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 */

char  rifname[128];                     /* rad input file name */

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;
{
#ifdef MSTATS
        if (code == 2 && errno == ENOMEM)
                printmemstats(stderr);
#endif
        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 (or free mem.) */
                if (badcom("frame")) {
                        if (badcom("free"))
                                goto commerr;
                        free_objmem();
                        break;
                }
                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 'V':                               /* save view */
                if (badcom("V"))
                        goto commerr;
                saveview(args);
                break;
        case 'L':                               /* load view */
                if (badcom("L"))
                        goto commerr;
                loadview(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 (or memstats) */
                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 = (((long)(pframe.r-pframe.l)<<pdepth)+hresolu-1) / hresolu;
        ysiz = (((long)(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:	2.12
Committed:	Tue Sep 7 16:11:12 1993 UTC (30 years, 7 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.11:	+2 -2 lines
Log Message:	bug fix for 16-bit integers in psample()
#	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	greg	2.11	char rifname[128]; /* rad input file name */
62
63	greg	1.1	VIEW oldview; /* previous view parameters */
64
65			PNODE ptrunk; /* the base of our image */
66			RECT pframe; /* current frame boundaries */
67			int pdepth; /* image depth in current frame */
68
69	greg	1.12	static char reserve_mem = NULL; / pre-allocated reserve memory */
70
71	greg	1.20	#define RESERVE_AMT 32768 /* amount of memory to reserve */
72	greg	1.12
73	greg	2.8	#define CTRL(c) ((c)-'@')
74	greg	1.1
75
76			quit(code) /* quit program */
77			int code;
78			{
79	greg	2.10	#ifdef MSTATS
80			if (code == 2 && errno == ENOMEM)
81			printmemstats(stderr);
82			#endif
83	greg	1.1	devclose();
84			exit(code);
85			}
86
87
88			devopen(dname) /* open device driver */
89			char *dname;
90			{
91	greg	1.6	extern char progname, octname;
92	greg	1.7	char *id;
93	greg	1.1	register int i;
94	greg	1.6
95	greg	1.7	id = octname!=NULL ? octname : progname;
96	greg	1.1	/* check device table */
97			for (i = 0; devtable[i].name; i++)
98			if (!strcmp(dname, devtable[i].name))
99	greg	1.7	if ((dev = (*devtable[i].init)(dname, id)) == NULL) {
100	greg	1.1	sprintf(errmsg, "cannot initialize %s", dname);
101			error(USER, errmsg);
102			} else
103			return;
104	greg	2.8	#ifndef NIX
105	greg	1.1	/* not there, try exec */
106	greg	1.7	if ((dev = comm_init(dname, id)) == NULL) {
107	greg	1.1	sprintf(errmsg, "cannot start device \"%s\"", dname);
108			error(USER, errmsg);
109			}
110	greg	2.8	#endif
111	greg	1.1	}
112
113
114			devclose() /* close our device */
115			{
116			if (dev != NULL)
117			(*dev->close)();
118			dev = NULL;
119			}
120
121
122			printdevices() /* print list of output devices */
123			{
