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  "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 */
        fputresolu(YMAJOR|YDECR, 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 (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");
}


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:	1.35
Committed:	Mon Oct 21 12:57:57 1991 UTC (32 years, 6 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.34:	+2 -1 lines
Log Message:	added source sampling (-ds option)
#	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			#include "random.h"
26
27	greg	1.25	int dimlist[MAXDIM]; /* sampling dimensions */
28			int ndims = 0; /* number of sampling dimensions */
29			int samplendx; /* sample index number */
30
31	greg	1.12	VIEW ourview = STDVIEW; /* view parameters */
32			int hresolu = 512; /* horizontal resolution */
33			int vresolu = 512; /* vertical resolution */
34	greg	1.13	double pixaspect = 1.0; /* pixel aspect ratio */
35	greg	1.1
36			int psample = 4; /* pixel sample size */
37			double maxdiff = .05; /* max. difference for interpolation */
38	greg	1.3	double dstrpix = 0.67; /* square pixel distribution */
39	greg	1.1
40			double dstrsrc = 0.0; /* square source distribution */
41	greg	1.4	double shadthresh = .05; /* shadow threshold */
42	greg	1.5	double shadcert = .5; /* shadow certainty */
43	greg	1.35	int directrelay = 1; /* number of source relays */
44	greg	1.29	int vspretest = 512; /* virtual source pretest density */
45	greg	1.30	int directinvis = 0; /* sources invisible? */
46	greg	1.35	double srcsizerat = .25; /* maximum ratio source size/dist. */
47	greg	1.1
48			int maxdepth = 6; /* maximum recursion depth */
49			double minweight = 5e-3; /* minimum ray weight */
50
51			COLOR ambval = BLKCOLOR; /* ambient value */
52			double ambacc = 0.2; /* ambient accuracy */
53	greg	1.6	int ambres = 32; /* ambient resolution */
54	greg	1.1	int ambdiv = 128; /* ambient divisions */
55			int ambssamp = 0; /* ambient super-samples */
56			int ambounce = 0; /* ambient bounces */
57			char amblist[128]; / ambient include/exclude list */
58			int ambincl = -1; /* include == 1, exclude == 0 */
59
60			int ralrm = 0; /* seconds between reports */
61
62			double pctdone = 0.0; /* percentage done */
63
64	greg	1.24	long tlastrept = 0L; /* time at last report */
65
66			extern long time();
67			extern long tstart; /* starting time */
68
69	greg	1.1	extern long nrays; /* number of rays traced */
70
71	greg	1.26	#define MAXDIV 15 /* maximum sample size */
72	greg	1.1
73			#define pixjitter() (.5+dstrpix*(.5-frandom()))
74
75	greg	1.11	double pixvalue();
76	greg	1.1
77	greg	1.11
78	greg	1.1	quit(code) /* quit program */
79			int code;
80			{
81			if (code \|\| ralrm > 0) /* report status */
82			report();
83
84			exit(code);
85			}
86
87
88	greg	1.24	#ifdef BSD
89	greg	1.1	report() /* report progress */
90			{
91			struct rusage rubuf;
92			double t;
93
94			getrusage(RUSAGE_SELF, &rubuf);
95			t = (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
96			t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;
97			getrusage(RUSAGE_CHILDREN, &rubuf);
98			t += (rubuf.ru_utime.tv_usec + rubuf.ru_stime.tv_usec) / 1e6;
99			t += rubuf.ru_utime.tv_sec + rubuf.ru_stime.tv_sec;
100
101			sprintf(errmsg, "%ld rays, %4.2f%% done after %5.4f CPU hours\n",
102			nrays, pctdone, t/3600.0);
103	greg	1.24	eputs(errmsg);
104			tlastrept = time((long *)0);
105			}
106	greg	1.1	#else
107	greg	1.24	report() /* report progress */
