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  <fcntl.h>

#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;
{
        extern long  lseek();
        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 */
        int  zfd;
        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 ((zfd = open(zfile, O_WRONLY|O_CREAT, 0666)) == -1) {
                        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 {
                zfd = -1;
                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 (zfd != -1 && lseek(zfd, (long)i*hresolu*sizeof(float), 0) == -1)
                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 (zfd != -1 && write(zfd, (char *)zbar[i],
                                        hresolu*sizeof(float))
                                        < hresolu*sizeof(float))
                                goto writerr;
                        if (fwritescan(scanbar[i], hresolu, stdout) < 0)
                                goto writerr;
                }
                if (fflush(stdout) == EOF)
                        goto writerr;
        }
                                                /* clean up */
        if (zfd != -1) {
                if (write(zfd, (char *)zbar[0], hresolu*sizeof(float))
                                < hresolu*sizeof(float))
                        goto writerr;
                close(zfd);
                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:	1.18
Committed:	Wed Feb 21 12:39:37 1990 UTC (34 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.17:	+1 -1 lines
Log Message:	changed include of fcntl.h
#	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	greg	1.18	#include <fcntl.h>
22	greg	1.1
23			#include "view.h"
24
25			#include "random.h"
26
27	greg	1.12	VIEW ourview = STDVIEW; /* view parameters */
28			int hresolu = 512; /* horizontal resolution */
29			int vresolu = 512; /* vertical resolution */
30	greg	1.13	double pixaspect = 1.0; /* pixel aspect ratio */
31	greg	1.1
32			int psample = 4; /* pixel sample size */
33			double maxdiff = .05; /* max. difference for interpolation */
34	greg	1.3	double dstrpix = 0.67; /* square pixel distribution */
35	greg	1.1
36			double dstrsrc = 0.0; /* square source distribution */
37	greg	1.4	double shadthresh = .05; /* shadow threshold */
38	greg	1.5	double shadcert = .5; /* shadow certainty */
39	greg	1.1
40			int maxdepth = 6; /* maximum recursion depth */
41			double minweight = 5e-3; /* minimum ray weight */
42
43			COLOR ambval = BLKCOLOR; /* ambient value */
44			double ambacc = 0.2; /* ambient accuracy */
45	greg	1.6	int ambres = 32; /* ambient resolution */
46	greg	1.1	int ambdiv = 128; /* ambient divisions */
47			int ambssamp = 0; /* ambient super-samples */
48			int ambounce = 0; /* ambient bounces */
49			char amblist[128]; / ambient include/exclude list */
50			int ambincl = -1; /* include == 1, exclude == 0 */
51
52			int ralrm = 0; /* seconds between reports */
53
54			double pctdone = 0.0; /* percentage done */
55
56			extern long nrays; /* number of rays traced */
57
58			#define MAXDIV 32 /* maximum sample size */
59
60			#define pixjitter() (.5+dstrpix*(.5-frandom()))
61
62	greg	1.11	double pixvalue();
63	greg	1.1
64	greg	1.11
65	greg	1.1	quit(code) /* quit program */
