src/rt/rv3.c

/* Copyright (c) 1987 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 *  rv3.c - miscellaneous routines for rview.
 *
 *     5/11/87
 */

#include  "ray.h"

#include  "octree.h"

#include  "rpaint.h"

#include  "random.h"

#ifndef WFLUSH
#define WFLUSH          30              /* flush after this many rays */
#endif


getrect(s, r)                           /* get a box */
char  *s;
register RECT  *r;
{
        int  x0, y0, x1, y1;

        if (*s && !strncmp(s, "all", strlen(s))) {
                r->l = r->d = 0;
                r->r = hresolu;
                r->u = vresolu;
                return(0);
        }
        if (sscanf(s, "%d %d %d %d", &x0, &y0, &x1, &y1) != 4) {
                if (dev->getcur == NULL)
                        return(-1);
                (*dev->comout)("Pick first corner\n");
                if ((*dev->getcur)(&x0, &y0) == ABORT)
                        return(-1);
                (*dev->comout)("Pick second corner\n");
                if ((*dev->getcur)(&x1, &y1) == ABORT)
                        return(-1);
        }
        if (x0 < x1) {
                r->l = x0;
                r->r = x1;
        } else {
                r->l = x1;
                r->r = x0;
        }
        if (y0 < y1) {
                r->d = y0;
                r->u = y1;
        } else {
                r->d = y1;
                r->u = y0;
        }
        if (r->l < 0) r->l = 0;
        if (r->d < 0) r->d = 0;
        if (r->r > hresolu) r->r = hresolu;
        if (r->u > vresolu) r->u = vresolu;
        if (r->l > r->r) r->l = r->r;
        if (r->d > r->u) r->d = r->u;
        return(0);
}


getinterest(s, direc, vec, mp)          /* get area of interest */
char  *s;
int  direc;
FVECT  vec;
double  *mp;
{
        int  x, y;
        RAY  thisray;
        register int  i;

        if (sscanf(s, "%lf", mp) != 1)
                *mp = 1.0;
        else if (*mp < -FTINY)          /* negative zoom is reduction */
                *mp = -1.0 / *mp;
        else if (*mp <= FTINY) {        /* too small */
                error(COMMAND, "illegal magnification");
                return(-1);
        }
        if (sscanf(s, "%*lf %lf %lf %lf", &vec[0], &vec[1], &vec[2]) != 3) {
                if (dev->getcur == NULL)
                        return(-1);
                (*dev->comout)("Pick view center\n");
                if ((*dev->getcur)(&x, &y) == ABORT)
                        return(-1);
                viewray(thisray.rorg, thisray.rdir, &ourview,
                                (x+.5)/hresolu, (y+.5)/vresolu);
                if (!direc || ourview.type == VT_PAR) {
                        rayorigin(&thisray, NULL, PRIMARY, 1.0);
                        if (!localhit(&thisray, &thescene)) {
                                error(COMMAND, "not a local object");
                                return(-1);
                        }
                }
                if (direc)
                        if (ourview.type == VT_PAR)
                                for (i = 0; i < 3; i++)
                                        vec[i] = thisray.rop[i] - ourview.vp[i];
                        else
                                VCOPY(vec, thisray.rdir);
                else
                        VCOPY(vec, thisray.rop);
        } else if (direc)
                        for (i = 0; i < 3; i++)
                                vec[i] -= ourview.vp[i];
        return(0);
}


float *         /* keep consistent with COLOR typedef */
greyof(col)                             /* convert color to greyscale */
register COLOR  col;
{
        static COLOR  gcol;
        double  b;

        b = bright(col);
        setcolor(gcol, b, b, b);
        return(gcol);
}


paint(p, xmin, ymin, xmax, ymax)        /* compute and paint a rectangle */
register PNODE  *p;
int  xmin, ymin, xmax, ymax;
{
        extern long  nrays;
        static long  lastflush = 0;
        static RAY  thisray;
        double  h, v;

