src/rt/rview.c

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

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

/*
 *  rview.c - routines and variables for interactive view generation.
 *
 *     3/24/87
 */

#include  "standard.h"

#include  "color.h"

#include  "rpaint.h"

#include  <signal.h>

#include  <ctype.h>

VIEW  ourview = STDVIEW;                /* viewing parameters */
int  hresolu, vresolu;                  /* image resolution */

int  psample = 8;                       /* pixel sample size */
double  maxdiff = .15;                  /* max. sample difference */

double  exposure = 1.0;                 /* exposure for scene */

double  dstrsrc = 0.0;                  /* square source distribution */
double  shadthresh = .1;                /* shadow threshold */
double  shadcert = .25;                 /* shadow certainty */

int  maxdepth = 4;                      /* maximum recursion depth */
double  minweight = 1e-2;               /* minimum ray weight */

COLOR  ambval = BLKCOLOR;               /* ambient value */
double  ambacc = 0.2;                   /* ambient accuracy */
int  ambres = 8;                        /* ambient resolution */
int  ambdiv = 32;                       /* ambient divisions */
int  ambssamp = 0;                      /* ambient super-samples */
int  ambounce = 0;                      /* ambient bounces */
char  *amblist[128];                    /* ambient include/exclude list */
int  ambincl = -1;                      /* include == 1, exclude == 0 */

int  greyscale = 0;                     /* map colors to brightness? */
char  *devname = dev_default;           /* output device name */

struct driver  *dev = NULL;             /* driver functions */

VIEW  oldview;                          /* previous view parameters */

PNODE  ptrunk;                          /* the base of our image */
RECT  pframe;                           /* current frame boundaries */
int  pdepth;                            /* image depth in current frame */

static char  *reserve_mem = NULL;       /* pre-allocated reserve memory */

#define RESERVE_AMT     8192            /* amount of memory to reserve */

#define  CTRL(c)        ('c'-'@')


quit(code)                      /* quit program */
int  code;
{
        devclose();
        exit(code);
}


devopen(dname)                          /* open device driver */
char  *dname;
{
        extern char  *progname, *octname;
        char  *id;
        register int  i;

        id = octname!=NULL ? octname : progname;
                                                /* check device table */
        for (i = 0; devtable[i].name; i++)
                if (!strcmp(dname, devtable[i].name))
                        if ((dev = (*devtable[i].init)(dname, id)) == NULL) {
                                sprintf(errmsg, "cannot initialize %s", dname);
                                error(USER, errmsg);
                        } else
                                return;
                                                /* not there, try exec */
        if ((dev = comm_init(dname, id)) == NULL) {
                sprintf(errmsg, "cannot start device \"%s\"", dname);
                error(USER, errmsg);
        }
}


devclose()                              /* close our device */
{
        if (dev != NULL)
                (*dev->close)();
        dev = NULL;
}


printdevices()                          /* print list of output devices */
{
        register int  i;

        for (i = 0; devtable[i].name; i++)
                printf("%-16s # %s\n", devtable[i].name, devtable[i].descrip);
}


rview()                         /* do a view */
{
        char  buf[32];

        devopen(devname);               /* open device */
        newimage();                     /* start image (calls fillreserves) */

        for ( ; ; ) {                   /* quit in command() */
                while (hresolu <= 1<<pdepth && vresolu <= 1<<pdepth)
                        command("done: ");
                while (reserve_mem == NULL)
                        command("out of memory: ");
                errno = 0;
                if (hresolu <= psample<<pdepth && vresolu <= psample<<pdepth) {
                        sprintf(buf, "%d sampling...\n", 1<<pdepth);
                        (*dev->comout)(buf);
                        rsample();
                } else {
                        sprintf(buf, "%d refining...\n", 1<<pdepth);
                        (*dev->comout)(buf);
                        refine(&ptrunk, 0, 0, hresolu, vresolu, pdepth+1);
                }
                if (errno == ENOMEM)            /* ran out of memory */
                        freereserves();
                else if (dev->inpready)         /* noticed some input */
                        command(": ");
                else                            /* finished this depth */
                        pdepth++;
        }
}