66			int code;
67			{
68			if (code \|\| ralrm > 0) /* report status */
69			report();
70
71			exit(code);
72			}
73
74
75			report() /* report progress */
76			{
77			#ifdef BSD
78			struct rusage rubuf;
79			double t;
80
81			getrusage(RUSAGE_SELF, &rubuf);
82			t = (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
83			t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;
84			getrusage(RUSAGE_CHILDREN, &rubuf);
85			t += (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
86			t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;
87
88			sprintf(errmsg, "%ld rays, %4.2f%% done after %5.4f CPU hours\n",
89			nrays, pctdone, t/3600.0);
90			#else
91	greg	1.14	signal(SIGALRM, report);
92	greg	1.1	sprintf(errmsg, "%ld rays, %4.2f%% done\n", nrays, pctdone);
93			#endif
94			eputs(errmsg);
95
96			if (ralrm > 0)
97			alarm(ralrm);
98			}
99
100
101	greg	1.11	render(zfile, oldfile) /* render the scene */
102			char zfile, oldfile;
103	greg	1.1	{
104	greg	1.16	extern long lseek();
105	greg	1.1	COLOR scanbar[MAXDIV+1]; / scanline arrays of pixel values */
106	greg	1.11	float zbar[MAXDIV+1]; / z values */
107	greg	1.1	int ypos; /* current scanline */
108	greg	1.15	int ystep; /* current y step size */
109	greg	1.16	int zfd;
110	greg	1.1	COLOR *colptr;
111	greg	1.11	float *zptr;
112	greg	1.1	register int i;
113	greg	1.10	/* check sampling */
114			if (psample < 1)
115	greg	1.1	psample = 1;
116	greg	1.10	else if (psample > MAXDIV)
117			psample = MAXDIV;
118	greg	1.9	/* allocate scanlines */
119	greg	1.1	for (i = 0; i <= psample; i++) {
120	greg	1.12	scanbar[i] = (COLOR )malloc(hresolusizeof(COLOR));
121	greg	1.1	if (scanbar[i] == NULL)
122	greg	1.11	goto memerr;
123	greg	1.1	}
124	greg	1.11	/* open z file */
125			if (zfile != NULL) {
126	greg	1.16	if ((zfd = open(zfile, O_WRONLY\|O_CREAT, 0666)) == -1) {
127	greg	1.11	sprintf(errmsg, "cannot open z file \"%s\"", zfile);
128			error(SYSTEM, errmsg);
129			}
130			for (i = 0; i <= psample; i++) {
131	greg	1.12	zbar[i] = (float )malloc(hresolusizeof(float));
132	greg	1.11	if (zbar[i] == NULL)
133			goto memerr;
134			}
135			} else {
136	greg	1.16	zfd = -1;
137	greg	1.11	for (i = 0; i <= psample; i++)
138			zbar[i] = NULL;
139			}
140	greg	1.1	/* write out boundaries */
141	greg	1.12	fputresolu(YMAJOR\|YDECR, hresolu, vresolu, stdout);
142	greg	1.10	/* recover file and compute first */
143	greg	1.11	i = salvage(oldfile);
144	greg	1.16	if (zfd != -1 && lseek(zfd, (long)ihresolusizeof(float), 0) == -1)
145	greg	1.11	error(SYSTEM, "z file seek error in render");
146	greg	1.12	ypos = vresolu-1 - i;
147			fillscanline(scanbar[0], zbar[0], hresolu, ypos, psample);
148	greg	1.15	ystep = psample;
149	greg	1.10	/* compute scanlines */
150	greg	1.15	for (ypos -= ystep; ypos > -ystep; ypos -= ystep) {
151			/* record progress */
152			pctdone = 100.0*(vresolu-ypos-ystep)/vresolu;
153			/* bottom adjust? */
154			if (ypos < 0) {
155			ystep += ypos;
156			ypos = 0;
157			}
158			colptr = scanbar[ystep]; /* move base to top */
159			scanbar[ystep] = scanbar[0];
160	greg	1.1	scanbar[0] = colptr;
161	greg	1.15	zptr = zbar[ystep];
162			zbar[ystep] = zbar[0];
163	greg	1.11	zbar[0] = zptr;
164	greg	1.10	/* fill base line */
