7 |
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/* |
8 |
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* ambient.c - routines dealing with ambient (inter-reflected) component. |
9 |
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* |
10 |
– |
* The macro AMBFLUSH (if defined) is the number of ambient values |
11 |
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* to wait before flushing to the ambient file. |
12 |
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* |
10 |
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* 5/9/86 |
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*/ |
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|
38 |
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static AMBTREE atrunk; /* our ambient trunk node */ |
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static FILE *ambfp = NULL; /* ambient file pointer */ |
44 |
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static char *afname; /* ambient file name */ |
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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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/* init ambient limits */ |
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setambres(ambres); |
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/* open ambient file */ |
78 |
< |
if ((afname = afile) != NULL) |
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> |
if (afile != NULL) |
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if ((ambfp = fopen(afile, "r+")) != NULL) { |
80 |
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initambfile(0); |
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headlen = ftell(ambfp); |
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thescene.cusize); |
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/* align */ |
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fseek(ambfp, -((ftell(ambfp)-headlen)%AMBVALSIZ), 1); |
87 |
< |
} else if ((ambfp = fopen(afile, "w")) != NULL) |
87 |
> |
} else if ((ambfp = fopen(afile, "w+")) != NULL) |
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initambfile(1); |
89 |
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else { |
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sprintf(errmsg, "cannot open ambient file \"%s\"", |
321 |
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putc('\n', ambfp); |
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putambmagic(ambfp); |
323 |
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fflush(ambfp); |
324 |
< |
} else if (checkheader(ambfp, AMBFMT, NULL) < 0 |
325 |
< |
|| !hasambmagic(ambfp)) { |
326 |
< |
sprintf(errmsg, "\"%s\" is not an ambient file", afname); |
327 |
< |
error(USER, errmsg); |
328 |
< |
} |
324 |
> |
#ifndef NIX |
325 |
> |
sync(); /* protect against NFS buffering */ |
326 |
> |
#endif |
327 |
> |
} else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp)) |
328 |
> |
error(USER, "bad ambient file"); |
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} |
330 |
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331 |
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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 |
+ |
ambsync() /* flush ambient file */ |
395 |
+ |
{ |
396 |
+ |
return(fflush(ambfp)); |
397 |
+ |
} |
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|
399 |
+ |
#else |
400 |
+ |
|
401 |
+ |
#include <fcntl.h> |
402 |
+ |
#include <sys/types.h> |
403 |
+ |
#include <sys/stat.h> |
404 |
+ |
|
405 |
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static |
406 |
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ambsync() /* synchronize ambient file */ |
407 |
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{ |
408 |
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static FILE *ambinp = NULL; |
409 |
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struct flock fls; |
410 |
+ |
struct stat sts; |
411 |
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AMBVAL avs; |
412 |
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long lastpos, flen; |
413 |
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register int n; |
420 |
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error(SYSTEM, "cannot lock ambient file"); |
421 |
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/* see if file has grown */ |
422 |
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lastpos = lseek(fileno(ambfp), 0L, 1); /* get previous position */ |
423 |
< |
flen = lseek(fileno(ambfp), 0L, 2); /* new(?) file length */ |
424 |
< |
if (n = (flen - lastpos)%AMBVALSIZ) /* assure alignment */ |
425 |
< |
lseek(fileno(ambfp), (long)-n, 1); |
423 |
> |
if (fstat(fileno(ambfp), &sts) < 0) /* get current length */ |
424 |
> |
error(SYSTEM, "cannot stat ambient file"); |
425 |
> |
flen = sts.st_size; |
426 |
|
if (n = (flen - lastpos)/AMBVALSIZ) { /* file has grown */ |
427 |
< |
if (ambinp == NULL && (ambinp = fopen(afname, "r")) == NULL) |
428 |
< |
error(SYSTEM, "cannot reopen ambient file"); |
420 |
< |
fseek(ambinp, lastpos, 0); /* go to previous position */ |
427 |
> |
if (ambinp == NULL) /* use duplicate file */ |
428 |
> |
ambinp = fdopen(dup(fileno(ambfp)), "r"); |
429 |
|
while (n--) { /* load contributed values */ |
430 |
|
readambval(&avs, ambinp); |
431 |
|
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 |
|
} |
436 |
|
n = fflush(ambfp); /* calls write() at last */ |
437 |
|
fls.l_type = F_UNLCK; /* release file */ |
438 |
|
fcntl(fileno(ambfp), F_SETLKW, &fls); |
439 |
|
return(n); |
440 |
|
} |
441 |
+ |
|
442 |
+ |
#endif |