108			{
109	greg	1.14	signal(SIGALRM, report);
110	greg	1.24	tlastrept = time((long *)0);
111			sprintf(errmsg, "%ld rays, %4.2f%% done after %5.4f hours\n",
112			nrays, pctdone, (tlastrept-tstart)/3600.0);
113	greg	1.1	eputs(errmsg);
114			}
115	greg	1.24	#endif
116	greg	1.1
117
118	greg	1.11	render(zfile, oldfile) /* render the scene */
119			char zfile, oldfile;
120	greg	1.1	{
121	greg	1.16	extern long lseek();
122	greg	1.1	COLOR scanbar[MAXDIV+1]; / scanline arrays of pixel values */
123	greg	1.11	float zbar[MAXDIV+1]; / z values */
124	greg	1.1	int ypos; /* current scanline */
125	greg	1.15	int ystep; /* current y step size */
126	greg	1.33	int hstep; /* h step size */
127	greg	1.16	int zfd;
128	greg	1.1	COLOR *colptr;
129	greg	1.11	float *zptr;
130	greg	1.1	register int i;
131	greg	1.10	/* check sampling */
132			if (psample < 1)
133	greg	1.1	psample = 1;
134	greg	1.26	else if (psample > MAXDIV) {
135			sprintf(errmsg, "pixel sampling reduced from %d to %d",
136			psample, MAXDIV);
137			error(WARNING, errmsg);
138	greg	1.10	psample = MAXDIV;
139	greg	1.26	}
140	greg	1.9	/* allocate scanlines */
141	greg	1.1	for (i = 0; i <= psample; i++) {
142	greg	1.12	scanbar[i] = (COLOR )malloc(hresolusizeof(COLOR));
143	greg	1.1	if (scanbar[i] == NULL)
144	greg	1.11	goto memerr;
145	greg	1.1	}
146	greg	1.11	/* open z file */
147			if (zfile != NULL) {
148	greg	1.16	if ((zfd = open(zfile, O_WRONLY\|O_CREAT, 0666)) == -1) {
149	greg	1.11	sprintf(errmsg, "cannot open z file \"%s\"", zfile);
150			error(SYSTEM, errmsg);
151			}
152			for (i = 0; i <= psample; i++) {
153	greg	1.12	zbar[i] = (float )malloc(hresolusizeof(float));
154	greg	1.11	if (zbar[i] == NULL)
155			goto memerr;
156			}
157			} else {
158	greg	1.16	zfd = -1;
159	greg	1.11	for (i = 0; i <= psample; i++)
160			zbar[i] = NULL;
161			}
162	greg	1.1	/* write out boundaries */
163	greg	1.12	fputresolu(YMAJOR\|YDECR, hresolu, vresolu, stdout);
164	greg	1.10	/* recover file and compute first */
165	greg	1.11	i = salvage(oldfile);
166	greg	1.23	if (zfd != -1 && i > 0 &&
167			lseek(zfd, (long)ihresolusizeof(float), 0) == -1)
168	greg	1.11	error(SYSTEM, "z file seek error in render");
169	greg	1.24	pctdone = 100.0*i/vresolu;
170			if (ralrm > 0) /* report init stats */
171			report();
172	greg	1.32	#ifndef BSD
173			else
174			#endif
175			signal(SIGALRM, report);
176	greg	1.12	ypos = vresolu-1 - i;
177	greg	1.33	hstep = (psample140+49)/99; / quincunx sampling */
178			ystep = (psample*99+70)/140;
179			fillscanline(scanbar[0], zbar[0], hresolu, ypos, hstep);
180	greg	1.10	/* compute scanlines */
181	greg	1.15	for (ypos -= ystep; ypos > -ystep; ypos -= ystep) {
182			/* bottom adjust? */
183			if (ypos < 0) {
184			ystep += ypos;
185			ypos = 0;
186			}
187			colptr = scanbar[ystep]; /* move base to top */
188			scanbar[ystep] = scanbar[0];
189	greg	1.1	scanbar[0] = colptr;
190	greg	1.15	zptr = zbar[ystep];
191			zbar[ystep] = zbar[0];
192	greg	1.11	zbar[0] = zptr;
193	greg	1.10	/* fill base line */
194	greg	1.33	fillscanline(scanbar[0], zbar[0], hresolu, ypos, hstep);
195	greg	1.10	/* fill bar */
196	greg	1.15	fillscanbar(scanbar, zbar, hresolu, ypos, ystep);
197	greg	1.10	/* write it out */
198	greg	1.32	#ifndef BSD
199			signal(SIGALRM, SIG_IGN); /* don't interrupt writes */
200			#endif
201	greg	1.15	for (i = ystep; i > 0; i--) {
202	greg	1.17	if (zfd != -1 && write(zfd, (char *)zbar[i],
203			hresolu*sizeof(float))
204	greg	1.16	< hresolu*sizeof(float))
205	greg	1.1	goto writerr;
