src/common/image.c

/* Copyright (c) 1986 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"

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");

        fcross(v->hvec, v->vdir, v->vup);       /* compute horiz dir */

        if (normalize(v->hvec) == 0.0)
                return("illegal view up vector");

        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);
}


viewpixel(xp, yp, zp, v, p)             /* find image location for point */
double  *xp, *yp, *zp;
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 */
                if (zp != NULL)
                        *zp = DOT(disp,v->vdir);
                break;
        case VT_PER:                    /* perspective view */
                d = DOT(disp,v->vdir);
                if (zp != NULL) {
                        *zp = sqrt(DOT(disp,disp));
                        if (d < 0.0)
                                *zp = -*zp;
                }
                if (d < 0.0)            /* fold pyramid */
                        d = -d;
                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 (zp != NULL) {
                        if (DOT(disp,v->vdir) < 0.0)
                                *zp = -d;
                        else
                                *zp = d;
                }
                break;
        case VT_ANG:                    /* angular fisheye */
                d = normalize(disp);
                if (zp != NULL)
                        *zp = d;
                *xp = 0.5 - v->hoff;
                *yp = 0.5 - v->voff;
                d = DOT(disp,v->vdir);
                if (d >= 1.0-FTINY)
                        return;
                if (d <= -(1.0-FTINY)) {
                        *xp += 180.0/v->horiz;
                        *yp += 180.0/v->vert;
                        return;
                }
                d = acos(d)/PI / sqrt(1.0 - d*d);
                *xp += DOT(disp,v->hvec)*d*180.0/v->horiz;
                *yp += DOT(disp,v->vvec)*d*180.0/v->vert;
                return;
        }
        *xp = DOT(disp,v->hvec)/v->hn2 + 0.5 - v->hoff;
        *yp = DOT(disp,v->vvec)/v->vn2 + 0.5 - v->voff;
}


int
getviewopt(v, ac, av)                   /* process view argument */
register VIEW  *v;
int  ac;
register char  *av[];
{
#define check(c,n)      if ((av[0][c]&&av[0][c]!=' ') || n>=ac) return(-1)
        extern double  atof();

        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(4,0);
                v->type = av[0][3];
                return(0);
        case 'p':                       /* point */
                check(3,3);
                v->vp[0] = atof(av[1]);
                v->vp[1] = atof(av[2]);
                v->vp[2] = atof(av[3]);
                return(3);
        case 'd':                       /* direction */
                check(3,3);
                v->vdir[0] = atof(av[1]);
                v->vdir[1] = atof(av[2]);
                v->vdir[2] = atof(av[3]);
                return(3);
        case 'u':                       /* up */
                check(3,3);
                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(3,1);
                v->horiz = atof(av[1]);
                return(1);
        case 'v':                       /* vertical size */
                check(3,1);
                v->vert = atof(av[1]);
                return(1);
        case 's':                       /* shift */
                check(3,1);
                v->hoff = atof(av[1]);
                return(1);
        case 'l':                       /* lift */
                check(3,1);
                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;

        while (*s == ' ')
                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);
}


static VIEW  *hview;                    /* view from header */
static int  gothview;                   /* success indicator */
static char  *altname[] = {NULL,"rpict","rview","pinterp",VIEWSTR,NULL};


static
gethview(s)                             /* get view from header */
char  *s;
{
        register char  **an;

        for (an = altname; *an != NULL; an++)
                if (!strncmp(*an, s, strlen(*an))) {
                        if (sscanview(hview, s+strlen(*an)) > 0)
                                gothview++;
                        return;
                }
}


int
viewfile(fname, vp, xp, yp)             /* get view from file */
char  *fname;
VIEW  *vp;
int  *xp, *yp;
{
        extern char  *progname;
        FILE  *fp;

        if ((fp = fopen(fname, "r")) == NULL)
                return(-1);

        altname[0] = progname;
        hview = vp;
        gothview = 0;

        getheader(fp, gethview);

        if (xp != NULL && yp != NULL
                        && fgetresolu(xp, yp, fp) == -1)
                gothview = 0;

        fclose(fp);

