src/rt/ambient.c

/* Copyright (c) 1993 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 *  ambient.c - routines dealing with ambient (inter-reflected) component.
 */

#include  "ray.h"

#include  "octree.h"

#include  "otypes.h"

#include  "ambient.h"

#include  "random.h"

#define  OCTSCALE       0.5     /* ceil((valid rad.)/(cube size)) */

typedef struct ambtree {
        AMBVAL  *alist;         /* ambient value list */
        struct ambtree  *kid;   /* 8 child nodes */
}  AMBTREE;                     /* ambient octree */

extern CUBE  thescene;          /* contains space boundaries */

#define  MAXASET        511     /* maximum number of elements in ambient set */
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 */

#define  AMBFLUSH       (BUFSIZ/AMBVALSIZ)

#define  newambval()    (AMBVAL *)bmalloc(sizeof(AMBVAL))

#define  newambtree()   (AMBTREE *)calloc(8, sizeof(AMBTREE))
#define  freeambtree(t) free((char *)(t))

extern long  ftell(), lseek();
static int  initambfile(), avsave(), avinsert(), loadatree();
static AMBVAL  *avstore();
#ifdef  F_SETLKW
static  aflock();
#endif


setambres(ar)                           /* 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 / 2.0;
        } else {
                minarad = thescene.cusize / ar;
                maxarad = 16 * minarad;                 /* heuristic */
                if (maxarad > thescene.cusize / 2.0)
                        maxarad = thescene.cusize / 2.0;
        }
        if (minarad <= FTINY)
                minarad = 10*FTINY;
        if (maxarad <= minarad)
                maxarad = 64 * minarad;
}


setambacc(newa)                         /* set ambient accuracy */
double  newa;
{
        static double  oldambacc = -1.0;
        AMBTREE  oldatrunk;

        ambacc = newa < 0.0 ? 0.0 : newa;       /* may be done already */
        if (oldambacc < -FTINY)
                oldambacc = ambacc;     /* do nothing first call */
        if (fabs(newa - oldambacc) < 0.01)
                return;                 /* insignificant -- don't bother */
        if (ambacc <= FTINY)
                return;                 /* cannot build new tree */
                                        /* else need to rebuild tree */
        copystruct(&oldatrunk, &atrunk);
        atrunk.alist = NULL;
        atrunk.kid = NULL;
        loadatree(&oldatrunk);
        oldambacc = ambacc;             /* remeber setting for next call */
}


setambient(afile)                       /* initialize calculation */
char  *afile;
{
        long  headlen;
        AMBVAL  amb;
                                                /* init ambient limits */
        setambres(ambres);
        setambacc(ambacc);
        if (afile == NULL)
                return;
        if (ambacc <= FTINY) {
                sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
                                afile);
                error(WARNING, errmsg);
                return;
        }
                                                /* open ambient file */
        if ((ambfp = fopen(afile, "r+")) != NULL) {
                initambfile(0);
                headlen = ftell(ambfp);
                while (readambval(&amb, ambfp))
                        avinsert(avstore(&amb));
                                                /* align */
                fseek(ambfp, -((ftell(ambfp)-headlen)%AMBVALSIZ), 1);
        } else if ((ambfp = fopen(afile, "w+")) != NULL)
                initambfile(1);
        else {
                sprintf(errmsg, "cannot open ambient file \"%s\"", afile);
                error(SYSTEM, errmsg);
        }
        nunflshed++;    /* lie */
        ambsync();
}


ambnotify(obj)                  /* record new modifier */
OBJECT  obj;
{
        static int  hitlimit = 0;
        register OBJREC  *o = objptr(obj);
        register char  **amblp;

        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;
                }
}


ambient(acol, r)                /* compute ambient component for ray */
COLOR  acol;
register RAY  *r;
{
        static int  rdepth = 0;                 /* ambient recursion */
        double  d;