        if (xmax - xmin <= 0 || ymax - ymin <= 0) {     /* empty */
                p->x = xmin;
                p->y = ymin;
                setcolor(p->v, 0.0, 0.0, 0.0);
                return;
        }
                                                /* jitter ray direction */
        h = xmin + (xmax-xmin)*frandom();
        v = ymin + (ymax-ymin)*frandom();
        
        viewray(thisray.rorg, thisray.rdir, &ourview, h/hresolu, v/vresolu);
        rayorigin(&thisray, NULL, PRIMARY, 1.0);
        rayvalue(&thisray);

        p->x = h;
        p->y = v;
        copycolor(p->v, thisray.rcol);
        scalecolor(p->v, exposure);

        (*dev->paintr)(greyscale?greyof(p->v):p->v, xmin, ymin, xmax, ymax);

        if (dev->flush != NULL && nrays - lastflush >= WFLUSH) {
                lastflush = nrays;
                (*dev->flush)();
        }
}


newimage()                              /* start a new image */
{
                                                /* free old image */
        freepkids(&ptrunk);
                                                /* compute resolution */
        hresolu = dev->xsiz;
        vresolu = dev->ysiz;
        normaspect(viewaspect(&ourview), &dev->pixaspect, &hresolu, &vresolu);
        pframe.l = pframe.d = 0;
        pframe.r = hresolu; pframe.u = vresolu;
        pdepth = 0;
                                                /* clear device */
        (*dev->clear)(hresolu, vresolu);
                                                /* get first value */
        paint(&ptrunk, 0, 0, hresolu, vresolu);
}


redraw()                                /* redraw the image */
{
        (*dev->clear)(hresolu, vresolu);
        (*dev->comout)("redrawing...\n");
        repaint(0, 0, hresolu, vresolu);
        (*dev->comout)("\n");
}


repaint(xmin, ymin, xmax, ymax)                 /* repaint a region */
int  xmin, ymin, xmax, ymax;
{
        RECT  reg;

        reg.l = xmin; reg.r = xmax;
        reg.d = ymin; reg.u = ymax;

        paintrect(&ptrunk, 0, 0, hresolu, vresolu, &reg);
}


paintrect(p, xmin, ymin, xmax, ymax, r)         /* paint picture rectangle */
register PNODE  *p;
int  xmin, ymin, xmax, ymax;
register RECT  *r;
{
        int  mx, my;

        if (xmax - xmin <= 0 || ymax - ymin <= 0)
                return;

        if (p->kid == NULL) {
                (*dev->paintr)(greyscale?greyof(p->v):p->v,
                                xmin, ymin, xmax, ymax);        /* do this */
                return;
        }
        mx = (xmin + xmax) >> 1;                                /* do kids */
        my = (ymin + ymax) >> 1;
        if (mx > r->l) {
                if (my > r->d)
                        paintrect(p->kid+DL, xmin, ymin, mx, my, r);
                if (my < r->u)
                        paintrect(p->kid+UL, xmin, my, mx, ymax, r);
        }
        if (mx < r->r) {
                if (my > r->d)
                        paintrect(p->kid+DR, mx, ymin, xmax, my, r);
                if (my < r->u)
                        paintrect(p->kid+UR, mx, my, xmax, ymax, r);
        }
}


PNODE *
findrect(x, y, p, r, pd)                /* find a rectangle */
int  x, y;
register PNODE  *p;
register RECT  *r;
int  pd;
{
        int  mx, my;

        while (p->kid != NULL && pd--) {

                mx = (r->l + r->r) >> 1;
                my = (r->d + r->u) >> 1;

                if (x < mx) {
                        r->r = mx;
                        if (y < my) {
                                r->u = my;
                                p = p->kid+DL;
                        } else {
                                r->d = my;
                                p = p->kid+UL;
                        }
                } else {
                        r->l = mx;
                        if (y < my) {
                                r->u = my;
                                p = p->kid+DR;
                        } else {
                                r->d = my;
                                p = p->kid+UR;
                        }
                }
        }
        return(p);
}


