src/util/rpiece.c

/* Copyright (c) 1992 Regents of the University of California */

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

/*
 * Generate sections of a picture.
 */
 
#include "standard.h"
#include <fcntl.h>
#include <signal.h>
#include "color.h"
#include "view.h"
#include "resolu.h"

                                /* rpict command */
char  *rpargv[128] = {"rpict", "-S", "1", "-x", "512", "-y", "512", "-pa", "1"};
int  rpargc = 9;
int  rpd[3];
FILE  *torp, *fromrp;
COLR  *pbuf;
                                /* our view parameters */
VIEW  ourview = STDVIEW;
double  pixaspect = 1.0;
int  hres = 512, vres = 512, hmult = 2, vmult = 2;
                                /* output file */
char  *outfile = NULL;
int  outfd;
long  scanorig;
int  syncfd = -1;               /* lock file descriptor */

char  *progname;
int  verbose = 0;

extern long  lseek(), ftell();

int  gotalrm = 0;
int  onalrm() { gotalrm++; }


main(argc, argv)
int  argc;
char  *argv[];
{
        register int  i, rval;
        
        progname = argv[0];
        for (i = 1; i < argc; i++) {
                if (argv[i][0] == '-')
                        switch (argv[i][1]) {
                        case 'v':
                                switch (argv[i][2]) {
                                case '\0':      /* verbose option */
                                        verbose = !verbose;
                                        continue;
                                case 'f':       /* view file */
                                        if (viewfile(argv[++i], &ourview, NULL) <= 0) {
                                                fprintf(stderr,
                                        "%s: not a view file\n", argv[i]);
                                                exit(1);
                                        }
                                        continue;
                                default:        /* view option? */
                                        rval = getviewopt(&ourview, argc-i, argv+i);
                                        if (rval >= 0) {
                                                i += rval;
                                                continue;
                                        }
                                        break;
                                }
                                break;
                        case 'p':               /* pixel aspect ratio? */
                                if (argv[i][2] == 'a' && !argv[i][3])
                                        pixaspect = atof(argv[i+1]);
                                break;
                        case 'x':               /* piece x resolution */
                                if (!argv[i][2])
                                        hres = atoi(argv[i+1]);
                                break;
                        case 'y':               /* piece y resolution */
                                if (!argv[i][2])
                                        vres = atoi(argv[i+1]);
                                break;
                        case 'X':               /* horizontal multiplier */
                                if (argv[i][2])
                                        break;
                                hmult = atoi(argv[++i]);
                                continue;
                        case 'Y':               /* vertical multiplier */
                                if (argv[i][2])
                                        break;
                                vmult = atoi(argv[++i]);
                                continue;
                        case 'F':               /* syncronization file */
                                if (argv[i][2])
                                        break;
                                if ((syncfd = open(argv[++i], O_RDWR)) < 0) {
                                        fprintf(stderr, "%s: cannot open\n",
                                                        argv[i]);
                                        exit(1);
                                }
                                continue;
                        case 'o':               /* output file */
                                if (argv[i][2])
                                        break;
                                outfile = argv[++i];
                                continue;
                        }
                rpargv[rpargc++] = argv[i];
        }
        rpargv[rpargc] = NULL;
        if (outfile == NULL) {
                fprintf(stderr, "%s: missing output file\n", argv[0]);
                exit(1);
        }
        init(argc, argv);
        rpiece();
        rval = cleanup();
        exit(rval);
}


