src/rt/rview.c

/* Copyright (c) 1992 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  directvis = 1;                     /* sources visible? */
double  srcsizerat = 0.;                /* maximum ratio source size/dist. */

double  specthresh = .3;                /* specular sampling threshold */
double  specjitter = 1.;                /* specular sampling jitter */

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;
#ifndef NIX                                                
                                                /* not there, try exec */
        if ((dev = comm_init(dname, id)) == NULL) {
                sprintf(errmsg, "cannot start device \"%s\"", dname);
                error(USER, errmsg);
        }
#endif
}


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)
        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"))
#ifdef  MSTATS
                {
                        if (badcom("memory"))
                                goto commerr;
                        printmemstats(stderr);
                        break;
                }
#else
                        goto commerr;
#endif
                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) {
                free((char *)rl);
                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
                 *  if 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:	2.9
Committed:	Thu Nov 19 20:25:55 1992 UTC (31 years, 5 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.8:	+1 -1 lines
Log Message:	changed -di to ! -dv
#	User	Rev	Content
1	greg	2.7	/* Copyright (c) 1992 Regents of the University of California */
2	greg	1.1
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	greg	2.8	double maxdiff = .15; /* max. sample difference */
30	greg	1.1
31	greg	2.8	double exposure = 1.0; /* exposure for scene */
32	greg	1.1
33	greg	2.8	double dstrsrc = 0.0; /* square source distribution */
34			double shadthresh = .1; /* shadow threshold */
35			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	2.9	int directvis = 1; /* sources visible? */
39	greg	2.8	double srcsizerat = 0.; /* maximum ratio source size/dist. */
40	greg	1.1
41	greg	2.8	double specthresh = .3; /* specular sampling threshold */
42			double specjitter = 1.; /* specular sampling jitter */
43	greg	2.5
44	greg	1.1	int maxdepth = 4; /* maximum recursion depth */
45	greg	2.8	double minweight = 1e-2; /* minimum ray weight */
46	greg	1.1
47			COLOR ambval = BLKCOLOR; /* ambient value */
48	greg	2.8	double ambacc = 0.2; /* ambient accuracy */
49	greg	1.5	int ambres = 8; /* ambient resolution */
50	greg	1.1	int ambdiv = 32; /* ambient divisions */
51			int ambssamp = 0; /* ambient super-samples */
52			int ambounce = 0; /* ambient bounces */
53			char amblist[128]; / ambient include/exclude list */
54			int ambincl = -1; /* include == 1, exclude == 0 */
55
56			int greyscale = 0; /* map colors to brightness? */
57	greg	1.11	char devname = dev_default; / output device name */
58	greg	1.1
59			struct driver dev = NULL; / driver functions */
60
61			VIEW oldview; /* previous view parameters */
62
63			PNODE ptrunk; /* the base of our image */
64			RECT pframe; /* current frame boundaries */
65			int pdepth; /* image depth in current frame */
66
67	greg	1.12	static char reserve_mem = NULL; / pre-allocated reserve memory */
68
69	greg	1.20	#define RESERVE_AMT 32768 /* amount of memory to reserve */
70	greg	1.12
71	greg	2.8	#define CTRL(c) ((c)-'@')
72	greg	1.1
73
74			quit(code) /* quit program */
75			int code;
76			{