scalepict(p, sf)                        /* scale picture values */
register PNODE  *p;
double  sf;
{
        scalecolor(p->v, sf);           /* do this node */

        if (p->kid == NULL)
                return;
                                        /* do children */
        scalepict(p->kid+DL, sf);
        scalepict(p->kid+DR, sf);
        scalepict(p->kid+UL, sf);
        scalepict(p->kid+UR, sf);
}


getpictcolrs(yoff, scan, p, xsiz, ysiz) /* get scanline from picture */
int  yoff;
register COLR  *scan;
register PNODE  *p;
int  xsiz, ysiz;
{
        register int  mx;
        int  my;

        if (p->kid == NULL) {                   /* do this node */
                setcolr(scan[0], colval(p->v,RED),
                                colval(p->v,GRN),
                                colval(p->v,BLU));
                for (mx = 1; mx < xsiz; mx++)
                        copycolr(scan[mx], scan[0]);
                return;
        }
                                                /* do kids */
        mx = xsiz >> 1;
        my = ysiz >> 1;
        if (yoff < my) {
                getpictcolrs(yoff, scan, p->kid+DL, mx, my);
                getpictcolrs(yoff, scan+mx, p->kid+DR, xsiz-mx, my);
        } else {
                getpictcolrs(yoff-my, scan, p->kid+UL, mx, ysiz-my);
                getpictcolrs(yoff-my, scan+mx, p->kid+UR, xsiz-mx, ysiz-my);
        }
}


pcopy(p1, p2)                           /* copy paint node p1 into p2 */
register PNODE  *p1, *p2;
{
        copycolor(p2->v, p1->v);
        p2->x = p1->x;
        p2->y = p1->y;
}


freepkids(p)                            /* free pnode's children */
register PNODE  *p;
{
        if (p->kid == NULL)
                return;
        freepkids(p->kid+DL);
        freepkids(p->kid+DR);
        freepkids(p->kid+UL);
        freepkids(p->kid+UR);
        free((char *)p->kid);
        p->kid = NULL;
}


newview(vp)                             /* change viewing parameters */
register VIEW  *vp;
{
        char  *err;

        if ((err = setview(vp)) != NULL) {
                sprintf(errmsg, "view not set - %s", err);
                error(COMMAND, errmsg);
        } else if (bcmp((char *)vp, (char *)&ourview, sizeof(VIEW))) {
                copystruct(&oldview, &ourview);
                copystruct(&ourview, vp);
                newimage();
        }
}


moveview(angle, elev, mag, vc)                  /* move viewpoint */
double  angle, elev, mag;
FVECT  vc;
{
        extern double  sqrt(), dist2();
        double  d;
        FVECT  v1;
        VIEW  nv;
        register int  i;

        VCOPY(nv.vup, ourview.vup);
        nv.hoff = ourview.hoff; nv.voff = ourview.voff;
        spinvector(nv.vdir, ourview.vdir, ourview.vup, angle*(PI/180.));
        if (elev != 0.0) {
                fcross(v1, ourview.vup, nv.vdir);
                normalize(v1);
                spinvector(nv.vdir, nv.vdir, v1, elev*(PI/180.));
        }
        if ((nv.type = ourview.type) == VT_PAR) {
                nv.horiz = ourview.horiz / mag;
                nv.vert = ourview.vert / mag;
                d = 0.0;                        /* don't move closer */
                for (i = 0; i < 3; i++)
                        d += (vc[i] - ourview.vp[i])*ourview.vdir[i];
        } else {
                nv.horiz = ourview.horiz;
                nv.vert = ourview.vert;
                d = sqrt(dist2(ourview.vp, vc)) / mag;
        }
        for (i = 0; i < 3; i++)
                nv.vp[i] = vc[i] - d*nv.vdir[i];
        newview(&nv);
}