init(ac, av)                    /* set up output file and start rpict */
int  ac;
char  **av;
{
        extern char  VersionID[];
        char  *err;
        FILE  *fp;
        int  hr, vr;
                                        /* set up view */
        if ((err = setview(&ourview)) != NULL) {
                fprintf(stderr, "%s: %s\n", progname, err);
                exit(1);
        }
        if (syncfd != -1) {
                char  buf[32];
                buf[read(syncfd, buf, sizeof(buf)-1)] = '\0';
                sscanf(buf, "%d %d", &hmult, &vmult);
        }
        normaspect(viewaspect(&ourview)*hmult/vmult, &pixaspect, &hres, &vres);
                                        /* open output file */
        if ((outfd = open(outfile, O_WRONLY|O_CREAT|O_EXCL, 0666)) >= 0) {
                if ((fp = fdopen(dup(outfd), "w")) == NULL)
                        goto filerr;
                printargs(ac, av, fp);          /* write header */
                fprintf(fp, "SOFTWARE= %s\n", VersionID);
                fputs(VIEWSTR, fp);
                fprintview(&ourview, fp);
                putc('\n', fp);
                if (pixaspect < .99 || pixaspect > 1.01)
                        fputaspect(pixaspect, fp);
                fputformat(COLRFMT, fp);
                putc('\n', fp);
                fprtresolu(hres*hmult, vres*vmult, fp);
        } else if ((outfd = open(outfile, O_RDWR)) >= 0) {
                if ((fp = fdopen(dup(outfd), "r+")) == NULL)
                        goto filerr;
                getheader(fp, NULL);            /* skip header */
                if (fscnresolu(&hr, &vr, fp) < 0 ||     /* check resolution */
                                hr != hres*hmult || vr != vres*vmult) {
                        fprintf(stderr, "%s: resolution mismatch on file \"%s\"\n",
                                        progname, outfile);
                        exit(1);
                }
        } else {
                fprintf(stderr, "%s: cannot open file \"%s\"\n",
                                progname, outfile);
                exit(1);
        }
        scanorig = ftell(fp);           /* record position of first scanline */
        if (fclose(fp) == -1)           /* done with stream i/o */
                goto filerr;
        sync();                         /* flush NFS buffers */
                                        /* start rpict process */
        if (open_process(rpd, rpargv) <= 0) {
                fprintf(stderr, "%s: cannot start %s\n", progname, rpargv[0]);
                exit(1);
        }
        if ((fromrp = fdopen(rpd[0], "r")) == NULL ||
                        (torp = fdopen(rpd[1], "w")) == NULL) {
                fprintf(stderr, "%s: cannot open stream to %s\n",
                                progname, rpargv[0]);
                exit(1);
        }
        if ((pbuf = (COLR *)malloc(hres*vres*sizeof(COLR))) == NULL) {
                fprintf(stderr, "%s: out of memory\n", progname);
                exit(1);
        }
        signal(SIGALRM, onalrm);
        return;
filerr:
        fprintf(stderr, "%s: i/o error on file \"%s\"\n", progname, outfile);
        exit(1);
}


int
nextpiece(xp, yp)               /* get next piece assignment */
int  *xp, *yp;
{
        extern char  *fgets();
        struct flock  fls;
        char  buf[64];

        if (gotalrm)                    /* someone wants us to quit */
                return(0);
        if (syncfd != -1) {             /* use sync file */
                fls.l_type = F_WRLCK;           /* gain exclusive access */
                fls.l_whence = 0;
                fls.l_start = 0L;
                fls.l_len = 0L;
                fcntl(syncfd, F_SETLKW, &fls);
                lseek(syncfd, 0L, 0);
                buf[read(syncfd, buf, sizeof(buf)-1)] = '\0';
                if (sscanf(buf, "%*d %*d %d %d", xp, yp) < 2) {
                        *xp = hmult-1;
                        *yp = vmult;
                }
                if (--(*yp) < 0) {              /* decrement position */
                        *yp = vmult-1;
                        if (--(*xp) < 0) {      /* all done! */
                                close(syncfd);
                                return(0);
                        }
                }
                sprintf(buf, "%d %d\n%d %d\n", hmult, vmult, *xp, *yp);
                lseek(syncfd, 0L, 0);           /* write new position */
                write(syncfd, buf, strlen(buf));
                fls.l_type = F_UNLCK;           /* release sync file */
                fcntl(syncfd, F_SETLKW, &fls);
                return(1);
        }
        if (fgets(buf, sizeof(buf), stdin) == NULL)     /* use stdin */
                return(0);
        if (sscanf(buf, "%d %d", xp, yp) == 2)
                return(1);
        fprintf(stderr, "%s: input format error\n", progname);
        exit(1);
}


int
cleanup()                       /* close rpict process and clean up */
{
        register int  rpstat;

        free((char *)pbuf);
        fclose(torp);
        fclose(fromrp);
        rpstat = close_process(rpd);
        if (rpstat == -1)
                rpstat = 0;
        return(rpstat);
}


rpiece()                        /* render picture piece by piece */
{
        VIEW  pview;
        int  xorg, yorg;
        
