src/rt/rview.c

/* Copyright (c) 1995 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. */

COLOR  cextinction = BLKCOLOR;          /* global extinction coefficient */
double  salbedo = 0.;                   /* global scattering albedo */
double  seccg = 0.;                     /* global scattering eccentricity */
double  ssampdist = 0.;                 /* scatter sampling distance */

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

int  backvis = 1;                       /* back face visibility */

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")) {
#ifdef  SIGTSTP
                        if (!badcom("stop"))
                                goto dostop;
#endif
                        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")) {
                                if (badcom("redraw"))
                                        goto commerr;
                                redraw();
                                break;
                        }
                        getrepaint(args);
                        break;
                }
                getrotate(args);
                break;
        case 'p':                               /* pivot view */
                if (badcom("pivot")) {
                        if (badcom("pause"))
                                goto commerr;
                        goto again;
                }
                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 */
dostop:
                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:	2.15
Committed:	Fri Dec 8 18:49:24 1995 UTC (29 years, 11 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.14:	+6 -1 lines
Log Message:	added M_MIST (mist) material and global participating medium
#	User	Rev	Content
1	greg	2.15	/* Copyright (c) 1995 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	2.15
41			COLOR cextinction = BLKCOLOR; /* global extinction coefficient */
42			double salbedo = 0.; /* global scattering albedo */
43			double seccg = 0.; /* global scattering eccentricity */
44			double ssampdist = 0.; /* scatter sampling distance */
45	greg	1.1
46	greg	2.8	double specthresh = .3; /* specular sampling threshold */
47			double specjitter = 1.; /* specular sampling jitter */
48	greg	2.5
49	greg	2.14	int backvis = 1; /* back face visibility */
50
51	greg	1.1	int maxdepth = 4; /* maximum recursion depth */
52	greg	2.8	double minweight = 1e-2; /* minimum ray weight */
53	greg	1.1
54			COLOR ambval = BLKCOLOR; /* ambient value */
55	greg	2.8	double ambacc = 0.2; /* ambient accuracy */
56	greg	1.5	int ambres = 8; /* ambient resolution */
57	greg	1.1	int ambdiv = 32; /* ambient divisions */
58			int ambssamp = 0; /* ambient super-samples */
59			int ambounce = 0; /* ambient bounces */
60			char amblist[128]; / ambient include/exclude list */
61			int ambincl = -1; /* include == 1, exclude == 0 */
62
63			int greyscale = 0; /* map colors to brightness? */
64	greg	1.11	char devname = dev_default; / output device name */
65	greg	1.1
66			struct driver dev = NULL; / driver functions */
67
68	greg	2.11	char rifname[128]; /* rad input file name */
69
70	greg	1.1	VIEW oldview; /* previous view parameters */
71
72			PNODE ptrunk; /* the base of our image */
73			RECT pframe; /* current frame boundaries */
74			int pdepth; /* image depth in current frame */
75
76	greg	1.12	static char reserve_mem = NULL; / pre-allocated reserve memory */
77
78	greg	1.20	#define RESERVE_AMT 32768 /* amount of memory to reserve */
79	greg	1.12
80	greg	2.8	#define CTRL(c) ((c)-'@')
81	greg	1.1
82
83			quit(code) /* quit program */
84			int code;
85			{
86	greg	2.10	#ifdef MSTATS
87			if (code == 2 && errno == ENOMEM)
88			printmemstats(stderr);
89			#endif
90	greg	1.1	devclose();
91			exit(code);
92			}
93
94
95			devopen(dname) /* open device driver */
