src/rt/rpict.c

/* Copyright (c) 1986 Regents of the University of California */

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

/*
 *  rpict.c - routines and variables for picture generation.
 *
 *     8/14/85
 */

#include  "ray.h"

#ifdef BSD
#include  <sys/time.h>
#include  <sys/resource.h>
#else
#include  <signal.h>
#endif

#include  "view.h"

#include  "random.h"

VIEW  ourview = STDVIEW;                /* view parameters */
int  hresolu = 512;                     /* horizontal resolution */
int  vresolu = 512;                     /* vertical resolution */
double  pixaspect = 1.0;                /* pixel aspect ratio */

int  psample = 4;                       /* pixel sample size */
double  maxdiff = .05;                  /* max. difference for interpolation */
double  dstrpix = 0.67;                 /* square pixel distribution */

double  dstrsrc = 0.0;                  /* square source distribution */
double  shadthresh = .05;               /* shadow threshold */
double  shadcert = .5;                  /* shadow certainty */

int  maxdepth = 6;                      /* maximum recursion depth */
double  minweight = 5e-3;               /* minimum ray weight */

COLOR  ambval = BLKCOLOR;               /* ambient value */
double  ambacc = 0.2;                   /* ambient accuracy */
int  ambres = 32;                       /* ambient resolution */
int  ambdiv = 128;                      /* 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  ralrm = 0;                         /* seconds between reports */

double  pctdone = 0.0;                  /* percentage done */

extern long  nrays;                     /* number of rays traced */

#define  MAXDIV         32              /* maximum sample size */

#define  pixjitter()    (.5+dstrpix*(.5-frandom()))

double  pixvalue();


quit(code)                      /* quit program */
int  code;
{
        if (code || ralrm > 0)          /* report status */
                report();

        exit(code);
}


report()                /* report progress */
{
#ifdef BSD
        struct rusage  rubuf;
        double  t;

        getrusage(RUSAGE_SELF, &rubuf);
        t = (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
        t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;
        getrusage(RUSAGE_CHILDREN, &rubuf);
        t += (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
        t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;

        sprintf(errmsg, "%ld rays, %4.2f%% done after %5.4f CPU hours\n",
                        nrays, pctdone, t/3600.0);
#else
        signal(SIGALRM, report);
        sprintf(errmsg, "%ld rays, %4.2f%% done\n", nrays, pctdone);
#endif
        eputs(errmsg);

        if (ralrm > 0)
                alarm(ralrm);
}


render(zfile, oldfile)                          /* render the scene */
char  *zfile, *oldfile;
{
        COLOR  *scanbar[MAXDIV+1];      /* scanline arrays of pixel values */
        float  *zbar[MAXDIV+1];         /* z values */
        int  ypos;                      /* current scanline */
        int  ystep;                     /* current y step size */
        FILE  *zfp;
        COLOR  *colptr;
        float  *zptr;
        register int  i;
                                        /* check sampling */
        if (psample < 1)
                psample = 1;
        else if (psample > MAXDIV)
                psample = MAXDIV;
                                        /* allocate scanlines */
        for (i = 0; i <= psample; i++) {
                scanbar[i] = (COLOR *)malloc(hresolu*sizeof(COLOR));
                if (scanbar[i] == NULL)
                        goto memerr;
        }
                                        /* open z file */
        if (zfile != NULL) {
                if ((zfp = fopen(zfile, "a+")) == NULL) {
                        sprintf(errmsg, "cannot open z file \"%s\"", zfile);
                        error(SYSTEM, errmsg);
                }
                for (i = 0; i <= psample; i++) {
                        zbar[i] = (float *)malloc(hresolu*sizeof(float));
                        if (zbar[i] == NULL)
                                goto memerr;
                }
        } else {
                zfp = NULL;
                for (i = 0; i <= psample; i++)
                        zbar[i] = NULL;
        }
                                        /* write out boundaries */
        fputresolu(YMAJOR|YDECR, hresolu, vresolu, stdout);
                                        /* recover file and compute first */
        i = salvage(oldfile);
        if (zfp != NULL && fseek(zfp, (long)i*hresolu*sizeof(float), 0) == EOF)
                error(SYSTEM, "z file seek error in render");
        ypos = vresolu-1 - i;
        fillscanline(scanbar[0], zbar[0], hresolu, ypos, psample);
        ystep = psample;
                                                /* compute scanlines */
        for (ypos -= ystep; ypos > -ystep; ypos -= ystep) {
                                                        /* record progress */
                pctdone = 100.0*(vresolu-ypos-ystep)/vresolu;
                                                        /* bottom adjust? */
                if (ypos < 0) {
                        ystep += ypos;
                        ypos = 0;
                }
                colptr = scanbar[ystep];                /* move base to top */
                scanbar[ystep] = scanbar[0];
                scanbar[0] = colptr;
                zptr = zbar[ystep];
                zbar[ystep] = zbar[0];
                zbar[0] = zptr;
                                                        /* fill base line */
                fillscanline(scanbar[0], zbar[0], hresolu, ypos, psample);
                                                        /* fill bar */
                fillscanbar(scanbar, zbar, hresolu, ypos, ystep);
                                                        /* write it out */
                for (i = ystep; i > 0; i--) {
                        if (zfp != NULL && fwrite(zbar[i],sizeof(float),hresolu,zfp) != hresolu)
                                goto writerr;
                        if (fwritescan(scanbar[i],hresolu,stdout) < 0)
                                goto writerr;
                }
                if (zfp != NULL && fflush(zfp) == EOF)
                        goto writerr;
                if (fflush(stdout) == EOF)
                        goto writerr;
        }
                                                /* clean up */
        if (zfp != NULL) {
                fwrite(zbar[0], sizeof(float), hresolu, zfp);
                if (fclose(zfp) == EOF)
                        goto writerr;
                for (i = 0; i <= psample; i++)
                        free((char *)zbar[i]);
        }
        fwritescan(scanbar[0], hresolu, stdout);
        if (fflush(stdout) == EOF)
                goto writerr;
        for (i = 0; i <= psample; i++)
                free((char *)scanbar[i]);
        pctdone = 100.0;
        return;
writerr:
        error(SYSTEM, "write error in render");
memerr:
        error(SYSTEM, "out of memory in render");
}


