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>
#endif

#include  "view.h"

#include  "random.h"

VIEW  ourview = STDVIEW;                /* view parameters */
int  hresolu = 512;                     /* horizontal resolution */
int  vresolu = 512;                     /* vertical resolution */

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
        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 */
        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);
                                                /* compute scanlines */
        for (ypos -= psample; ypos >= 0; ypos -= psample) {
        
                pctdone = 100.0*(vresolu-ypos-psample)/vresolu;

                colptr = scanbar[psample];              /* move base to top */
                scanbar[psample] = scanbar[0];
                scanbar[0] = colptr;
                zptr = zbar[psample];
                zbar[psample] = zbar[0];
                zbar[0] = zptr;
                                                        /* fill base line */
                fillscanline(scanbar[0], zbar[0], hresolu, ypos, psample);
                                                        /* fill bar */
                fillscanbar(scanbar, zbar, hresolu, ypos, psample);
                                                        /* write it out */
                for (i = psample; 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;
        }
                                                /* compute residual */
        colptr = scanbar[psample];
        scanbar[psample] = scanbar[0];
        scanbar[0] = colptr;
        zptr = zbar[psample];
        zbar[psample] = zbar[0];
        zbar[0] = zptr;
        if (ypos > -psample) {
                fillscanline(scanbar[-ypos], zbar[-ypos], hresolu, 0, psample);
                fillscanbar(scanbar-ypos, zbar-ypos, hresolu, 0, psample+ypos);
        }
        for (i = psample; i+ypos >= 0; i--) {
                if (zfp != NULL && fwrite(zbar[i],sizeof(float),hresolu,zfp) != hresolu)
                        goto writerr;
                if (fwritescan(scanbar[i], hresolu, stdout) < 0)
                        goto writerr;
        }
                                                /* clean up */
        if (zfp != NULL) {
                if (fclose(zfp) == EOF)
                        goto writerr;
                for (i = 0; i <= psample; i++)
                        free((char *)zbar[i]);
        }
        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; i += xstep) {
        
