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RadiancePmap/ambient.c
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ambient.c
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static const char RCSid[] = "$Id: ambient.c,v 2.114 2022/04/11 00:45:30 greg Exp $";
/*
* ambient.c - routines dealing with ambient (inter-reflected) component.
*
* Declarations of external symbols in ambient.h
*/
#include "copyright.h"
#include <string.h>
#include "platform.h"
#include "ray.h"
#include "otypes.h"
#include "otspecial.h"
#include "resolu.h"
#include "ambient.h"
#include "random.h"
#include "pmapamb.h"
#ifndef OCTSCALE
#define OCTSCALE 1.0 /* ceil((valid rad.)/(cube size)) */
#endif
#ifndef MAXASET
#define MAXASET 4095 /* maximum number of elements in ambient set */
#endif
OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */
double maxarad; /* maximum ambient radius */
double minarad; /* minimum ambient radius */
static AMBTREE atrunk; /* our ambient trunk node */
static FILE *ambfp = NULL; /* ambient file pointer */
static int nunflshed = 0; /* number of unflushed ambient values */
static double avsum = 0.; /* computed ambient value sum (log) */
static unsigned int navsum = 0; /* number of values in avsum */
static unsigned int nambvals = 0; /* total number of indirect values */
static unsigned int nambshare = 0; /* number of values from file */
static FILE *ambinp = NULL; /* auxiliary file for input */
static long lastpos = -1; /* last flush position */
#define AMBFLUSH (BUFSIZ/AMBVALSIZ)
#define newambval() (AMBVAL *)malloc(sizeof(AMBVAL))
#define tfunc(lwr, x, upr) (((x)-(lwr))/((upr)-(lwr)))
static void initambfile(int creat);
static void avsave(AMBVAL *av);
static AMBVAL *avstore(AMBVAL *aval);
static AMBTREE *newambtree(void);
static void freeambtree(AMBTREE *atp);
typedef void unloadtf_t(AMBVAL *);
static unloadtf_t avinsert;
static unloadtf_t avfree;
static void unloadatree(AMBTREE *at, unloadtf_t *f);
static void sortambvals(void);
static int plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang);
static double sumambient(COLOR acol, RAY *r, FVECT rn, int al,
AMBTREE *at, FVECT c0, double s);
static int makeambient(COLOR acol, RAY *r, FVECT rn, int al);
static int extambient(COLOR cr, AMBVAL *ap, FVECT pv, FVECT nv,
FVECT uvw[3]);
#ifdef F_SETLKW
static void aflock(int typ);
#endif
void
setambres( /* set ambient resolution */
int ar
)
{
ambres = ar < 0 ? 0 : ar; /* may be done already */
/* set min & max radii */
if (ar <= 0) {
minarad = 0;
maxarad = thescene.cusize*0.2;
} else {
minarad = thescene.cusize / ar;
maxarad = 64.0 * minarad; /* heuristic */
if (maxarad > thescene.cusize*0.2)
maxarad = thescene.cusize*0.2;
}
if (minarad <= FTINY)
minarad = 10.0*FTINY;
if (maxarad <= minarad)
maxarad = 64.0 * minarad;
}
void
setambacc( /* set ambient accuracy */
double newa
)
{
static double olda; /* remember previous setting here */
newa *= (newa > 0);
if (fabs(newa - olda) >= .05*(newa + olda)) {
ambacc = newa;
if (ambacc > FTINY && nambvals > 0)
sortambvals(); /* rebuild tree */
}
}
void
setambient(void) /* initialize calculation */
{
int readonly = 0;
long flen;
AMBVAL amb;
