| 7 |
|
/* |
| 8 |
|
* ambient.c - routines dealing with ambient (inter-reflected) component. |
| 9 |
|
* |
| 10 |
– |
* The macro AMBFLUSH (if defined) is the number of ambient values |
| 11 |
– |
* to wait before flushing to the ambient file. |
| 12 |
– |
* |
| 10 |
|
* 5/9/86 |
| 11 |
|
*/ |
| 12 |
|
|
| 39 |
|
|
| 40 |
|
static FILE *ambfp = NULL; /* ambient file pointer */ |
| 41 |
|
|
| 42 |
+ |
#define AMBFLUSH (BUFSIZ/AMBVALSIZ) |
| 43 |
+ |
|
| 44 |
|
#define newambval() (AMBVAL *)bmalloc(sizeof(AMBVAL)) |
| 45 |
|
|
| 46 |
|
#define newambtree() (AMBTREE *)calloc(8, sizeof(AMBTREE)) |
| 47 |
|
|
| 48 |
+ |
extern long ftell(), lseek(); |
| 49 |
+ |
static int initambfile(), avsave(), avinsert(), ambsync(); |
| 50 |
|
|
| 51 |
+ |
|
| 52 |
|
setambres(ar) /* set ambient resolution */ |
| 53 |
|
int ar; |
| 54 |
|
{ |
| 70 |
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setambient(afile) /* initialize calculation */ |
| 71 |
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char *afile; |
| 72 |
|
{ |
| 73 |
< |
long ftell(); |
| 73 |
> |
long headlen; |
| 74 |
|
AMBVAL amb; |
| 75 |
|
/* init ambient limits */ |
| 76 |
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setambres(ambres); |
| 77 |
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/* open ambient file */ |
| 78 |
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if (afile != NULL) |
| 79 |
|
if ((ambfp = fopen(afile, "r+")) != NULL) { |
| 80 |
< |
while (fread((char *)&amb,sizeof(AMBVAL),1,ambfp) == 1) |
| 80 |
> |
initambfile(0); |
| 81 |
> |
headlen = ftell(ambfp); |
| 82 |
> |
while (readambval(&amb, ambfp)) |
| 83 |
|
avinsert(&amb, &atrunk, thescene.cuorg, |
| 84 |
|
thescene.cusize); |
| 85 |
|
/* align */ |
| 86 |
< |
fseek(ambfp, -(ftell(ambfp)%sizeof(AMBVAL)), 1); |
| 87 |
< |
} else if ((ambfp = fopen(afile, "w")) == NULL) { |
| 86 |
> |
fseek(ambfp, -((ftell(ambfp)-headlen)%AMBVALSIZ), 1); |
| 87 |
> |
} else if ((ambfp = fopen(afile, "w+")) != NULL) |
| 88 |
> |
initambfile(1); |
| 89 |
> |
else { |
| 90 |
|
sprintf(errmsg, "cannot open ambient file \"%s\"", |
| 91 |
|
afile); |
| 92 |
|
error(SYSTEM, errmsg); |
| 270 |
|
VCOPY(amb.gpos, gp); |
| 271 |
|
VCOPY(amb.gdir, gd); |
| 272 |
|
/* insert into tree */ |
| 273 |
< |
avinsert(&amb, &atrunk, thescene.cuorg, thescene.cusize); |
| 268 |
< |
avsave(&amb); /* write to file */ |
| 273 |
> |
avsave(&amb); /* and save to file */ |
| 274 |
|
return(amb.rad); |
| 275 |
|
} |
| 276 |
|
|
| 302 |
|
|
| 303 |
|
|
| 304 |
|
static |
| 305 |
< |
avsave(av) /* save an ambient value */ |
| 305 |
> |
initambfile(creat) /* initialize ambient file */ |
| 306 |
> |
int creat; |
| 307 |
> |
{ |
| 308 |
> |
extern char *progname, *octname, VersionID[]; |
| 309 |
> |
|
| 310 |
> |
setbuf(ambfp, bmalloc(BUFSIZ)); |
| 311 |
> |
