src/rt/rpict.c

/* Copyright (c) 1991 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  <signal.h>
#include  <fcntl.h>

#include  "view.h"

#include  "resolu.h"

#include  "random.h"

int  dimlist[MAXDIM];                   /* sampling dimensions */
int  ndims = 0;                         /* number of sampling dimensions */
int  samplendx;                         /* sample index number */

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  directrelay = 1;                   /* number of source relays */
int  vspretest = 512;                   /* virtual source pretest density */
int  directinvis = 0;                   /* sources invisible? */
double  srcsizerat = .25;               /* maximum ratio source size/dist. */

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 */

long  tlastrept = 0L;                   /* time at last report */

extern long  time();
extern long  tstart;                    /* starting time */

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

#define  MAXDIV         15              /* 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);
}


#ifdef BSD
report()                /* report progress */
{
        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);
        eputs(errmsg);
        tlastrept = time((long *)0);
}
#else
report()                /* report progress */
{
        signal(SIGALRM, report);
        tlastrept = time((long *)0);
        sprintf(errmsg, "%ld rays, %4.2f%% done after %5.4f hours\n",
                        nrays, pctdone, (tlastrept-tstart)/3600.0);
        eputs(errmsg);
}
#endif


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  hstep;                     /* h step size */
        int  zfd;
        COLOR  *colptr;
        float  *zptr;
        register int  i;
                                        /* check sampling */
        if (psample < 1)
                psample = 1;
        else if (psample > MAXDIV) {
                sprintf(errmsg, "pixel sampling reduced from %d to %d",
                                psample, MAXDIV);
                error(WARNING, errmsg);
                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 */
        fprtresolu(hresolu, vresolu, stdout);
                                        /* recover file and compute first */
        i = salvage(oldfile);
        if (zfd != -1 && i > 0 &&
                        lseek(zfd, (long)i*hresolu*sizeof(float), 0) == -1)
                error(SYSTEM, "z file seek error in render");
        pctdone = 100.0*i/vresolu;
        if (ralrm > 0)                  /* report init stats */
                report();
#ifndef  BSD
        else
#endif
        signal(SIGALRM, report);
        ypos = vresolu-1 - i;
        hstep = (psample*140+49)/99;            /* quincunx sampling */
        ystep = (psample*99+70)/140;
        fillscanline(scanbar[0], zbar[0], hresolu, ypos, hstep);
                                                /* compute scanlines */
        for (ypos -= ystep; ypos > -ystep; ypos -= ystep) {
                                                        /* 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, hstep);
                                                        /* fill bar */
                fillscanbar(scanbar, zbar, hresolu, ypos, ystep);
                                                        /* write it out */
#ifndef  BSD
                signal(SIGALRM, SIG_IGN);       /* don't interrupt writes */
#endif
                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;
                                                        /* record progress */
                pctdone = 100.0*(vresolu-1-ypos)/vresolu;
                if (ralrm > 0 && time((long *)0) >= tlastrept+ralrm)
                        report();
#ifndef  BSD
                else
                        signal(SIGALRM, report);
#endif
        }
                                                /* clean up */
        if (zfd != -1) {
                if (write(zfd, (char *)zbar[0], hresolu*sizeof(float))
                                < hresolu*sizeof(float))
                        goto writerr;
                if (close(zfd) == -1)
                        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;
{
        static int  nc = 0;             /* number of calls */
        int  b = xstep;
        double  z;
        register int  i;
        
        z = pixvalue(scanline[0], 0, y);
        if (zline) zline[0] = z;
                                /* zig-zag start for quincunx pattern */
        for (i = nc++ & 1 ? xstep/2 : 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;
        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;

        if (viewray(thisray.rorg, thisray.rdir, &ourview,
                        (x+pixjitter())/hresolu, (y+pixjitter())/vresolu) < 0) {
                setcolor(col, 0.0, 0.0, 0.0);
                return(0.0);
        }

        rayorigin(&thisray, NULL, PRIMARY, 1.0);

        samplendx = pixnumber(x,y,hresolu,vresolu);     /* set pixel index */

        rayvalue(&thisray);                     /* trace ray */

        copycolor(col, thisray.rcol);           /* return color */
        
        return(thisray.rt);                     /* 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 (!fscnresolu(&x, &y, fp)) {
                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");
}