124			register int i;
125
126			for (i = 0; devtable[i].name; i++)
127			printf("%-16s # %s\n", devtable[i].name, devtable[i].descrip);
128			}
129
130
131			rview() /* do a view */
132			{
133			char buf[32];
134
135			devopen(devname); /* open device */
136	greg	1.14	newimage(); /* start image (calls fillreserves) */
137
138	greg	1.1	for ( ; ; ) { /* quit in command() */
139	greg	1.14	while (hresolu <= 1<<pdepth && vresolu <= 1<<pdepth)
140	greg	1.1	command("done: ");
141	greg	1.14	while (reserve_mem == NULL)
142			command("out of memory: ");
143			errno = 0;
144			if (hresolu <= psample<<pdepth && vresolu <= psample<<pdepth) {
145	greg	1.1	sprintf(buf, "%d sampling...\n", 1<<pdepth);
146			(*dev->comout)(buf);
147			rsample();
148			} else {
149			sprintf(buf, "%d refining...\n", 1<<pdepth);
150			(*dev->comout)(buf);
151	greg	1.9	refine(&ptrunk, 0, 0, hresolu, vresolu, pdepth+1);
152	greg	1.1	}
153	greg	1.14	if (errno == ENOMEM) /* ran out of memory */
154			freereserves();
155			else if (dev->inpready) /* noticed some input */
156	greg	1.1	command(": ");
157	greg	1.14	else /* finished this depth */
158	greg	1.1	pdepth++;
159			}
160			}
161
162
163	greg	1.14	fillreserves() /* fill memory reserves */
164	greg	1.12	{
165			if (reserve_mem != NULL)
166	greg	1.14	return;
167	greg	1.12	reserve_mem = malloc(RESERVE_AMT);
168			}
169
170
171	greg	1.14	freereserves() /* free memory reserves */
172	greg	1.12	{
173	greg	1.14	if (reserve_mem == NULL)
174			return;
175	greg	1.12	free(reserve_mem);
176			reserve_mem = NULL;
177			}
178
179
180	greg	1.1	command(prompt) /* get/execute command */
181			char *prompt;
182			{
183	greg	2.8	#define badcom(s) strncmp(s, inpbuf, args-inpbuf-1)
184	greg	1.1	char inpbuf[256];
185			char *args;
186			again:
187	greg	1.10	(dev->comin)(inpbuf, prompt); / get command + arguments */
188	greg	1.1	for (args = inpbuf; args && args != ' '; args++)
189			;
190			if (args) args++ = '\0';
191			else *++args = '\0';
192
193			switch (inpbuf[0]) {
194	greg	2.10	case 'f': /* new frame (or free mem.) */
195			if (badcom("frame")) {
196			if (badcom("free"))
197			goto commerr;
198			free_objmem();
199			break;
200			}
201	greg	1.1	getframe(args);
202			break;
203			case 'v': /* view */
204			if (badcom("view"))
205			goto commerr;
206			getview(args);
207			break;
208			case 'l': /* last view */
209			if (badcom("last"))
210			goto commerr;
211			lastview(args);
212	greg	2.11	break;
213			case 'V': /* save view */
214			if (badcom("V"))
215			goto commerr;
216			saveview(args);
217			break;
218			case 'L': /* load view */
219			if (badcom("L"))
220			goto commerr;
221			loadview(args);
222	greg	1.1	break;
223			case 'e': /* exposure */
224			if (badcom("exposure"))
225			goto commerr;
226			getexposure(args);
227			break;
228			case 's': /* set a parameter */
229			if (badcom("set"))
230			goto commerr;
231			setparam(args);
232			break;
233			case 'n': /* new picture */
234			if (badcom("new"))
235			goto commerr;
236			newimage();
237			break;
238			case 't': /* trace a ray */
239			if (badcom("trace"))
240			goto commerr;
241			traceray(args);
242			break;
243			case 'a': /* aim camera */
244			if (badcom("aim"))
245			goto commerr;