        return(gothview);
}
Revision:	1.13
Committed:	Mon Oct 15 14:17:05 1990 UTC (33 years, 6 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.12:	+7 -13 lines
Log Message:	fixed bug in hemispherical view calculation
#	User	Rev	Content
1	greg	1.1	/* Copyright (c) 1986 Regents of the University of California */
2
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	1.5	VIEW stdview = STDVIEW; /* default view parameters */
18	greg	1.1
19
20			char *
21	greg	1.5	setview(v) /* set hvec and vvec, return message on error */
22			register VIEW *v;
23	greg	1.3	{
24	greg	1.12	static char ill_horiz[] = "illegal horizontal view size";
25			static char ill_vert[] = "illegal vertical view size";
26
27	greg	1.1	if (normalize(v->vdir) == 0.0) /* normalize direction */
28			return("zero view direction");
29
30	greg	1.5	fcross(v->hvec, v->vdir, v->vup); /* compute horiz dir */
31
32			if (normalize(v->hvec) == 0.0)
33	greg	1.1	return("illegal view up vector");
34
35	greg	1.5	fcross(v->vvec, v->hvec, v->vdir); /* compute vert dir */
36
37	greg	1.12	if (v->horiz <= FTINY)
38			return(ill_horiz);
39			if (v->vert <= FTINY)
40			return(ill_vert);
41
42			switch (v->type) {
43			case VT_PAR: /* parallel view */
44	greg	1.5	v->hn2 = v->horiz;
45	greg	1.12	v->vn2 = v->vert;
46			break;
47			case VT_PER: /* perspective view */
48			if (v->horiz >= 180.0-FTINY)
49			return(ill_horiz);
50			if (v->vert >= 180.0-FTINY)
51			return(ill_vert);
52	greg	1.5	v->hn2 = 2.0 * tan(v->horiz*(PI/180.0/2.0));
53	greg	1.12	v->vn2 = 2.0 * tan(v->vert*(PI/180.0/2.0));
54			break;
55			case VT_ANG: /* angular fisheye */
56			if (v->horiz > 360.0+FTINY)
57			return(ill_horiz);
58			if (v->vert > 360.0+FTINY)
59			return(ill_vert);
60			v->hn2 = v->horiz / 90.0;
61			v->vn2 = v->vert / 90.0;
62			break;
63			case VT_HEM: /* hemispherical fisheye */
64			if (v->horiz > 180.0+FTINY)
65			return(ill_horiz);
66			if (v->vert > 180.0+FTINY)
67			return(ill_vert);
68			v->hn2 = 2.0 * sin(v->horiz*(PI/180.0/2.0));
69			v->vn2 = 2.0 * sin(v->vert*(PI/180.0/2.0));
70			break;
71			default:
72	greg	1.1	return("unknown view type");
73	greg	1.12	}
74	greg	1.13	if (v->type != VT_ANG) {
75	greg	1.12	v->hvec[0] *= v->hn2;
76			v->hvec[1] *= v->hn2;
77			v->hvec[2] *= v->hn2;
78			v->vvec[0] *= v->vn2;
79			v->vvec[1] *= v->vn2;
80			v->vvec[2] *= v->vn2;
81			}
82	greg	1.5	v->hn2 *= v->hn2;
83			v->vn2 *= v->vn2;
84	greg	1.1
85			return(NULL);
86			}
87
88
89	greg	1.7	normaspect(va, ap, xp, yp) /* fix pixel aspect or resolution */
90			double va; /* view aspect ratio */
91			double ap; / pixel aspect in (or out if 0) */
92			int xp, yp; /* x and y resolution in (or out if ap!=0) /
93	greg	1.6	{
94			if (*ap <= FTINY)
95	greg	1.7	ap = va xp / yp; /* compute pixel aspect */
96	greg	1.6	else if (va * xp > ap * *yp)
97	greg	1.10	xp = yp / va * ap + .5; / reduce x resolution */
98	greg	1.6	else
99	greg	1.10	yp = xp * va / ap + .5; / reduce y resolution */
100	greg	1.6	}
101
102
103	greg	1.5	viewray(orig, direc, v, x, y) /* compute ray origin and direction */
104	greg	1.1	FVECT orig, direc;
105			register VIEW *v;
106			double x, y;
107			{
108	greg	1.12	double d, z;
109
110	greg	1.5	x += v->hoff - 0.5;
111			y += v->voff - 0.5;
112	greg	1.1
113	greg	1.12	switch(v->type) {
114			case VT_PAR: /* parallel view */
115	greg	1.5	orig[0] = v->vp[0] + xv->hvec[0] + yv->vvec[0];
116			orig[1] = v->vp[1] + xv->hvec[1] + yv->vvec[1];