96			char *dname;
97			{
98	greg	1.6	extern char progname, octname;
99	greg	1.7	char *id;
100	greg	1.1	register int i;
101	greg	1.6
102	greg	1.7	id = octname!=NULL ? octname : progname;
103	greg	1.1	/* check device table */
104			for (i = 0; devtable[i].name; i++)
105			if (!strcmp(dname, devtable[i].name))
106	greg	1.7	if ((dev = (*devtable[i].init)(dname, id)) == NULL) {
107	greg	1.1	sprintf(errmsg, "cannot initialize %s", dname);
108			error(USER, errmsg);
109			} else
110			return;
111	greg	2.8	#ifndef NIX
112	greg	1.1	/* not there, try exec */
113	greg	1.7	if ((dev = comm_init(dname, id)) == NULL) {
114	greg	1.1	sprintf(errmsg, "cannot start device \"%s\"", dname);
115			error(USER, errmsg);
116			}
117	greg	2.8	#endif
118	greg	1.1	}
119
120
121			devclose() /* close our device */
122			{
123			if (dev != NULL)
124			(*dev->close)();
125			dev = NULL;
126			}
127
128
129			printdevices() /* print list of output devices */
130			{
131			register int i;
132
133			for (i = 0; devtable[i].name; i++)
134			printf("%-16s # %s\n", devtable[i].name, devtable[i].descrip);
135			}
136
137
138			rview() /* do a view */
139			{
140			char buf[32];
141
142			devopen(devname); /* open device */
143	greg	1.14	newimage(); /* start image (calls fillreserves) */
144
145	greg	1.1	for ( ; ; ) { /* quit in command() */
146	greg	1.14	while (hresolu <= 1<<pdepth && vresolu <= 1<<pdepth)
147	greg	1.1	command("done: ");
148	greg	1.14	while (reserve_mem == NULL)
149			command("out of memory: ");
150			errno = 0;
151			if (hresolu <= psample<<pdepth && vresolu <= psample<<pdepth) {
152	greg	1.1	sprintf(buf, "%d sampling...\n", 1<<pdepth);
153			(*dev->comout)(buf);
154			rsample();
155			} else {
156			sprintf(buf, "%d refining...\n", 1<<pdepth);
157			(*dev->comout)(buf);
158	greg	1.9	refine(&ptrunk, 0, 0, hresolu, vresolu, pdepth+1);
159	greg	1.1	}
160	greg	1.14	if (errno == ENOMEM) /* ran out of memory */
161			freereserves();
162			else if (dev->inpready) /* noticed some input */
163	greg	1.1	command(": ");
164	greg	1.14	else /* finished this depth */
165	greg	1.1	pdepth++;
166			}
167			}
168
169
170	greg	1.14	fillreserves() /* fill memory reserves */
171	greg	1.12	{
172			if (reserve_mem != NULL)
173	greg	1.14	return;
174	greg	1.12	reserve_mem = malloc(RESERVE_AMT);
175			}
176
177
178	greg	1.14	freereserves() /* free memory reserves */
179	greg	1.12	{
180	greg	1.14	if (reserve_mem == NULL)
181			return;
182	greg	1.12	free(reserve_mem);
183			reserve_mem = NULL;
184			}
185
186
187	greg	1.1	command(prompt) /* get/execute command */
188			char *prompt;
189			{
190	greg	2.8	#define badcom(s) strncmp(s, inpbuf, args-inpbuf-1)
191	greg	1.1	char inpbuf[256];
192			char *args;
193			again:
194	greg	1.10	(dev->comin)(inpbuf, prompt); / get command + arguments */
195	greg	1.1	for (args = inpbuf; args && args != ' '; args++)
196			;
197			if (args) args++ = '\0';
198			else *++args = '\0';
199
200			switch (inpbuf[0]) {
201	greg	2.10	case 'f': /* new frame (or free mem.) */
202			if (badcom("frame")) {
203			if (badcom("free"))
204			goto commerr;
205			free_objmem();
206			break;
207			}
208	greg	1.1	getframe(args);
209			break;
210			case 'v': /* view */
211			if (badcom("view"))
212			goto commerr;
213			getview(args);
214			break;
215			case 'l': /* last view */
216			if (badcom("last"))
217			goto commerr;
218			lastview(args);
219	greg	2.11	break;
220			case 'V': /* save view */
221			if (badcom("V"))
222			goto commerr;
223			saveview(args);
224			break;
225			case 'L': /* load view */
226			if (badcom("L"))
227			goto commerr;
228			loadview(args);
229	greg	1.1	break;
230			case 'e': /* exposure */
231			if (badcom("exposure"))
232			goto commerr;
233			getexposure(args);
234			break;
235			case 's': /* set a parameter */
236	greg	2.13	if (badcom("set")) {
237			#ifdef SIGTSTP