        while (nextpiece(&xorg, &yorg)) {
                copystruct(&pview, &ourview);   /* compute view for piece */
                switch (ourview.type) {
                case VT_PER:
                        pview.horiz = 2.*180./PI*atan(
                                        tan(PI/180./2.*ourview.horiz)/hmult );
                        pview.vert = 2.*180./PI*atan(
                                        tan(PI/180./2.*ourview.vert)/vmult );
                        break;
                case VT_PAR:
                case VT_ANG:
                        pview.horiz = ourview.horiz / hmult;
                        pview.vert = ourview.vert / vmult;
                        break;
                case VT_HEM:
                        pview.horiz = 2.*180./PI*asin(
                                        sin(PI/180./2.*ourview.horiz)/hmult );
                        pview.vert = 2.*180./PI*asin(
                                        sin(PI/180./2.*ourview.vert)/vmult );
                        break;
                default:
                        fprintf(stderr, "%s: unknown view type '-vt%c'\n",
                                        progname, ourview.type);
                        exit(1);
                }
                pview.hoff += xorg - 0.5*(hmult-1);
                pview.voff += yorg - 0.5*(vmult-1);
                fputs(VIEWSTR, torp);
                fprintview(&pview, torp);
                putc('\n', torp);
                fflush(torp);                   /* assign piece to rpict */
                putpiece(xorg, yorg);           /* place piece in output */
                if (verbose) {                  /* notify caller */
                        printf("%d %d done\n", xorg, yorg);
                        fflush(stdout);
                }
        }
}