int
pixnumber(x, y, xres, yres)             /* compute pixel index (brushed) */
register int  x, y;
int  xres, yres;
{
        x -= y;
        while (x < 0)
                x += xres;
        return((((x>>2)*yres + y) << 2) + (x & 3));
}
Revision:	1.36
Committed:	Mon Nov 11 14:02:45 1991 UTC (32 years, 5 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.35:	+4 -2 lines
Log Message:	Improved handling of scanline ordering
#	User	Rev	Content
1	greg	1.24	/* Copyright (c) 1991 Regents of the University of California */
2	greg	1.1
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	1.34	#endif
19
20	greg	1.14	#include <signal.h>
21	greg	1.18	#include <fcntl.h>
22	greg	1.1
23			#include "view.h"
24
25	greg	1.36	#include "resolu.h"
26
27	greg	1.1	#include "random.h"
28
29	greg	1.25	int dimlist[MAXDIM]; /* sampling dimensions */
30			int ndims = 0; /* number of sampling dimensions */
31			int samplendx; /* sample index number */
32
33	greg	1.12	VIEW ourview = STDVIEW; /* view parameters */
34			int hresolu = 512; /* horizontal resolution */
35			int vresolu = 512; /* vertical resolution */
36	greg	1.13	double pixaspect = 1.0; /* pixel aspect ratio */
37	greg	1.1
38			int psample = 4; /* pixel sample size */
39			double maxdiff = .05; /* max. difference for interpolation */
40	greg	1.3	double dstrpix = 0.67; /* square pixel distribution */
41	greg	1.1
42			double dstrsrc = 0.0; /* square source distribution */
43	greg	1.4	double shadthresh = .05; /* shadow threshold */
44	greg	1.5	double shadcert = .5; /* shadow certainty */
45	greg	1.35	int directrelay = 1; /* number of source relays */
46	greg	1.29	int vspretest = 512; /* virtual source pretest density */
47	greg	1.30	int directinvis = 0; /* sources invisible? */
48	greg	1.35	double srcsizerat = .25; /* maximum ratio source size/dist. */
49	greg	1.1
50			int maxdepth = 6; /* maximum recursion depth */
51			double minweight = 5e-3; /* minimum ray weight */
52
53			COLOR ambval = BLKCOLOR; /* ambient value */
54			double ambacc = 0.2; /* ambient accuracy */
55	greg	1.6	int ambres = 32; /* ambient resolution */
56	greg	1.1	int ambdiv = 128; /* ambient divisions */
57			int ambssamp = 0; /* ambient super-samples */
58			int ambounce = 0; /* ambient bounces */
59			char amblist[128]; / ambient include/exclude list */
60			int ambincl = -1; /* include == 1, exclude == 0 */
61
62			int ralrm = 0; /* seconds between reports */
63
64			double pctdone = 0.0; /* percentage done */
65
66	greg	1.24	long tlastrept = 0L; /* time at last report */
67
68			extern long time();
69			extern long tstart; /* starting time */
70
71	greg	1.1	extern long nrays; /* number of rays traced */
72
73	greg	1.26	#define MAXDIV 15 /* maximum sample size */
74	greg	1.1
75			#define pixjitter() (.5+dstrpix*(.5-frandom()))
76
77	greg	1.11	double pixvalue();
78	greg	1.1
79	greg	1.11
80	greg	1.1	quit(code) /* quit program */
81			int code;
82			{
83			if (code \|\| ralrm > 0) /* report status */
84			report();
85
86			exit(code);
87			}
88
89
90	greg	1.24	#ifdef BSD
91	greg	1.1	report() /* report progress */
92			{
93			struct rusage rubuf;
94			double t;
95
96			getrusage(RUSAGE_SELF, &rubuf);
97			t = (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
98			t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;
99			getrusage(RUSAGE_CHILDREN, &rubuf);
100			t += (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
101			t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;
102
103			sprintf(errmsg, "%ld rays, %4.2f%% done after %5.4f CPU hours\n",
