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 |
– |
* to wait before flushing to the ambient file. |
12 |
– |
* |
10 |
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* 5/9/86 |
11 |
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*/ |
12 |
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|
39 |
|
|
40 |
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static FILE *ambfp = NULL; /* ambient file pointer */ |
41 |
|
|
42 |
+ |
#define AMBFLUSH (BUFSIZ/AMBVALSIZ) |
43 |
+ |
|
44 |
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#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 |
+ |
{ |
55 |
+ |
/* set min & max radii */ |
56 |
+ |
if (ar <= 0) { |
57 |
+ |
minarad = 0.0; |
58 |
+ |
maxarad = thescene.cusize / 2.0; |
59 |
+ |
} else { |
60 |
+ |
minarad = thescene.cusize / ar; |
61 |
+ |
maxarad = 16.0 * minarad; /* heuristic */ |
62 |
+ |
if (maxarad > thescene.cusize / 2.0) |
63 |
+ |
maxarad = thescene.cusize / 2.0; |
64 |
+ |
} |
65 |
+ |
if (maxarad <= FTINY) |
66 |
+ |
maxarad = .001; |
67 |
+ |
} |
68 |
+ |
|
69 |
+ |
|
70 |
|
setambient(afile) /* initialize calculation */ |
71 |
|
char *afile; |
72 |
|
{ |
73 |
< |
long ftell(); |
73 |
> |
long headlen; |
74 |
|
AMBVAL amb; |
75 |
< |
|
76 |
< |
maxarad = thescene.cusize / 2.0; /* maximum radius */ |
77 |
< |
/* minimum radius */ |
58 |
< |
minarad = ambres > 0 ? thescene.cusize/ambres : 0.0; |
59 |
< |
|
60 |
< |
/* open ambient file */ |
75 |
> |
/* init ambient limits */ |
76 |
> |
setambres(ambres); |
77 |
> |
/* open ambient file */ |
78 |
|
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); |
207 |
|
for (j = 0; j < 3; j++) |
208 |
|
d += (r->rop[j] - av->pos[j]) * |
209 |
|
(av->dir[j] + r->ron[j]); |
210 |
< |
if (d*0.5 < -minarad*ambacc) |
210 |
> |
if (d*0.5 < -minarad*ambacc-.001) |
211 |
|
continue; |
212 |
|
/* |
213 |
|
* Jittering final test reduces image artifacts. |
214 |
|
*/ |
215 |
|
wt = sqrt(e1) + sqrt(e2); |
216 |
< |
wt *= .9 + .2*frandom(); |
216 |
> |
wt *= .9 + .2*urand(9015+samplendx); |
217 |
|
if (wt > ambacc) |
218 |
|
continue; |
219 |
|
if (wt <= 1e-3) |
270 |
|
VCOPY(amb.gpos, gp); |
271 |
|
VCOPY(amb.gdir, gd); |
272 |
|
/* insert into tree */ |
273 |
< |
avinsert(&amb, &atrunk, thescene.cuorg, thescene.cusize); |
253 |
< |
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 |
|
{ |
288 |
– |
#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; |
295 |
– |
#ifdef AMBFLUSH |
343 |
|
if (++nunflshed >= AMBFLUSH) { |
344 |
< |
if (fflush(ambfp) == EOF) |
344 |
> |
if (ambsync() == EOF) |
345 |
|
goto writerr; |
346 |
|
nunflshed = 0; |
347 |
|
} |
301 |
– |
#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 |