fillreserves()                  /* fill memory reserves */
{
        if (reserve_mem != NULL)
                return;
        reserve_mem = malloc(RESERVE_AMT);
}


freereserves()                  /* free memory reserves */
{
        if (reserve_mem == NULL)
                return;
        free(reserve_mem);
        reserve_mem = NULL;
}


command(prompt)                 /* get/execute command */
char  *prompt;
{
#define  badcom(s)      strncmp(s, inpbuf, args-inpbuf-1)
        double  atof();
        char  inpbuf[256];
        char  *args;
again:
        (*dev->comin)(inpbuf, prompt);          /* get command + arguments */
        for (args = inpbuf; *args && *args != ' '; args++)
                ;
        if (*args) *args++ = '\0';
        else *++args = '\0';
        
        switch (inpbuf[0]) {
        case 'f':                               /* new frame */
                if (badcom("frame"))
                        goto commerr;
                getframe(args);
                break;
        case 'v':                               /* view */
                if (badcom("view"))
                        goto commerr;
                getview(args);
                break;
        case 'l':                               /* last view */
                if (badcom("last"))
                        goto commerr;
                lastview(args);
                break;
        case 'e':                               /* exposure */
                if (badcom("exposure"))
                        goto commerr;
                getexposure(args);
                break;
        case 's':                               /* set a parameter */
                if (badcom("set"))
                        goto commerr;
                setparam(args);
                break;
        case 'n':                               /* new picture */
                if (badcom("new"))
                        goto commerr;
                newimage();
                break;
        case 't':                               /* trace a ray */
                if (badcom("trace"))
                        goto commerr;
                traceray(args);
                break;
        case 'a':                               /* aim camera */
                if (badcom("aim"))
                        goto commerr;
                getaim(args);
                break;
        case 'm':                               /* move camera */
                if (badcom("move"))
                        goto commerr;
                getmove(args);
                break;
        case 'r':                               /* rotate/repaint */
                if (badcom("rotate")) {
                        if (badcom("repaint"))
                                goto commerr;
                        getrepaint(args);
                        break;
                }
                getrotate(args);
                break;
        case 'p':                               /* pivot view */
                if (badcom("pivot"))
                        goto commerr;
                getpivot(args);
                break;
        case CTRL(R):                           /* redraw */
                redraw();
                break;
        case 'w':                               /* write */
                if (badcom("write"))
                        goto commerr;
                writepict(args);
                break;
        case 'q':                               /* quit */
                if (badcom("quit"))
                        goto commerr;
                quit(0);
        case CTRL(C):                           /* interrupt */
                goto again;
#ifdef  SIGTSTP
        case CTRL(Z):                           /* stop */
                devclose();
                kill(0, SIGTSTP);
                /* pc stops here */
                devopen(devname);
                redraw();
                break;
#endif
        case '\0':                              /* continue */
                break;
        default:;
commerr:
                if (iscntrl(inpbuf[0]))
                        sprintf(errmsg, "^%c: unknown control",
                                        inpbuf[0]|0100);
                else
                        sprintf(errmsg, "%s: unknown command", inpbuf);
                error(COMMAND, errmsg);
                break;
        }
#undef  badcom
}