104			nrays, pctdone, t/3600.0);
105	greg	1.24	eputs(errmsg);
106			tlastrept = time((long *)0);
107			}
108	greg	1.1	#else
109	greg	1.24	report() /* report progress */
110			{
111	greg	1.14	signal(SIGALRM, report);
112	greg	1.24	tlastrept = time((long *)0);
113			sprintf(errmsg, "%ld rays, %4.2f%% done after %5.4f hours\n",
114			nrays, pctdone, (tlastrept-tstart)/3600.0);
115	greg	1.1	eputs(errmsg);
116			}
117	greg	1.24	#endif
118	greg	1.1
119
120	greg	1.11	render(zfile, oldfile) /* render the scene */
121			char zfile, oldfile;
122	greg	1.1	{
123	greg	1.16	extern long lseek();
124	greg	1.1	COLOR scanbar[MAXDIV+1]; / scanline arrays of pixel values */
125	greg	1.11	float zbar[MAXDIV+1]; / z values */
126	greg	1.1	int ypos; /* current scanline */
127	greg	1.15	int ystep; /* current y step size */
128	greg	1.33	int hstep; /* h step size */
129	greg	1.16	int zfd;
130	greg	1.1	COLOR *colptr;
131	greg	1.11	float *zptr;
132	greg	1.1	register int i;
133	greg	1.10	/* check sampling */
134			if (psample < 1)
135	greg	1.1	psample = 1;
136	greg	1.26	else if (psample > MAXDIV) {
137			sprintf(errmsg, "pixel sampling reduced from %d to %d",
138			psample, MAXDIV);
139			error(WARNING, errmsg);
140	greg	1.10	psample = MAXDIV;
141	greg	1.26	}
142	greg	1.9	/* allocate scanlines */
143	greg	1.1	for (i = 0; i <= psample; i++) {
144	greg	1.12	scanbar[i] = (COLOR )malloc(hresolusizeof(COLOR));
145	greg	1.1	if (scanbar[i] == NULL)
146	greg	1.11	goto memerr;
147	greg	1.1	}
148	greg	1.11	/* open z file */
149			if (zfile != NULL) {
150	greg	1.16	if ((zfd = open(zfile, O_WRONLY\|O_CREAT, 0666)) == -1) {
151	greg	1.11	sprintf(errmsg, "cannot open z file \"%s\"", zfile);
152			error(SYSTEM, errmsg);
153			}
154			for (i = 0; i <= psample; i++) {
155	greg	1.12	zbar[i] = (float )malloc(hresolusizeof(float));
156	greg	1.11	if (zbar[i] == NULL)
157			goto memerr;
158			}
159			} else {
160	greg	1.16	zfd = -1;
161	greg	1.11	for (i = 0; i <= psample; i++)
162			zbar[i] = NULL;
163			}
164	greg	1.1	/* write out boundaries */
165	greg	1.36	fprtresolu(hresolu, vresolu, stdout);
166	greg	1.10	/* recover file and compute first */
167	greg	1.11	i = salvage(oldfile);
168	greg	1.23	if (zfd != -1 && i > 0 &&
169			lseek(zfd, (long)ihresolusizeof(float), 0) == -1)
170	greg	1.11	error(SYSTEM, "z file seek error in render");
171	greg	1.24	pctdone = 100.0*i/vresolu;
172			if (ralrm > 0) /* report init stats */
173			report();
174	greg	1.32	#ifndef BSD
175			else
176			#endif
177			signal(SIGALRM, report);
178	greg	1.12	ypos = vresolu-1 - i;
179	greg	1.33	hstep = (psample140+49)/99; / quincunx sampling */
180			ystep = (psample*99+70)/140;
181			fillscanline(scanbar[0], zbar[0], hresolu, ypos, hstep);
182	greg	1.10	/* compute scanlines */
183	greg	1.15	for (ypos -= ystep; ypos > -ystep; ypos -= ystep) {
184			/* bottom adjust? */
185			if (ypos < 0) {
186			ystep += ypos;
187			ypos = 0;
188			}
189			colptr = scanbar[ystep]; /* move base to top */
190			scanbar[ystep] = scanbar[0];
191	greg	1.1	scanbar[0] = colptr;
192	greg	1.15	zptr = zbar[ystep];
193			zbar[ystep] = zbar[0];
194	greg	1.11	zbar[0] = zptr;
195	greg	1.10	/* fill base line */
196	greg	1.33	fillscanline(scanbar[0], zbar[0], hresolu, ypos, hstep);
197	greg	1.10	/* fill bar */
198	greg	1.15	fillscanbar(scanbar, zbar, hresolu, ypos, ystep);
199	greg	1.10	/* write it out */
200	greg	1.32	#ifndef BSD
201			signal(SIGALRM, SIG_IGN); /* don't interrupt writes */
202			#endif
203	greg	1.15	for (i = ystep; i > 0; i--) {
204	greg	1.17	if (zfd != -1 && write(zfd, (char *)zbar[i],