putpiece(xpos, ypos)            /* get next piece from rpict */
int  xpos, ypos;
{
        struct flock  fls;
        int  hr, vr;
        register int  y;
                                /* check bounds */
        if (xpos < 0 | ypos < 0 | xpos >= hmult | ypos >= vmult) {
                fprintf(stderr, "%s: requested piece (%d,%d) out of range\n",
                                progname, xpos, ypos);
                exit(1);
        }
                                /* check header from rpict */
        getheader(fromrp, NULL);
        if (fscnresolu(&hr, &vr, fromrp) < 0 || hr != hres || vr != vres) {
                fprintf(stderr, "%s: resolution mismatch from %s\n",
                                progname, rpargv[0]);
                exit(1);
        }
                                /* load new piece into buffer */
        for (y = 0; y < vr; y++)
                if (freadcolrs(pbuf+y*hr, hr, fromrp) < 0) {
                        fprintf(stderr, "%s: read error from %s\n",
                                        progname, rpargv[0]);
                        exit(1);
                }
                                /* lock file section so NFS doesn't mess up */
        fls.l_whence = 0;
        fls.l_len = (long)vres*hmult*hres*sizeof(COLR);
        fls.l_start = scanorig + (vmult-1-ypos)*fls.l_len;
        fls.l_type = F_WRLCK;
        fcntl(outfd, F_SETLKW, &fls);
                                /* write new piece to file */
        if (lseek(outfd, fls.l_start+(long)xpos*hres*sizeof(COLR), 0) == -1)
                goto seekerr;
        for (y = 0; y < vr; y++) {
                if (writebuf(outfd, (char *)(pbuf+y*hr), hr*sizeof(COLR)) !=
                                hr*sizeof(COLR)) {
                        fprintf(stderr, "%s: write error on file \"%s\"\n",
                                        progname, outfile);
                        exit(1);
                }
                if (hmult != 1 && y < vr-1 && lseek(outfd,
                                (long)(hmult-1)*hr*sizeof(COLR), 1) == -1)
                        goto seekerr;
        }
                                /* unlock file section */
        fls.l_type = F_UNLCK;
        fcntl(outfd, F_SETLKW, &fls);
        return;
seekerr:
        fprintf(stderr, "%s: seek error on file \"%s\"\n", progname, outfile);
        exit(1);
}
Revision:	2.8
Committed:	Sun Aug 9 12:12:48 1992 UTC (31 years, 8 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.7:	+45 -34 lines
Log Message:	improved locking with use of local buffer for picture piece
#	User	Rev	Content
1	greg	2.1	/* Copyright (c) 1992 Regents of the University of California */
2
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* Generate sections of a picture.
9			*/
10
11			#include "standard.h"
12			#include <fcntl.h>
13	greg	2.6	#include <signal.h>
14	greg	2.1	#include "color.h"
15			#include "view.h"
16			#include "resolu.h"
17
18			/* rpict command */
19	greg	2.4	char *rpargv[128] = {"rpict", "-S", "1", "-x", "512", "-y", "512", "-pa", "1"};
20			int rpargc = 9;
21	greg	2.1	int rpd[3];
22			FILE torp, fromrp;
23	greg	2.8	COLR *pbuf;
24	greg	2.1	/* our view parameters */
25			VIEW ourview = STDVIEW;
26	greg	2.4	double pixaspect = 1.0;
27	greg	2.1	int hres = 512, vres = 512, hmult = 2, vmult = 2;
28			/* output file */
29			char *outfile = NULL;
30			int outfd;
31			long scanorig;
32	greg	2.5	int syncfd = -1; /* lock file descriptor */
33	greg	2.1
34			char *progname;
35			int verbose = 0;
36
37			extern long lseek(), ftell();
38
39	greg	2.6	int gotalrm = 0;
40			int onalrm() { gotalrm++; }
41	greg	2.1
42	greg	2.6
43	greg	2.1	main(argc, argv)
44			int argc;
45			char *argv[];
46			{
47			register int i, rval;
48
49			progname = argv[0];
50			for (i = 1; i < argc; i++) {
51			if (argv[i][0] == '-')
52			switch (argv[i][1]) {
53			case 'v':
54			switch (argv[i][2]) {
55			case '\0': /* verbose option */
56			verbose = !verbose;
57			continue;
58			case 'f': /* view file */
59			if (viewfile(argv[++i], &ourview, NULL) <= 0) {
60			fprintf(stderr,
61			"%s: not a view file\n", argv[i]);
62			exit(1);
63			}
64			continue;
65			default: /* view option? */
66			rval = getviewopt(&ourview, argc-i, argv+i);
67			if (rval >= 0) {
68			i += rval;
69			continue;
70			}
71			break;
72			}
73			break;
74			case 'p': /* pixel aspect ratio? */