206	greg	1.17	if (fwritescan(scanbar[i], hresolu, stdout) < 0)
207	greg	1.11	goto writerr;
208			}
209	greg	1.1	if (fflush(stdout) == EOF)
210			goto writerr;
211	greg	1.24	/* record progress */
212			pctdone = 100.0*(vresolu-1-ypos)/vresolu;
213			if (ralrm > 0 && time((long *)0) >= tlastrept+ralrm)
214			report();
215	greg	1.32	#ifndef BSD
216			else
217			signal(SIGALRM, report);
218			#endif
219	greg	1.1	}
220	greg	1.11	/* clean up */
221	greg	1.16	if (zfd != -1) {
222	greg	1.17	if (write(zfd, (char )zbar[0], hresolusizeof(float))
223	greg	1.16	< hresolu*sizeof(float))
224	greg	1.11	goto writerr;
225	greg	1.20	if (close(zfd) == -1)
226			goto writerr;
227	greg	1.11	for (i = 0; i <= psample; i++)
228			free((char *)zbar[i]);
229			}
230	greg	1.15	fwritescan(scanbar[0], hresolu, stdout);
231	greg	1.10	if (fflush(stdout) == EOF)
232			goto writerr;
233	greg	1.1	for (i = 0; i <= psample; i++)
234			free((char *)scanbar[i]);
235	greg	1.11	pctdone = 100.0;
236	greg	1.1	return;
237			writerr:
238			error(SYSTEM, "write error in render");
239	greg	1.11	memerr:
240			error(SYSTEM, "out of memory in render");
241	greg	1.1	}
242
243
244	greg	1.11	fillscanline(scanline, zline, xres, y, xstep) /* fill scan line at y */
245	greg	1.1	register COLOR *scanline;
246	greg	1.11	register float *zline;
247	greg	1.9	int xres, y, xstep;
248	greg	1.1	{
249	greg	1.33	static int nc = 0; /* number of calls */
250	greg	1.1	int b = xstep;
251	greg	1.11	double z;
252	greg	1.1	register int i;
253
254	greg	1.11	z = pixvalue(scanline[0], 0, y);
255			if (zline) zline[0] = z;
256	greg	1.33	/* zig-zag start for quincunx pattern */
257			for (i = nc++ & 1 ? xstep/2 : xstep; i < xres-1+xstep; i += xstep) {
258	greg	1.15	if (i >= xres) {
259			xstep += xres-1-i;
260			i = xres-1;
261			}
262	greg	1.11	z = pixvalue(scanline[i], i, y);
263			if (zline) zline[i] = z;
264	greg	1.1
265	greg	1.11	b = fillsample(scanline+i-xstep, zline ? zline+i-xstep : NULL,
266			i-xstep, y, xstep, 0, b/2);
267	greg	1.1	}
268			}
269
270
271	greg	1.11	fillscanbar(scanbar, zbar, xres, y, ysize) /* fill interior */
272	greg	1.1	register COLOR *scanbar[];
273	greg	1.11	register float *zbar[];
274	greg	1.9	int xres, y, ysize;
275	greg	1.1	{
276			COLOR vline[MAXDIV+1];
277	greg	1.11	float zline[MAXDIV+1];
278	greg	1.1	int b = ysize;
279			register int i, j;
280
281	greg	1.8	for (i = 0; i < xres; i++) {
282	greg	1.1
283			copycolor(vline[0], scanbar[0][i]);
284			copycolor(vline[ysize], scanbar[ysize][i]);
285	greg	1.11	if (zbar[0]) {
286			zline[0] = zbar[0][i];
287			zline[ysize] = zbar[ysize][i];
288			}
289	greg	1.1
290	greg	1.11	b = fillsample(vline, zbar[0] ? zline : NULL,
291			i, y, 0, ysize, b/2);
292	greg	1.1
293			for (j = 1; j < ysize; j++)
294			copycolor(scanbar[j][i], vline[j]);
295	greg	1.11	if (zbar[0])
296			for (j = 1; j < ysize; j++)
297			zbar[j][i] = zline[j];
298	greg	1.1	}
299			}
300
301
302			int
303	greg	1.11	fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */
304	greg	1.1	register COLOR *colline;
305	greg	1.11	register float *zline;
306	greg	1.1	int x, y;
307			int xlen, ylen;
308			int b;
309			{
310	greg	1.11	extern double fabs();
311	greg	1.1	double ratio;
312	greg	1.11	double z;
313	greg	1.1	COLOR ctmp;
314			int ncut;
315			register int len;
316
317			if (xlen > 0) /* x or y length is zero */
318			len = xlen;
319			else
320			len = ylen;
321
322			if (len <= 1) /* limit recursion */
323			return(0);
324
325	greg	1.11	if (b > 0