205			hresolu*sizeof(float))
206	greg	1.16	< hresolu*sizeof(float))
207	greg	1.1	goto writerr;
208	greg	1.17	if (fwritescan(scanbar[i], hresolu, stdout) < 0)
209	greg	1.11	goto writerr;
210			}
211	greg	1.1	if (fflush(stdout) == EOF)
212			goto writerr;
213	greg	1.24	/* record progress */
214			pctdone = 100.0*(vresolu-1-ypos)/vresolu;
215			if (ralrm > 0 && time((long *)0) >= tlastrept+ralrm)
216			report();
217	greg	1.32	#ifndef BSD
218			else
219			signal(SIGALRM, report);
220			#endif
221	greg	1.1	}
222	greg	1.11	/* clean up */
223	greg	1.16	if (zfd != -1) {
224	greg	1.17	if (write(zfd, (char )zbar[0], hresolusizeof(float))
225	greg	1.16	< hresolu*sizeof(float))
226	greg	1.11	goto writerr;
227	greg	1.20	if (close(zfd) == -1)
228			goto writerr;
229	greg	1.11	for (i = 0; i <= psample; i++)
230			free((char *)zbar[i]);
231			}
232	greg	1.15	fwritescan(scanbar[0], hresolu, stdout);
233	greg	1.10	if (fflush(stdout) == EOF)
234			goto writerr;
235	greg	1.1	for (i = 0; i <= psample; i++)
236			free((char *)scanbar[i]);
237	greg	1.11	pctdone = 100.0;
238	greg	1.1	return;
239			writerr:
240			error(SYSTEM, "write error in render");
241	greg	1.11	memerr:
242			error(SYSTEM, "out of memory in render");
243	greg	1.1	}
244
245
246	greg	1.11	fillscanline(scanline, zline, xres, y, xstep) /* fill scan line at y */
247	greg	1.1	register COLOR *scanline;
248	greg	1.11	register float *zline;
249	greg	1.9	int xres, y, xstep;
250	greg	1.1	{
251	greg	1.33	static int nc = 0; /* number of calls */
252	greg	1.1	int b = xstep;
253	greg	1.11	double z;
254	greg	1.1	register int i;
255
256	greg	1.11	z = pixvalue(scanline[0], 0, y);
257			if (zline) zline[0] = z;
258	greg	1.33	/* zig-zag start for quincunx pattern */
259			for (i = nc++ & 1 ? xstep/2 : xstep; i < xres-1+xstep; i += xstep) {
260	greg	1.15	if (i >= xres) {
261			xstep += xres-1-i;
262			i = xres-1;
263			}
264	greg	1.11	z = pixvalue(scanline[i], i, y);
265			if (zline) zline[i] = z;
266	greg	1.1
267	greg	1.11	b = fillsample(scanline+i-xstep, zline ? zline+i-xstep : NULL,
268			i-xstep, y, xstep, 0, b/2);
269	greg	1.1	}
270			}
271
272
273	greg	1.11	fillscanbar(scanbar, zbar, xres, y, ysize) /* fill interior */
274	greg	1.1	register COLOR *scanbar[];
275	greg	1.11	register float *zbar[];
276	greg	1.9	int xres, y, ysize;
277	greg	1.1	{
278			COLOR vline[MAXDIV+1];
279	greg	1.11	float zline[MAXDIV+1];
280	greg	1.1	int b = ysize;
281			register int i, j;
282
283	greg	1.8	for (i = 0; i < xres; i++) {
284	greg	1.1
285			copycolor(vline[0], scanbar[0][i]);
286			copycolor(vline[ysize], scanbar[ysize][i]);
287	greg	1.11	if (zbar[0]) {
288			zline[0] = zbar[0][i];
289			zline[ysize] = zbar[ysize][i];
290			}
291	greg	1.1
292	greg	1.11	b = fillsample(vline, zbar[0] ? zline : NULL,
293			i, y, 0, ysize, b/2);
294	greg	1.1
295			for (j = 1; j < ysize; j++)
296			copycolor(scanbar[j][i], vline[j]);
297	greg	1.11	if (zbar[0])
298			for (j = 1; j < ysize; j++)
299			zbar[j][i] = zline[j];
300	greg	1.1	}
301			}
302
303
304			int
305	greg	1.11	fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */
306	greg	1.1	register COLOR *colline;
307	greg	1.11	register float *zline;
308	greg	1.1	int x, y;
309			int xlen, ylen;
310			int b;
311			{
312	greg	1.11	extern double fabs();
313	greg	1.1	double ratio;
314	greg	1.11	double z;
315	greg	1.1	COLOR ctmp;
316			int ncut;
317			register int len;
318
319			if (xlen > 0) /* x or y length is zero */
320			len = xlen;
321			else
322			len = ylen;
323
324			if (len <= 1) /* limit recursion */