fillscanline(scanline, zline, xres, y, xstep)   /* fill scan line at y */
register COLOR  *scanline;
register float  *zline;
int  xres, y, xstep;
{
        int  b = xstep;
        double  z;
        register int  i;
        
        z = pixvalue(scanline[0], 0, y);
        if (zline) zline[0] = z;

        for (i = xstep; i < xres-1+xstep; i += xstep) {
                if (i >= xres) {
                        xstep += xres-1-i;
                        i = xres-1;
                }
                z = pixvalue(scanline[i], i, y);
                if (zline) zline[i] = z;
                
                b = fillsample(scanline+i-xstep, zline ? zline+i-xstep : NULL,
                                i-xstep, y, xstep, 0, b/2);
        }
}


fillscanbar(scanbar, zbar, xres, y, ysize)      /* fill interior */
register COLOR  *scanbar[];
register float  *zbar[];
int  xres, y, ysize;
{
        COLOR  vline[MAXDIV+1];
        float  zline[MAXDIV+1];
        int  b = ysize;
        double  z;
        register int  i, j;
        
        for (i = 0; i < xres; i++) {
                
                copycolor(vline[0], scanbar[0][i]);
                copycolor(vline[ysize], scanbar[ysize][i]);
                if (zbar[0]) {
                        zline[0] = zbar[0][i];
                        zline[ysize] = zbar[ysize][i];
                }
                
                b = fillsample(vline, zbar[0] ? zline : NULL,
                                i, y, 0, ysize, b/2);
                
                for (j = 1; j < ysize; j++)
                        copycolor(scanbar[j][i], vline[j]);
                if (zbar[0])
                        for (j = 1; j < ysize; j++)
                                zbar[j][i] = zline[j];
        }
}


int
fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */
register COLOR  *colline;
register float  *zline;
int  x, y;
int  xlen, ylen;
int  b;
{
        extern double  fabs();
        double  ratio;
        double  z;
        COLOR  ctmp;
        int  ncut;
        register int  len;
        
        if (xlen > 0)                   /* x or y length is zero */
                len = xlen;
        else
                len = ylen;
                
        if (len <= 1)                   /* limit recursion */
                return(0);
        
        if (b > 0
        || (zline && 2.*fabs(zline[0]-zline[len]) > maxdiff*(zline[0]+zline[len]))
                        || bigdiff(colline[0], colline[len], maxdiff)) {
        
                z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
                if (zline) zline[len>>1] = z;
                ncut = 1;
                