spinvector(vres, vorig, vnorm, theta)   /* rotate vector around normal */
FVECT  vres, vorig, vnorm;
double  theta;
{
        extern double  sin(), cos();
        double  sint, cost, dotp;
        FVECT  vperp;
        register int  i;
        
        if (theta == 0.0) {
                VCOPY(vres, vorig);
                return;
        }
        sint = sin(theta);
        cost = cos(theta);
        dotp = DOT(vorig, vnorm);
        fcross(vperp, vnorm, vorig);
        for (i = 0; i < 3; i++)
                vres[i] = vnorm[i]*dotp*(1.-cost) +
                                vorig[i]*cost + vperp[i]*sint;
}
Revision:	1.16
Committed:	Tue Jun 26 09:00:19 1990 UTC (33 years, 10 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.15:	+0 -1 lines
Log Message:	Nit-picking for Stardent C-compiler
#	User	Rev	Content
1	greg	1.1	/* Copyright (c) 1987 Regents of the University of California */
2
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* rv3.c - miscellaneous routines for rview.
9			*
10			* 5/11/87
11			*/
12
13			#include "ray.h"
14
15	greg	1.7	#include "octree.h"
16
17	greg	1.1	#include "rpaint.h"
18
19			#include "random.h"
20	greg	1.7
21	greg	1.13	#ifndef WFLUSH
22			#define WFLUSH 30 /* flush after this many rays */
23			#endif
24	greg	1.7
25	greg	1.13
26	greg	1.7	getrect(s, r) /* get a box */
27			char *s;
28			register RECT *r;
29			{
30			int x0, y0, x1, y1;
31
32			if (*s && !strncmp(s, "all", strlen(s))) {
33			r->l = r->d = 0;
34	greg	1.9	r->r = hresolu;
35			r->u = vresolu;
36	greg	1.7	return(0);
37			}
38			if (sscanf(s, "%d %d %d %d", &x0, &y0, &x1, &y1) != 4) {
39			if (dev->getcur == NULL)
40			return(-1);
41			(*dev->comout)("Pick first corner\n");
42			if ((*dev->getcur)(&x0, &y0) == ABORT)
43			return(-1);
44			(*dev->comout)("Pick second corner\n");
45			if ((*dev->getcur)(&x1, &y1) == ABORT)
46			return(-1);
47			}
48			if (x0 < x1) {
49			r->l = x0;
50			r->r = x1;
51			} else {
52			r->l = x1;
53			r->r = x0;
54			}
55			if (y0 < y1) {
56			r->d = y0;
57			r->u = y1;
58			} else {
59			r->d = y1;
60			r->u = y0;
61			}
62			if (r->l < 0) r->l = 0;
63			if (r->d < 0) r->d = 0;
64	greg	1.9	if (r->r > hresolu) r->r = hresolu;
65			if (r->u > vresolu) r->u = vresolu;
66	greg	1.7	if (r->l > r->r) r->l = r->r;
67			if (r->d > r->u) r->d = r->u;
68			return(0);
69			}
70
71
72			getinterest(s, direc, vec, mp) /* get area of interest */
73			char *s;
74			int direc;
75			FVECT vec;
76			double *mp;
77			{
78			int x, y;
79			RAY thisray;
80			register int i;
81
82			if (sscanf(s, "%lf", mp) != 1)
83			*mp = 1.0;
84			else if (mp < -FTINY) / negative zoom is reduction */
85			mp = -1.0 / mp;
86			else if (mp <= FTINY) { / too small */
87			error(COMMAND, "illegal magnification");
88			return(-1);
89			}
90			if (sscanf(s, "%*lf %lf %lf %lf", &vec[0], &vec[1], &vec[2]) != 3) {
