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  "ray.h"

#include  "rpaint.h"

#include  <signal.h>

#include  <ctype.h>

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

int  dimlist[MAXDIM];                   /* sampling dimensions */
int  ndims = 0;                         /* number of sampling dimensions */
int  samplendx = 0;                     /* index for this sample */

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  directrelay = 0;                   /* number of source relays */
int  vspretest = 128;                   /* virtual source pretest density */
int  directinvis = 0;                   /* sources invisible? */

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     32768           /* 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 || errno == ENOMEM)
                                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 || errno == ENOMEM)
                                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(0);
                /*
                 *  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:	1.20
Committed:	Mon Aug 26 12:53:17 1991 UTC (34 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.19:	+4 -4 lines
Log Message:	improved memory handing
#	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	greg	1.15	#include "ray.h"
14	greg	1.1
15			#include "rpaint.h"
16
17			#include <signal.h>
18
19			#include <ctype.h>
20
21	greg	1.9	VIEW ourview = STDVIEW; /* viewing parameters */
22			int hresolu, vresolu; /* image resolution */
23	greg	1.15
24			int dimlist[MAXDIM]; /* sampling dimensions */
25			int ndims = 0; /* number of sampling dimensions */
26			int samplendx = 0; /* index for this sample */
27	greg	1.1
28			int psample = 8; /* pixel sample size */
29			double maxdiff = .15; /* max. sample difference */
30
31			double exposure = 1.0; /* exposure for scene */
32
33			double dstrsrc = 0.0; /* square source distribution */
34	greg	1.3	double shadthresh = .1; /* shadow threshold */
35	greg	1.4	double shadcert = .25; /* shadow certainty */
36	greg	1.16	int directrelay = 0; /* number of source relays */
37	greg	1.18	int vspretest = 128; /* virtual source pretest density */
38	greg	1.19	int directinvis = 0; /* sources invisible? */
39	greg	1.1
40			int maxdepth = 4; /* maximum recursion depth */
41			double minweight = 1e-2; /* minimum ray weight */
42
43			COLOR ambval = BLKCOLOR; /* ambient value */
44			double ambacc = 0.2; /* ambient accuracy */
45	greg	1.5	int ambres = 8; /* ambient resolution */
46	greg	1.1	int ambdiv = 32; /* ambient divisions */
47			int ambssamp = 0; /* ambient super-samples */
48			int ambounce = 0; /* ambient bounces */
49			char amblist[128]; / ambient include/exclude list */
50			int ambincl = -1; /* include == 1, exclude == 0 */
51
52			int greyscale = 0; /* map colors to brightness? */
53	greg	1.11	char devname = dev_default; / output device name */
54	greg	1.1
55			struct driver dev = NULL; / driver functions */
56
57			VIEW oldview; /* previous view parameters */
58
59			PNODE ptrunk; /* the base of our image */
60			RECT pframe; /* current frame boundaries */
61			int pdepth; /* image depth in current frame */
62
63	greg	1.12	static char reserve_mem = NULL; / pre-allocated reserve memory */