        } else {                                        /* interpolate */
        
                copycolor(colline[len>>1], colline[len]);
                ratio = (double)(len>>1) / len;
                scalecolor(colline[len>>1], ratio);
                if (zline) zline[len>>1] = zline[len] * ratio;
                ratio = 1.0 - ratio;
                copycolor(ctmp, colline[0]);
                scalecolor(ctmp, ratio);
                addcolor(colline[len>>1], ctmp);
                if (zline) zline[len>>1] += zline[0] * ratio;
                ncut = 0;
        }
                                                        /* recurse */
        ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
        
        ncut += fillsample(colline+(len>>1), zline ? zline+(len>>1) : NULL,
                        x+(xlen>>1), y+(ylen>>1),
                        xlen-(xlen>>1), ylen-(ylen>>1), b/2);

        return(ncut);
}


double
pixvalue(col, x, y)             /* compute pixel value */
COLOR  col;                     /* returned color */
int  x, y;                      /* pixel position */
{
        static RAY  thisray;    /* our ray for this pixel */

        viewray(thisray.rorg, thisray.rdir, &ourview,
                        (x+pixjitter())/hresolu, (y+pixjitter())/vresolu);

        rayorigin(&thisray, NULL, PRIMARY, 1.0);
        
        rayvalue(&thisray);                     /* trace ray */

        copycolor(col, thisray.rcol);           /* return color */
        
        return(thisray.rot);                    /* return distance */
}


int
salvage(oldfile)                /* salvage scanlines from killed program */
char  *oldfile;
{
        COLR  *scanline;
        FILE  *fp;
        int  x, y;

        if (oldfile == NULL)
                return(0);
        
        if ((fp = fopen(oldfile, "r")) == NULL) {
                sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
                error(WARNING, errmsg);
                return(0);
        }
                                /* discard header */
        getheader(fp, NULL);
                                /* get picture size */
        if (fgetresolu(&x, &y, fp) != (YMAJOR|YDECR)) {
                sprintf(errmsg, "bad recover file \"%s\"", oldfile);
                error(WARNING, errmsg);
                fclose(fp);
                return(0);
        }

        if (x != hresolu || y != vresolu) {
                sprintf(errmsg, "resolution mismatch in recover file \"%s\"",
                                oldfile);
                error(USER, errmsg);
        }