117			orig[2] = v->vp[2] + xv->hvec[2] + yv->vvec[2];
118	greg	1.1	VCOPY(direc, v->vdir);
119	greg	1.12	return(0);
120			case VT_PER: /* perspective view */
121	greg	1.1	VCOPY(orig, v->vp);
122	greg	1.5	direc[0] = v->vdir[0] + xv->hvec[0] + yv->vvec[0];
123			direc[1] = v->vdir[1] + xv->hvec[1] + yv->vvec[1];
124			direc[2] = v->vdir[2] + xv->hvec[2] + yv->vvec[2];
125	greg	1.1	normalize(direc);
126	greg	1.12	return(0);
127			case VT_HEM: /* hemispherical fisheye */
128	greg	1.13	z = 1.0 - xxv->hn2 - yyv->vn2;
129	greg	1.12	if (z < 0.0)
130			return(-1);
131			z = sqrt(z);
132			VCOPY(orig, v->vp);
133			direc[0] = zv->vdir[0] + xv->hvec[0] + y*v->vvec[0];
134			direc[1] = zv->vdir[1] + xv->hvec[1] + y*v->vvec[1];
135			direc[2] = zv->vdir[2] + xv->hvec[2] + y*v->vvec[2];
136			return(0);
137			case VT_ANG: /* angular fisheye */
138			x *= v->horiz/180.0;
139			y *= v->vert/180.0;
140			d = xx + yy;
141			if (d > 1.0)
142			return(-1);
143			VCOPY(orig, v->vp);
144			if (d <= FTINY) {
145			VCOPY(direc, v->vdir);
146			return(0);
147			}
148			d = sqrt(d);
149			z = cos(PI*d);
150			d = sqrt(1 - z*z)/d;
151			x *= d;
152			y *= d;
153			direc[0] = zv->vdir[0] + xv->hvec[0] + y*v->vvec[0];
154			direc[1] = zv->vdir[1] + xv->hvec[1] + y*v->vvec[1];
155			direc[2] = zv->vdir[2] + xv->hvec[2] + y*v->vvec[2];
156			return(0);
157	greg	1.1	}
158	greg	1.12	return(-1);
159	greg	1.1	}
160
161
162	greg	1.5	viewpixel(xp, yp, zp, v, p) /* find image location for point */
163	greg	1.3	double xp, yp, *zp;
164			register VIEW *v;
165			FVECT p;
166			{
167			double d;
168			FVECT disp;
169	greg	1.5
170	greg	1.3	disp[0] = p[0] - v->vp[0];
171			disp[1] = p[1] - v->vp[1];
172			disp[2] = p[2] - v->vp[2];
173
174	greg	1.12	switch (v->type) {
175			case VT_PAR: /* parallel view */
176	greg	1.3	if (zp != NULL)
177			*zp = DOT(disp,v->vdir);
178	greg	1.13	break;
179	greg	1.12	case VT_PER: /* perspective view */
180	greg	1.11	d = DOT(disp,v->vdir);
181	greg	1.3	if (zp != NULL) {
182			*zp = sqrt(DOT(disp,disp));
183			if (d < 0.0)
184			zp = -zp;
185			}
186	greg	1.11	if (d < 0.0) /* fold pyramid */
187			d = -d;
188			if (d > FTINY) {
189			d = 1.0/d;
190			disp[0] *= d;
191			disp[1] *= d;
192			disp[2] *= d;
193			}
194	greg	1.13	break;
195	greg	1.12	case VT_HEM: /* hemispherical fisheye */
196			d = normalize(disp);
197			if (zp != NULL) {
198			if (DOT(disp,v->vdir) < 0.0)
199			*zp = -d;
200			else
201			*zp = d;
202			}
203	greg	1.13	break;
204	greg	1.12	case VT_ANG: /* angular fisheye */
205			d = normalize(disp);
206			if (zp != NULL)
207			*zp = d;
208			*xp = 0.5 - v->hoff;
209			*yp = 0.5 - v->voff;
210			d = DOT(disp,v->vdir);
211			if (d >= 1.0-FTINY)
212			return;
213			if (d <= -(1.0-FTINY)) {
214			*xp += 180.0/v->horiz;
215			*yp += 180.0/v->vert;
216			return;
217			}
218			d = acos(d)/PI / sqrt(1.0 - d*d);
219			xp += DOT(disp,v->hvec)d*180.0/v->horiz;
220			yp += DOT(disp,v->vvec)d*180.0/v->vert;
221			return;
222	greg	1.3	}
223	greg	1.13	*xp = DOT(disp,v->hvec)/v->hn2 + 0.5 - v->hoff;
224			*yp = DOT(disp,v->vvec)/v->vn2 + 0.5 - v->voff;
225	greg	1.3	}
226
227
228	greg	1.5	int
229			getviewopt(v, ac, av) /* process view argument */
230			register VIEW *v;
231			int ac;
232			register char *av[];
233			{
234			#define check(c,n) if ((av[0][c]&&av[0][c]!=' ') \|\| n>=ac) return(-1)
235			extern double atof();
236
