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/* |
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* ambient.c - routines dealing with ambient (inter-reflected) component. |
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* |
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* The macro AMBFLUSH (if defined) is the number of ambient values |
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* to wait before flushing to the ambient file. |
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* |
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* 5/9/86 |
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*/ |
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|
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static AMBTREE atrunk; /* our ambient trunk node */ |
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static FILE *ambfp = NULL; /* ambient file pointer */ |
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static char *afname; /* ambient file name */ |
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static long ambheadlen; /* length of ambient file header */ |
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|
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#define AMBFLUSH (BUFSIZ/AMBVALSIZ) |
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#define newambtree() (AMBTREE *)calloc(8, sizeof(AMBTREE)) |
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extern long ftell(), lseek(); |
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static int initambfile(), avsave(), avinsert(), ambsync(); |
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setambres(ar) /* set ambient resolution */ |
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setambient(afile) /* initialize calculation */ |
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char *afile; |
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{ |
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long headlen; |
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AMBVAL amb; |
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/* init ambient limits */ |
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setambres(ambres); |
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/* open ambient file */ |
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if ((afname = afile) != NULL) |
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if (afile != NULL) |
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if ((ambfp = fopen(afile, "r+")) != NULL) { |
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initambfile(0); |
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headlen = ftell(ambfp); |
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while (readambval(&amb, ambfp)) |
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avinsert(&amb, &atrunk, thescene.cuorg, |
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thescene.cusize); |
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/* align */ |
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< |
fseek(ambfp, -((ftell(ambfp)-ambheadlen)%AMBVALSIZ), 1); |
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} else if ((ambfp = fopen(afile, "w")) != NULL) |
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fseek(ambfp, -((ftell(ambfp)-headlen)%AMBVALSIZ), 1); |
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} else if ((ambfp = fopen(afile, "w+")) != NULL) |
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initambfile(1); |
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else { |
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sprintf(errmsg, "cannot open ambient file \"%s\"", |
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} |
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initambfile(creat) /* initialize ambient file */ |
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int creat; |
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{ |
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extern char *progname, *octname; |
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|
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setbuf(ambfp, bmalloc(BUFSIZ)); |
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if (creat) { /* new file */ |
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fprintf(ambfp, "%s -av %g %g %g -ab %d -aa %g ", |
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progname, colval(ambval,RED), |
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colval(ambval,GRN), colval(ambval,BLU), |
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ambounce, ambacc); |
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fprintf(ambfp, "-ad %d -as %d -ar %d %s\n", |
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ambdiv, ambssamp, ambres, |
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octname==NULL ? "" : octname); |
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fputformat(AMBFMT, ambfp); |
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putc('\n', ambfp); |
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putambmagic(ambfp); |
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fflush(ambfp); |
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} else if (checkheader(ambfp, AMBFMT, NULL) < 0 |
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|| !hasambmagic(ambfp)) { |
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sprintf(errmsg, "\"%s\" is not an ambient file", afname); |
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error(USER, afname); |
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} |
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ambheadlen = ftell(ambfp); |
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} |
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|
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|
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ambnotify(obj) /* record new modifier */ |
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OBJECT obj; |
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{ |
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static |
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initambfile(creat) /* initialize ambient file */ |
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int creat; |
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{ |
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extern char *progname, *octname, VersionID[]; |
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|
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setbuf(ambfp, bmalloc(BUFSIZ)); |
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if (creat) { /* new file */ |
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fprintf(ambfp, "%s -av %g %g %g -ab %d -aa %g ", |
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progname, colval(ambval,RED), |
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colval(ambval,GRN), colval(ambval,BLU), |
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ambounce, ambacc); |
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fprintf(ambfp, "-ad %d -as %d -ar %d %s\n", |
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ambdiv, ambssamp, ambres, |
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octname==NULL ? "" : octname); |
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fprintf(ambfp, "SOFTWARE= %s\n", VersionID); |
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fputformat(AMBFMT, ambfp); |
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putc('\n', ambfp); |
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putambmagic(ambfp); |
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fflush(ambfp); |
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#ifndef NIX |
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sync(); /* protect against NFS buffering */ |
326 |
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#endif |
327 |
+ |
} else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp)) |
328 |
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error(USER, "bad ambient file"); |
329 |
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} |
330 |
+ |
|
331 |
+ |
|
332 |
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static |
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avsave(av) /* insert and save an ambient value */ |
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AMBVAL *av; |
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{ |
388 |
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} |
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|
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|
391 |
< |
#include <fcntl.h> |
391 |
> |
#ifdef NIX |
392 |
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|
393 |
+ |
static |
394 |
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ambsync() /* flush ambient file */ |
395 |
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{ |
396 |
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return(fflush(ambfp)); |
397 |
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} |
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|
399 |
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#else |
400 |
+ |
|
401 |
+ |
#include <fcntl.h> |
402 |
+ |
#include <sys/types.h> |
403 |
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#include <sys/stat.h> |
404 |
+ |
|
405 |
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static |
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ambsync() /* synchronize ambient file */ |
407 |
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{ |
408 |
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static FILE *ambinp = NULL; |
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struct flock fls; |
410 |
+ |
struct stat sts; |
411 |
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AMBVAL avs; |
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long lastpos, flen; |
413 |
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register int n; |
419 |
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if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0) |
420 |
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error(SYSTEM, "cannot lock ambient file"); |
421 |
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/* see if file has grown */ |
422 |
< |
lastpos = lseek(fileno(ambfp), 0L, 2); /* may move pointer */ |
423 |
< |
flen = lseek(fileno(ambfp), 0L, 1); /* new(?) file length */ |
424 |
< |
if (n = (flen - lastpos)%AMBVALSIZ) /* assure alignment */ |
425 |
< |
lseek(fileno(ambfp), flen -= n, 0); |
422 |
> |
lastpos = lseek(fileno(ambfp), 0L, 1); /* get previous position */ |
423 |
> |
if (fstat(fileno(ambfp), &sts) < 0) /* get current length */ |
424 |
> |
error(SYSTEM, "cannot stat ambient file"); |
425 |
> |
flen = sts.st_size; |
426 |
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if (n = (flen - lastpos)/AMBVALSIZ) { /* file has grown */ |
427 |
< |
if (ambinp == NULL && (ambinp = fopen(afname, "r")) == NULL) |
428 |
< |
error(SYSTEM, "cannot reopen ambient file"); |
418 |
< |
fseek(ambinp, lastpos, 0); /* go to previous position */ |
427 |
> |
if (ambinp == NULL) /* use duplicate file */ |
428 |
> |
ambinp = fdopen(dup(fileno(ambfp)), "r"); |
429 |
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while (n--) { /* load contributed values */ |
430 |
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readambval(&avs, ambinp); |
431 |
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avinsert(&avs,&atrunk,thescene.cuorg,thescene.cusize); |
432 |
< |
} |
432 |
> |
} /* moves shared file pointer */ |
433 |
> |
if (n = (flen - lastpos)%AMBVALSIZ) /* alignment */ |
434 |
> |
lseek(fileno(ambfp), flen-n, 0); |
435 |
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} |
436 |
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n = fflush(ambfp); /* calls write() at last */ |
437 |
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fls.l_type = F_UNLCK; /* release file */ |
438 |
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fcntl(fileno(ambfp), F_SETLKW, &fls); |
439 |
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return(n); |
440 |
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} |
441 |
+ |
|
442 |
+ |
#endif |