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;
        register int  i;

        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 */
        p->x = h = xmin + (xmax-xmin)*frandom();
        h /= hresolu;
        p->y = v = ymin + (ymax-ymin)*frandom();
        v /= vresolu;
        
        viewray(thisray.rorg, thisray.rdir, &ourview, h, v);

        rayorigin(&thisray, NULL, PRIMARY, 1.0);
        
        rayvalue(&thisray);

        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:	1.14
Committed:	Tue Feb 27 09:51:00 1990 UTC (34 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.13:	+1 -1 lines
Log Message:	minor fixes in comments etc.
#	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			register int i;
142
143			if (xmax - xmin <= 0 \|\| ymax - ymin <= 0) { /* empty */
144			p->x = xmin;
145			p->y = ymin;
146			setcolor(p->v, 0.0, 0.0, 0.0);
147			return;
148			}
149			/* jitter ray direction */
150			p->x = h = xmin + (xmax-xmin)*frandom();
151	greg	1.9	h /= hresolu;
152	greg	1.1	p->y = v = ymin + (ymax-ymin)*frandom();
153	greg	1.9	v /= vresolu;
154	greg	1.1
155	greg	1.9	viewray(thisray.rorg, thisray.rdir, &ourview, h, v);
156	greg	1.1
157			rayorigin(&thisray, NULL, PRIMARY, 1.0);
158
159			rayvalue(&thisray);
160
161			copycolor(p->v, thisray.rcol);
162
163			scalecolor(p->v, exposure);
164
165			(*dev->paintr)(greyscale?greyof(p->v):p->v, xmin, ymin, xmax, ymax);
166	greg	1.13
167			if (dev->flush != NULL && nrays - lastflush >= WFLUSH) {
168			lastflush = nrays;
169			(*dev->flush)();
170			}
171	greg	1.1	}
172
173
174			newimage() /* start a new image */
175			{
176			/* free old image */
177			freepkids(&ptrunk);
178	greg	1.9	/* compute resolution */
179	greg	1.10	hresolu = dev->xsiz;
180			vresolu = dev->ysiz;
181	greg	1.11	normaspect(viewaspect(&ourview), &dev->pixaspect, &hresolu, &vresolu);
182	greg	1.1	pframe.l = pframe.d = 0;
183	greg	1.9	pframe.r = hresolu; pframe.u = vresolu;
184	greg	1.1	pdepth = 0;
185			/* clear device */
186	greg	1.9	(*dev->clear)(hresolu, vresolu);
187	greg	1.1	/* get first value */
188	greg	1.9	paint(&ptrunk, 0, 0, hresolu, vresolu);
189	greg	1.1	}
190
191
192			redraw() /* redraw the image */
193			{
194	greg	1.9	(*dev->clear)(hresolu, vresolu);
195	greg	1.1	(*dev->comout)("redrawing...\n");
196	greg	1.9	repaint(0, 0, hresolu, vresolu);
197	greg	1.1	(*dev->comout)("\n");
198			}
199
200
201			repaint(xmin, ymin, xmax, ymax) /* repaint a region */
202			int xmin, ymin, xmax, ymax;
203			{
204			RECT reg;
205
206			reg.l = xmin; reg.r = xmax;
207			reg.d = ymin; reg.u = ymax;
208
209	greg	1.9	paintrect(&ptrunk, 0, 0, hresolu, vresolu, &reg);
210	greg	1.1	}
211
212
213			paintrect(p, xmin, ymin, xmax, ymax, r) /* paint picture rectangle */
214			register PNODE *p;
215			int xmin, ymin, xmax, ymax;
216			register RECT *r;
217			{
218			int mx, my;
219
220			if (xmax - xmin <= 0 \|\| ymax - ymin <= 0)
221			return;
222
223			if (p->kid == NULL) {
224			(*dev->paintr)(greyscale?greyof(p->v):p->v,
225			xmin, ymin, xmax, ymax); /* do this */
226			return;
227			}
228			mx = (xmin + xmax) >> 1; /* do kids */
229			my = (ymin + ymax) >> 1;
230			if (mx > r->l) {
231			if (my > r->d)
232			paintrect(p->kid+DL, xmin, ymin, mx, my, r);
233			if (my < r->u)
234			paintrect(p->kid+UL, xmin, my, mx, ymax, r);
235			}
236			if (mx < r->r) {
237			if (my > r->d)
238			paintrect(p->kid+DR, mx, ymin, xmax, my, r);
239			if (my < r->u)
240			paintrect(p->kid+UR, mx, my, xmax, ymax, r);
241			}
242			}
243
244
245			PNODE *
246			findrect(x, y, p, r, pd) /* find a rectangle */
247			int x, y;
248			register PNODE *p;
249			register RECT *r;
250			int pd;
251			{
252			int mx, my;
253
254			while (p->kid != NULL && pd--) {
255
256			mx = (r->l + r->r) >> 1;
257			my = (r->d + r->u) >> 1;
258
259			if (x < mx) {
260			r->r = mx;
261			if (y < my) {
262			r->u = my;
263			p = p->kid+DL;
264			} else {
265			r->d = my;
266			p = p->kid+UL;
267			}