/* make sure we're fresh */
ambdone();
/* init ambient limits */
setambres(ambres);
setambacc(ambacc);
if (ambfile == NULL || !ambfile[0])
return;
if (ambacc <= FTINY) {
sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
ambfile);
error(WARNING, errmsg);
return;
}
/* open ambient file */
if ((ambfp = fopen(ambfile, "r+")) == NULL)
readonly = (ambfp = fopen(ambfile, "r")) != NULL;
if (ambfp != NULL) {
initambfile(0); /* file exists */
lastpos = ftell(ambfp);
while (readambval(&amb, ambfp))
avstore(&amb);
nambshare = nambvals; /* share loaded values */
if (readonly) {
sprintf(errmsg,
"loaded %u values from read-only ambient file",
nambvals);
error(WARNING, errmsg);
fclose(ambfp); /* close file so no writes */
ambfp = NULL;
return; /* avoid ambsync() */
}
/* align file pointer */
lastpos += (long)nambvals*AMBVALSIZ;
flen = lseek(fileno(ambfp), (off_t)0, SEEK_END);
if (flen != lastpos) {
sprintf(errmsg,
"ignoring last %ld values in ambient file (corrupted)",
(flen - lastpos)/AMBVALSIZ);
error(WARNING, errmsg);
fseek(ambfp, lastpos, SEEK_SET);
ftruncate(fileno(ambfp), (off_t)lastpos);
}
} else if ((ambfp = fopen(ambfile, "w+")) != NULL) {
initambfile(1); /* else create new file */
fflush(ambfp);
lastpos = ftell(ambfp);
} else {
sprintf(errmsg, "cannot open ambient file \"%s\"", ambfile);
error(SYSTEM, errmsg);
}
#ifdef F_SETLKW
aflock(F_UNLCK); /* release file */
#endif
}
void
ambdone(void) /* close ambient file and free memory */
{
if (ambfp != NULL) { /* close ambient file */
ambsync();
fclose(ambfp);
ambfp = NULL;
if (ambinp != NULL) {
fclose(ambinp);
ambinp = NULL;
}
lastpos = -1;
}
/* free ambient tree */
unloadatree(&atrunk, avfree);
/* reset state variables */
avsum = 0.;
navsum = 0;
nambvals = 0;
nambshare = 0;
}
void
ambnotify( /* record new modifier */
OBJECT obj
)
{
static int hitlimit = 0;
OBJREC *o;
char **amblp;
if (obj == OVOID) { /* starting over */
ambset[0] = 0;
hitlimit = 0;
return;
}
o = objptr(obj);
if (hitlimit || !ismodifier(o->otype))
return;
for (amblp = amblist; *amblp != NULL; amblp++)
if (!strcmp(o->oname, *amblp)) {
if (ambset[0] >= MAXASET) {
error(WARNING, "too many modifiers in ambient list");
hitlimit++;
return; /* should this be fatal? */
}
insertelem(ambset, obj);
return;
}
}
void
multambient( /* compute ambient component & multiply by coef. */
COLOR aval,
RAY *r,
FVECT nrm
)
{
static double logAvgAbsorp = 1;
static int rdepth = 0; /* ambient recursion */
COLOR acol, caustic;
int i, ok;
double d, l;
/* PMAP: Factor in ambient from photon map, if enabled and ray is
* ambient. Return as all ambient components accounted for, else
* continue. */
if (ambPmap(aval, r, rdepth))
return;
if (logAvgAbsorp > 0) /* exclude in -aw to avoid growth */
logAvgAbsorp = log(1.-AVGREFL);
/* PMAP: Factor in specular-diffuse ambient (caustics) from photon
* map, if enabled and ray is primary, else caustic is zero. Continue
* with RADIANCE ambient calculation */
copycolor(caustic, aval);
ambPmapCaustic(caustic, r, rdepth);
if (ambdiv <= 0) /* no ambient calculation */
goto dumbamb;
/* check number of bounces */
if (rdepth >= ambounce)
goto dumbamb;
/* check ambient list */
if (ambincl != -1 && r->ro != NULL &&