rsample()                       /* sample the image */
{
        int  xsiz, ysiz, y;
        RECT  r;
        PNODE  *p;
        register RECT  *rl;
        register PNODE  **pl;
        register int  x;
        /*
         *     We initialize the bottom row in the image at our current
         * resolution.  During sampling, we check super-pixels to the
         * right and above by calling bigdiff().  If there is a significant
         * difference, we subsample the super-pixels.  The testing process
         * includes initialization of the next row.
         */
        xsiz = (((pframe.r-pframe.l)<<pdepth)+hresolu-1) / hresolu;
        ysiz = (((pframe.u-pframe.d)<<pdepth)+vresolu-1) / vresolu;
        rl = (RECT *)malloc(xsiz*sizeof(RECT));
        if (rl == NULL)
                return;
        pl = (PNODE **)malloc(xsiz*sizeof(PNODE *));
        if (pl == NULL)
                return;
        /*
         * Initialize the bottom row.
         */
        rl[0].l = rl[0].d = 0;
        rl[0].r = hresolu; rl[0].u = vresolu;
        pl[0] = findrect(pframe.l, pframe.d, &ptrunk, rl, pdepth);
        for (x = 1; x < xsiz; x++) {
                rl[x].l = rl[x].d = 0;
                rl[x].r = hresolu; rl[x].u = vresolu;
                pl[x] = findrect(pframe.l+((x*hresolu)>>pdepth),
                                pframe.d, &ptrunk, rl+x, pdepth);
        }
                                                /* sample the image */
        for (y = 0; /* y < ysiz */ ; y++) {
                for (x = 0; x < xsiz-1; x++) {
                        if (dev->inpready)
                                goto escape;
                        /*
                         * Test super-pixel to the right.
                         */
                        if (pl[x] != pl[x+1] && bigdiff(pl[x]->v,
                                        pl[x+1]->v, maxdiff)) {
                                refine(pl[x], rl[x].l, rl[x].d,
                                                rl[x].r, rl[x].u, 1);
                                refine(pl[x+1], rl[x+1].l, rl[x+1].d,
                                                rl[x+1].r, rl[x+1].u, 1);
                        }
                }
                if (y >= ysiz-1)
                        break;
                for (x = 0; x < xsiz; x++) {
                        if (dev->inpready)
                                goto escape;
                        /*
                         * Find super-pixel at this position in next row.
                         */
                        r.l = r.d = 0;
                        r.r = hresolu; r.u = vresolu;
                        p = findrect(pframe.l+((x*hresolu)>>pdepth),
                                pframe.d+(((y+1)*vresolu)>>pdepth),
                                        &ptrunk, &r, pdepth);
                        /*
                         * Test super-pixel in next row.
                         */
                        if (pl[x] != p && bigdiff(pl[x]->v, p->v, maxdiff)) {
                                refine(pl[x], rl[x].l, rl[x].d,
                                                rl[x].r, rl[x].u, 1);
                                refine(p, r.l, r.d, r.r, r.u, 1);
                        }
                        /*
                         * Copy into super-pixel array.
                         */
                        rl[x].l = r.l; rl[x].d = r.d;
                        rl[x].r = r.r; rl[x].u = r.u;
                        pl[x] = p;
                }
        }
escape:
        free((char *)rl);
        free((char *)pl);
}


int
refine(p, xmin, ymin, xmax, ymax, pd)           /* refine a node */
register PNODE  *p;
int  xmin, ymin, xmax, ymax;
int  pd;
{
        int  growth;
        int  mx, my;
        int  i;

        if (dev->inpready)                      /* quit for input */
                return(0);

        if (pd <= 0)                            /* depth limit */
                return(0);

        mx = (xmin + xmax) >> 1;
        my = (ymin + ymax) >> 1;
        growth = 0;

        if (p->kid == NULL) {                   /* subdivide */

                if ((p->kid = newptree()) == NULL)
                        return(growth);
                /*
                 *  The following paint order can leave a black pixel
                 *  when redraw() is called in (*dev->paintr)().
                 */
                if (p->x >= mx && p->y >= my)
                        pcopy(p, p->kid+UR);
                else
                        paint(p->kid+UR, mx, my, xmax, ymax);
                if (p->x < mx && p->y >= my)
                        pcopy(p, p->kid+UL);
                else
                        paint(p->kid+UL, xmin, my, mx, ymax);
                if (p->x >= mx && p->y < my)
                        pcopy(p, p->kid+DR);
                else
                        paint(p->kid+DR, mx, ymin, xmax, my);
                if (p->x < mx && p->y < my)
                        pcopy(p, p->kid+DL);
                else
                        paint(p->kid+DL, xmin, ymin, mx, my);