        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 */
                rdepth++;
                d = doambient(acol, r, r->rweight, NULL, NULL);
                rdepth--;
                if (d == 0.0)
                        goto dumbamb;
                return;
        }
                                                /* get ambient value */
        setcolor(acol, 0.0, 0.0, 0.0);
        d = sumambient(acol, r, rdepth,
                        &atrunk, thescene.cuorg, thescene.cusize);
        if (d > FTINY)
                scalecolor(acol, 1.0/d);
        else {
                d = makeambient(acol, r, rdepth++);
                rdepth--;
        }
        if (d > FTINY)
                return;
dumbamb:                                        /* return global value */
        copycolor(acol, ambval);
}


double
sumambient(acol, r, al, at, c0, s)      /* get interpolated ambient value */
COLOR  acol;
register RAY  *r;
int  al;
AMBTREE  *at;
FVECT  c0;
double  s;
{
        double  d, e1, e2, wt, wsum;
        COLOR  ct;
        FVECT  ck0;
        int  i;
        register int  j;
        register AMBVAL  *av;
                                        /* do this node */
        wsum = 0.0;
        for (av = at->alist; av != NULL; av = av->next) {
                /*
                 *  Ambient level test.
                 */
                if (av->lvl > al)       /* list sorted, so this works */
                        break;
                if (av->weight < r->rweight-FTINY)
                        continue;
                /*
                 *  Ambient radius test.
                 */
                e1 = 0.0;
                for (j = 0; j < 3; j++) {
                        d = av->pos[j] - r->rop[j];
                        e1 += d * d;
                }
                e1 /= av->rad * av->rad;
                if (e1 > ambacc*ambacc*1.21)
                        continue;
                /*
                 *  Normal direction test.
                 */
                e2 = (1.0 - DOT(av->dir, r->ron)) * r->rweight;
                if (e2 < 0.0) e2 = 0.0;
                if (e1 + e2 > ambacc*ambacc*1.21)
                        continue;
                /*
                 *  Ray behind test.
                 */
                d = 0.0;
                for (j = 0; j < 3; j++)
                        d += (r->rop[j] - av->pos[j]) *
                                        (av->dir[j] + r->ron[j]);
                if (d*0.5 < -minarad*ambacc-.001)
                        continue;
                /*
                 *  Jittering final test reduces image artifacts.
                 */
                wt = sqrt(e1) + sqrt(e2);
                wt *= .9 + .2*urand(9015+samplendx);
                if (wt > ambacc)
                        continue;
                if (wt <= 1e-3)
                        wt = 1e3;
                else
                        wt = 1.0 / wt;
                wsum += wt;
                extambient(ct, av, r->rop, r->ron);
                scalecolor(ct, wt);
                addcolor(acol, ct);
        }
        if (at->kid == NULL)
                return(wsum);
                                        /* do children */
        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, al, at->kid+i, ck0, s);
        }
        return(wsum);
}


double
makeambient(acol, r, al)        /* make a new ambient value */
COLOR  acol;
register RAY  *r;
int  al;
{
        AMBVAL  amb;
        FVECT   gp, gd;
                                                /* compute weight */
        amb.weight = pow(AVGREFL, (double)al);
        if (r->rweight < 0.2*amb.weight)        /* heuristic */
                amb.weight = r->rweight;
                                                /* compute ambient */
        amb.rad = doambient(acol, r, amb.weight, gp, gd);
        if (amb.rad == 0.0)
                return(0.0);
                                                /* store it */
        VCOPY(amb.pos, r->rop);
        VCOPY(amb.dir, r->ron);
        amb.lvl = al;
        copycolor(amb.val, acol);
        VCOPY(amb.gpos, gp);
        VCOPY(amb.gdir, gd);
                                                /* insert into tree */
        avsave(&amb);                           /* and save to file */
        return(amb.rad);
}


extambient(cr, ap, pv, nv)              /* extrapolate value at pv, nv */
COLOR  cr;
register AMBVAL  *ap;
FVECT  pv, nv;
{
        FVECT  v1, v2;
        register int  i;
        double  d;

        d = 1.0;                        /* zeroeth order */
                                        /* gradient due to translation */
        for (i = 0; i < 3; i++)
                d += ap->gpos[i]*(pv[i]-ap->pos[i]);
                                        /* gradient due to rotation */
        VCOPY(v1, ap->dir);
        fcross(v2, v1, nv);
        d += DOT(ap->gdir, v2);
        if (d <= 0.0) {
                setcolor(cr, 0.0, 0.0, 0.0);
                return;
        }
        copycolor(cr, ap->val);
        scalecolor(cr, d);
}


static
initambfile(creat)              /* initialize ambient file */
int  creat;
{
        extern char  *progname, *octname, VersionID[];