237	greg	1.9	if (ac <= 0 \|\| av[0][0] != '-' \|\| av[0][1] != 'v')
238	greg	1.5	return(-1);
239			switch (av[0][2]) {
240			case 't': /* type */
241			if (!av[0][3] \|\| av[0][3]==' ')
242			return(-1);
243			check(4,0);
244			v->type = av[0][3];
245			return(0);
246			case 'p': /* point */
247			check(3,3);
248			v->vp[0] = atof(av[1]);
249			v->vp[1] = atof(av[2]);
250			v->vp[2] = atof(av[3]);
251			return(3);
252			case 'd': /* direction */
253			check(3,3);
254			v->vdir[0] = atof(av[1]);
255			v->vdir[1] = atof(av[2]);
256			v->vdir[2] = atof(av[3]);
257			return(3);
258			case 'u': /* up */
259			check(3,3);
260			v->vup[0] = atof(av[1]);
261			v->vup[1] = atof(av[2]);
262			v->vup[2] = atof(av[3]);
263			return(3);
264			case 'h': /* horizontal size */
265			check(3,1);
266			v->horiz = atof(av[1]);
267			return(1);
268			case 'v': /* vertical size */
269			check(3,1);
270			v->vert = atof(av[1]);
271			return(1);
272			case 's': /* shift */
273			check(3,1);
274			v->hoff = atof(av[1]);
275			return(1);
276			case 'l': /* lift */
277			check(3,1);
278			v->voff = atof(av[1]);
279			return(1);
280			default:
281			return(-1);
282			}
283			#undef check
284			}
285
286
287			int
288			sscanview(vp, s) /* get view parameters from string */
289			VIEW *vp;
290	greg	1.1	register char *s;
291			{
292	greg	1.5	int ac;
293			char *av[4];
294			int na;
295			int nvopts = 0;
296
297			while (*s == ' ')
298			s++;
299	greg	1.9	while (*s) {
300	greg	1.5	ac = 0;
301			do {
302			av[ac++] = s;
303			while (s && s != ' ')
304			s++;
305			while (*s == ' ')
306			s++;
307			} while (*s && ac < 4);
308			if ((na = getviewopt(vp, ac, av)) >= 0) {
309			if (na+1 < ac)
310			s = av[na+1];
311			nvopts++;
312	greg	1.9	} else if (ac > 1)
313			s = av[1];
314			}
315	greg	1.5	return(nvopts);
316	greg	1.1	}
317
318
319			fprintview(vp, fp) /* write out view parameters */
320			register VIEW *vp;
321			FILE *fp;
322			{
323			fprintf(fp, " -vt%c", vp->type);
324			fprintf(fp, " -vp %.6g %.6g %.6g", vp->vp[0], vp->vp[1], vp->vp[2]);
325			fprintf(fp, " -vd %.6g %.6g %.6g", vp->vdir[0], vp->vdir[1], vp->vdir[2]);
326			fprintf(fp, " -vu %.6g %.6g %.6g", vp->vup[0], vp->vup[1], vp->vup[2]);
327			fprintf(fp, " -vh %.6g -vv %.6g", vp->horiz, vp->vert);
328	greg	1.9	fprintf(fp, " -vs %.6g -vl %.6g", vp->hoff, vp->voff);
329	greg	1.1	}
330
331
332			static VIEW hview; / view from header */
333			static int gothview; /* success indicator */
334	greg	1.3	static char *altname[] = {NULL,"rpict","rview","pinterp",VIEWSTR,NULL};
335	greg	1.1
336
337			static
338			gethview(s) /* get view from header */
339			char *s;
340			{
341			register char **an;
342
343			for (an = altname; *an != NULL; an++)
344			if (!strncmp(an, s, strlen(an))) {
345	greg	1.5	if (sscanview(hview, s+strlen(*an)) > 0)
346	greg	1.1	gothview++;
347			return;
348			}
349			}
350
351
352			int
353	greg	1.8	viewfile(fname, vp, xp, yp) /* get view from file */
354	greg	1.1	char *fname;
355			VIEW *vp;
356	greg	1.8	int xp, yp;
357	greg	1.1	{
358			extern char *progname;
359			FILE *fp;
360
361			if ((fp = fopen(fname, "r")) == NULL)
362			return(-1);
363
364			altname[0] = progname;
365			hview = vp;
366			gothview = 0;
367
368			getheader(fp, gethview);
369	greg	1.8
370			if (xp != NULL && yp != NULL
371			&& fgetresolu(xp, yp, fp) == -1)
372			gothview = 0;
373	greg	1.1
374			fclose(fp);
375
376			return(gothview);
377			}