                growth++;
        }
                                                /* do children */
        if (mx > pframe.l) {
                if (my > pframe.d)
                        growth += refine(p->kid+DL, xmin, ymin, mx, my, pd-1);
                if (my < pframe.u)
                        growth += refine(p->kid+UL, xmin, my, mx, ymax, pd-1);
        }
        if (mx < pframe.r) {
                if (my > pframe.d)
                        growth += refine(p->kid+DR, mx, ymin, xmax, my, pd-1);
                if (my < pframe.u)
                        growth += refine(p->kid+UR, mx, my, xmax, ymax, pd-1);
        }
                                                /* recompute sum */
        if (growth) {
                setcolor(p->v, 0.0, 0.0, 0.0);
                for (i = 0; i < 4; i++)
                        addcolor(p->v, p->kid[i].v);
                scalecolor(p->v, 0.25);
        }
        return(growth);
}
Revision:	1.14
Committed:	Fri May 3 16:12:34 1991 UTC (33 years ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.13:	+19 -27 lines
Log Message:	final version of memory recovery during image refinement
#	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			* rview.c - routines and variables for interactive view generation.
9			*
10			* 3/24/87
11			*/
12
13			#include "standard.h"
14
15			#include "color.h"
16
17			#include "rpaint.h"
18
19			#include <signal.h>
20
21			#include <ctype.h>
22
23	greg	1.9	VIEW ourview = STDVIEW; /* viewing parameters */
24			int hresolu, vresolu; /* image resolution */
25	greg	1.1
26			int psample = 8; /* pixel sample size */
27			double maxdiff = .15; /* max. sample difference */
28
29			double exposure = 1.0; /* exposure for scene */
30
31			double dstrsrc = 0.0; /* square source distribution */
32	greg	1.3	double shadthresh = .1; /* shadow threshold */
33	greg	1.4	double shadcert = .25; /* shadow certainty */
34	greg	1.1
35			int maxdepth = 4; /* maximum recursion depth */
36			double minweight = 1e-2; /* minimum ray weight */
37
38			COLOR ambval = BLKCOLOR; /* ambient value */
39			double ambacc = 0.2; /* ambient accuracy */
40	greg	1.5	int ambres = 8; /* ambient resolution */
41	greg	1.1	int ambdiv = 32; /* ambient divisions */
42			int ambssamp = 0; /* ambient super-samples */
43			int ambounce = 0; /* ambient bounces */
44			char amblist[128]; / ambient include/exclude list */
45			int ambincl = -1; /* include == 1, exclude == 0 */
46
47			int greyscale = 0; /* map colors to brightness? */
48	greg	1.11	char devname = dev_default; / output device name */
49	greg	1.1
50			struct driver dev = NULL; / driver functions */
51
52			VIEW oldview; /* previous view parameters */
53
54			PNODE ptrunk; /* the base of our image */
55			RECT pframe; /* current frame boundaries */
56			int pdepth; /* image depth in current frame */
57
58	greg	1.12	static char reserve_mem = NULL; / pre-allocated reserve memory */
59
60			#define RESERVE_AMT 8192 /* amount of memory to reserve */
61
62	greg	1.1	#define CTRL(c) ('c'-'@')
63
64
65			quit(code) /* quit program */
66			int code;
67			{
68			devclose();
69			exit(code);
70			}
71
72
73			devopen(dname) /* open device driver */