#ifdef  F_SETLKW
        aflock(creat ? F_WRLCK : F_RDLCK);
#endif
#ifdef MSDOS
        setmode(fileno(ambfp), O_BINARY);
#endif
        setbuf(ambfp, bmalloc(BUFSIZ+8));
        if (creat) {                    /* new file */
                newheader("RADIANCE", ambfp);
                fprintf(ambfp, "%s -av %g %g %g -ab %d -aa %g ",
                                progname, colval(ambval,RED),
                                colval(ambval,GRN), colval(ambval,BLU),
                                ambounce, ambacc);
                fprintf(ambfp, "-ad %d -as %d -ar %d %s\n",
                                ambdiv, ambssamp, ambres,
                                octname==NULL ? "" : octname);
                fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
                fputformat(AMBFMT, ambfp);
                putc('\n', ambfp);
                putambmagic(ambfp);
        } else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
                error(USER, "bad ambient file");
}


static
avsave(av)                              /* insert and save an ambient value */
AMBVAL  *av;
{
        avinsert(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 ambient file");
}


static AMBVAL *
avstore(aval)                           /* allocate memory and store aval */
register AMBVAL  *aval;
{
        register AMBVAL  *av;

        if ((av = newambval()) == NULL)
                error(SYSTEM, "out of memory in avstore");
        copystruct(av, aval);
        return(av);
}


static
avinsert(av)                            /* insert ambient value in our tree */
register AMBVAL  *av;
{
        register AMBTREE  *at;
        register AMBVAL  *ap;
        AMBVAL  avh;
        FVECT  ck0;
        double  s;
        int  branch;
        register int  i;

        if (av->rad <= FTINY)
                error(CONSISTENCY, "zero ambient radius in avinsert");
        at = &atrunk;
        VCOPY(ck0, thescene.cuorg);
        s = thescene.cusize;
        while (s*(OCTSCALE/2) > av->rad*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)
                        break;
        av->next = ap->next;
        ap->next = av;
        at->alist = avh.next;
}


static
loadatree(at)                           /* move tree to main store */
register AMBTREE  *at;
{
        register AMBVAL  *av;
        register int  i;
                                        /* transfer values at this node */
        for (av = at->alist; av != NULL; av = at->alist) {
                at->alist = av->next;
                avinsert(av);
        }
        if (at->kid == NULL)
                return;
        for (i = 0; i < 8; i++)         /* transfer and free children */
                loadatree(at->kid+i);
        freeambtree(at->kid);
}


#ifdef  F_SETLKW

static
aflock(typ)                     /* lock/unlock ambient file */
int  typ;
{
        static struct flock  fls;       /* static so initialized to zeroes */

        fls.l_type = typ;
        if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
                error(SYSTEM, "cannot (un)lock ambient file");
}


int
ambsync()                       /* synchronize ambient file */
{
        static FILE  *ambinp = NULL;
        static long  lastpos = -1;
        long  flen;
        AMBVAL  avs;
        register int  n;