91			if (dev->getcur == NULL)
92			return(-1);
93			(*dev->comout)("Pick view center\n");
94			if ((*dev->getcur)(&x, &y) == ABORT)
95			return(-1);
96	greg	1.9	viewray(thisray.rorg, thisray.rdir, &ourview,
97			(x+.5)/hresolu, (y+.5)/vresolu);
98	greg	1.7	if (!direc \|\| ourview.type == VT_PAR) {
99			rayorigin(&thisray, NULL, PRIMARY, 1.0);
100			if (!localhit(&thisray, &thescene)) {
101			error(COMMAND, "not a local object");
102			return(-1);
103			}
104			}
105			if (direc)
106			if (ourview.type == VT_PAR)
107			for (i = 0; i < 3; i++)
108			vec[i] = thisray.rop[i] - ourview.vp[i];
109			else
110			VCOPY(vec, thisray.rdir);
111			else
112			VCOPY(vec, thisray.rop);
113			} else if (direc)
114			for (i = 0; i < 3; i++)
115			vec[i] -= ourview.vp[i];
116			return(0);
117			}
118	greg	1.1
119
120			float * /* keep consistent with COLOR typedef */
121			greyof(col) /* convert color to greyscale */
122			register COLOR col;
123			{
124			static COLOR gcol;
125			double b;
126
127			b = bright(col);
128			setcolor(gcol, b, b, b);
129			return(gcol);
130			}
131
132
133			paint(p, xmin, ymin, xmax, ymax) /* compute and paint a rectangle */
134			register PNODE *p;
135			int xmin, ymin, xmax, ymax;
136			{
137	greg	1.13	extern long nrays;
138			static long lastflush = 0;
139	greg	1.1	static RAY thisray;
140			double h, v;
141
142			if (xmax - xmin <= 0 \|\| ymax - ymin <= 0) { /* empty */
143			p->x = xmin;
144			p->y = ymin;
145			setcolor(p->v, 0.0, 0.0, 0.0);
146			return;
147			}
148			/* jitter ray direction */
149	greg	1.15	h = xmin + (xmax-xmin)*frandom();
150			v = ymin + (ymax-ymin)*frandom();
151	greg	1.1
152	greg	1.15	viewray(thisray.rorg, thisray.rdir, &ourview, h/hresolu, v/vresolu);
153	greg	1.1	rayorigin(&thisray, NULL, PRIMARY, 1.0);
154			rayvalue(&thisray);
155
156	greg	1.15	p->x = h;
157			p->y = v;
158	greg	1.1	copycolor(p->v, thisray.rcol);
159			scalecolor(p->v, exposure);
160
161			(*dev->paintr)(greyscale?greyof(p->v):p->v, xmin, ymin, xmax, ymax);
162	greg	1.13
163			if (dev->flush != NULL && nrays - lastflush >= WFLUSH) {
164			lastflush = nrays;
165			(*dev->flush)();
166			}
167	greg	1.1	}
168
169
170			newimage() /* start a new image */
171			{
172			/* free old image */
173			freepkids(&ptrunk);
174	greg	1.9	/* compute resolution */
175	greg	1.10	hresolu = dev->xsiz;
176			vresolu = dev->ysiz;
177	greg	1.11	normaspect(viewaspect(&ourview), &dev->pixaspect, &hresolu, &vresolu);
178	greg	1.1	pframe.l = pframe.d = 0;
179	greg	1.9	pframe.r = hresolu; pframe.u = vresolu;
180	greg	1.1	pdepth = 0;
181			/* clear device */
182	greg	1.9	(*dev->clear)(hresolu, vresolu);
183	greg	1.1	/* get first value */
184	greg	1.9	paint(&ptrunk, 0, 0, hresolu, vresolu);
185	greg	1.1	}
186
187
188			redraw() /* redraw the image */
189			{
190	greg	1.9	(*dev->clear)(hresolu, vresolu);