74			char *dname;
75			{
76	greg	1.6	extern char progname, octname;
77	greg	1.7	char *id;
78	greg	1.1	register int i;
79	greg	1.6
80	greg	1.7	id = octname!=NULL ? octname : progname;
81	greg	1.1	/* check device table */
82			for (i = 0; devtable[i].name; i++)
83			if (!strcmp(dname, devtable[i].name))
84	greg	1.7	if ((dev = (*devtable[i].init)(dname, id)) == NULL) {
85	greg	1.1	sprintf(errmsg, "cannot initialize %s", dname);
86			error(USER, errmsg);
87			} else
88			return;
89			/* not there, try exec */
90	greg	1.7	if ((dev = comm_init(dname, id)) == NULL) {
91	greg	1.1	sprintf(errmsg, "cannot start device \"%s\"", dname);
92			error(USER, errmsg);
93			}
94			}
95
96
97			devclose() /* close our device */
98			{
99			if (dev != NULL)
100			(*dev->close)();
101			dev = NULL;
102			}
103
104
105			printdevices() /* print list of output devices */
106			{
107			register int i;
108
109			for (i = 0; devtable[i].name; i++)
110			printf("%-16s # %s\n", devtable[i].name, devtable[i].descrip);
111			}
112
113
114			rview() /* do a view */
115			{
116			char buf[32];
117
118			devopen(devname); /* open device */
119	greg	1.14	newimage(); /* start image (calls fillreserves) */
120
121	greg	1.1	for ( ; ; ) { /* quit in command() */
122	greg	1.14	while (hresolu <= 1<<pdepth && vresolu <= 1<<pdepth)
123	greg	1.1	command("done: ");
124	greg	1.14	while (reserve_mem == NULL)
125			command("out of memory: ");
126			errno = 0;
127			if (hresolu <= psample<<pdepth && vresolu <= psample<<pdepth) {
128	greg	1.1	sprintf(buf, "%d sampling...\n", 1<<pdepth);
129			(*dev->comout)(buf);
130			rsample();
131			} else {
132			sprintf(buf, "%d refining...\n", 1<<pdepth);
133			(*dev->comout)(buf);
134	greg	1.9	refine(&ptrunk, 0, 0, hresolu, vresolu, pdepth+1);
135	greg	1.1	}
136	greg	1.14	if (errno == ENOMEM) /* ran out of memory */
137			freereserves();
138			else if (dev->inpready) /* noticed some input */
139	greg	1.1	command(": ");
140	greg	1.14	else /* finished this depth */
141	greg	1.1	pdepth++;
142			}
143			}
144
145
146	greg	1.14	fillreserves() /* fill memory reserves */
147	greg	1.12	{
148			if (reserve_mem != NULL)
149	greg	1.14	return;
150	greg	1.12	reserve_mem = malloc(RESERVE_AMT);
151			}
152
153
154	greg	1.14	freereserves() /* free memory reserves */
155	greg	1.12	{
156	greg	1.14	if (reserve_mem == NULL)
157			return;
158	greg	1.12	free(reserve_mem);
159			reserve_mem = NULL;
160			}
161
162
163	greg	1.1	command(prompt) /* get/execute command */
164			char *prompt;
165			{
166			#define badcom(s) strncmp(s, inpbuf, args-inpbuf-1)
167			double atof();
168			char inpbuf[256];
169			char *args;
170			again:
171	greg	1.10	(dev->comin)(inpbuf, prompt); / get command + arguments */
172	greg	1.1	for (args = inpbuf; args && args != ' '; args++)
173			;
174			if (args) args++ = '\0';
175			else *++args = '\0';
176
177			switch (inpbuf[0]) {
178			case 'f': /* new frame */
179			if (badcom("frame"))
180			goto commerr;
181			getframe(args);
182			break;
183			case 'v': /* view */
184			if (badcom("view"))
185			goto commerr;
186			getview(args);
187			break;
188			case 'l': /* last view */
189			if (badcom("last"))