77			devclose();
78			exit(code);
79			}
80
81
82			devopen(dname) /* open device driver */
83			char *dname;
84			{
85	greg	1.6	extern char progname, octname;
86	greg	1.7	char *id;
87	greg	1.1	register int i;
88	greg	1.6
89	greg	1.7	id = octname!=NULL ? octname : progname;
90	greg	1.1	/* check device table */
91			for (i = 0; devtable[i].name; i++)
92			if (!strcmp(dname, devtable[i].name))
93	greg	1.7	if ((dev = (*devtable[i].init)(dname, id)) == NULL) {
94	greg	1.1	sprintf(errmsg, "cannot initialize %s", dname);
95			error(USER, errmsg);
96			} else
97			return;
98	greg	2.8	#ifndef NIX
99	greg	1.1	/* not there, try exec */
100	greg	1.7	if ((dev = comm_init(dname, id)) == NULL) {
101	greg	1.1	sprintf(errmsg, "cannot start device \"%s\"", dname);
102			error(USER, errmsg);
103			}
104	greg	2.8	#endif
105	greg	1.1	}
106
107
108			devclose() /* close our device */
109			{
110			if (dev != NULL)
111			(*dev->close)();
112			dev = NULL;
113			}
114
115
116			printdevices() /* print list of output devices */
117			{
118			register int i;
119
120			for (i = 0; devtable[i].name; i++)
121			printf("%-16s # %s\n", devtable[i].name, devtable[i].descrip);
122			}
123
124
125			rview() /* do a view */
126			{
127			char buf[32];
128
129			devopen(devname); /* open device */
130	greg	1.14	newimage(); /* start image (calls fillreserves) */
131
132	greg	1.1	for ( ; ; ) { /* quit in command() */
133	greg	1.14	while (hresolu <= 1<<pdepth && vresolu <= 1<<pdepth)
134	greg	1.1	command("done: ");
135	greg	1.14	while (reserve_mem == NULL)
136			command("out of memory: ");
137			errno = 0;
138			if (hresolu <= psample<<pdepth && vresolu <= psample<<pdepth) {
139	greg	1.1	sprintf(buf, "%d sampling...\n", 1<<pdepth);
140			(*dev->comout)(buf);
141			rsample();
142			} else {
143			sprintf(buf, "%d refining...\n", 1<<pdepth);
144			(*dev->comout)(buf);
145	greg	1.9	refine(&ptrunk, 0, 0, hresolu, vresolu, pdepth+1);
146	greg	1.1	}
147	greg	1.14	if (errno == ENOMEM) /* ran out of memory */
148			freereserves();
149			else if (dev->inpready) /* noticed some input */
150	greg	1.1	command(": ");
151	greg	1.14	else /* finished this depth */
152	greg	1.1	pdepth++;
153			}
154			}
155
156
157	greg	1.14	fillreserves() /* fill memory reserves */
158	greg	1.12	{
159			if (reserve_mem != NULL)
160	greg	1.14	return;
161	greg	1.12	reserve_mem = malloc(RESERVE_AMT);
162			}
163
164
165	greg	1.14	freereserves() /* free memory reserves */
166	greg	1.12	{
167	greg	1.14	if (reserve_mem == NULL)
168			return;
169	greg	1.12	free(reserve_mem);
170			reserve_mem = NULL;
171			}
172
173
174	greg	1.1	command(prompt) /* get/execute command */
175			char *prompt;
176			{
177	greg	2.8	#define badcom(s) strncmp(s, inpbuf, args-inpbuf-1)
178	greg	1.1	char inpbuf[256];
179			char *args;
180			again:
181	greg	1.10	(dev->comin)(inpbuf, prompt); / get command + arguments */
182	greg	1.1	for (args = inpbuf; args && args != ' '; args++)
183			;
184			if (args) args++ = '\0';
185			else *++args = '\0';
186
187			switch (inpbuf[0]) {
188			case 'f': /* new frame */
189			if (badcom("frame"))
190			goto commerr;
191			getframe(args);
192			break;
193			case 'v': /* view */
194			if (badcom("view"))
195			goto commerr;
196			getview(args);
197			break;
198			case 'l': /* last view */
199			if (badcom("last"))
200			goto commerr;
201			lastview(args);
202			break;
203			case 'e': /* exposure */
204			if (badcom("exposure"))
205			goto commerr;
206			getexposure(args);
207			break;
208			case 's': /* set a parameter */
209			if (badcom("set"))