ambincl != inset(ambset, r->ro->omod))
goto dumbamb;
if (ambacc <= FTINY) { /* no ambient storage */
FVECT uvd[2];
float dgrad[2], *dgp = NULL;
if (nrm != r->ron && DOT(nrm,r->ron) < 0.9999)
dgp = dgrad; /* compute rotational grad. */
copycolor(acol, aval);
rdepth++;
ok = doambient(acol, r, r->rweight,
uvd, NULL, NULL, dgp, NULL);
rdepth--;
if (!ok)
goto dumbamb;
if ((ok > 0) & (dgp != NULL)) { /* apply texture */
FVECT v1;
VCROSS(v1, r->ron, nrm);
d = 1.0;
for (i = 3; i--; )
d += v1[i] * (dgp[0]*uvd[0][i] + dgp[1]*uvd[1][i]);
if (d >= 0.05)
scalecolor(acol, d);
}
copycolor(aval, acol);
/* PMAP: add in caustic */
addcolor(aval, caustic);
return;
}
/* interpolate ambient value */
setcolor(acol, 0.0, 0.0, 0.0);
d = sumambient(acol, r, nrm, rdepth,
&atrunk, thescene.cuorg, thescene.cusize);
if (d > FTINY) {
d = 1.0/d;
scalecolor(acol, d);
multcolor(aval, acol);
/* PMAP: add in caustic */
addcolor(aval, caustic);
return;
}
rdepth++; /* need to cache new value */
ok = makeambient(acol, r, nrm, rdepth-1);
rdepth--;
if (ok) {
multcolor(aval, acol); /* computed new value */
/* PMAP: add in caustic */
addcolor(aval, caustic);
return;
}
dumbamb: /* return global value */
if ((ambvwt <= 0) | (navsum == 0)) {
multcolor(aval, ambval);
/* PMAP: add in caustic */
addcolor(aval, caustic);
return;
}
l = bright(ambval); /* average in computations */
if (l > FTINY) {
d = (log(l)*(double)ambvwt + avsum + logAvgAbsorp*navsum) /
(double)(ambvwt + navsum);
d = exp(d) / l;
scalecolor(aval, d);
multcolor(aval, ambval); /* apply color of ambval */
} else {
d = exp( avsum/(double)navsum + logAvgAbsorp );
scalecolor(aval, d); /* neutral color */
}
}
/* Plug a potential leak where ambient cache value is occluded */
static int
plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang)
{
const double cost70sq = 0.1169778; /* cos(70deg)^2 */
RAY rtst;
FVECT vdif;
double normdot, ndotd, nadotd;
double a, b, c, t[2];
ang += 2.*PI*(ang < 0); /* check direction flags */
if ( !(ap->corral>>(int)(ang*(16./PI)) & 1) )
return(0);
/*
* Generate test ray, targeting 20 degrees above sample point plane
* along surface normal from cache position. This should be high
* enough to miss local geometry we don't really care about.
*/
VSUB(vdif, ap->pos, r->rop);
normdot = DOT(anorm, r->ron);
ndotd = DOT(vdif, r->ron);
nadotd = DOT(vdif, anorm);
a = normdot*normdot - cost70sq;
b = 2.0*(normdot*ndotd - nadotd*cost70sq);
c = ndotd*ndotd - DOT(vdif,vdif)*cost70sq;
if (quadratic(t, a, b, c) != 2)
return(1); /* should rarely happen */
if (t[1] <= FTINY)
return(0); /* should fail behind test */
rayorigin(&rtst, SHADOW, r, NULL);
VSUM(rtst.rdir, vdif, anorm, t[1]); /* further dist. > plane */
rtst.rmax = normalize(rtst.rdir); /* short ray test */
while (localhit(&rtst, &thescene)) { /* check for occluder */
OBJREC *m = findmaterial(rtst.ro);
if (m != NULL && !istransp(m->otype) && !isBSDFproxy(m) &&
(rtst.clipset == NULL ||
!inset(rtst.clipset, rtst.ro->omod)))
return(1); /* plug light leak */
VCOPY(rtst.rorg, rtst.rop); /* skip invisible surface */
rtst.rmax -= rtst.rot;
rayclear(&rtst);
}
return(0); /* seems we're OK */
}
static double