190			goto commerr;
191			lastview(args);
192			break;
193			case 'e': /* exposure */
194			if (badcom("exposure"))
195			goto commerr;
196			getexposure(args);
197			break;
198			case 's': /* set a parameter */
199			if (badcom("set"))
200			goto commerr;
201			setparam(args);
202			break;
203			case 'n': /* new picture */
204			if (badcom("new"))
205			goto commerr;
206			newimage();
207			break;
208			case 't': /* trace a ray */
209			if (badcom("trace"))
210			goto commerr;
211			traceray(args);
212			break;
213			case 'a': /* aim camera */
214			if (badcom("aim"))
215			goto commerr;
216			getaim(args);
217			break;
218			case 'm': /* move camera */
219			if (badcom("move"))
220			goto commerr;
221			getmove(args);
222			break;
223	greg	1.8	case 'r': /* rotate/repaint */
224			if (badcom("rotate")) {
225			if (badcom("repaint"))
226			goto commerr;
227			getrepaint(args);
228			break;
229			}
230	greg	1.1	getrotate(args);
231			break;
232			case 'p': /* pivot view */
233			if (badcom("pivot"))
234			goto commerr;
235			getpivot(args);
236			break;
237			case CTRL(R): /* redraw */
238			redraw();
239			break;
240			case 'w': /* write */
241			if (badcom("write"))
242			goto commerr;
243			writepict(args);
244			break;
245			case 'q': /* quit */
246			if (badcom("quit"))
247			goto commerr;
248			quit(0);
249			case CTRL(C): /* interrupt */
250			goto again;
251			#ifdef SIGTSTP
252			case CTRL(Z): /* stop */
253			devclose();
254			kill(0, SIGTSTP);
255			/* pc stops here */
256			devopen(devname);
257			redraw();
258			break;
259			#endif
260			case '\0': /* continue */
261			break;
262			default:;
263			commerr:
264			if (iscntrl(inpbuf[0]))
265			sprintf(errmsg, "^%c: unknown control",
266			inpbuf[0]\|0100);
267			else
268			sprintf(errmsg, "%s: unknown command", inpbuf);
269			error(COMMAND, errmsg);
270			break;
271			}
272			#undef badcom
273			}
274
275
276			rsample() /* sample the image */
277			{
278			int xsiz, ysiz, y;
279			RECT r;
280			PNODE *p;
281			register RECT *rl;
282			register PNODE **pl;
283			register int x;
284			/*
285			* We initialize the bottom row in the image at our current
286			* resolution. During sampling, we check super-pixels to the
287			* right and above by calling bigdiff(). If there is a significant
288			* difference, we subsample the super-pixels. The testing process
289			* includes initialization of the next row.
290			*/
291	greg	1.9	xsiz = (((pframe.r-pframe.l)<<pdepth)+hresolu-1) / hresolu;
292			ysiz = (((pframe.u-pframe.d)<<pdepth)+vresolu-1) / vresolu;
293	greg	1.1	rl = (RECT )malloc(xsizsizeof(RECT));
294	greg	1.12	if (rl == NULL)
295	greg	1.14	return;
296	greg	1.1	pl = (PNODE *)malloc(xsizsizeof(PNODE *));
297	greg	1.12	if (pl == NULL)
298	greg	1.14	return;
299	greg	1.1	/*
300			* Initialize the bottom row.
301			*/
302			rl[0].l = rl[0].d = 0;
303	greg	1.9	rl[0].r = hresolu; rl[0].u = vresolu;
304	greg	1.1	pl[0] = findrect(pframe.l, pframe.d, &ptrunk, rl, pdepth);
305			for (x = 1; x < xsiz; x++) {
306			rl[x].l = rl[x].d = 0;
307	greg	1.9	rl[x].r = hresolu; rl[x].u = vresolu;
308			pl[x] = findrect(pframe.l+((x*hresolu)>>pdepth),