64
65	greg	1.20	#define RESERVE_AMT 32768 /* amount of memory to reserve */
66	greg	1.12
67	greg	1.1	#define CTRL(c) ('c'-'@')
68
69
70			quit(code) /* quit program */
71			int code;
72			{
73			devclose();
74			exit(code);
75			}
76
77
78			devopen(dname) /* open device driver */
79			char *dname;
80			{
81	greg	1.6	extern char progname, octname;
82	greg	1.7	char *id;
83	greg	1.1	register int i;
84	greg	1.6
85	greg	1.7	id = octname!=NULL ? octname : progname;
86	greg	1.1	/* check device table */
87			for (i = 0; devtable[i].name; i++)
88			if (!strcmp(dname, devtable[i].name))
89	greg	1.7	if ((dev = (*devtable[i].init)(dname, id)) == NULL) {
90	greg	1.1	sprintf(errmsg, "cannot initialize %s", dname);
91			error(USER, errmsg);
92			} else
93			return;
94			/* not there, try exec */
95	greg	1.7	if ((dev = comm_init(dname, id)) == NULL) {
96	greg	1.1	sprintf(errmsg, "cannot start device \"%s\"", dname);
97			error(USER, errmsg);
98			}
99			}
100
101
102			devclose() /* close our device */
103			{
104			if (dev != NULL)
105			(*dev->close)();
106			dev = NULL;
107			}
108
109
110			printdevices() /* print list of output devices */
111			{
112			register int i;
113
114			for (i = 0; devtable[i].name; i++)
115			printf("%-16s # %s\n", devtable[i].name, devtable[i].descrip);
116			}
117
118
119			rview() /* do a view */
120			{
121			char buf[32];
122
123			devopen(devname); /* open device */
124	greg	1.14	newimage(); /* start image (calls fillreserves) */
125
126	greg	1.1	for ( ; ; ) { /* quit in command() */
127	greg	1.14	while (hresolu <= 1<<pdepth && vresolu <= 1<<pdepth)
128	greg	1.1	command("done: ");
129	greg	1.14	while (reserve_mem == NULL)
130			command("out of memory: ");
131			errno = 0;
132			if (hresolu <= psample<<pdepth && vresolu <= psample<<pdepth) {
133	greg	1.1	sprintf(buf, "%d sampling...\n", 1<<pdepth);
134			(*dev->comout)(buf);
135			rsample();
136			} else {
137			sprintf(buf, "%d refining...\n", 1<<pdepth);
138			(*dev->comout)(buf);
139	greg	1.9	refine(&ptrunk, 0, 0, hresolu, vresolu, pdepth+1);
140	greg	1.1	}
141	greg	1.14	if (errno == ENOMEM) /* ran out of memory */
142			freereserves();
143			else if (dev->inpready) /* noticed some input */
144	greg	1.1	command(": ");
145	greg	1.14	else /* finished this depth */
146	greg	1.1	pdepth++;
147			}
148			}
149
150
151	greg	1.14	fillreserves() /* fill memory reserves */
152	greg	1.12	{
153			if (reserve_mem != NULL)
154	greg	1.14	return;
155	greg	1.12	reserve_mem = malloc(RESERVE_AMT);
156			}
157
158
159	greg	1.14	freereserves() /* free memory reserves */
160	greg	1.12	{
161	greg	1.14	if (reserve_mem == NULL)
162			return;
163	greg	1.12	free(reserve_mem);
164			reserve_mem = NULL;
165			}
166
167
168	greg	1.1	command(prompt) /* get/execute command */
169			char *prompt;
170			{
171			#define badcom(s) strncmp(s, inpbuf, args-inpbuf-1)
172			double atof();
173			char inpbuf[256];
174			char *args;
175			again:
176	greg	1.10	(dev->comin)(inpbuf, prompt); / get command + arguments */
177	greg	1.1	for (args = inpbuf; args && args != ' '; args++)
178			;
179			if (args) args++ = '\0';
180			else *++args = '\0';
181
182			switch (inpbuf[0]) {
183			case 'f': /* new frame */
184			if (badcom("frame"))
185			goto commerr;
186			getframe(args);
187			break;