        if (nunflshed == 0)
                return(0);
        if (lastpos < 0)        /* initializing (locked in initambfile) */
                goto syncend;
                                /* gain exclusive access */
        aflock(F_WRLCK);
                                /* see if file has grown */
        if ((flen = lseek(fileno(ambfp), 0L, 2)) < 0)
                goto seekerr;
        if (n = flen - lastpos) {               /* file has grown */
                if (ambinp == NULL) {           /* use duplicate filedes */
                        ambinp = fdopen(dup(fileno(ambfp)), "r");
                        if (ambinp == NULL)
                                error(SYSTEM, "fdopen failed in ambsync");
                }
                if (fseek(ambinp, lastpos, 0) < 0)
                        goto seekerr;
                while (n >= AMBVALSIZ) {        /* load contributed values */
                        readambval(&avs, ambinp);
                        avinsert(avstore(&avs));
                        n -= AMBVALSIZ;
                }
                /*** seek always as safety measure
                if (n) ***/                     /* alignment */
                        if (lseek(fileno(ambfp), flen-n, 0) < 0)
                                goto seekerr;
        }
#ifdef  DEBUG
        if (ambfp->_ptr - ambfp->_base != nunflshed*AMBVALSIZ) {
                sprintf(errmsg, "ambient file buffer at %d rather than %d",
                                ambfp->_ptr - ambfp->_base,
                                nunflshed*AMBVALSIZ);
                error(CONSISTENCY, errmsg);
        }
#endif
syncend:
        n = fflush(ambfp);                      /* calls write() at last */
        if ((lastpos = lseek(fileno(ambfp), 0L, 1)) < 0)
                goto seekerr;
        aflock(F_UNLCK);                        /* release file */
        nunflshed = 0;
        return(n);
seekerr:
        error(SYSTEM, "seek failed in ambsync");
}

#else

int
ambsync()                       /* flush ambient file */
{
        if (nunflshed == 0)
                return(0);
        nunflshed = 0;
        return(fflush(ambfp));
}