309	greg	1.1	pframe.d, &ptrunk, rl+x, pdepth);
310			}
311			/* sample the image */
312			for (y = 0; /* y < ysiz */ ; y++) {
313			for (x = 0; x < xsiz-1; x++) {
314			if (dev->inpready)
315			goto escape;
316			/*
317			* Test super-pixel to the right.
318			*/
319			if (pl[x] != pl[x+1] && bigdiff(pl[x]->v,
320			pl[x+1]->v, maxdiff)) {
321			refine(pl[x], rl[x].l, rl[x].d,
322			rl[x].r, rl[x].u, 1);
323			refine(pl[x+1], rl[x+1].l, rl[x+1].d,
324			rl[x+1].r, rl[x+1].u, 1);
325			}
326			}
327			if (y >= ysiz-1)
328			break;
329			for (x = 0; x < xsiz; x++) {
330			if (dev->inpready)
331			goto escape;
332			/*
333			* Find super-pixel at this position in next row.
334			*/
335			r.l = r.d = 0;
336	greg	1.9	r.r = hresolu; r.u = vresolu;
337			p = findrect(pframe.l+((x*hresolu)>>pdepth),
338			pframe.d+(((y+1)*vresolu)>>pdepth),
339	greg	1.1	&ptrunk, &r, pdepth);
340			/*
341			* Test super-pixel in next row.
342			*/
343			if (pl[x] != p && bigdiff(pl[x]->v, p->v, maxdiff)) {
344			refine(pl[x], rl[x].l, rl[x].d,
345			rl[x].r, rl[x].u, 1);
346			refine(p, r.l, r.d, r.r, r.u, 1);
347			}
348			/*
349			* Copy into super-pixel array.
350			*/
351			rl[x].l = r.l; rl[x].d = r.d;
352			rl[x].r = r.r; rl[x].u = r.u;
353			pl[x] = p;
354			}
355			}
356			escape:
357			free((char *)rl);
358			free((char *)pl);
359			}
360
361
362			int
363			refine(p, xmin, ymin, xmax, ymax, pd) /* refine a node */
364			register PNODE *p;
365			int xmin, ymin, xmax, ymax;
366			int pd;
367			{
368			int growth;
369			int mx, my;
370			int i;
371
372			if (dev->inpready) /* quit for input */
373			return(0);
374
375			if (pd <= 0) /* depth limit */
376			return(0);
377
378			mx = (xmin + xmax) >> 1;
379			my = (ymin + ymax) >> 1;
380			growth = 0;
381
382			if (p->kid == NULL) { /* subdivide */
383
384			if ((p->kid = newptree()) == NULL)
385	greg	1.14	return(growth);
386	greg	1.1	/*
387			* The following paint order can leave a black pixel
388			* when redraw() is called in (*dev->paintr)().
389			*/
390			if (p->x >= mx && p->y >= my)
391			pcopy(p, p->kid+UR);
392			else
393			paint(p->kid+UR, mx, my, xmax, ymax);
394			if (p->x < mx && p->y >= my)
395			pcopy(p, p->kid+UL);
396			else
397			paint(p->kid+UL, xmin, my, mx, ymax);
398			if (p->x >= mx && p->y < my)
399			pcopy(p, p->kid+DR);
400			else
401			paint(p->kid+DR, mx, ymin, xmax, my);
402			if (p->x < mx && p->y < my)
403			pcopy(p, p->kid+DL);
404			else
405			paint(p->kid+DL, xmin, ymin, mx, my);
406
407			growth++;
408			}
409			/* do children */
410			if (mx > pframe.l) {
411			if (my > pframe.d)
412			growth += refine(p->kid+DL, xmin, ymin, mx, my, pd-1);
413			if (my < pframe.u)
414			growth += refine(p->kid+UL, xmin, my, mx, ymax, pd-1);
415			}
416			if (mx < pframe.r) {
417			if (my > pframe.d)
418			growth += refine(p->kid+DR, mx, ymin, xmax, my, pd-1);
419			if (my < pframe.u)
420			growth += refine(p->kid+UR, mx, my, xmax, ymax, pd-1);
421			}
422			/* recompute sum */
423			if (growth) {
424			setcolor(p->v, 0.0, 0.0, 0.0);
425			for (i = 0; i < 4; i++)
426			addcolor(p->v, p->kid[i].v);
427			scalecolor(p->v, 0.25);
428			}
429			return(growth);
430			}