325			return(0);
326
327	greg	1.11	if (b > 0
328			\|\| (zline && 2.fabs(zline[0]-zline[len]) > maxdiff(zline[0]+zline[len]))
329			\|\| bigdiff(colline[0], colline[len], maxdiff)) {
330	greg	1.1
331	greg	1.11	z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
332			if (zline) zline[len>>1] = z;
333	greg	1.1	ncut = 1;
334
335			} else { /* interpolate */
336
337			copycolor(colline[len>>1], colline[len]);
338			ratio = (double)(len>>1) / len;
339			scalecolor(colline[len>>1], ratio);
340	greg	1.11	if (zline) zline[len>>1] = zline[len] * ratio;
341			ratio = 1.0 - ratio;
342	greg	1.1	copycolor(ctmp, colline[0]);
343			scalecolor(ctmp, ratio);
344			addcolor(colline[len>>1], ctmp);
345	greg	1.11	if (zline) zline[len>>1] += zline[0] * ratio;
346	greg	1.1	ncut = 0;
347			}
348			/* recurse */
349	greg	1.11	ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
350	greg	1.1
351	greg	1.11	ncut += fillsample(colline+(len>>1), zline ? zline+(len>>1) : NULL,
352			x+(xlen>>1), y+(ylen>>1),
353			xlen-(xlen>>1), ylen-(ylen>>1), b/2);
354	greg	1.1
355			return(ncut);
356			}
357
358
359	greg	1.11	double
360	greg	1.1	pixvalue(col, x, y) /* compute pixel value */
361			COLOR col; /* returned color */
362			int x, y; /* pixel position */
363			{
364	greg	1.25	static RAY thisray;
365	greg	1.1
366	greg	1.22	if (viewray(thisray.rorg, thisray.rdir, &ourview,
367			(x+pixjitter())/hresolu, (y+pixjitter())/vresolu) < 0) {
368			setcolor(col, 0.0, 0.0, 0.0);
369			return(0.0);
370			}
371	greg	1.1
372			rayorigin(&thisray, NULL, PRIMARY, 1.0);
373	greg	1.25
374	greg	1.31	samplendx = pixnumber(x,y,hresolu,vresolu); /* set pixel index */
375	greg	1.25
376	greg	1.1	rayvalue(&thisray); /* trace ray */
377
378			copycolor(col, thisray.rcol); /* return color */
379	greg	1.11
380	greg	1.20	return(thisray.rt); /* return distance */
381	greg	1.1	}
382
383
384			int
385			salvage(oldfile) /* salvage scanlines from killed program */
386			char *oldfile;
387			{
388			COLR *scanline;
389			FILE *fp;
390			int x, y;
391
392			if (oldfile == NULL)
393			return(0);
394	greg	1.9
395			if ((fp = fopen(oldfile, "r")) == NULL) {
396	greg	1.1	sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
397			error(WARNING, errmsg);
398			return(0);
399			}
400			/* discard header */
401			getheader(fp, NULL);
402			/* get picture size */
403	greg	1.36	if (!fscnresolu(&x, &y, fp)) {
404	greg	1.2	sprintf(errmsg, "bad recover file \"%s\"", oldfile);
405			error(WARNING, errmsg);
406	greg	1.1	fclose(fp);
407			return(0);
408			}
409
410	greg	1.12	if (x != hresolu \|\| y != vresolu) {
411	greg	1.1	sprintf(errmsg, "resolution mismatch in recover file \"%s\"",
412			oldfile);
413			error(USER, errmsg);
414			}
415
416	greg	1.12	scanline = (COLR )malloc(hresolusizeof(COLR));
417	greg	1.1	if (scanline == NULL)
418			error(SYSTEM, "out of memory in salvage");
419	greg	1.12	for (y = 0; y < vresolu; y++) {
420			if (freadcolrs(scanline, hresolu, fp) < 0)
421	greg	1.1	break;
422	greg	1.12	if (fwritecolrs(scanline, hresolu, stdout) < 0)
423	greg	1.1	goto writerr;
424			}
425			if (fflush(stdout) == EOF)
426			goto writerr;
427			free((char *)scanline);
428			fclose(fp);
429			unlink(oldfile);
430			return(y);
431			writerr:
432			error(SYSTEM, "write error in salvage");
433	greg	1.31	}
434
435
436			int
437			pixnumber(x, y, xres, yres) /* compute pixel index (brushed) */
438			register int x, y;
439			int xres, yres;
440			{
441			x -= y;
442			while (x < 0)
443			x += xres;
444			return((((x>>2)*yres + y) << 2) + (x & 3));
445	greg	1.1	}