268			} else {
269			r->l = mx;
270			if (y < my) {
271			r->u = my;
272			p = p->kid+DR;
273			} else {
274			r->d = my;
275			p = p->kid+UR;
276			}
277			}
278			}
279			return(p);
280			}
281
282
283			scalepict(p, sf) /* scale picture values */
284			register PNODE *p;
285			double sf;
286			{
287			scalecolor(p->v, sf); /* do this node */
288
289			if (p->kid == NULL)
290			return;
291			/* do children */
292			scalepict(p->kid+DL, sf);
293			scalepict(p->kid+DR, sf);
294			scalepict(p->kid+UL, sf);
295			scalepict(p->kid+UR, sf);
296			}
297
298
299			getpictcolrs(yoff, scan, p, xsiz, ysiz) /* get scanline from picture */
300			int yoff;
301			register COLR *scan;
302			register PNODE *p;
303			int xsiz, ysiz;
304			{
305			register int mx;
306			int my;
307
308			if (p->kid == NULL) { /* do this node */
309			setcolr(scan[0], colval(p->v,RED),
310			colval(p->v,GRN),
311			colval(p->v,BLU));
312			for (mx = 1; mx < xsiz; mx++)
313			copycolr(scan[mx], scan[0]);
314			return;
315			}
316			/* do kids */
317			mx = xsiz >> 1;
318			my = ysiz >> 1;
319			if (yoff < my) {
320			getpictcolrs(yoff, scan, p->kid+DL, mx, my);
321			getpictcolrs(yoff, scan+mx, p->kid+DR, xsiz-mx, my);
322			} else {
323			getpictcolrs(yoff-my, scan, p->kid+UL, mx, ysiz-my);
324			getpictcolrs(yoff-my, scan+mx, p->kid+UR, xsiz-mx, ysiz-my);
325			}
326			}
327
328
329			pcopy(p1, p2) /* copy paint node p1 into p2 */
330			register PNODE p1, p2;
331			{
332			copycolor(p2->v, p1->v);
333			p2->x = p1->x;
334			p2->y = p1->y;
335			}
336
337
338			freepkids(p) /* free pnode's children */
339			register PNODE *p;
340			{
341			if (p->kid == NULL)
342			return;
343			freepkids(p->kid+DL);
344			freepkids(p->kid+DR);
345			freepkids(p->kid+UL);
346			freepkids(p->kid+UR);
347			free((char *)p->kid);
348			p->kid = NULL;
349			}
350
351
352			newview(vp) /* change viewing parameters */
353			register VIEW *vp;
354			{
355			char *err;
356
357	greg	1.6	if ((err = setview(vp)) != NULL) {
358	greg	1.1	sprintf(errmsg, "view not set - %s", err);
359			error(COMMAND, errmsg);
360	greg	1.12	} else if (bcmp((char )vp, (char )&ourview, sizeof(VIEW))) {
361			copystruct(&oldview, &ourview);
362			copystruct(&ourview, vp);
363	greg	1.14	newimage();
364	greg	1.1	}
365			}
366
367
368	greg	1.4	moveview(angle, elev, mag, vc) /* move viewpoint */
369			double angle, elev, mag;
370	greg	1.1	FVECT vc;
371			{
372			extern double sqrt(), dist2();
373			double d;
374	greg	1.4	FVECT v1;
375	greg	1.1	VIEW nv;
376			register int i;
377
378			VCOPY(nv.vup, ourview.vup);
379	greg	1.9	nv.hoff = ourview.hoff; nv.voff = ourview.voff;
380	greg	1.1	spinvector(nv.vdir, ourview.vdir, ourview.vup, angle*(PI/180.));
381	greg	1.4	if (elev != 0.0) {
382	greg	1.5	fcross(v1, ourview.vup, nv.vdir);
383	greg	1.4	normalize(v1);
384			spinvector(nv.vdir, nv.vdir, v1, elev*(PI/180.));
385			}
386	greg	1.1	if ((nv.type = ourview.type) == VT_PAR) {
387			nv.horiz = ourview.horiz / mag;
388			nv.vert = ourview.vert / mag;
389	greg	1.3	d = 0.0; /* don't move closer */
390	greg	1.2	for (i = 0; i < 3; i++)
391	greg	1.3	d += (vc[i] - ourview.vp[i])*ourview.vdir[i];
392	greg	1.1	} else {
393			nv.horiz = ourview.horiz;
394			nv.vert = ourview.vert;
395	greg	1.2	d = sqrt(dist2(ourview.vp, vc)) / mag;
396	greg	1.1	}
397	greg	1.2	for (i = 0; i < 3; i++)
398			nv.vp[i] = vc[i] - d*nv.vdir[i];
399	greg	1.1	newview(&nv);
400			}
401
402
403			spinvector(vres, vorig, vnorm, theta) /* rotate vector around normal */
404			FVECT vres, vorig, vnorm;
405			double theta;
406			{
407			extern double sin(), cos();
408			double sint, cost, dotp;
409			FVECT vperp;
410			register int i;
411
412			if (theta == 0.0) {
413			VCOPY(vres, vorig);
414			return;
415			}
416			sint = sin(theta);
417			cost = cos(theta);
418			dotp = DOT(vorig, vnorm);
419			fcross(vperp, vnorm, vorig);
420			for (i = 0; i < 3; i++)
421			vres[i] = vnorm[i]dotp(1.-cost) +
422			vorig[i]cost + vperp[i]sint;
423			}