                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);
        }
        if (i-xstep < xres-1) {
                z = pixvalue(scanline[xres-1], xres-1, y);
                if (zline) zline[xres-1] = z;
                fillsample(scanline+i-xstep, zline ? zline+i-xstep : NULL,
                                i-xstep, y, xres-1-(i-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:	1.12
Committed:	Mon Jan 8 13:38:01 1990 UTC (34 years, 3 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.11:	+25 -25 lines
Log Message:	Changed handling of view parameters
#	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			#endif
19
20			#include "view.h"
21
22			#include "random.h"
23
24	greg	1.12	VIEW ourview = STDVIEW; /* view parameters */
25			int hresolu = 512; /* horizontal resolution */
26			int vresolu = 512; /* vertical resolution */
27	greg	1.1
28			int psample = 4; /* pixel sample size */
29			double maxdiff = .05; /* max. difference for interpolation */
30	greg	1.3	double dstrpix = 0.67; /* square pixel distribution */
31	greg	1.1
32			double dstrsrc = 0.0; /* square source distribution */
33	greg	1.4	double shadthresh = .05; /* shadow threshold */
34	greg	1.5	double shadcert = .5; /* shadow certainty */
35	greg	1.1
36			int maxdepth = 6; /* maximum recursion depth */
37			double minweight = 5e-3; /* minimum ray weight */
38
39			COLOR ambval = BLKCOLOR; /* ambient value */
40			double ambacc = 0.2; /* ambient accuracy */
41	greg	1.6	int ambres = 32; /* ambient resolution */
42	greg	1.1	int ambdiv = 128; /* ambient divisions */
43			int ambssamp = 0; /* ambient super-samples */
44			int ambounce = 0; /* ambient bounces */
45			char amblist[128]; / ambient include/exclude list */
46			int ambincl = -1; /* include == 1, exclude == 0 */
47
48			int ralrm = 0; /* seconds between reports */
49
50			double pctdone = 0.0; /* percentage done */
51
52			extern long nrays; /* number of rays traced */
53
54			#define MAXDIV 32 /* maximum sample size */
55
56			#define pixjitter() (.5+dstrpix*(.5-frandom()))
57
58	greg	1.11	double pixvalue();
59	greg	1.1
60	greg	1.11
61	greg	1.1	quit(code) /* quit program */
62			int code;
63			{
64			if (code \|\| ralrm > 0) /* report status */
65			report();
66
67			exit(code);
68			}
69
70
71			report() /* report progress */
72			{
73			#ifdef BSD
74			struct rusage rubuf;
75			double t;
76
77			getrusage(RUSAGE_SELF, &rubuf);
78			t = (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
79			t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;
80			getrusage(RUSAGE_CHILDREN, &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
84			sprintf(errmsg, "%ld rays, %4.2f%% done after %5.4f CPU hours\n",
85			nrays, pctdone, t/3600.0);
86			#else
87			sprintf(errmsg, "%ld rays, %4.2f%% done\n", nrays, pctdone);
88			#endif
89			eputs(errmsg);
90
91			if (ralrm > 0)
92			alarm(ralrm);
93			}
94
95
96	greg	1.11	render(zfile, oldfile) /* render the scene */
97			char zfile, oldfile;
98	greg	1.1	{
99			COLOR scanbar[MAXDIV+1]; / scanline arrays of pixel values */
100	greg	1.11	float zbar[MAXDIV+1]; / z values */
101	greg	1.1	int ypos; /* current scanline */
102	greg	1.11	FILE *zfp;
103	greg	1.1	COLOR *colptr;
104	greg	1.11	float *zptr;
105	greg	1.1	register int i;
106	greg	1.10	/* check sampling */
107			if (psample < 1)
108	greg	1.1	psample = 1;
109	greg	1.10	else if (psample > MAXDIV)
110			psample = MAXDIV;
111	greg	1.9	/* allocate scanlines */
112	greg	1.1	for (i = 0; i <= psample; i++) {
113	greg	1.12	scanbar[i] = (COLOR )malloc(hresolusizeof(COLOR));
114	greg	1.1	if (scanbar[i] == NULL)
115	greg	1.11	goto memerr;
116	greg	1.1	}
117	greg	1.11	/* open z file */
118			if (zfile != NULL) {
119			if ((zfp = fopen(zfile, "a+")) == NULL) {
120			sprintf(errmsg, "cannot open z file \"%s\"", zfile);
121			error(SYSTEM, errmsg);
122			}
123			for (i = 0; i <= psample; i++) {
124	greg	1.12	zbar[i] = (float )malloc(hresolusizeof(float));
125	greg	1.11	if (zbar[i] == NULL)
126			goto memerr;
127			}
128			} else {
129			zfp = NULL;
130			for (i = 0; i <= psample; i++)