75			if (argv[i][2] == 'a' && !argv[i][3])
76			pixaspect = atof(argv[i+1]);
77			break;
78			case 'x': /* piece x resolution */
79			if (!argv[i][2])
80			hres = atoi(argv[i+1]);
81			break;
82			case 'y': /* piece y resolution */
83			if (!argv[i][2])
84			vres = atoi(argv[i+1]);
85			break;
86			case 'X': /* horizontal multiplier */
87			if (argv[i][2])
88			break;
89			hmult = atoi(argv[++i]);
90			continue;
91			case 'Y': /* vertical multiplier */
92			if (argv[i][2])
93			break;
94			vmult = atoi(argv[++i]);
95			continue;
96	greg	2.5	case 'F': /* syncronization file */
97			if (argv[i][2])
98			break;
99			if ((syncfd = open(argv[++i], O_RDWR)) < 0) {
100			fprintf(stderr, "%s: cannot open\n",
101			argv[i]);
102			exit(1);
103			}
104			continue;
105	greg	2.1	case 'o': /* output file */
106			if (argv[i][2])
107			break;
108			outfile = argv[++i];
109			continue;
110			}
111			rpargv[rpargc++] = argv[i];
112			}
113			rpargv[rpargc] = NULL;
114			if (outfile == NULL) {
115			fprintf(stderr, "%s: missing output file\n", argv[0]);
116			exit(1);
117			}
118			init(argc, argv);
119			rpiece();
120			rval = cleanup();
121			exit(rval);
122			}
123
124
125			init(ac, av) /* set up output file and start rpict */
126			int ac;
127			char **av;
128			{
129	greg	2.2	extern char VersionID[];
130	greg	2.1	char *err;
131			FILE *fp;
132			int hr, vr;
133			/* set up view */
134			if ((err = setview(&ourview)) != NULL) {
135			fprintf(stderr, "%s: %s\n", progname, err);
136			exit(1);
137			}
138	greg	2.5	if (syncfd != -1) {
139			char buf[32];
140			buf[read(syncfd, buf, sizeof(buf)-1)] = '\0';
141			sscanf(buf, "%d %d", &hmult, &vmult);
142			}
143	greg	2.1	normaspect(viewaspect(&ourview)*hmult/vmult, &pixaspect, &hres, &vres);
144			/* open output file */
145			if ((outfd = open(outfile, O_WRONLY\|O_CREAT\|O_EXCL, 0666)) >= 0) {
146			if ((fp = fdopen(dup(outfd), "w")) == NULL)
147			goto filerr;
148			printargs(ac, av, fp); /* write header */
149	greg	2.2	fprintf(fp, "SOFTWARE= %s\n", VersionID);
150	greg	2.1	fputs(VIEWSTR, fp);
151			fprintview(&ourview, fp);
152			putc('\n', fp);
153			if (pixaspect < .99 \|\| pixaspect > 1.01)
154			fputaspect(pixaspect, fp);
155			fputformat(COLRFMT, fp);
156			putc('\n', fp);
157			fprtresolu(hreshmult, vresvmult, fp);
158			} else if ((outfd = open(outfile, O_RDWR)) >= 0) {
159			if ((fp = fdopen(dup(outfd), "r+")) == NULL)
160			goto filerr;
161			getheader(fp, NULL); /* skip header */
162			if (fscnresolu(&hr, &vr, fp) < 0 \|\| /* check resolution */
163			hr != hreshmult \|\| vr != vresvmult) {
164	greg	2.8	fprintf(stderr, "%s: resolution mismatch on file \"%s\"\n",
165			progname, outfile);
166	greg	2.1	exit(1);
167			}
168			} else {
169	greg	2.8	fprintf(stderr, "%s: cannot open file \"%s\"\n",
170			progname, outfile);
171	greg	2.1	exit(1);
172			}
173			scanorig = ftell(fp); /* record position of first scanline */
174			if (fclose(fp) == -1) /* done with stream i/o */
175			goto filerr;
176	greg	2.8	sync(); /* flush NFS buffers */
177	greg	2.1	/* start rpict process */
178			if (open_process(rpd, rpargv) <= 0) {
179	greg	2.3	fprintf(stderr, "%s: cannot start %s\n", progname, rpargv[0]);
180	greg	2.1	exit(1);
181			}
182			if ((fromrp = fdopen(rpd[0], "r")) == NULL \|\|
183			(torp = fdopen(rpd[1], "w")) == NULL) {
184			fprintf(stderr, "%s: cannot open stream to %s\n",
185			progname, rpargv[0]);
186			exit(1);
187			}
188	greg	2.8	if ((pbuf = (COLR )malloc(hresvres*sizeof(COLR))) == NULL) {
189	greg	2.1	fprintf(stderr, "%s: out of memory\n", progname);
190			exit(1);
191			}
192	greg	2.6	signal(SIGALRM, onalrm);
193	greg	2.1	return;
194			filerr:
195	greg	2.8	fprintf(stderr, "%s: i/o error on file \"%s\"\n", progname, outfile);
196	greg	2.1	exit(1);
197			}
198
199
200			int
201	greg	2.5	nextpiece(xp, yp) /* get next piece assignment */
202			int xp, yp;
203			{
204			extern char *fgets();
205			struct flock fls;
206			char buf[64];
207
208	greg	2.6	if (gotalrm) /* someone wants us to quit */
209			return(0);
210			if (syncfd != -1) { /* use sync file */
211	greg	2.5	fls.l_type = F_WRLCK; /* gain exclusive access */
212			fls.l_whence = 0;
213			fls.l_start = 0L;
214			fls.l_len = 0L;
215			fcntl(syncfd, F_SETLKW, &fls);
216			lseek(syncfd, 0L, 0);
217			buf[read(syncfd, buf, sizeof(buf)-1)] = '\0';