326			\|\| (zline && 2.fabs(zline[0]-zline[len]) > maxdiff(zline[0]+zline[len]))
327			\|\| bigdiff(colline[0], colline[len], maxdiff)) {
328	greg	1.1
329	greg	1.11	z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
330			if (zline) zline[len>>1] = z;
331	greg	1.1	ncut = 1;
332
333			} else { /* interpolate */
334
335			copycolor(colline[len>>1], colline[len]);
336			ratio = (double)(len>>1) / len;
337			scalecolor(colline[len>>1], ratio);
338	greg	1.11	if (zline) zline[len>>1] = zline[len] * ratio;
339			ratio = 1.0 - ratio;
340	greg	1.1	copycolor(ctmp, colline[0]);
341			scalecolor(ctmp, ratio);
342			addcolor(colline[len>>1], ctmp);
343	greg	1.11	if (zline) zline[len>>1] += zline[0] * ratio;
344	greg	1.1	ncut = 0;
345			}
346			/* recurse */
347	greg	1.11	ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
348	greg	1.1
349	greg	1.11	ncut += fillsample(colline+(len>>1), zline ? zline+(len>>1) : NULL,
350			x+(xlen>>1), y+(ylen>>1),
351			xlen-(xlen>>1), ylen-(ylen>>1), b/2);
352	greg	1.1
353			return(ncut);
354			}
355
356
357	greg	1.11	double
358	greg	1.1	pixvalue(col, x, y) /* compute pixel value */
359			COLOR col; /* returned color */
360			int x, y; /* pixel position */
361			{
362	greg	1.25	static RAY thisray;
363	greg	1.1
364	greg	1.22	if (viewray(thisray.rorg, thisray.rdir, &ourview,
365			(x+pixjitter())/hresolu, (y+pixjitter())/vresolu) < 0) {
366			setcolor(col, 0.0, 0.0, 0.0);
367			return(0.0);
368			}
369	greg	1.1
370			rayorigin(&thisray, NULL, PRIMARY, 1.0);
371	greg	1.25
372	greg	1.31	samplendx = pixnumber(x,y,hresolu,vresolu); /* set pixel index */
373	greg	1.25
374	greg	1.1	rayvalue(&thisray); /* trace ray */
375
376			copycolor(col, thisray.rcol); /* return color */
377	greg	1.11
378	greg	1.20	return(thisray.rt); /* return distance */
379	greg	1.1	}
380
381
382			int
383			salvage(oldfile) /* salvage scanlines from killed program */
384			char *oldfile;
385			{
386			COLR *scanline;
387			FILE *fp;
388			int x, y;
389
390			if (oldfile == NULL)
391			return(0);
392	greg	1.9
393			if ((fp = fopen(oldfile, "r")) == NULL) {
394	greg	1.1	sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
395			error(WARNING, errmsg);
396			return(0);
397			}
398			/* discard header */
399			getheader(fp, NULL);
400			/* get picture size */
401	greg	1.7	if (fgetresolu(&x, &y, fp) != (YMAJOR\|YDECR)) {
402	greg	1.2	sprintf(errmsg, "bad recover file \"%s\"", oldfile);
403			error(WARNING, errmsg);
404	greg	1.1	fclose(fp);
405			return(0);
406			}
407
408	greg	1.12	if (x != hresolu \|\| y != vresolu) {
409	greg	1.1	sprintf(errmsg, "resolution mismatch in recover file \"%s\"",
410			oldfile);
411			error(USER, errmsg);
412			}
413
414	greg	1.12	scanline = (COLR )malloc(hresolusizeof(COLR));
415	greg	1.1	if (scanline == NULL)
416			error(SYSTEM, "out of memory in salvage");
417	greg	1.12	for (y = 0; y < vresolu; y++) {
418			if (freadcolrs(scanline, hresolu, fp) < 0)
419	greg	1.1	break;
420	greg	1.12	if (fwritecolrs(scanline, hresolu, stdout) < 0)
421	greg	1.1	goto writerr;
422			}
423			if (fflush(stdout) == EOF)
424			goto writerr;
425			free((char *)scanline);
426			fclose(fp);
427			unlink(oldfile);
428			return(y);
429			writerr:
430			error(SYSTEM, "write error in salvage");
431	greg	1.31	}
432
433
434			int
435			pixnumber(x, y, xres, yres) /* compute pixel index (brushed) */
436			register int x, y;
437			int xres, yres;
438			{
439			x -= y;
440			while (x < 0)
441			x += xres;
442			return((((x>>2)*yres + y) << 2) + (x & 3));
443	greg	1.1	}