#endif
Revision:	2.25
Committed:	Thu Jun 2 11:45:27 1994 UTC (29 years, 11 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.24:	+6 -4 lines
Log Message:	changed setting of minarad for -ar 0
#	User	Rev	Content
1	greg	2.15	/* Copyright (c) 1993 Regents of the University of California */
2	greg	1.1
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* ambient.c - routines dealing with ambient (inter-reflected) component.
9			*/
10
11			#include "ray.h"
12
13			#include "octree.h"
14
15	greg	1.8	#include "otypes.h"
16
17	greg	1.14	#include "ambient.h"
18
19	greg	1.1	#include "random.h"
20
21	greg	2.12	#define OCTSCALE 0.5 /* ceil((valid rad.)/(cube size)) */
22	greg	1.1
23	greg	1.14	typedef struct ambtree {
24	greg	2.12	AMBVAL alist; / ambient value list */
25			struct ambtree kid; / 8 child nodes */
26	greg	1.14	} AMBTREE; /* ambient octree */
27
28	greg	1.1	extern CUBE thescene; /* contains space boundaries */
29
30	greg	2.12	#define MAXASET 511 /* maximum number of elements in ambient set */
31			OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */
32	greg	1.1
33	greg	2.12	double maxarad; /* maximum ambient radius */
34			double minarad; /* minimum ambient radius */
35	greg	1.1
36	greg	2.12	static AMBTREE atrunk; /* our ambient trunk node */
37	greg	1.1
38			static FILE ambfp = NULL; / ambient file pointer */
39	greg	2.16	static int nunflshed = 0; /* number of unflushed ambient values */
40	greg	1.1
41	greg	2.12	#define AMBFLUSH (BUFSIZ/AMBVALSIZ)
42	greg	2.6
43	greg	2.12	#define newambval() (AMBVAL *)bmalloc(sizeof(AMBVAL))
44	greg	1.1
45	greg	2.12	#define newambtree() (AMBTREE *)calloc(8, sizeof(AMBTREE))
46	greg	2.20	#define freeambtree(t) free((char *)(t))
47	greg	1.1
48	greg	2.7	extern long ftell(), lseek();
49	greg	2.21	static int initambfile(), avsave(), avinsert(), loadatree();
50	greg	2.20	static AMBVAL *avstore();
51	greg	2.19	#ifdef F_SETLKW
52			static aflock();
53			#endif
54	greg	1.1
55	greg	2.7
56	greg	2.3	setambres(ar) /* set ambient resolution */
57			int ar;
58			{
59	greg	2.21	ambres = ar < 0 ? 0 : ar; /* may be done already */
60	greg	2.3	/* set min & max radii */
61			if (ar <= 0) {
62	greg	2.25	minarad = 0;
63	greg	2.3	maxarad = thescene.cusize / 2.0;
64			} else {
65			minarad = thescene.cusize / ar;
66	greg	2.25	maxarad = 16 * minarad; /* heuristic */
67	greg	2.3	if (maxarad > thescene.cusize / 2.0)
68			maxarad = thescene.cusize / 2.0;
69			}
70	greg	2.25	if (minarad <= FTINY)
71			minarad = 10*FTINY;
72			if (maxarad <= minarad)
73			maxarad = 64 * minarad;
74	greg	2.3	}
75
76
77	greg	2.21	setambacc(newa) /* set ambient accuracy */
78	greg	2.20	double newa;
79			{
80	greg	2.21	static double oldambacc = -1.0;
81	greg	2.20	AMBTREE oldatrunk;
82
83	greg	2.21	ambacc = newa < 0.0 ? 0.0 : newa; /* may be done already */
84			if (oldambacc < -FTINY)
85			oldambacc = ambacc; /* do nothing first call */
86			if (fabs(newa - oldambacc) < 0.01)
87	greg	2.20	return; /* insignificant -- don't bother */
88			if (ambacc <= FTINY)
89			return; /* cannot build new tree */
90			/* else need to rebuild tree */
91			copystruct(&oldatrunk, &atrunk);
92			atrunk.alist = NULL;
93			atrunk.kid = NULL;
94	greg	2.21	loadatree(&oldatrunk);
95			oldambacc = ambacc; /* remeber setting for next call */
96	greg	2.20	}
97
98
99	greg	1.1	setambient(afile) /* initialize calculation */
100			char *afile;
101			{
102	greg	2.9	long headlen;
103	greg	2.12	AMBVAL amb;
104	greg	2.3	/* init ambient limits */
105			setambres(ambres);
106	greg	2.21	setambacc(ambacc);
107	greg	2.19	if (afile == NULL)
108			return;
109	greg	2.20	if (ambacc <= FTINY) {
110	greg	2.21	sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
111	greg	2.20	afile);
112			error(WARNING, errmsg);
113			return;
114			}
115	greg	2.3	/* open ambient file */
116	greg	2.19	if ((ambfp = fopen(afile, "r+")) != NULL) {