246			getaim(args);
247			break;
248	greg	2.10	case 'm': /* move camera (or memstats) */
249	greg	1.1	if (badcom("move"))
250	greg	2.8	#ifdef MSTATS
251	greg	2.2	{
252			if (badcom("memory"))
253			goto commerr;
254			printmemstats(stderr);
255			break;
256			}
257			#else
258	greg	1.1	goto commerr;
259	greg	2.2	#endif
260	greg	1.1	getmove(args);
261			break;
262	greg	1.8	case 'r': /* rotate/repaint */
263			if (badcom("rotate")) {
264			if (badcom("repaint"))
265			goto commerr;
266			getrepaint(args);
267			break;
268			}
269	greg	1.1	getrotate(args);
270			break;
271			case 'p': /* pivot view */
272			if (badcom("pivot"))
273			goto commerr;
274			getpivot(args);
275			break;
276	greg	2.4	case CTRL('R'): /* redraw */
277	greg	1.1	redraw();
278			break;
279			case 'w': /* write */
280			if (badcom("write"))
281			goto commerr;
282			writepict(args);
283			break;
284			case 'q': /* quit */
285			if (badcom("quit"))
286			goto commerr;
287			quit(0);
288	greg	2.4	case CTRL('C'): /* interrupt */
289	greg	1.1	goto again;
290	greg	2.8	#ifdef SIGTSTP
291	greg	2.4	case CTRL('Z'): /* stop */
292	greg	1.1	devclose();
293			kill(0, SIGTSTP);
294			/* pc stops here */
295			devopen(devname);
296			redraw();
297			break;
298			#endif
299			case '\0': /* continue */
300			break;
301			default:;
302			commerr:
303			if (iscntrl(inpbuf[0]))
304			sprintf(errmsg, "^%c: unknown control",
305			inpbuf[0]\|0100);
306			else
307			sprintf(errmsg, "%s: unknown command", inpbuf);
308			error(COMMAND, errmsg);
309			break;
310			}
311	greg	2.8	#undef badcom
312	greg	1.1	}
313
314
315			rsample() /* sample the image */
316			{
317			int xsiz, ysiz, y;
318			RECT r;
319			PNODE *p;
320			register RECT *rl;
321	greg	2.8	register PNODE **pl;
322	greg	1.1	register int x;
323			/*
324			* We initialize the bottom row in the image at our current
325	greg	2.8	* resolution. During sampling, we check super-pixels to the
326	greg	1.1	* right and above by calling bigdiff(). If there is a significant
327			* difference, we subsample the super-pixels. The testing process
328			* includes initialization of the next row.
329			*/
330	greg	2.12	xsiz = (((long)(pframe.r-pframe.l)<<pdepth)+hresolu-1) / hresolu;
331			ysiz = (((long)(pframe.u-pframe.d)<<pdepth)+vresolu-1) / vresolu;
332	greg	1.1	rl = (RECT )malloc(xsizsizeof(RECT));
333	greg	1.12	if (rl == NULL)
334	greg	1.14	return;
335	greg	1.1	pl = (PNODE *)malloc(xsizsizeof(PNODE *));
336	greg	2.7	if (pl == NULL) {
337			free((char *)rl);
338	greg	1.14	return;
339	greg	2.7	}
340	greg	1.1	/*
341			* Initialize the bottom row.
342			*/
343			rl[0].l = rl[0].d = 0;
344	greg	1.9	rl[0].r = hresolu; rl[0].u = vresolu;
345	greg	1.1	pl[0] = findrect(pframe.l, pframe.d, &ptrunk, rl, pdepth);
346			for (x = 1; x < xsiz; x++) {
347			rl[x].l = rl[x].d = 0;
348	greg	1.9	rl[x].r = hresolu; rl[x].u = vresolu;
349			pl[x] = findrect(pframe.l+((x*hresolu)>>pdepth),
350	greg	1.1	pframe.d, &ptrunk, rl+x, pdepth);
351			}
352			/* sample the image */
353			for (y = 0; /* y < ysiz */ ; y++) {
354			for (x = 0; x < xsiz-1; x++) {
355	greg	1.20	if (dev->inpready \|\| errno == ENOMEM)
356	greg	1.1	goto escape;
357			/*
358			* Test super-pixel to the right.