165	greg	1.12	fillscanline(scanbar[0], zbar[0], hresolu, ypos, psample);
166	greg	1.10	/* fill bar */
167	greg	1.15	fillscanbar(scanbar, zbar, hresolu, ypos, ystep);
168	greg	1.10	/* write it out */
169	greg	1.15	for (i = ystep; i > 0; i--) {
170	greg	1.17	if (zfd != -1 && write(zfd, (char *)zbar[i],
171			hresolu*sizeof(float))
172	greg	1.16	< hresolu*sizeof(float))
173	greg	1.1	goto writerr;
174	greg	1.17	if (fwritescan(scanbar[i], hresolu, stdout) < 0)
175	greg	1.11	goto writerr;
176			}
177	greg	1.1	if (fflush(stdout) == EOF)
178			goto writerr;
179			}
180	greg	1.11	/* clean up */
181	greg	1.16	if (zfd != -1) {
182	greg	1.17	if (write(zfd, (char )zbar[0], hresolusizeof(float))
183	greg	1.16	< hresolu*sizeof(float))
184	greg	1.11	goto writerr;
185	greg	1.16	close(zfd);
186	greg	1.11	for (i = 0; i <= psample; i++)
187			free((char *)zbar[i]);
188			}
189	greg	1.15	fwritescan(scanbar[0], hresolu, stdout);
190	greg	1.10	if (fflush(stdout) == EOF)
191			goto writerr;
192	greg	1.1	for (i = 0; i <= psample; i++)
193			free((char *)scanbar[i]);
194	greg	1.11	pctdone = 100.0;
195	greg	1.1	return;
196			writerr:
197			error(SYSTEM, "write error in render");
198	greg	1.11	memerr:
199			error(SYSTEM, "out of memory in render");
200	greg	1.1	}
201
202
203	greg	1.11	fillscanline(scanline, zline, xres, y, xstep) /* fill scan line at y */
204	greg	1.1	register COLOR *scanline;
205	greg	1.11	register float *zline;
206	greg	1.9	int xres, y, xstep;
207	greg	1.1	{
208			int b = xstep;
209	greg	1.11	double z;
210	greg	1.1	register int i;
211
212	greg	1.11	z = pixvalue(scanline[0], 0, y);
213			if (zline) zline[0] = z;
214	greg	1.1
215	greg	1.15	for (i = xstep; i < xres-1+xstep; i += xstep) {
216			if (i >= xres) {
217			xstep += xres-1-i;
218			i = xres-1;
219			}
220	greg	1.11	z = pixvalue(scanline[i], i, y);
221			if (zline) zline[i] = z;
222	greg	1.1
223	greg	1.11	b = fillsample(scanline+i-xstep, zline ? zline+i-xstep : NULL,
224			i-xstep, y, xstep, 0, b/2);
225	greg	1.1	}
226			}
227
228
229	greg	1.11	fillscanbar(scanbar, zbar, xres, y, ysize) /* fill interior */
230	greg	1.1	register COLOR *scanbar[];
231	greg	1.11	register float *zbar[];
232	greg	1.9	int xres, y, ysize;
233	greg	1.1	{
234			COLOR vline[MAXDIV+1];
235	greg	1.11	float zline[MAXDIV+1];
236	greg	1.1	int b = ysize;
237	greg	1.11	double z;
238	greg	1.1	register int i, j;
239
240	greg	1.8	for (i = 0; i < xres; i++) {
241	greg	1.1
242			copycolor(vline[0], scanbar[0][i]);
243			copycolor(vline[ysize], scanbar[ysize][i]);
244	greg	1.11	if (zbar[0]) {
245			zline[0] = zbar[0][i];
246			zline[ysize] = zbar[ysize][i];
247			}
248	greg	1.1
249	greg	1.11	b = fillsample(vline, zbar[0] ? zline : NULL,
250			i, y, 0, ysize, b/2);
251	greg	1.1
252			for (j = 1; j < ysize; j++)
253			copycolor(scanbar[j][i], vline[j]);
254	greg	1.11	if (zbar[0])
255			for (j = 1; j < ysize; j++)
256			zbar[j][i] = zline[j];
257	greg	1.1	}
258			}
259
260
261			int
262	greg	1.11	fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */
263	greg	1.1	register COLOR *colline;
264	greg	1.11	register float *zline;
265	greg	1.1	int x, y;
266			int xlen, ylen;
267			int b;
268			{
269	greg	1.11	extern double fabs();
270	greg	1.1	double ratio;
271	greg	1.11	double z;
272	greg	1.1	COLOR ctmp;
273			int ncut;
274			register int len;