191	greg	1.1	(*dev->comout)("redrawing...\n");
192	greg	1.9	repaint(0, 0, hresolu, vresolu);
193	greg	1.1	(*dev->comout)("\n");
194			}
195
196
197			repaint(xmin, ymin, xmax, ymax) /* repaint a region */
198			int xmin, ymin, xmax, ymax;
199			{
200			RECT reg;
201
202			reg.l = xmin; reg.r = xmax;
203			reg.d = ymin; reg.u = ymax;
204
205	greg	1.9	paintrect(&ptrunk, 0, 0, hresolu, vresolu, &reg);
206	greg	1.1	}
207
208
209			paintrect(p, xmin, ymin, xmax, ymax, r) /* paint picture rectangle */
210			register PNODE *p;
211			int xmin, ymin, xmax, ymax;
212			register RECT *r;
213			{
214			int mx, my;
215
216			if (xmax - xmin <= 0 \|\| ymax - ymin <= 0)
217			return;
218
219			if (p->kid == NULL) {
220			(*dev->paintr)(greyscale?greyof(p->v):p->v,
221			xmin, ymin, xmax, ymax); /* do this */
222			return;
223			}
224			mx = (xmin + xmax) >> 1; /* do kids */
225			my = (ymin + ymax) >> 1;
226			if (mx > r->l) {
227			if (my > r->d)
228			paintrect(p->kid+DL, xmin, ymin, mx, my, r);
229			if (my < r->u)
230			paintrect(p->kid+UL, xmin, my, mx, ymax, r);
231			}
232			if (mx < r->r) {
233			if (my > r->d)
234			paintrect(p->kid+DR, mx, ymin, xmax, my, r);
235			if (my < r->u)
236			paintrect(p->kid+UR, mx, my, xmax, ymax, r);
237			}
238			}
239
240
241			PNODE *
242			findrect(x, y, p, r, pd) /* find a rectangle */
243			int x, y;
244			register PNODE *p;
245			register RECT *r;
246			int pd;
247			{
248			int mx, my;
249
250			while (p->kid != NULL && pd--) {
251
252			mx = (r->l + r->r) >> 1;
253			my = (r->d + r->u) >> 1;
254
255			if (x < mx) {
256			r->r = mx;
257			if (y < my) {
258			r->u = my;
259			p = p->kid+DL;
260			} else {
261			r->d = my;
262			p = p->kid+UL;
263			}
264			} else {
265			r->l = mx;
266			if (y < my) {
267			r->u = my;
268			p = p->kid+DR;
269			} else {
270			r->d = my;
271			p = p->kid+UR;
272			}
273			}
274			}
275			return(p);
276			}
277
278
279			scalepict(p, sf) /* scale picture values */
280			register PNODE *p;
281			double sf;
282			{
283			scalecolor(p->v, sf); /* do this node */
284
285			if (p->kid == NULL)
286			return;
287			/* do children */
288			scalepict(p->kid+DL, sf);
289			scalepict(p->kid+DR, sf);
290			scalepict(p->kid+UL, sf);
291			scalepict(p->kid+UR, sf);
292			}
293
294
295			getpictcolrs(yoff, scan, p, xsiz, ysiz) /* get scanline from picture */
296			int yoff;
297			register COLR *scan;
298			register PNODE *p;
299			int xsiz, ysiz;
300			{
301			register int mx;
302			int my;
303
304			if (p->kid == NULL) { /* do this node */
305			setcolr(scan[0], colval(p->v,RED),
306			colval(p->v,GRN),
307			colval(p->v,BLU));
308			for (mx = 1; mx < xsiz; mx++)
309			copycolr(scan[mx], scan[0]);
310			return;
311			}
312			/* do kids */
313			mx = xsiz >> 1;
314			my = ysiz >> 1;
315			if (yoff < my) {
316			getpictcolrs(yoff, scan, p->kid+DL, mx, my);
