", vp->type);
390			fprintf(fp, " -vp %.6g %.6g %.6g", vp->vp[0], vp->vp[1], vp->vp[2]);
391			fprintf(fp, " -vd %.6g %.6g %.6g", vp->vdir[0], vp->vdir[1], vp->vdir[2]);
392			fprintf(fp, " -vu %.6g %.6g %.6g", vp->vup[0], vp->vup[1], vp->vup[2]);
393			fprintf(fp, " -vh %.6g -vv %.6g", vp->horiz, vp->vert);
394	greg	2.7	fprintf(fp, " -vo %.6g -va %.6g", vp->vfore, vp->vaft);
395	greg	1.9	fprintf(fp, " -vs %.6g -vl %.6g", vp->hoff, vp->voff);
396	greg	1.1	}
397
398
399	greg	2.3	int
400			isview(s) /* is this a view string? */
401			char *s;
402			{
403	greg	2.5	static char *altname[]={NULL,VIEWSTR,"rpict","rview","pinterp",NULL};
404			extern char *progname;
405	greg	2.3	register char *cp;
406			register char **an;
407			/* add program name to list */
408	greg	2.5	if (altname[0] == NULL) {
409			for (cp = progname; *cp; cp++)
410			;
411			while (cp > progname && !ISDIRSEP(cp[-1]))
412			cp--;
413			altname[0] = cp;
414			}
415	greg	2.3	/* skip leading path */
416			cp = s;
417			while (cp && cp != ' ')
418			cp++;
419	greg	2.5	while (cp > s && !ISDIRSEP(cp[-1]))
420	greg	2.3	cp--;
421			for (an = altname; *an != NULL; an++)
422			if (!strncmp(an, cp, strlen(an)))
423			return(1);
424			return(0);
425			}
426	greg	1.1
427	greg	2.3
428	greg	1.15	struct myview {
429			VIEW *hv;
430			int ok;
431			};
432	greg	1.1
433	greg	1.15
434	greg	1.1	static
435	greg	1.15	gethview(s, v) /* get view from header */
436	greg	1.1	char *s;
437	greg	1.15	register struct myview *v;
438	greg	1.1	{
439	greg	2.3	if (isview(s) && sscanview(v->hv, s) > 0)
440			v->ok++;
441	greg	1.1	}
442
443
444			int
445	greg	1.17	viewfile(fname, vp, rp) /* get view from file */
446	greg	1.1	char *fname;
447			VIEW *vp;
448	greg	1.17	RESOLU *rp;
449	greg	1.1	{
450	greg	1.15	struct myview mvs;
451	greg	1.1	FILE *fp;
452
453			if ((fp = fopen(fname, "r")) == NULL)
454			return(-1);
455
456	greg	1.15	mvs.hv = vp;
457			mvs.ok = 0;
458	greg	1.1
459	greg	1.15	getheader(fp, gethview, &mvs);
460	greg	1.8
461	greg	1.17	if (rp != NULL && !fgetsresolu(rp, fp))
462	greg	1.15	mvs.ok = 0;
463	greg	1.1
464			fclose(fp);
465
466	greg	1.15	return(mvs.ok);
467	greg	1.1	}