275
276			if (xlen > 0) /* x or y length is zero */
277			len = xlen;
278			else
279			len = ylen;
280
281			if (len <= 1) /* limit recursion */
282			return(0);
283
284	greg	1.11	if (b > 0
285			\|\| (zline && 2.fabs(zline[0]-zline[len]) > maxdiff(zline[0]+zline[len]))
286			\|\| bigdiff(colline[0], colline[len], maxdiff)) {
287	greg	1.1
288	greg	1.11	z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
289			if (zline) zline[len>>1] = z;
290	greg	1.1	ncut = 1;
291
292			} else { /* interpolate */
293
294			copycolor(colline[len>>1], colline[len]);
295			ratio = (double)(len>>1) / len;
296			scalecolor(colline[len>>1], ratio);
297	greg	1.11	if (zline) zline[len>>1] = zline[len] * ratio;
298			ratio = 1.0 - ratio;
299	greg	1.1	copycolor(ctmp, colline[0]);
300			scalecolor(ctmp, ratio);
301			addcolor(colline[len>>1], ctmp);
302	greg	1.11	if (zline) zline[len>>1] += zline[0] * ratio;
303	greg	1.1	ncut = 0;
304			}
305			/* recurse */
306	greg	1.11	ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
307	greg	1.1
308	greg	1.11	ncut += fillsample(colline+(len>>1), zline ? zline+(len>>1) : NULL,
309			x+(xlen>>1), y+(ylen>>1),
310			xlen-(xlen>>1), ylen-(ylen>>1), b/2);
311	greg	1.1
312			return(ncut);
313			}
314
315
316	greg	1.11	double
317	greg	1.1	pixvalue(col, x, y) /* compute pixel value */
318			COLOR col; /* returned color */
319			int x, y; /* pixel position */
320			{
321			static RAY thisray; /* our ray for this pixel */
322
323	greg	1.12	viewray(thisray.rorg, thisray.rdir, &ourview,
324			(x+pixjitter())/hresolu, (y+pixjitter())/vresolu);
325	greg	1.1
326			rayorigin(&thisray, NULL, PRIMARY, 1.0);
327
328			rayvalue(&thisray); /* trace ray */
329
330			copycolor(col, thisray.rcol); /* return color */
331	greg	1.11
332			return(thisray.rot); /* return distance */
333	greg	1.1	}
334
335
336			int
337			salvage(oldfile) /* salvage scanlines from killed program */
338			char *oldfile;
339			{
340			COLR *scanline;
341			FILE *fp;
342			int x, y;
343
344			if (oldfile == NULL)
345			return(0);
346	greg	1.9
347			if ((fp = fopen(oldfile, "r")) == NULL) {
348	greg	1.1	sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
349			error(WARNING, errmsg);
350			return(0);
351			}
352			/* discard header */
353			getheader(fp, NULL);
354			/* get picture size */
355	greg	1.7	if (fgetresolu(&x, &y, fp) != (YMAJOR\|YDECR)) {
356	greg	1.2	sprintf(errmsg, "bad recover file \"%s\"", oldfile);
357			error(WARNING, errmsg);
358	greg	1.1	fclose(fp);
359			return(0);
360			}
361
362	greg	1.12	if (x != hresolu \|\| y != vresolu) {
363	greg	1.1	sprintf(errmsg, "resolution mismatch in recover file \"%s\"",
364			oldfile);
365			error(USER, errmsg);
366			}
367
368	greg	1.12	scanline = (COLR )malloc(hresolusizeof(COLR));
369	greg	1.1	if (scanline == NULL)
370			error(SYSTEM, "out of memory in salvage");
371	greg	1.12	for (y = 0; y < vresolu; y++) {
372			if (freadcolrs(scanline, hresolu, fp) < 0)
373	greg	1.1	break;
374	greg	1.12	if (fwritecolrs(scanline, hresolu, stdout) < 0)
375	greg	1.1	goto writerr;
376			}
377			if (fflush(stdout) == EOF)
378			goto writerr;
379			free((char *)scanline);
380			fclose(fp);
381			unlink(oldfile);
382			return(y);
383			writerr:
384			error(SYSTEM, "write error in salvage");
385			}