188			case 'v': /* view */
189			if (badcom("view"))
190			goto commerr;
191			getview(args);
192			break;
193			case 'l': /* last view */
194			if (badcom("last"))
195			goto commerr;
196			lastview(args);
197			break;
198			case 'e': /* exposure */
199			if (badcom("exposure"))
200			goto commerr;
201			getexposure(args);
202			break;
203			case 's': /* set a parameter */
204			if (badcom("set"))
205			goto commerr;
206			setparam(args);
207			break;
208			case 'n': /* new picture */
209			if (badcom("new"))
210			goto commerr;
211			newimage();
212			break;
213			case 't': /* trace a ray */
214			if (badcom("trace"))
215			goto commerr;
216			traceray(args);
217			break;
218			case 'a': /* aim camera */
219			if (badcom("aim"))
220			goto commerr;
221			getaim(args);
222			break;
223			case 'm': /* move camera */
224			if (badcom("move"))
225			goto commerr;
226			getmove(args);
227			break;
228	greg	1.8	case 'r': /* rotate/repaint */
229			if (badcom("rotate")) {
230			if (badcom("repaint"))
231			goto commerr;
232			getrepaint(args);
233			break;
234			}
235	greg	1.1	getrotate(args);
236			break;
237			case 'p': /* pivot view */
238			if (badcom("pivot"))
239			goto commerr;
240			getpivot(args);
241			break;
242			case CTRL(R): /* redraw */
243			redraw();
244			break;
245			case 'w': /* write */
246			if (badcom("write"))
247			goto commerr;
248			writepict(args);
249			break;
250			case 'q': /* quit */
251			if (badcom("quit"))
252			goto commerr;
253			quit(0);
254			case CTRL(C): /* interrupt */
255			goto again;
256			#ifdef SIGTSTP
257			case CTRL(Z): /* stop */
258			devclose();
259			kill(0, SIGTSTP);
260			/* pc stops here */
261			devopen(devname);
262			redraw();
263			break;
264			#endif
265			case '\0': /* continue */
266			break;
267			default:;
268			commerr:
269			if (iscntrl(inpbuf[0]))
270			sprintf(errmsg, "^%c: unknown control",
271			inpbuf[0]\|0100);
272			else
273			sprintf(errmsg, "%s: unknown command", inpbuf);
274			error(COMMAND, errmsg);
275			break;
276			}
277			#undef badcom
278			}
279
280
281			rsample() /* sample the image */
282			{
283			int xsiz, ysiz, y;
284			RECT r;
285			PNODE *p;
286			register RECT *rl;
287			register PNODE **pl;
288			register int x;
289			/*
290			* We initialize the bottom row in the image at our current
291			* resolution. During sampling, we check super-pixels to the
292			* right and above by calling bigdiff(). If there is a significant
293			* difference, we subsample the super-pixels. The testing process
294			* includes initialization of the next row.
295			*/
296	greg	1.9	xsiz = (((pframe.r-pframe.l)<<pdepth)+hresolu-1) / hresolu;
297			ysiz = (((pframe.u-pframe.d)<<pdepth)+vresolu-1) / vresolu;
298	greg	1.1	rl = (RECT )malloc(xsizsizeof(RECT));
299	greg	1.12	if (rl == NULL)
300	greg	1.14	return;
301	greg	1.1	pl = (PNODE *)malloc(xsizsizeof(PNODE *));
302	greg	1.12	if (pl == NULL)
303	greg	1.14	return;
304	greg	1.1	/*
305			* Initialize the bottom row.
306			*/
307			rl[0].l = rl[0].d = 0;
308	greg	1.9	rl[0].r = hresolu; rl[0].u = vresolu;
309	greg	1.1	pl[0] = findrect(pframe.l, pframe.d, &ptrunk, rl, pdepth);
310			for (x = 1; x < xsiz; x++) {
311			rl[x].l = rl[x].d = 0;
312	greg	1.9	rl[x].r = hresolu; rl[x].u = vresolu;