218			if (sscanf(buf, "%d %d %d %d", xp, yp) < 2) {
219	greg	2.8	*xp = hmult-1;
220			*yp = vmult;
221			}
222			if (--(yp) < 0) { / decrement position */
223	greg	2.5	*yp = vmult-1;
224	greg	2.8	if (--(xp) < 0) { / all done! */
225	greg	2.5	close(syncfd);
226			return(0);
227			}
228			}
229			sprintf(buf, "%d %d\n%d %d\n", hmult, vmult, xp, yp);
230			lseek(syncfd, 0L, 0); /* write new position */
231			write(syncfd, buf, strlen(buf));
232			fls.l_type = F_UNLCK; /* release sync file */
233			fcntl(syncfd, F_SETLKW, &fls);
234			return(1);
235			}
236	greg	2.6	if (fgets(buf, sizeof(buf), stdin) == NULL) /* use stdin */
237	greg	2.5	return(0);
238			if (sscanf(buf, "%d %d", xp, yp) == 2)
239			return(1);
240			fprintf(stderr, "%s: input format error\n", progname);
241			exit(1);
242			}
243
244
245			int
246	greg	2.1	cleanup() /* close rpict process and clean up */
247			{
248			register int rpstat;
249
250	greg	2.8	free((char *)pbuf);
251	greg	2.1	fclose(torp);
252			fclose(fromrp);
253			rpstat = close_process(rpd);
254			if (rpstat == -1)
255			rpstat = 0;
256			return(rpstat);
257			}
258
259
260			rpiece() /* render picture piece by piece */
261			{
262			VIEW pview;
263			int xorg, yorg;
264
265	greg	2.5	while (nextpiece(&xorg, &yorg)) {
266	greg	2.1	copystruct(&pview, &ourview); /* compute view for piece */
267			switch (ourview.type) {
268			case VT_PER:
269			pview.horiz = 2.180./PIatan(
270			tan(PI/180./2.*ourview.horiz)/hmult );
271			pview.vert = 2.180./PIatan(
272			tan(PI/180./2.*ourview.vert)/vmult );
273			break;
274			case VT_PAR:
275			case VT_ANG:
276			pview.horiz = ourview.horiz / hmult;
277			pview.vert = ourview.vert / vmult;
278			break;
279			case VT_HEM:
280	greg	2.3	pview.horiz = 2.180./PIasin(
281			sin(PI/180./2.*ourview.horiz)/hmult );
282			pview.vert = 2.180./PIasin(
283			sin(PI/180./2.*ourview.vert)/vmult );
284			break;
285	greg	2.1	default:
286			fprintf(stderr, "%s: unknown view type '-vt%c'\n",
287			progname, ourview.type);
288			exit(1);
289			}
290			pview.hoff += xorg - 0.5*(hmult-1);
291			pview.voff += yorg - 0.5*(vmult-1);
292			fputs(VIEWSTR, torp);
293			fprintview(&pview, torp);
294			putc('\n', torp);
295			fflush(torp); /* assign piece to rpict */
296			putpiece(xorg, yorg); /* place piece in output */
297			if (verbose) { /* notify caller */
298	greg	2.5	printf("%d %d done\n", xorg, yorg);
299			fflush(stdout);
300	greg	2.1	}
301			}
302			}
303
304
305			putpiece(xpos, ypos) /* get next piece from rpict */
306			int xpos, ypos;
307			{
308	greg	2.7	struct flock fls;
309	greg	2.1	int hr, vr;
310	greg	2.8	register int y;
311			/* check bounds */
312	greg	2.5	if (xpos < 0 \| ypos < 0 \| xpos >= hmult \| ypos >= vmult) {
313			fprintf(stderr, "%s: requested piece (%d,%d) out of range\n",
314			progname, xpos, ypos);
315			exit(1);
316			}
317	greg	2.8	/* check header from rpict */
318			getheader(fromrp, NULL);
319			if (fscnresolu(&hr, &vr, fromrp) < 0 \|\| hr != hres \|\| vr != vres) {
320	greg	2.3	fprintf(stderr, "%s: resolution mismatch from %s\n",
321			progname, rpargv[0]);
322	greg	2.1	exit(1);
323			}
324	greg	2.8	/* load new piece into buffer */
325			for (y = 0; y < vr; y++)
326			if (freadcolrs(pbuf+y*hr, hr, fromrp) < 0) {
327	greg	2.3	fprintf(stderr, "%s: read error from %s\n",
328			progname, rpargv[0]);
329	greg	2.1	exit(1);
330			}
331	greg	2.8	/* lock file section so NFS doesn't mess up */
332			fls.l_whence = 0;
333			fls.l_len = (long)vreshmulthres*sizeof(COLR);
334			fls.l_start = scanorig + (vmult-1-ypos)*fls.l_len;
335			fls.l_type = F_WRLCK;
336			fcntl(outfd, F_SETLKW, &fls);
337			/* write new piece to file */
338			if (lseek(outfd, fls.l_start+(long)xposhressizeof(COLR), 0) == -1)
339			goto seekerr;
340			for (y = 0; y < vr; y++) {
341			if (writebuf(outfd, (char )(pbuf+yhr), hr*sizeof(COLR)) !=
342	greg	2.1	hr*sizeof(COLR)) {
343	greg	2.8	fprintf(stderr, "%s: write error on file \"%s\"\n",
344			progname, outfile);
345	greg	2.1	exit(1);
346			}
347	greg	2.8	if (hmult != 1 && y < vr-1 && lseek(outfd,
348			(long)(hmult-1)hrsizeof(COLR), 1) == -1)
349			goto seekerr;
350	greg	2.1	}
351	greg	2.8	/* unlock file section */
352			fls.l_type = F_UNLCK;
353			fcntl(outfd, F_SETLKW, &fls);
354			return;
355			seekerr:
356			fprintf(stderr, "%s: seek error on file \"%s\"\n", progname, outfile);
357			exit(1);
358	greg	2.1	}