        scanline = (COLR *)malloc(hresolu*sizeof(COLR));
        if (scanline == NULL)
                error(SYSTEM, "out of memory in salvage");
        for (y = 0; y < vresolu; y++) {
                if (freadcolrs(scanline, hresolu, fp) < 0)
                        break;
                if (fwritecolrs(scanline, hresolu, stdout) < 0)
                        goto writerr;
        }
        if (fflush(stdout) == EOF)
                goto writerr;
        free((char *)scanline);
        fclose(fp);
        unlink(oldfile);
        return(y);
writerr:
        error(SYSTEM, "write error in salvage");
}
Revision:	1.15
Committed:	Fri Jan 12 09:27:11 1990 UTC (34 years, 3 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.14:	+23 -35 lines
Log Message:	simplified residual calculation
#	User	Rev	Content
1	greg	1.1	/* Copyright (c) 1986 Regents of the University of California */
2
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* rpict.c - routines and variables for picture generation.
9			*
10			* 8/14/85
11			*/
12
13			#include "ray.h"
14
15			#ifdef BSD
16			#include <sys/time.h>
17			#include <sys/resource.h>
18	greg	1.14	#else
19			#include <signal.h>
20	greg	1.1	#endif
21
22			#include "view.h"
23
24			#include "random.h"
25
26	greg	1.12	VIEW ourview = STDVIEW; /* view parameters */
27			int hresolu = 512; /* horizontal resolution */
28			int vresolu = 512; /* vertical resolution */
29	greg	1.13	double pixaspect = 1.0; /* pixel aspect ratio */
30	greg	1.1
31			int psample = 4; /* pixel sample size */
32			double maxdiff = .05; /* max. difference for interpolation */
33	greg	1.3	double dstrpix = 0.67; /* square pixel distribution */
34	greg	1.1
35			double dstrsrc = 0.0; /* square source distribution */
36	greg	1.4	double shadthresh = .05; /* shadow threshold */
37	greg	1.5	double shadcert = .5; /* shadow certainty */
38	greg	1.1
39			int maxdepth = 6; /* maximum recursion depth */
40			double minweight = 5e-3; /* minimum ray weight */
41
42			COLOR ambval = BLKCOLOR; /* ambient value */
43			double ambacc = 0.2; /* ambient accuracy */
44	greg	1.6	int ambres = 32; /* ambient resolution */
45	greg	1.1	int ambdiv = 128; /* ambient divisions */
46			int ambssamp = 0; /* ambient super-samples */
47			int ambounce = 0; /* ambient bounces */
48			char amblist[128]; / ambient include/exclude list */
49			int ambincl = -1; /* include == 1, exclude == 0 */
50
51			int ralrm = 0; /* seconds between reports */
52
53			double pctdone = 0.0; /* percentage done */
54
55			extern long nrays; /* number of rays traced */
56
57			#define MAXDIV 32 /* maximum sample size */
58
59			#define pixjitter() (.5+dstrpix*(.5-frandom()))
60
61	greg	1.11	double pixvalue();
62	greg	1.1
63	greg	1.11
64	greg	1.1	quit(code) /* quit program */
65			int code;
66			{
67			if (code \|\| ralrm > 0) /* report status */
68			report();
69
70			exit(code);
71			}
72
73
74			report() /* report progress */
75			{
76			#ifdef BSD
77			struct rusage rubuf;
78			double t;
79
80			getrusage(RUSAGE_SELF, &rubuf);
81			t = (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
82			t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;
83			getrusage(RUSAGE_CHILDREN, &rubuf);
84			t += (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
85			t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;
86
87			sprintf(errmsg, "%ld rays, %4.2f%% done after %5.4f CPU hours\n",
88			nrays, pctdone, t/3600.0);
89			#else
90	greg	1.14	signal(SIGALRM, report);
91	greg	1.1	sprintf(errmsg, "%ld rays, %4.2f%% done\n", nrays, pctdone);
92			#endif
93			eputs(errmsg);
94
95			if (ralrm > 0)
96			alarm(ralrm);
97			}
98
99
100	greg	1.11	render(zfile, oldfile) /* render the scene */
101			char zfile, oldfile;
102	greg	1.1	{
103			COLOR scanbar[MAXDIV+1]; / scanline arrays of pixel values */
104	greg	1.11	float zbar[MAXDIV+1]; / z values */
105	greg	1.1	int ypos; /* current scanline */
106	greg	1.15	int ystep; /* current y step size */
107	greg	1.11	FILE *zfp;
108	greg	1.1	COLOR *colptr;
109	greg	1.11	float *zptr;
110	greg	1.1	register int i;
111	greg	1.10	/* check sampling */
112			if (psample < 1)
113	greg	1.1	psample = 1;