313			pl[x] = findrect(pframe.l+((x*hresolu)>>pdepth),
314	greg	1.1	pframe.d, &ptrunk, rl+x, pdepth);
315			}
316			/* sample the image */
317			for (y = 0; /* y < ysiz */ ; y++) {
318			for (x = 0; x < xsiz-1; x++) {
319	greg	1.20	if (dev->inpready \|\| errno == ENOMEM)
320	greg	1.1	goto escape;
321			/*
322			* Test super-pixel to the right.
323			*/
324			if (pl[x] != pl[x+1] && bigdiff(pl[x]->v,
325			pl[x+1]->v, maxdiff)) {
326			refine(pl[x], rl[x].l, rl[x].d,
327			rl[x].r, rl[x].u, 1);
328			refine(pl[x+1], rl[x+1].l, rl[x+1].d,
329			rl[x+1].r, rl[x+1].u, 1);
330			}
331			}
332			if (y >= ysiz-1)
333			break;
334			for (x = 0; x < xsiz; x++) {
335	greg	1.20	if (dev->inpready \|\| errno == ENOMEM)
336	greg	1.1	goto escape;
337			/*
338			* Find super-pixel at this position in next row.
339			*/
340			r.l = r.d = 0;
341	greg	1.9	r.r = hresolu; r.u = vresolu;
342			p = findrect(pframe.l+((x*hresolu)>>pdepth),
343			pframe.d+(((y+1)*vresolu)>>pdepth),
344	greg	1.1	&ptrunk, &r, pdepth);
345			/*
346			* Test super-pixel in next row.
347			*/
348			if (pl[x] != p && bigdiff(pl[x]->v, p->v, maxdiff)) {
349			refine(pl[x], rl[x].l, rl[x].d,
350			rl[x].r, rl[x].u, 1);
351			refine(p, r.l, r.d, r.r, r.u, 1);
352			}
353			/*
354			* Copy into super-pixel array.
355			*/
356			rl[x].l = r.l; rl[x].d = r.d;
357			rl[x].r = r.r; rl[x].u = r.u;
358			pl[x] = p;
359			}
360			}
361			escape:
362			free((char *)rl);
363			free((char *)pl);
364			}
365
366
367			int
368			refine(p, xmin, ymin, xmax, ymax, pd) /* refine a node */
369			register PNODE *p;
370			int xmin, ymin, xmax, ymax;
371			int pd;
372			{
373			int growth;
374			int mx, my;
375			int i;
376
377			if (dev->inpready) /* quit for input */
378			return(0);
379
380			if (pd <= 0) /* depth limit */
381			return(0);
382
383			mx = (xmin + xmax) >> 1;
384			my = (ymin + ymax) >> 1;
385			growth = 0;
386
387			if (p->kid == NULL) { /* subdivide */
388
389			if ((p->kid = newptree()) == NULL)
390	greg	1.20	return(0);
391	greg	1.1	/*
392			* The following paint order can leave a black pixel
393			* when redraw() is called in (*dev->paintr)().
394			*/
395			if (p->x >= mx && p->y >= my)
396			pcopy(p, p->kid+UR);
397			else
398			paint(p->kid+UR, mx, my, xmax, ymax);
399			if (p->x < mx && p->y >= my)
400			pcopy(p, p->kid+UL);
401			else
402			paint(p->kid+UL, xmin, my, mx, ymax);
403			if (p->x >= mx && p->y < my)
404			pcopy(p, p->kid+DR);
405			else
406			paint(p->kid+DR, mx, ymin, xmax, my);
407			if (p->x < mx && p->y < my)
408			pcopy(p, p->kid+DL);
409			else
410			paint(p->kid+DL, xmin, ymin, mx, my);
411
412			growth++;
413			}
414			/* do children */
415			if (mx > pframe.l) {
416			if (my > pframe.d)
417			growth += refine(p->kid+DL, xmin, ymin, mx, my, pd-1);
418			if (my < pframe.u)
419			growth += refine(p->kid+UL, xmin, my, mx, ymax, pd-1);
420			}
421			if (mx < pframe.r) {
422			if (my > pframe.d)
423			growth += refine(p->kid+DR, mx, ymin, xmax, my, pd-1);
424			if (my < pframe.u)
425			growth += refine(p->kid+UR, mx, my, xmax, ymax, pd-1);
426			}
427			/* recompute sum */
428			if (growth) {
429			setcolor(p->v, 0.0, 0.0, 0.0);
430			for (i = 0; i < 4; i++)
431			addcolor(p->v, p->kid[i].v);
432			scalecolor(p->v, 0.25);
433			}
434			return(growth);
435			}