210			goto commerr;
211			setparam(args);
212			break;
213			case 'n': /* new picture */
214			if (badcom("new"))
215			goto commerr;
216			newimage();
217			break;
218			case 't': /* trace a ray */
219			if (badcom("trace"))
220			goto commerr;
221			traceray(args);
222			break;
223			case 'a': /* aim camera */
224			if (badcom("aim"))
225			goto commerr;
226			getaim(args);
227			break;
228			case 'm': /* move camera */
229			if (badcom("move"))
230	greg	2.8	#ifdef MSTATS
231	greg	2.2	{
232			if (badcom("memory"))
233			goto commerr;
234			printmemstats(stderr);
235			break;
236			}
237			#else
238	greg	1.1	goto commerr;
239	greg	2.2	#endif
240	greg	1.1	getmove(args);
241			break;
242	greg	1.8	case 'r': /* rotate/repaint */
243			if (badcom("rotate")) {
244			if (badcom("repaint"))
245			goto commerr;
246			getrepaint(args);
247			break;
248			}
249	greg	1.1	getrotate(args);
250			break;
251			case 'p': /* pivot view */
252			if (badcom("pivot"))
253			goto commerr;
254			getpivot(args);
255			break;
256	greg	2.4	case CTRL('R'): /* redraw */
257	greg	1.1	redraw();
258			break;
259			case 'w': /* write */
260			if (badcom("write"))
261			goto commerr;
262			writepict(args);
263			break;
264			case 'q': /* quit */
265			if (badcom("quit"))
266			goto commerr;
267			quit(0);
268	greg	2.4	case CTRL('C'): /* interrupt */
269	greg	1.1	goto again;
270	greg	2.8	#ifdef SIGTSTP
271	greg	2.4	case CTRL('Z'): /* stop */
272	greg	1.1	devclose();
273			kill(0, SIGTSTP);
274			/* pc stops here */
275			devopen(devname);
276			redraw();
277			break;
278			#endif
279			case '\0': /* continue */
280			break;
281			default:;
282			commerr:
283			if (iscntrl(inpbuf[0]))
284			sprintf(errmsg, "^%c: unknown control",
285			inpbuf[0]\|0100);
286			else
287			sprintf(errmsg, "%s: unknown command", inpbuf);
288			error(COMMAND, errmsg);
289			break;
290			}
291	greg	2.8	#undef badcom
292	greg	1.1	}
293
294
295			rsample() /* sample the image */
296			{
297			int xsiz, ysiz, y;
298			RECT r;
299			PNODE *p;
300			register RECT *rl;
301	greg	2.8	register PNODE **pl;
302	greg	1.1	register int x;
303			/*
304			* We initialize the bottom row in the image at our current
305	greg	2.8	* resolution. During sampling, we check super-pixels to the
306	greg	1.1	* right and above by calling bigdiff(). If there is a significant
307			* difference, we subsample the super-pixels. The testing process
308			* includes initialization of the next row.
309			*/
310	greg	1.9	xsiz = (((pframe.r-pframe.l)<<pdepth)+hresolu-1) / hresolu;
311			ysiz = (((pframe.u-pframe.d)<<pdepth)+vresolu-1) / vresolu;
312	greg	1.1	rl = (RECT )malloc(xsizsizeof(RECT));
313	greg	1.12	if (rl == NULL)
314	greg	1.14	return;
315	greg	1.1	pl = (PNODE *)malloc(xsizsizeof(PNODE *));
316	greg	2.7	if (pl == NULL) {
317			free((char *)rl);
318	greg	1.14	return;
319	greg	2.7	}
320	greg	1.1	/*
321			* Initialize the bottom row.
322			*/
323			rl[0].l = rl[0].d = 0;
324	greg	1.9	rl[0].r = hresolu; rl[0].u = vresolu;
325	greg	1.1	pl[0] = findrect(pframe.l, pframe.d, &ptrunk, rl, pdepth);
326			for (x = 1; x < xsiz; x++) {
327			rl[x].l = rl[x].d = 0;
328	greg	1.9	rl[x].r = hresolu; rl[x].u = vresolu;
329			pl[x] = findrect(pframe.l+((x*hresolu)>>pdepth),
330	greg	1.1	pframe.d, &ptrunk, rl+x, pdepth);
331			}
332			/* sample the image */
333			for (y = 0; /* y < ysiz */ ; y++) {
334			for (x = 0; x < xsiz-1; x++) {
335	greg	1.20	if (dev->inpready \|\| errno == ENOMEM)
336	greg	1.1	goto escape;
337			/*
338			* Test super-pixel to the right.