131			zbar[i] = NULL;
132			}
133	greg	1.1	/* write out boundaries */
134	greg	1.12	fputresolu(YMAJOR\|YDECR, hresolu, vresolu, stdout);
135	greg	1.10	/* recover file and compute first */
136	greg	1.11	i = salvage(oldfile);
137	greg	1.12	if (zfp != NULL && fseek(zfp, (long)ihresolusizeof(float), 0) == EOF)
138	greg	1.11	error(SYSTEM, "z file seek error in render");
139	greg	1.12	ypos = vresolu-1 - i;
140			fillscanline(scanbar[0], zbar[0], hresolu, ypos, psample);
141	greg	1.10	/* compute scanlines */
142			for (ypos -= psample; ypos >= 0; ypos -= psample) {
143	greg	1.1
144	greg	1.12	pctdone = 100.0*(vresolu-ypos-psample)/vresolu;
145	greg	1.9
146			colptr = scanbar[psample]; /* move base to top */
147	greg	1.1	scanbar[psample] = scanbar[0];
148			scanbar[0] = colptr;
149	greg	1.11	zptr = zbar[psample];
150			zbar[psample] = zbar[0];
151			zbar[0] = zptr;
152	greg	1.10	/* fill base line */
153	greg	1.12	fillscanline(scanbar[0], zbar[0], hresolu, ypos, psample);
154	greg	1.10	/* fill bar */
155	greg	1.12	fillscanbar(scanbar, zbar, hresolu, ypos, psample);
156	greg	1.10	/* write it out */
157	greg	1.11	for (i = psample; i > 0; i--) {
158	greg	1.12	if (zfp != NULL && fwrite(zbar[i],sizeof(float),hresolu,zfp) != hresolu)
159	greg	1.1	goto writerr;
160	greg	1.12	if (fwritescan(scanbar[i],hresolu,stdout) < 0)
161	greg	1.11	goto writerr;
162			}
163			if (zfp != NULL && fflush(zfp) == EOF)
164			goto writerr;
165	greg	1.1	if (fflush(stdout) == EOF)
166			goto writerr;
167			}
168	greg	1.10	/* compute residual */
169			colptr = scanbar[psample];
170			scanbar[psample] = scanbar[0];
171			scanbar[0] = colptr;
172	greg	1.11	zptr = zbar[psample];
173			zbar[psample] = zbar[0];
174			zbar[0] = zptr;
175	greg	1.10	if (ypos > -psample) {
176	greg	1.12	fillscanline(scanbar[-ypos], zbar[-ypos], hresolu, 0, psample);
177			fillscanbar(scanbar-ypos, zbar-ypos, hresolu, 0, psample+ypos);
178	greg	1.10	}
179	greg	1.11	for (i = psample; i+ypos >= 0; i--) {
180	greg	1.12	if (zfp != NULL && fwrite(zbar[i],sizeof(float),hresolu,zfp) != hresolu)
181	greg	1.11	goto writerr;
182	greg	1.12	if (fwritescan(scanbar[i], hresolu, stdout) < 0)
183	greg	1.10	goto writerr;
184	greg	1.11	}
185			/* clean up */
186			if (zfp != NULL) {
187			if (fclose(zfp) == EOF)
188			goto writerr;
189			for (i = 0; i <= psample; i++)
190			free((char *)zbar[i]);
191			}
192	greg	1.10	if (fflush(stdout) == EOF)
193			goto writerr;
194	greg	1.1	for (i = 0; i <= psample; i++)
195			free((char *)scanbar[i]);
196	greg	1.11	pctdone = 100.0;
197	greg	1.1	return;
198			writerr:
199			error(SYSTEM, "write error in render");
200	greg	1.11	memerr:
201			error(SYSTEM, "out of memory in render");
202	greg	1.1	}
203
204
205	greg	1.11	fillscanline(scanline, zline, xres, y, xstep) /* fill scan line at y */
206	greg	1.1	register COLOR *scanline;
207	greg	1.11	register float *zline;
208	greg	1.9	int xres, y, xstep;
209	greg	1.1	{
210			int b = xstep;
211	greg	1.11	double z;
212	greg	1.1	register int i;
213
214	greg	1.11	z = pixvalue(scanline[0], 0, y);
215			if (zline) zline[0] = z;
216	greg	1.1
217	greg	1.9	for (i = xstep; i < xres; i += xstep) {
218	greg	1.1
219	greg	1.11	z = pixvalue(scanline[i], i, y);
220			if (zline) zline[i] = z;
221	greg	1.1
222	greg	1.11	b = fillsample(scanline+i-xstep, zline ? zline+i-xstep : NULL,
223			i-xstep, y, xstep, 0, b/2);
224	greg	1.10	}
225			if (i-xstep < xres-1) {
226	greg	1.11	z = pixvalue(scanline[xres-1], xres-1, y);
227			if (zline) zline[xres-1] = z;
228			fillsample(scanline+i-xstep, zline ? zline+i-xstep : NULL,
229			i-xstep, y, xres-1-(i-xstep), 0, b/2);
230	greg	1.1	}
231			}
232
233
234	greg	1.11	fillscanbar(scanbar, zbar, xres, y, ysize) /* fill interior */
235	greg	1.1	register COLOR *scanbar[];
236	greg	1.11	register float *zbar[];
237	greg	1.9	int xres, y, ysize;
238	greg	1.1	{
239			COLOR vline[MAXDIV+1];
240	greg	1.11	float zline[MAXDIV+1];
241	greg	1.1	int b = ysize;
242	greg	1.11	double z;
243	greg	1.1	register int i, j;
244
245	greg	1.8	for (i = 0; i < xres; i++) {
246	greg	1.1
247			copycolor(vline[0], scanbar[0][i]);