sumambient( /* get interpolated ambient value */
COLOR acol,
RAY *r,
FVECT rn,
int al,
AMBTREE *at,
FVECT c0,
double s
)
{ /* initial limit is 10 degrees plus ambacc radians */
const double minangle = 10.0 * PI/180.;
double maxangle = minangle + ambacc;
double wsum = 0.0;
FVECT ck0;
int i, j;
AMBVAL *av;
if (at->kid != NULL) { /* sum children first */
s *= 0.5;
for (i = 0; i < 8; i++) {
for (j = 0; j < 3; j++) {
ck0[j] = c0[j];
if (1<<j & i)
ck0[j] += s;
if (r->rop[j] < ck0[j] - OCTSCALE*s)
break;
if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
break;
}
if (j == 3)
wsum += sumambient(acol, r, rn, al,
at->kid+i, ck0, s);
}
/* good enough? */
if (wsum >= 0.05 && s > minarad*10.0)
return(wsum);
}
/* adjust maximum angle */
if (at->alist != NULL && (at->alist->lvl <= al) & (r->rweight < 0.6))
maxangle = (maxangle - PI/2.)*pow(r->rweight,0.13) + PI/2.;
/* sum this node */
for (av = at->alist; av != NULL; av = av->next) {
double u, v, d, delta_r2, delta_t2;
COLOR ct;
FVECT uvw[3];
/*
* Ambient level test
*/
if (av->lvl > al || /* list sorted, so this works */
(av->lvl == al) & (av->weight < 0.9*r->rweight))
break;
/*
* Direction test using unperturbed normal
*/
decodedir(uvw[2], av->ndir);
d = DOT(uvw[2], r->ron);
if (d <= 0.0) /* >= 90 degrees */
continue;
delta_r2 = 2.0 - 2.0*d; /* approx. radians^2 */
if (delta_r2 >= maxangle*maxangle)
continue;
/*
* Modified ray behind test
*/
VSUB(ck0, r->rop, av->pos);
d = DOT(ck0, uvw[2]);
if (d < -minarad*ambacc-.001)
continue;
d /= av->rad[0];
delta_t2 = d*d;
if (delta_t2 >= ambacc*ambacc)
continue;
/*
* Elliptical radii test based on Hessian
*/
decodedir(uvw[0], av->udir);
VCROSS(uvw[1], uvw[2], uvw[0]);
d = (u = DOT(ck0, uvw[0])) / av->rad[0];
delta_t2 += d*d;
d = (v = DOT(ck0, uvw[1])) / av->rad[1];
delta_t2 += d*d;
if (delta_t2 >= ambacc*ambacc)
continue;
/*
* Test for potential light leak
*/
if (av->corral && plugaleak(r, av, uvw[2], atan2a(v,u)))
continue;
/*
* Extrapolate value and compute final weight (hat function)
*/
if (!extambient(ct, av, r->rop, rn, uvw))
continue;
d = tfunc(maxangle, sqrt(delta_r2), 0.0) *
tfunc(ambacc, sqrt(delta_t2), 0.0);
scalecolor(ct, d);
addcolor(acol, ct);
wsum += d;
}
return(wsum);
}
static int
makeambient( /* make a new ambient value for storage */
COLOR acol,
RAY *r,
FVECT rn,
int al
)
{
AMBVAL amb;
FVECT uvw[3];
int i;
amb.weight = 1.0; /* compute weight */
for (i = al; i-- > 0; )
amb.weight *= AVGREFL;
if (r->rweight < 0.1*amb.weight) /* heuristic override */
amb.weight = 1.25*r->rweight;
setcolor(acol, AVGREFL, AVGREFL, AVGREFL);
/* compute ambient */
i = doambient(acol, r, amb.weight,
uvw, amb.rad, amb.gpos, amb.gdir, &amb.corral);
scalecolor(acol, 1./AVGREFL); /* undo assumed reflectance */
if (i <= 0 || amb.rad[0] <= FTINY) /* no Hessian or zero radius */
return(i);
/* store value */
VCOPY(amb.pos, r->rop);
amb.ndir = encodedir(r->ron);
amb.udir = encodedir(uvw[0]);
amb.lvl = al;
copycolor(amb.val, acol);
/* insert into tree */
avsave(&amb); /* and save to file */
if (rn != r->ron) { /* texture */
VCOPY(uvw[2], r->ron);
extambient(acol, &amb, r->rop, rn, uvw);
}
return(1);
}
static int
extambient( /* extrapolate value at pv, nv */