238			if (!badcom("stop"))
239			goto dostop;
240			#endif
241	greg	1.1	goto commerr;
242	greg	2.13	}
243	greg	1.1	setparam(args);
244			break;
245			case 'n': /* new picture */
246			if (badcom("new"))
247			goto commerr;
248			newimage();
249			break;
250			case 't': /* trace a ray */
251			if (badcom("trace"))
252			goto commerr;
253			traceray(args);
254			break;
255			case 'a': /* aim camera */
256			if (badcom("aim"))
257			goto commerr;
258			getaim(args);
259			break;
260	greg	2.10	case 'm': /* move camera (or memstats) */
261	greg	1.1	if (badcom("move"))
262	greg	2.8	#ifdef MSTATS
263	greg	2.2	{
264			if (badcom("memory"))
265			goto commerr;
266			printmemstats(stderr);
267			break;
268			}
269			#else
270	greg	1.1	goto commerr;
271	greg	2.2	#endif
272	greg	1.1	getmove(args);
273			break;
274	greg	1.8	case 'r': /* rotate/repaint */
275			if (badcom("rotate")) {
276	greg	2.13	if (badcom("repaint")) {
277			if (badcom("redraw"))
278			goto commerr;
279			redraw();
280			break;
281			}
282	greg	1.8	getrepaint(args);
283			break;
284			}
285	greg	1.1	getrotate(args);
286			break;
287			case 'p': /* pivot view */
288	greg	2.13	if (badcom("pivot")) {
289			if (badcom("pause"))
290			goto commerr;
291			goto again;
292			}
293	greg	1.1	getpivot(args);
294			break;
295	greg	2.4	case CTRL('R'): /* redraw */
296	greg	1.1	redraw();
297			break;
298			case 'w': /* write */
299			if (badcom("write"))
300			goto commerr;
301			writepict(args);
302			break;
303			case 'q': /* quit */
304			if (badcom("quit"))
305			goto commerr;
306			quit(0);
307	greg	2.4	case CTRL('C'): /* interrupt */
308	greg	1.1	goto again;
309	greg	2.8	#ifdef SIGTSTP
310	greg	2.13	case CTRL('Z'):; /* stop */
311			dostop:
312	greg	1.1	devclose();
313			kill(0, SIGTSTP);
314			/* pc stops here */
315			devopen(devname);
316			redraw();
317			break;
318			#endif
319			case '\0': /* continue */
320			break;
321			default:;
322			commerr:
323			if (iscntrl(inpbuf[0]))
324			sprintf(errmsg, "^%c: unknown control",
325			inpbuf[0]\|0100);
326			else
327			sprintf(errmsg, "%s: unknown command", inpbuf);
328			error(COMMAND, errmsg);
329			break;
330			}
331	greg	2.8	#undef badcom
332	greg	1.1	}
333
334
335			rsample() /* sample the image */
336			{
337			int xsiz, ysiz, y;
338			RECT r;
339			PNODE *p;
340			register RECT *rl;
341	greg	2.8	register PNODE **pl;
342	greg	1.1	register int x;
343			/*
344			* We initialize the bottom row in the image at our current
345	greg	2.8	* resolution. During sampling, we check super-pixels to the
346	greg	1.1	* right and above by calling bigdiff(). If there is a significant
347			* difference, we subsample the super-pixels. The testing process
348			* includes initialization of the next row.
349			*/
350	greg	2.12	xsiz = (((long)(pframe.r-pframe.l)<<pdepth)+hresolu-1) / hresolu;
351			ysiz = (((long)(pframe.u-pframe.d)<<pdepth)+vresolu-1) / vresolu;
352	greg	1.1	rl = (RECT )malloc(xsizsizeof(RECT));
353	greg	1.12	if (rl == NULL)
354	greg	1.14	return;
355	greg	1.1	pl = (PNODE *)malloc(xsizsizeof(PNODE *));
356	greg	2.7	if (pl == NULL) {
357			free((char *)rl);
358	greg	1.14	return;
359	greg	2.7	}
360	greg	1.1	/*
361			* Initialize the bottom row.
362			*/
363			rl[0].l = rl[0].d = 0;
364	greg	1.9	rl[0].r = hresolu; rl[0].u = vresolu;
365	greg	1.1	pl[0] = findrect(pframe.l, pframe.d, &ptrunk, rl, pdepth);
366			for (x = 1; x < xsiz; x++) {
367			rl[x].l = rl[x].d = 0;
368	greg	1.9	rl[x].r = hresolu; rl[x].u = vresolu;
369			pl[x] = findrect(pframe.l+((x*hresolu)>>pdepth),
370	greg	1.1	pframe.d, &ptrunk, rl+x, pdepth);
371			}
372			/* sample the image */
373			for (y = 0; /* y < ysiz */ ; y++) {
374			for (x = 0; x < xsiz-1; x++) {
375	greg	1.20	if (dev->inpready \|\| errno == ENOMEM)
376	greg	1.1	goto escape;
377			/*
378			* Test super-pixel to the right.
