1 |
< |
/* Copyright (c) 1992 Regents of the University of California */ |
1 |
> |
/* Copyright (c) 1993 Regents of the University of California */ |
2 |
|
|
3 |
|
#ifndef lint |
4 |
|
static char SCCSid[] = "$SunId$ LBL"; |
6 |
|
|
7 |
|
/* |
8 |
|
* ambient.c - routines dealing with ambient (inter-reflected) component. |
9 |
– |
* |
10 |
– |
* 5/9/86 |
9 |
|
*/ |
10 |
|
|
11 |
|
#include "ray.h" |
35 |
|
|
36 |
|
static AMBTREE atrunk; /* our ambient trunk node */ |
37 |
|
|
38 |
+ |
static char *ambfname = NULL; /* ambient file name */ |
39 |
|
static FILE *ambfp = NULL; /* ambient file pointer */ |
40 |
|
|
41 |
|
#define AMBFLUSH (BUFSIZ/AMBVALSIZ) |
74 |
|
/* init ambient limits */ |
75 |
|
setambres(ambres); |
76 |
|
/* open ambient file */ |
77 |
< |
if (afile != NULL) |
77 |
> |
if ((ambfname = afile) != NULL) |
78 |
|
if ((ambfp = fopen(afile, "r+")) != NULL) { |
79 |
|
initambfile(0); |
80 |
|
headlen = ftell(ambfp); |
166 |
|
FVECT c0; |
167 |
|
double s; |
168 |
|
{ |
170 |
– |
extern double sqrt(); |
169 |
|
double d, e1, e2, wt, wsum; |
170 |
|
COLOR ct; |
171 |
|
FVECT ck0; |
321 |
|
fputformat(AMBFMT, ambfp); |
322 |
|
putc('\n', ambfp); |
323 |
|
putambmagic(ambfp); |
326 |
– |
fflush(ambfp); |
327 |
– |
#ifndef NIX |
328 |
– |
sync(); /* protect against NFS buffering */ |
329 |
– |
#endif |
324 |
|
} else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp)) |
325 |
|
error(USER, "bad ambient file"); |
326 |
+ |
ambsync(); |
327 |
|
} |
328 |
|
|
329 |
|
|
396 |
|
|
397 |
|
#else |
398 |
|
|
404 |
– |
#include <fcntl.h> |
405 |
– |
#include <sys/types.h> |
406 |
– |
#include <sys/stat.h> |
407 |
– |
|
399 |
|
static |
400 |
|
ambsync() /* synchronize ambient file */ |
401 |
|
{ |
402 |
|
static FILE *ambinp = NULL; |
403 |
+ |
static long lastpos = -1; |
404 |
|
struct flock fls; |
405 |
< |
struct stat sts; |
405 |
> |
long flen; |
406 |
|
AMBVAL avs; |
415 |
– |
long lastpos, flen; |
407 |
|
register int n; |
408 |
|
/* gain exclusive access */ |
409 |
|
fls.l_type = F_WRLCK; |
412 |
|
fls.l_len = 0L; |
413 |
|
if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0) |
414 |
|
error(SYSTEM, "cannot lock ambient file"); |
415 |
+ |
if (lastpos < 0) /* initializing */ |
416 |
+ |
goto syncend; |
417 |
|
/* see if file has grown */ |
418 |
< |
lastpos = lseek(fileno(ambfp), 0L, 1); /* get previous position */ |
419 |
< |
if (fstat(fileno(ambfp), &sts) < 0) /* get current length */ |
420 |
< |
error(SYSTEM, "cannot stat ambient file"); |
421 |
< |
flen = sts.st_size; |
422 |
< |
if (n = (flen - lastpos)/AMBVALSIZ) { /* file has grown */ |
423 |
< |
if (ambinp == NULL) /* use duplicate file */ |
424 |
< |
ambinp = fdopen(dup(fileno(ambfp)), "r"); |
425 |
< |
while (n--) { /* load contributed values */ |
418 |
> |
if ((flen = lseek(fileno(ambfp), 0L, 2)) < 0) |
419 |
> |
error(SYSTEM, "cannot seek on ambient file"); |
420 |
> |
if (n = flen - lastpos) { /* file has grown */ |
421 |
> |
if (ambinp == NULL) { |
422 |
> |
ambinp = fopen(ambfname, "r"); |
423 |
> |
if (ambinp == NULL) |
424 |
> |
error(SYSTEM, "fopen failed in ambsync"); |
425 |
> |
} |
426 |
> |
if (fseek(ambinp, lastpos, 0) < 0) |
427 |
> |
error(SYSTEM, "fseek failed in ambsync"); |
428 |
> |
while (n >= AMBVALSIZ) { /* load contributed values */ |
429 |
|
readambval(&avs, ambinp); |
430 |
|
avinsert(&avs,&atrunk,thescene.cuorg,thescene.cusize); |
431 |
< |
} /* moves shared file pointer */ |
432 |
< |
if (n = (flen - lastpos)%AMBVALSIZ) /* alignment */ |
431 |
> |
n -= AMBVALSIZ; |
432 |
> |
} |
433 |
> |
if (n) /* alignment */ |
434 |
|
lseek(fileno(ambfp), flen-n, 0); |
435 |
|
} |
436 |
+ |
syncend: |
437 |
|
n = fflush(ambfp); /* calls write() at last */ |
438 |
+ |
lastpos = lseek(fileno(ambfp), 0L, 1); |
439 |
|
fls.l_type = F_UNLCK; /* release file */ |
440 |
|
fcntl(fileno(ambfp), F_SETLKW, &fls); |
441 |
|
return(n); |