COLOR cr,
AMBVAL *ap,
FVECT pv,
FVECT nv,
FVECT uvw[3]
)
{
const double min_d = 0.05;
const double max_d = 20.;
static FVECT my_uvw[3];
FVECT v1;
int i;
double d = 1.0; /* zeroeth order */
if (uvw == NULL) { /* need local coordinates? */
decodedir(my_uvw[2], ap->ndir);
decodedir(my_uvw[0], ap->udir);
VCROSS(my_uvw[1], my_uvw[2], my_uvw[0]);
uvw = my_uvw;
}
for (i = 3; i--; ) /* gradient due to translation */
d += (pv[i] - ap->pos[i]) *
(ap->gpos[0]*uvw[0][i] + ap->gpos[1]*uvw[1][i]);
VCROSS(v1, uvw[2], nv); /* gradient due to rotation */
for (i = 3; i--; )
d += v1[i] * (ap->gdir[0]*uvw[0][i] + ap->gdir[1]*uvw[1][i]);
if (d < min_d) /* clamp min/max scaling */
d = min_d;
else if (d > max_d)
d = max_d;
copycolor(cr, ap->val);
scalecolor(cr, d);
return(d > min_d);
}
static void
avinsert( /* insert ambient value in our tree */
AMBVAL *av
)
{
AMBTREE *at;
AMBVAL *ap;
AMBVAL avh;
FVECT ck0;
double s;
int branch;
int i;
if (av->rad[0] <= FTINY)
error(CONSISTENCY, "zero ambient radius in avinsert");
at = &atrunk;
VCOPY(ck0, thescene.cuorg);
s = thescene.cusize;
while (s*(OCTSCALE/2) > av->rad[1]*ambacc) {
if (at->kid == NULL)
if ((at->kid = newambtree()) == NULL)
error(SYSTEM, "out of memory in avinsert");
s *= 0.5;
branch = 0;
for (i = 0; i < 3; i++)
if (av->pos[i] > ck0[i] + s) {
ck0[i] += s;
branch |= 1 << i;
}
at = at->kid + branch;
}
avh.next = at->alist; /* order by increasing level */
for (ap = &avh; ap->next != NULL; ap = ap->next)
if ( ap->next->lvl > av->lvl ||
(ap->next->lvl == av->lvl) &
(ap->next->weight <= av->weight) )
break;
av->next = ap->next;
ap->next = (AMBVAL*)av;
at->alist = avh.next;
}
static void
initambfile( /* initialize ambient file */
int cre8
)
{
extern char *progname, *octname;
static char *mybuf = NULL;
#ifdef F_SETLKW
aflock(cre8 ? F_WRLCK : F_RDLCK);
#endif
SET_FILE_BINARY(ambfp);
if (mybuf == NULL)
mybuf = (char *)bmalloc(BUFSIZ+8);
setbuf(ambfp, mybuf);
if (cre8) { /* new file */
newheader("RADIANCE", ambfp);
fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
progname, colval(ambval,RED),
colval(ambval,GRN), colval(ambval,BLU),
ambvwt, ambounce, ambacc);
fprintf(ambfp, "-ad %d -as %d -ar %d ",
ambdiv, ambssamp, ambres);
fprintf(ambfp, "-dt %g -dc %g -ss %g -lr %d -lw %g ",
shadthresh, shadcert, specjitter,
maxdepth, minweight);
if (octname != NULL)
fputs(octname, ambfp);
fputc('\n', ambfp);
fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
fputnow(ambfp);
fputformat(AMBFMT, ambfp);
fputc('\n', ambfp);
putambmagic(ambfp);
} else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
error(USER, "bad ambient file");
}
static void
avsave( /* insert and save an ambient value */
AMBVAL *av
)
{
avstore(av);
if (ambfp == NULL)
return;
if (writambval(av, ambfp) < 0)
goto writerr;
if (++nunflshed >= AMBFLUSH)
if (ambsync() == EOF)
goto writerr;
return;
writerr:
error(SYSTEM, "error writing to ambient file");
}
static AMBVAL *
avstore( /* allocate memory and save aval */
AMBVAL *aval
)
{
AMBVAL *av;
double d;
if ((av = newambval()) == NULL)
error(SYSTEM, "out of memory in avstore");
*av = *aval;
av->next = NULL;
nambvals++;
d = bright(av->val);