114	greg	1.10	else if (psample > MAXDIV)
115			psample = MAXDIV;
116	greg	1.9	/* allocate scanlines */
117	greg	1.1	for (i = 0; i <= psample; i++) {
118	greg	1.12	scanbar[i] = (COLOR )malloc(hresolusizeof(COLOR));
119	greg	1.1	if (scanbar[i] == NULL)
120	greg	1.11	goto memerr;
121	greg	1.1	}
122	greg	1.11	/* open z file */
123			if (zfile != NULL) {
124			if ((zfp = fopen(zfile, "a+")) == NULL) {
125			sprintf(errmsg, "cannot open z file \"%s\"", zfile);
126			error(SYSTEM, errmsg);
127			}
128			for (i = 0; i <= psample; i++) {
129	greg	1.12	zbar[i] = (float )malloc(hresolusizeof(float));
130	greg	1.11	if (zbar[i] == NULL)
131			goto memerr;
132			}
133			} else {
134			zfp = NULL;
135			for (i = 0; i <= psample; i++)
136			zbar[i] = NULL;
137			}
138	greg	1.1	/* write out boundaries */
139	greg	1.12	fputresolu(YMAJOR\|YDECR, hresolu, vresolu, stdout);
140	greg	1.10	/* recover file and compute first */
141	greg	1.11	i = salvage(oldfile);
142	greg	1.12	if (zfp != NULL && fseek(zfp, (long)ihresolusizeof(float), 0) == EOF)
143	greg	1.11	error(SYSTEM, "z file seek error in render");
144	greg	1.12	ypos = vresolu-1 - i;
145			fillscanline(scanbar[0], zbar[0], hresolu, ypos, psample);
146	greg	1.15	ystep = psample;
147	greg	1.10	/* compute scanlines */
148	greg	1.15	for (ypos -= ystep; ypos > -ystep; ypos -= ystep) {
149			/* record progress */
150			pctdone = 100.0*(vresolu-ypos-ystep)/vresolu;
151			/* bottom adjust? */
152			if (ypos < 0) {
153			ystep += ypos;
154			ypos = 0;
155			}
156			colptr = scanbar[ystep]; /* move base to top */
157			scanbar[ystep] = scanbar[0];
158	greg	1.1	scanbar[0] = colptr;
159	greg	1.15	zptr = zbar[ystep];
160			zbar[ystep] = zbar[0];
161	greg	1.11	zbar[0] = zptr;
162	greg	1.10	/* fill base line */
163	greg	1.12	fillscanline(scanbar[0], zbar[0], hresolu, ypos, psample);
164	greg	1.10	/* fill bar */
165	greg	1.15	fillscanbar(scanbar, zbar, hresolu, ypos, ystep);
166	greg	1.10	/* write it out */
167	greg	1.15	for (i = ystep; i > 0; i--) {
168	greg	1.12	if (zfp != NULL && fwrite(zbar[i],sizeof(float),hresolu,zfp) != hresolu)
169	greg	1.1	goto writerr;
170	greg	1.12	if (fwritescan(scanbar[i],hresolu,stdout) < 0)
171	greg	1.11	goto writerr;
172			}
173			if (zfp != NULL && fflush(zfp) == EOF)
174			goto writerr;
175	greg	1.1	if (fflush(stdout) == EOF)
176			goto writerr;
177			}
178	greg	1.11	/* clean up */
179			if (zfp != NULL) {
180	greg	1.15	fwrite(zbar[0], sizeof(float), hresolu, zfp);
181	greg	1.11	if (fclose(zfp) == EOF)
182			goto writerr;
183			for (i = 0; i <= psample; i++)
184			free((char *)zbar[i]);
185			}
186	greg	1.15	fwritescan(scanbar[0], hresolu, stdout);
187	greg	1.10	if (fflush(stdout) == EOF)
188			goto writerr;
189	greg	1.1	for (i = 0; i <= psample; i++)
190			free((char *)scanbar[i]);
191	greg	1.11	pctdone = 100.0;
192	greg	1.1	return;
193			writerr:
194			error(SYSTEM, "write error in render");
195	greg	1.11	memerr:
196			error(SYSTEM, "out of memory in render");
197	greg	1.1	}
198
199
200	greg	1.11	fillscanline(scanline, zline, xres, y, xstep) /* fill scan line at y */
201	greg	1.1	register COLOR *scanline;
202	greg	1.11	register float *zline;
203	greg	1.9	int xres, y, xstep;
204	greg	1.1	{
205			int b = xstep;
206	greg	1.11	double z;
207	greg	1.1	register int i;
208
209	greg	1.11	z = pixvalue(scanline[0], 0, y);
210			if (zline) zline[0] = z;
211	greg	1.1
212	greg	1.15	for (i = xstep; i < xres-1+xstep; i += xstep) {
213			if (i >= xres) {
214			xstep += xres-1-i;
215			i = xres-1;
216			}
217	greg	1.11	z = pixvalue(scanline[i], i, y);
218			if (zline) zline[i] = z;
219	greg	1.1
220	greg	1.11	b = fillsample(scanline+i-xstep, zline ? zline+i-xstep : NULL,
221			i-xstep, y, xstep, 0, b/2);
222	greg	1.1	}
223			}
224
225
226	greg	1.11	fillscanbar(scanbar, zbar, xres, y, ysize) /* fill interior */
227	greg	1.1	register COLOR *scanbar[];
228	greg	1.11	register float *zbar[];
229	greg	1.9	int xres, y, ysize;
230	greg	1.1	{
231			COLOR vline[MAXDIV+1];
232	greg	1.11	float zline[MAXDIV+1];
233	greg	1.1	int b = ysize;
234	greg	1.11	double z;
235	greg	1.1	register int i, j;
236
237	greg	1.8	for (i = 0; i < xres; i++) {
238	greg	1.1