317			getpictcolrs(yoff, scan+mx, p->kid+DR, xsiz-mx, my);
318			} else {
319			getpictcolrs(yoff-my, scan, p->kid+UL, mx, ysiz-my);
320			getpictcolrs(yoff-my, scan+mx, p->kid+UR, xsiz-mx, ysiz-my);
321			}
322			}
323
324
325			pcopy(p1, p2) /* copy paint node p1 into p2 */
326			register PNODE p1, p2;
327			{
328			copycolor(p2->v, p1->v);
329			p2->x = p1->x;
330			p2->y = p1->y;
331			}
332
333
334			freepkids(p) /* free pnode's children */
335			register PNODE *p;
336			{
337			if (p->kid == NULL)
338			return;
339			freepkids(p->kid+DL);
340			freepkids(p->kid+DR);
341			freepkids(p->kid+UL);
342			freepkids(p->kid+UR);
343			free((char *)p->kid);
344			p->kid = NULL;
345			}
346
347
348			newview(vp) /* change viewing parameters */
349			register VIEW *vp;
350			{
351			char *err;
352
353	greg	1.6	if ((err = setview(vp)) != NULL) {
354	greg	1.1	sprintf(errmsg, "view not set - %s", err);
355			error(COMMAND, errmsg);
356	greg	1.12	} else if (bcmp((char )vp, (char )&ourview, sizeof(VIEW))) {
357			copystruct(&oldview, &ourview);
358			copystruct(&ourview, vp);
359	greg	1.14	newimage();
360	greg	1.1	}
361			}
362
363
364	greg	1.4	moveview(angle, elev, mag, vc) /* move viewpoint */
365			double angle, elev, mag;
366	greg	1.1	FVECT vc;
367			{
368			extern double sqrt(), dist2();
369			double d;
370	greg	1.4	FVECT v1;
371	greg	1.1	VIEW nv;
372			register int i;
373
374			VCOPY(nv.vup, ourview.vup);
375	greg	1.9	nv.hoff = ourview.hoff; nv.voff = ourview.voff;
376	greg	1.1	spinvector(nv.vdir, ourview.vdir, ourview.vup, angle*(PI/180.));
377	greg	1.4	if (elev != 0.0) {
378	greg	1.5	fcross(v1, ourview.vup, nv.vdir);
379	greg	1.4	normalize(v1);
380			spinvector(nv.vdir, nv.vdir, v1, elev*(PI/180.));
381			}
382	greg	1.1	if ((nv.type = ourview.type) == VT_PAR) {
383			nv.horiz = ourview.horiz / mag;
384			nv.vert = ourview.vert / mag;
385	greg	1.3	d = 0.0; /* don't move closer */
386	greg	1.2	for (i = 0; i < 3; i++)
387	greg	1.3	d += (vc[i] - ourview.vp[i])*ourview.vdir[i];
388	greg	1.1	} else {
389			nv.horiz = ourview.horiz;
390			nv.vert = ourview.vert;
391	greg	1.2	d = sqrt(dist2(ourview.vp, vc)) / mag;
392	greg	1.1	}
393	greg	1.2	for (i = 0; i < 3; i++)
394			nv.vp[i] = vc[i] - d*nv.vdir[i];
395	greg	1.1	newview(&nv);
396			}
397
398
399			spinvector(vres, vorig, vnorm, theta) /* rotate vector around normal */
400			FVECT vres, vorig, vnorm;
401			double theta;
402			{
403			extern double sin(), cos();
404			double sint, cost, dotp;
405			FVECT vperp;
406			register int i;
407
408			if (theta == 0.0) {
409			VCOPY(vres, vorig);
410			return;
411			}
412			sint = sin(theta);
413			cost = cos(theta);
414			dotp = DOT(vorig, vnorm);
415			fcross(vperp, vnorm, vorig);
416			for (i = 0; i < 3; i++)
417			vres[i] = vnorm[i]dotp(1.-cost) +
418			vorig[i]cost + vperp[i]sint;
419			}