339			*/
340			if (pl[x] != pl[x+1] && bigdiff(pl[x]->v,
341			pl[x+1]->v, maxdiff)) {
342			refine(pl[x], rl[x].l, rl[x].d,
343			rl[x].r, rl[x].u, 1);
344			refine(pl[x+1], rl[x+1].l, rl[x+1].d,
345			rl[x+1].r, rl[x+1].u, 1);
346			}
347			}
348			if (y >= ysiz-1)
349			break;
350			for (x = 0; x < xsiz; x++) {
351	greg	1.20	if (dev->inpready \|\| errno == ENOMEM)
352	greg	1.1	goto escape;
353			/*
354			* Find super-pixel at this position in next row.
355			*/
356			r.l = r.d = 0;
357	greg	1.9	r.r = hresolu; r.u = vresolu;
358			p = findrect(pframe.l+((x*hresolu)>>pdepth),
359			pframe.d+(((y+1)*vresolu)>>pdepth),
360	greg	1.1	&ptrunk, &r, pdepth);
361			/*
362			* Test super-pixel in next row.
363			*/
364			if (pl[x] != p && bigdiff(pl[x]->v, p->v, maxdiff)) {
365			refine(pl[x], rl[x].l, rl[x].d,
366			rl[x].r, rl[x].u, 1);
367			refine(p, r.l, r.d, r.r, r.u, 1);
368			}
369			/*
370			* Copy into super-pixel array.
371			*/
372			rl[x].l = r.l; rl[x].d = r.d;
373			rl[x].r = r.r; rl[x].u = r.u;
374			pl[x] = p;
375			}
376			}
377			escape:
378			free((char *)rl);
379			free((char *)pl);
380			}
381
382
383			int
384			refine(p, xmin, ymin, xmax, ymax, pd) /* refine a node */
385	greg	2.8	register PNODE *p;
386	greg	1.1	int xmin, ymin, xmax, ymax;
387			int pd;
388			{
389			int growth;
390			int mx, my;
391			int i;
392
393			if (dev->inpready) /* quit for input */
394			return(0);
395
396			if (pd <= 0) /* depth limit */
397			return(0);
398
399			mx = (xmin + xmax) >> 1;
400			my = (ymin + ymax) >> 1;
401			growth = 0;
402
403			if (p->kid == NULL) { /* subdivide */
404
405			if ((p->kid = newptree()) == NULL)
406	greg	1.20	return(0);
407	greg	1.1	/*
408			* The following paint order can leave a black pixel
409	greg	2.7	* if redraw() is called in (*dev->paintr)().
410	greg	1.1	*/
411			if (p->x >= mx && p->y >= my)
412			pcopy(p, p->kid+UR);
413			else
414			paint(p->kid+UR, mx, my, xmax, ymax);
415			if (p->x < mx && p->y >= my)
416			pcopy(p, p->kid+UL);
417			else
418			paint(p->kid+UL, xmin, my, mx, ymax);
419			if (p->x >= mx && p->y < my)
420			pcopy(p, p->kid+DR);
421			else
422			paint(p->kid+DR, mx, ymin, xmax, my);
423			if (p->x < mx && p->y < my)
424			pcopy(p, p->kid+DL);
425			else
426			paint(p->kid+DL, xmin, ymin, mx, my);
427
428			growth++;
429			}
430			/* do children */
431			if (mx > pframe.l) {
432			if (my > pframe.d)
433			growth += refine(p->kid+DL, xmin, ymin, mx, my, pd-1);
434			if (my < pframe.u)
435			growth += refine(p->kid+UL, xmin, my, mx, ymax, pd-1);
436			}
437			if (mx < pframe.r) {
438			if (my > pframe.d)
439			growth += refine(p->kid+DR, mx, ymin, xmax, my, pd-1);
440			if (my < pframe.u)
441			growth += refine(p->kid+UR, mx, my, xmax, ymax, pd-1);
442			}
443			/* recompute sum */
444			if (growth) {
445			setcolor(p->v, 0.0, 0.0, 0.0);
446			for (i = 0; i < 4; i++)
447			addcolor(p->v, p->kid[i].v);
448			scalecolor(p->v, 0.25);
449			}
450			return(growth);
451			}