239			copycolor(vline[0], scanbar[0][i]);
240			copycolor(vline[ysize], scanbar[ysize][i]);
241	greg	1.11	if (zbar[0]) {
242			zline[0] = zbar[0][i];
243			zline[ysize] = zbar[ysize][i];
244			}
245	greg	1.1
246	greg	1.11	b = fillsample(vline, zbar[0] ? zline : NULL,
247			i, y, 0, ysize, b/2);
248	greg	1.1
249			for (j = 1; j < ysize; j++)
250			copycolor(scanbar[j][i], vline[j]);
251	greg	1.11	if (zbar[0])
252			for (j = 1; j < ysize; j++)
253			zbar[j][i] = zline[j];
254	greg	1.1	}
255			}
256
257
258			int
259	greg	1.11	fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */
260	greg	1.1	register COLOR *colline;
261	greg	1.11	register float *zline;
262	greg	1.1	int x, y;
263			int xlen, ylen;
264			int b;
265			{
266	greg	1.11	extern double fabs();
267	greg	1.1	double ratio;
268	greg	1.11	double z;
269	greg	1.1	COLOR ctmp;
270			int ncut;
271			register int len;
272
273			if (xlen > 0) /* x or y length is zero */
274			len = xlen;
275			else
276			len = ylen;
277
278			if (len <= 1) /* limit recursion */
279			return(0);
280
281	greg	1.11	if (b > 0
282			\|\| (zline && 2.fabs(zline[0]-zline[len]) > maxdiff(zline[0]+zline[len]))
283			\|\| bigdiff(colline[0], colline[len], maxdiff)) {
284	greg	1.1
285	greg	1.11	z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
286			if (zline) zline[len>>1] = z;
287	greg	1.1	ncut = 1;
288
289			} else { /* interpolate */
290
291			copycolor(colline[len>>1], colline[len]);
292			ratio = (double)(len>>1) / len;
293			scalecolor(colline[len>>1], ratio);
294	greg	1.11	if (zline) zline[len>>1] = zline[len] * ratio;
295			ratio = 1.0 - ratio;
296	greg	1.1	copycolor(ctmp, colline[0]);
297			scalecolor(ctmp, ratio);
298			addcolor(colline[len>>1], ctmp);
299	greg	1.11	if (zline) zline[len>>1] += zline[0] * ratio;
300	greg	1.1	ncut = 0;
301			}
302			/* recurse */
303	greg	1.11	ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
304	greg	1.1
305	greg	1.11	ncut += fillsample(colline+(len>>1), zline ? zline+(len>>1) : NULL,
306			x+(xlen>>1), y+(ylen>>1),
307			xlen-(xlen>>1), ylen-(ylen>>1), b/2);
308	greg	1.1
309			return(ncut);
310			}
311
312
313	greg	1.11	double
314	greg	1.1	pixvalue(col, x, y) /* compute pixel value */
315			COLOR col; /* returned color */
316			int x, y; /* pixel position */
317			{
318			static RAY thisray; /* our ray for this pixel */
319
320	greg	1.12	viewray(thisray.rorg, thisray.rdir, &ourview,
321			(x+pixjitter())/hresolu, (y+pixjitter())/vresolu);
322	greg	1.1
323			rayorigin(&thisray, NULL, PRIMARY, 1.0);
324
325			rayvalue(&thisray); /* trace ray */
326
327			copycolor(col, thisray.rcol); /* return color */
328	greg	1.11
329			return(thisray.rot); /* return distance */
330	greg	1.1	}
331
332
333			int
334			salvage(oldfile) /* salvage scanlines from killed program */
335			char *oldfile;
336			{
337			COLR *scanline;
338			FILE *fp;
339			int x, y;
340
341			if (oldfile == NULL)
342			return(0);
343	greg	1.9
344			if ((fp = fopen(oldfile, "r")) == NULL) {
345	greg	1.1	sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
346			error(WARNING, errmsg);
347			return(0);
348			}
349			/* discard header */
350			getheader(fp, NULL);
351			/* get picture size */
352	greg	1.7	if (fgetresolu(&x, &y, fp) != (YMAJOR\|YDECR)) {
353	greg	1.2	sprintf(errmsg, "bad recover file \"%s\"", oldfile);
354			error(WARNING, errmsg);
355	greg	1.1	fclose(fp);
356			return(0);
357			}
358
359	greg	1.12	if (x != hresolu \|\| y != vresolu) {
360	greg	1.1	sprintf(errmsg, "resolution mismatch in recover file \"%s\"",
361			oldfile);
362			error(USER, errmsg);
363			}
364
365	greg	1.12	scanline = (COLR )malloc(hresolusizeof(COLR));
366	greg	1.1	if (scanline == NULL)
367			error(SYSTEM, "out of memory in salvage");
368	greg	1.12	for (y = 0; y < vresolu; y++) {
369			if (freadcolrs(scanline, hresolu, fp) < 0)
370	greg	1.1	break;
371	greg	1.12	if (fwritecolrs(scanline, hresolu, stdout) < 0)
372	greg	1.1	goto writerr;
373			}
374			if (fflush(stdout) == EOF)
375			goto writerr;
376			free((char *)scanline);
377			fclose(fp);
378			unlink(oldfile);
379			return(y);
380			writerr:
381			error(SYSTEM, "write error in salvage");
382			}