if (creat) { /* new file */ |
| 312 |
> |
fprintf(ambfp, "%s -av %g %g %g -ab %d -aa %g ", |
| 313 |
> |
progname, colval(ambval,RED), |
| 314 |
> |
colval(ambval,GRN), colval(ambval,BLU), |
| 315 |
> |
ambounce, ambacc); |
| 316 |
> |
fprintf(ambfp, "-ad %d -as %d -ar %d %s\n", |
| 317 |
> |
ambdiv, ambssamp, ambres, |
| 318 |
> |
octname==NULL ? "" : octname); |
| 319 |
> |
fprintf(ambfp, "SOFTWARE= %s\n", VersionID); |
| 320 |
> |
fputformat(AMBFMT, ambfp); |
| 321 |
> |
putc('\n', ambfp); |
| 322 |
> |
putambmagic(ambfp); |
| 323 |
> |
fflush(ambfp); |
| 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"); |
| 329 |
> |
} |
| 330 |
> |
|
| 331 |
> |
|
| 332 |
> |
static |
| 333 |
> |
avsave(av) /* insert and save an ambient value */ |
| 334 |
|
AMBVAL *av; |
| 335 |
|
{ |
| 303 |
– |
#ifdef AMBFLUSH |
| 336 |
|
static int nunflshed = 0; |
| 337 |
< |
#endif |
| 337 |
> |
|
| 338 |
> |
avinsert(av, &atrunk, thescene.cuorg, thescene.cusize); |
| 339 |
|
if (ambfp == NULL) |
| 340 |
|
return; |
| 341 |
< |
if (fwrite((char *)av, sizeof(AMBVAL), 1, ambfp) != 1) |
| 341 |
> |
if (writambval(av, ambfp) < 0) |
| 342 |
|
goto writerr; |
| 310 |
– |
#ifdef AMBFLUSH |
| 343 |
|
if (++nunflshed >= AMBFLUSH) { |
| 344 |
< |
if (fflush(ambfp) == EOF) |
| 344 |
> |
if (ambsync() == EOF) |
| 345 |
|
goto writerr; |
| 346 |
|
nunflshed = 0; |
| 347 |
|
} |
| 316 |
– |
#endif |
| 348 |
|
return; |
| 349 |
|
writerr: |
| 350 |
|
error(SYSTEM, "error writing ambient file"); |
| 386 |
|
memerr: |
| 387 |
|
error(SYSTEM, "out of memory in avinsert"); |
| 388 |
|
} |
| 389 |
+ |
|
| 390 |
+ |
|
| 391 |
+ |
#ifdef NIX |
| 392 |
+ |
|
| 393 |
+ |
static |
| 394 |
+ |
ambsync() /* flush ambient file */ |
| 395 |
+ |
{ |
| 396 |
+ |
return(fflush(ambfp)); |
| 397 |
+ |
} |
| 398 |
+ |
|
| 399 |
+ |
#else |
| 400 |
+ |
|
| 401 |
+ |
#include <fcntl.h> |
| 402 |
+ |
#include <sys/types.h> |
| 403 |
+ |
#include <sys/stat.h> |
| 404 |
+ |
|
| 405 |
+ |
static |
| 406 |
+ |
ambsync() /* synchronize ambient file */ |
| 407 |
+ |
{ |
| 408 |
+ |
static FILE *ambinp = NULL; |
| 409 |
+ |
struct flock fls; |
| 410 |
+ |
struct stat sts; |
| 411 |
+ |
AMBVAL avs; |
| 412 |
+ |
long lastpos, flen; |
| 413 |
+ |
register int n; |
| 414 |
+ |
/* gain exclusive access */ |
| 415 |
+ |
fls.l_type = F_WRLCK; |
| 416 |
+ |
fls.l_whence = 0; |
| 417 |
+ |
fls.l_start = 0L; |
| 418 |
+ |
fls.l_len = 0L; |
| 419 |
+ |
if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0) |
| 420 |
+ |
error(SYSTEM, "cannot lock ambient file"); |
| 421 |
+ |
/* see if file has grown */ |
| 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 |
+ |
if (n = (flen - lastpos)/AMBVALSIZ) { /* file has grown */ |
| 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 |
+ |
} /* 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 |