248			copycolor(vline[ysize], scanbar[ysize][i]);
249	greg	1.11	if (zbar[0]) {
250			zline[0] = zbar[0][i];
251			zline[ysize] = zbar[ysize][i];
252			}
253	greg	1.1
254	greg	1.11	b = fillsample(vline, zbar[0] ? zline : NULL,
255			i, y, 0, ysize, b/2);
256	greg	1.1
257			for (j = 1; j < ysize; j++)
258			copycolor(scanbar[j][i], vline[j]);
259	greg	1.11	if (zbar[0])
260			for (j = 1; j < ysize; j++)
261			zbar[j][i] = zline[j];
262	greg	1.1	}
263			}
264
265
266			int
267	greg	1.11	fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */
268	greg	1.1	register COLOR *colline;
269	greg	1.11	register float *zline;
270	greg	1.1	int x, y;
271			int xlen, ylen;
272			int b;
273			{
274	greg	1.11	extern double fabs();
275	greg	1.1	double ratio;
276	greg	1.11	double z;
277	greg	1.1	COLOR ctmp;
278			int ncut;
279			register int len;
280
281			if (xlen > 0) /* x or y length is zero */
282			len = xlen;
283			else
284			len = ylen;
285
286			if (len <= 1) /* limit recursion */
287			return(0);
288
289	greg	1.11	if (b > 0
290			\|\| (zline && 2.fabs(zline[0]-zline[len]) > maxdiff(zline[0]+zline[len]))
291			\|\| bigdiff(colline[0], colline[len], maxdiff)) {
292	greg	1.1
293	greg	1.11	z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
294			if (zline) zline[len>>1] = z;
295	greg	1.1	ncut = 1;
296
297			} else { /* interpolate */
298
299			copycolor(colline[len>>1], colline[len]);
300			ratio = (double)(len>>1) / len;
301			scalecolor(colline[len>>1], ratio);
302	greg	1.11	if (zline) zline[len>>1] = zline[len] * ratio;
303			ratio = 1.0 - ratio;
304	greg	1.1	copycolor(ctmp, colline[0]);
305			scalecolor(ctmp, ratio);
306			addcolor(colline[len>>1], ctmp);
307	greg	1.11	if (zline) zline[len>>1] += zline[0] * ratio;
308	greg	1.1	ncut = 0;
309			}
310			/* recurse */
311	greg	1.11	ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
312	greg	1.1
313	greg	1.11	ncut += fillsample(colline+(len>>1), zline ? zline+(len>>1) : NULL,
314			x+(xlen>>1), y+(ylen>>1),
315			xlen-(xlen>>1), ylen-(ylen>>1), b/2);
316	greg	1.1
317			return(ncut);
318			}
319
320
321	greg	1.11	double
322	greg	1.1	pixvalue(col, x, y) /* compute pixel value */
323			COLOR col; /* returned color */
324			int x, y; /* pixel position */
325			{
326			static RAY thisray; /* our ray for this pixel */
327
328	greg	1.12	viewray(thisray.rorg, thisray.rdir, &ourview,
329			(x+pixjitter())/hresolu, (y+pixjitter())/vresolu);
330	greg	1.1
331			rayorigin(&thisray, NULL, PRIMARY, 1.0);
332
333			rayvalue(&thisray); /* trace ray */
334
335			copycolor(col, thisray.rcol); /* return color */
336	greg	1.11
337			return(thisray.rot); /* return distance */
338	greg	1.1	}
339
340
341			int
342			salvage(oldfile) /* salvage scanlines from killed program */
343			char *oldfile;
344			{
345			COLR *scanline;
346			FILE *fp;
347			int x, y;
348
349			if (oldfile == NULL)
350			return(0);
351	greg	1.9
352			if ((fp = fopen(oldfile, "r")) == NULL) {
353	greg	1.1	sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
354			error(WARNING, errmsg);
355			return(0);
356			}
357			/* discard header */
358			getheader(fp, NULL);
359			/* get picture size */
360	greg	1.7	if (fgetresolu(&x, &y, fp) != (YMAJOR\|YDECR)) {
361	greg	1.2	sprintf(errmsg, "bad recover file \"%s\"", oldfile);
362			error(WARNING, errmsg);
363	greg	1.1	fclose(fp);
364			return(0);
365			}
366
367	greg	1.12	if (x != hresolu \|\| y != vresolu) {
368	greg	1.1	sprintf(errmsg, "resolution mismatch in recover file \"%s\"",
369			oldfile);
370			error(USER, errmsg);
371			}
372
373	greg	1.12	scanline = (COLR )malloc(hresolusizeof(COLR));
374	greg	1.1	if (scanline == NULL)
375			error(SYSTEM, "out of memory in salvage");
376	greg	1.12	for (y = 0; y < vresolu; y++) {
377			if (freadcolrs(scanline, hresolu, fp) < 0)
378	greg	1.1	break;
379	greg	1.12	if (fwritecolrs(scanline, hresolu, stdout) < 0)
380	greg	1.1	goto writerr;
381			}
382			if (fflush(stdout) == EOF)
383			goto writerr;
384			free((char *)scanline);
385			fclose(fp);
386			unlink(oldfile);
387			return(y);
388			writerr:
389			error(SYSTEM, "write error in salvage");
390			}