359			*/
360			if (pl[x] != pl[x+1] && bigdiff(pl[x]->v,
361			pl[x+1]->v, maxdiff)) {
362			refine(pl[x], rl[x].l, rl[x].d,
363			rl[x].r, rl[x].u, 1);
364			refine(pl[x+1], rl[x+1].l, rl[x+1].d,
365			rl[x+1].r, rl[x+1].u, 1);
366			}
367			}
368			if (y >= ysiz-1)
369			break;
370			for (x = 0; x < xsiz; x++) {
371	greg	1.20	if (dev->inpready \|\| errno == ENOMEM)
372	greg	1.1	goto escape;
373			/*
374			* Find super-pixel at this position in next row.
375			*/
376			r.l = r.d = 0;
377	greg	1.9	r.r = hresolu; r.u = vresolu;
378			p = findrect(pframe.l+((x*hresolu)>>pdepth),
379			pframe.d+(((y+1)*vresolu)>>pdepth),
380	greg	1.1	&ptrunk, &r, pdepth);
381			/*
382			* Test super-pixel in next row.
383			*/
384			if (pl[x] != p && bigdiff(pl[x]->v, p->v, maxdiff)) {
385			refine(pl[x], rl[x].l, rl[x].d,
386			rl[x].r, rl[x].u, 1);
387			refine(p, r.l, r.d, r.r, r.u, 1);
388			}
389			/*
390			* Copy into super-pixel array.
391			*/
392			rl[x].l = r.l; rl[x].d = r.d;
393			rl[x].r = r.r; rl[x].u = r.u;
394			pl[x] = p;
395			}
396			}
397			escape:
398			free((char *)rl);
399			free((char *)pl);
400			}
401
402
403			int
404			refine(p, xmin, ymin, xmax, ymax, pd) /* refine a node */
405	greg	2.8	register PNODE *p;
406	greg	1.1	int xmin, ymin, xmax, ymax;
407			int pd;
408			{
409			int growth;
410			int mx, my;
411			int i;
412
413			if (dev->inpready) /* quit for input */
414			return(0);
415
416			if (pd <= 0) /* depth limit */
417			return(0);
418
419			mx = (xmin + xmax) >> 1;
420			my = (ymin + ymax) >> 1;
421			growth = 0;
422
423			if (p->kid == NULL) { /* subdivide */
424
425			if ((p->kid = newptree()) == NULL)
426	greg	1.20	return(0);
427	greg	1.1	/*
428			* The following paint order can leave a black pixel
429	greg	2.7	* if redraw() is called in (*dev->paintr)().
430	greg	1.1	*/
431			if (p->x >= mx && p->y >= my)
432			pcopy(p, p->kid+UR);
433			else
434			paint(p->kid+UR, mx, my, xmax, ymax);
435			if (p->x < mx && p->y >= my)
436			pcopy(p, p->kid+UL);
437			else
438			paint(p->kid+UL, xmin, my, mx, ymax);
439			if (p->x >= mx && p->y < my)
440			pcopy(p, p->kid+DR);
441			else
442			paint(p->kid+DR, mx, ymin, xmax, my);
443			if (p->x < mx && p->y < my)
444			pcopy(p, p->kid+DL);
445			else
446			paint(p->kid+DL, xmin, ymin, mx, my);
447
448			growth++;
449			}
450			/* do children */
451			if (mx > pframe.l) {
452			if (my > pframe.d)
453			growth += refine(p->kid+DL, xmin, ymin, mx, my, pd-1);
454			if (my < pframe.u)
455			growth += refine(p->kid+UL, xmin, my, mx, ymax, pd-1);
456			}
457			if (mx < pframe.r) {
458			if (my > pframe.d)
459			growth += refine(p->kid+DR, mx, ymin, xmax, my, pd-1);
460			if (my < pframe.u)
461			growth += refine(p->kid+UR, mx, my, xmax, ymax, pd-1);
462			}
463			/* recompute sum */
464			if (growth) {
465			setcolor(p->v, 0.0, 0.0, 0.0);
466			for (i = 0; i < 4; i++)
467			addcolor(p->v, p->kid[i].v);
468			scalecolor(p->v, 0.25);
469			}
470			return(growth);
471			}