117			initambfile(0);
118			headlen = ftell(ambfp);
119			while (readambval(&amb, ambfp))
120	greg	2.21	avinsert(avstore(&amb));
121	greg	2.19	/* align */
122			fseek(ambfp, -((ftell(ambfp)-headlen)%AMBVALSIZ), 1);
123			} else if ((ambfp = fopen(afile, "w+")) != NULL)
124			initambfile(1);
125			else {
126			sprintf(errmsg, "cannot open ambient file \"%s\"", afile);
127			error(SYSTEM, errmsg);
128	greg	2.16	}
129	greg	2.19	nunflshed++; /* lie */
130			ambsync();
131	greg	1.8	}
132
133
134			ambnotify(obj) /* record new modifier */
135	greg	2.12	OBJECT obj;
136	greg	1.8	{
137	greg	1.11	static int hitlimit = 0;
138	greg	2.12	register OBJREC *o = objptr(obj);
139	greg	1.8	register char **amblp;
140
141	greg	1.11	if (hitlimit \|\| !ismodifier(o->otype))
142	greg	1.8	return;
143			for (amblp = amblist; *amblp != NULL; amblp++)
144			if (!strcmp(o->oname, *amblp)) {
145	greg	1.11	if (ambset[0] >= MAXASET) {
146			error(WARNING, "too many modifiers in ambient list");
147			hitlimit++;
148			return; /* should this be fatal? */
149			}
150	greg	1.8	insertelem(ambset, obj);
151			return;
152	greg	1.1	}
153			}
154
155
156			ambient(acol, r) /* compute ambient component for ray */
157			COLOR acol;
158			register RAY *r;
159			{
160			static int rdepth = 0; /* ambient recursion */
161	greg	2.12	double d;
162	greg	1.1
163			if (ambdiv <= 0) /* no ambient calculation */
164			goto dumbamb;
165			/* check number of bounces */
166	greg	1.16	if (rdepth >= ambounce)
167	greg	1.1	goto dumbamb;
168			/* check ambient list */
169			if (ambincl != -1 && r->ro != NULL &&
170			ambincl != inset(ambset, r->ro->omod))
171			goto dumbamb;
172
173			if (ambacc <= FTINY) { /* no ambient storage */
174	greg	1.16	rdepth++;
175			d = doambient(acol, r, r->rweight, NULL, NULL);
176			rdepth--;
177			if (d == 0.0)
178	greg	1.1	goto dumbamb;
179	greg	1.16	return;
180	greg	1.1	}
181			/* get ambient value */
182			setcolor(acol, 0.0, 0.0, 0.0);
183	greg	1.16	d = sumambient(acol, r, rdepth,
184			&atrunk, thescene.cuorg, thescene.cusize);
185			if (d > FTINY)
186			scalecolor(acol, 1.0/d);
187			else {
188			d = makeambient(acol, r, rdepth++);
189			rdepth--;
190			}
191			if (d > FTINY)
192			return;
193	greg	1.1	dumbamb: /* return global value */
194			copycolor(acol, ambval);
195			}
196
197
198			double
199	greg	1.16	sumambient(acol, r, al, at, c0, s) /* get interpolated ambient value */
200	greg	1.1	COLOR acol;
201			register RAY *r;
202	greg	1.16	int al;
203	greg	2.12	AMBTREE *at;
204	greg	1.1	FVECT c0;
205	greg	2.12	double s;
206	greg	1.1	{
207	greg	2.12	double d, e1, e2, wt, wsum;
208	greg	1.1	COLOR ct;
209			FVECT ck0;
210			int i;
211			register int j;
212	greg	2.12	register AMBVAL *av;
213	greg	1.7	/* do this node */
214	greg	1.1	wsum = 0.0;
215			for (av = at->alist; av != NULL; av = av->next) {
216			/*
217	greg	1.16	* Ambient level test.
218	greg	1.1	*/
219	greg	2.23	if (av->lvl > al) /* list sorted, so this works */
220			break;
221			if (av->weight < r->rweight-FTINY)
222	greg	1.1	continue;
223			/*
224			* Ambient radius test.
225			*/
226			e1 = 0.0;
227			for (j = 0; j < 3; j++) {
228			d = av->pos[j] - r->rop[j];
229			e1 += d * d;
230			}
231			e1 /= av->rad * av->rad;
232			if (e1 > ambaccambacc1.21)
233			continue;
234			/*
235			* Normal direction test.
236			*/
237			e2 = (1.0 - DOT(av->dir, r->ron)) * r->rweight;
238			if (e2 < 0.0) e2 = 0.0;
239			if (e1 + e2 > ambaccambacc1.21)
240			continue;
241			/*
242			* Ray behind test.
243			*/
244			d = 0.0;
245			for (j = 0; j < 3; j++)
246			d += (r->rop[j] - av->pos[j]) *
247			(av->dir[j] + r->ron[j]);
248	greg	1.18	if (d0.5 < -minaradambacc-.001)
249	greg	1.1	continue;
250			/*
251			* Jittering final test reduces image artifacts.
252			*/
253			wt = sqrt(e1) + sqrt(e2);
254	greg	2.2	wt = .9 + .2urand(9015+samplendx);
255	greg	1.6	if (wt > ambacc)