379			*/
380			if (pl[x] != pl[x+1] && bigdiff(pl[x]->v,
381			pl[x+1]->v, maxdiff)) {
382			refine(pl[x], rl[x].l, rl[x].d,
383			rl[x].r, rl[x].u, 1);
384			refine(pl[x+1], rl[x+1].l, rl[x+1].d,
385			rl[x+1].r, rl[x+1].u, 1);
386			}
387			}
388			if (y >= ysiz-1)
389			break;
390			for (x = 0; x < xsiz; x++) {
391	greg	1.20	if (dev->inpready \|\| errno == ENOMEM)
392	greg	1.1	goto escape;
393			/*
394			* Find super-pixel at this position in next row.
395			*/
396			r.l = r.d = 0;
397	greg	1.9	r.r = hresolu; r.u = vresolu;
398			p = findrect(pframe.l+((x*hresolu)>>pdepth),
399			pframe.d+(((y+1)*vresolu)>>pdepth),
400	greg	1.1	&ptrunk, &r, pdepth);
401			/*
402			* Test super-pixel in next row.
403			*/
404			if (pl[x] != p && bigdiff(pl[x]->v, p->v, maxdiff)) {
405			refine(pl[x], rl[x].l, rl[x].d,
406			rl[x].r, rl[x].u, 1);
407			refine(p, r.l, r.d, r.r, r.u, 1);
408			}
409			/*
410			* Copy into super-pixel array.
411			*/
412			rl[x].l = r.l; rl[x].d = r.d;
413			rl[x].r = r.r; rl[x].u = r.u;
414			pl[x] = p;
415			}
416			}
417			escape:
418			free((char *)rl);
419			free((char *)pl);
420			}
421
422
423			int
424			refine(p, xmin, ymin, xmax, ymax, pd) /* refine a node */
425	greg	2.8	register PNODE *p;
426	greg	1.1	int xmin, ymin, xmax, ymax;
427			int pd;
428			{
429			int growth;
430			int mx, my;
431			int i;
432
433			if (dev->inpready) /* quit for input */
434			return(0);
435
436			if (pd <= 0) /* depth limit */
437			return(0);
438
439			mx = (xmin + xmax) >> 1;
440			my = (ymin + ymax) >> 1;
441			growth = 0;
442
443			if (p->kid == NULL) { /* subdivide */
444
445			if ((p->kid = newptree()) == NULL)
446	greg	1.20	return(0);
447	greg	1.1	/*
448			* The following paint order can leave a black pixel
449	greg	2.7	* if redraw() is called in (*dev->paintr)().
450	greg	1.1	*/
451			if (p->x >= mx && p->y >= my)
452			pcopy(p, p->kid+UR);
453			else
454			paint(p->kid+UR, mx, my, xmax, ymax);
455			if (p->x < mx && p->y >= my)
456			pcopy(p, p->kid+UL);
457			else
458			paint(p->kid+UL, xmin, my, mx, ymax);
459			if (p->x >= mx && p->y < my)
460			pcopy(p, p->kid+DR);
461			else
462			paint(p->kid+DR, mx, ymin, xmax, my);
463			if (p->x < mx && p->y < my)
464			pcopy(p, p->kid+DL);
465			else
466			paint(p->kid+DL, xmin, ymin, mx, my);
467
468			growth++;
469			}
470			/* do children */
471			if (mx > pframe.l) {
472			if (my > pframe.d)
473			growth += refine(p->kid+DL, xmin, ymin, mx, my, pd-1);
474			if (my < pframe.u)
475			growth += refine(p->kid+UL, xmin, my, mx, ymax, pd-1);
476			}
477			if (mx < pframe.r) {
478			if (my > pframe.d)
479			growth += refine(p->kid+DR, mx, ymin, xmax, my, pd-1);
480			if (my < pframe.u)
481			growth += refine(p->kid+UR, mx, my, xmax, ymax, pd-1);
482			}
483			/* recompute sum */
484			if (growth) {
485			setcolor(p->v, 0.0, 0.0, 0.0);
486			for (i = 0; i < 4; i++)
487			addcolor(p->v, p->kid[i].v);
488			scalecolor(p->v, 0.25);
489			}
490			return(growth);
491			}