if (d > FTINY) { /* add to log sum for averaging */
avsum += log(d);
navsum++;
}
avinsert(av); /* insert in our cache tree */
return(av);
}
#define ATALLOCSZ 512 /* #/8 trees to allocate at once */
static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
static AMBTREE *
newambtree(void) /* allocate 8 ambient tree structs */
{
AMBTREE *atp, *upperlim;
if (atfreelist == NULL) { /* get more nodes */
atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
if (atfreelist == NULL)
return(NULL);
/* link new free list */
upperlim = atfreelist + 8*(ATALLOCSZ-1);
for (atp = atfreelist; atp < upperlim; atp += 8)
atp->kid = atp + 8;
atp->kid = NULL;
}
atp = atfreelist;
atfreelist = atp->kid;
memset(atp, 0, 8*sizeof(AMBTREE));
return(atp);
}
static void
freeambtree( /* free 8 ambient tree structs */
AMBTREE *atp
)
{
atp->kid = atfreelist;
atfreelist = atp;
}
static void
unloadatree( /* unload an ambient value tree */
AMBTREE *at,
unloadtf_t *f
)
{
AMBVAL *av;
int i;
/* transfer values at this node */
for (av = at->alist; av != NULL; av = at->alist) {
at->alist = av->next;
av->next = NULL;
(*f)(av);
}
if (at->kid == NULL)
return;
for (i = 0; i < 8; i++) /* transfer and free children */
unloadatree(at->kid+i, f);
freeambtree(at->kid);
at->kid = NULL;
}
static void
avfree(AMBVAL *av)
{
free(av);
}
static void
sortambvals(void) /* resort ambient values */
{
AMBTREE oldatrunk = atrunk;
atrunk.alist = NULL;
atrunk.kid = NULL;
unloadatree(&oldatrunk, avinsert);
}
#ifdef F_SETLKW
static void
aflock( /* lock/unlock ambient file */
int typ
)
{
static struct flock fls; /* static so initialized to zeroes */
if (typ == fls.l_type) /* already called? */
return;
fls.l_type = typ;
do
if (fcntl(fileno(ambfp), F_SETLKW, &fls) != -1)
return;
while (errno == EINTR);
error(SYSTEM, "cannot (un)lock ambient file");
}
int
ambsync(void) /* synchronize ambient file */
{
long flen;
AMBVAL avs;
int n;
if (ambfp == NULL) /* no ambient file? */
return(0);
/* gain appropriate access */
aflock(nunflshed ? F_WRLCK : F_RDLCK);
/* see if file has grown */
if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
goto seekerr;
if ((n = flen - lastpos) > 0) { /* file has grown */
if (ambinp == NULL) { /* get new file pointer */
ambinp = fopen(ambfile, "rb");
if (ambinp == NULL)
error(SYSTEM, "fopen failed in ambsync");
}
if (fseek(ambinp, lastpos, SEEK_SET) < 0)
goto seekerr;
while (n >= AMBVALSIZ) { /* load contributed values */
if (!readambval(&avs, ambinp)) {
sprintf(errmsg,
"ambient file \"%s\" corrupted near character %ld",
ambfile, flen - n);
error(WARNING, errmsg);
break;
}
avstore(&avs);
n -= AMBVALSIZ;
}
lastpos = flen - n; /* check alignment */
if (n && lseek(fileno(ambfp), (off_t)lastpos, SEEK_SET) < 0)
goto seekerr;
}
n = fflush(ambfp); /* calls write() at last */
lastpos += (long)nunflshed*AMBVALSIZ;
aflock(F_UNLCK); /* release file */
nunflshed = 0;
return(n);
seekerr:
error(SYSTEM, "seek failed in ambsync");
return(EOF); /* pro forma return */
}
#else /* ! F_SETLKW */
int
ambsync(void) /* flush ambient file */
{
if (ambfp == NULL)
return(0);
nunflshed = 0;
return(fflush(ambfp));
}
#endif /* ! F_SETLKW */
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