256	greg	1.1	continue;
257			if (wt <= 1e-3)
258			wt = 1e3;
259			else
260			wt = 1.0 / wt;
261			wsum += wt;
262	greg	1.15	extambient(ct, av, r->rop, r->ron);
263	greg	1.1	scalecolor(ct, wt);
264			addcolor(acol, ct);
265	greg	1.7	}
266			if (at->kid == NULL)
267			return(wsum);
268			/* do children */
269			s *= 0.5;
270			for (i = 0; i < 8; i++) {
271			for (j = 0; j < 3; j++) {
272			ck0[j] = c0[j];
273			if (1<<j & i)
274			ck0[j] += s;
275			if (r->rop[j] < ck0[j] - OCTSCALE*s)
276			break;
277			if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
278			break;
279			}
280			if (j == 3)
281	greg	1.16	wsum += sumambient(acol, r, al, at->kid+i, ck0, s);
282	greg	1.1	}
283			return(wsum);
284			}
285
286
287			double
288	greg	1.16	makeambient(acol, r, al) /* make a new ambient value */
289	greg	1.1	COLOR acol;
290			register RAY *r;
291	greg	1.16	int al;
292	greg	1.1	{
293	greg	2.12	AMBVAL amb;
294	greg	1.14	FVECT gp, gd;
295	greg	1.16	/* compute weight */
296			amb.weight = pow(AVGREFL, (double)al);
297	greg	1.17	if (r->rweight < 0.2amb.weight) / heuristic */
298	greg	1.16	amb.weight = r->rweight;
299			/* compute ambient */
300			amb.rad = doambient(acol, r, amb.weight, gp, gd);
301	greg	1.1	if (amb.rad == 0.0)
302			return(0.0);
303			/* store it */
304			VCOPY(amb.pos, r->rop);
305			VCOPY(amb.dir, r->ron);
306	greg	1.16	amb.lvl = al;
307	greg	1.1	copycolor(amb.val, acol);
308	greg	1.14	VCOPY(amb.gpos, gp);
309			VCOPY(amb.gdir, gd);
310	greg	1.1	/* insert into tree */
311	greg	2.7	avsave(&amb); /* and save to file */
312	greg	1.1	return(amb.rad);
313	greg	1.15	}
314
315
316			extambient(cr, ap, pv, nv) /* extrapolate value at pv, nv */
317			COLOR cr;
318	greg	2.12	register AMBVAL *ap;
319	greg	1.15	FVECT pv, nv;
320			{
321			FVECT v1, v2;
322			register int i;
323	greg	2.12	double d;
324	greg	1.15
325			d = 1.0; /* zeroeth order */
326			/* gradient due to translation */
327			for (i = 0; i < 3; i++)
328			d += ap->gpos[i]*(pv[i]-ap->pos[i]);
329			/* gradient due to rotation */
330			VCOPY(v1, ap->dir);
331			fcross(v2, v1, nv);
332			d += DOT(ap->gdir, v2);
333			if (d <= 0.0) {
334			setcolor(cr, 0.0, 0.0, 0.0);
335			return;
336			}
337			copycolor(cr, ap->val);
338			scalecolor(cr, d);
339	greg	1.1	}
340
341
342			static
343	greg	2.9	initambfile(creat) /* initialize ambient file */
344			int creat;
345			{
346			extern char progname, octname, VersionID[];
347
348	greg	2.19	#ifdef F_SETLKW
349			aflock(creat ? F_WRLCK : F_RDLCK);
350			#endif
351	greg	2.12	#ifdef MSDOS
352			setmode(fileno(ambfp), O_BINARY);
353			#endif
354	greg	2.21	setbuf(ambfp, bmalloc(BUFSIZ+8));
355	greg	2.9	if (creat) { /* new file */
356	greg	2.24	newheader("RADIANCE", ambfp);
357	greg	2.9	fprintf(ambfp, "%s -av %g %g %g -ab %d -aa %g ",
358			progname, colval(ambval,RED),
359			colval(ambval,GRN), colval(ambval,BLU),
360			ambounce, ambacc);
361			fprintf(ambfp, "-ad %d -as %d -ar %d %s\n",
362			ambdiv, ambssamp, ambres,
363			octname==NULL ? "" : octname);
364			fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
365			fputformat(AMBFMT, ambfp);
366			putc('\n', ambfp);
367			putambmagic(ambfp);
368	greg	2.17	} else if (checkheader(ambfp, AMBFMT, NULL) < 0 \|\| !hasambmagic(ambfp))
369			error(USER, "bad ambient file");
370	greg	2.9	}
371
372
373			static
374	greg	2.7	avsave(av) /* insert and save an ambient value */
375	greg	2.12	AMBVAL *av;
376	greg	1.1	{
377	greg	2.21	avinsert(avstore(av));
378	greg	1.1	if (ambfp == NULL)
379			return;
380	greg	2.5	if (writambval(av, ambfp) < 0)
381	greg	1.1	goto writerr;
382	greg	2.16	if (++nunflshed >= AMBFLUSH)
383	greg	2.7	if (ambsync() == EOF)
384	greg	1.1	goto writerr;
385			return;
386			writerr:
387	greg	2.17	error(SYSTEM, "error writing ambient file");
388	greg	1.1	}
389
390
391	greg	2.20	static AMBVAL *
392			avstore(aval) /* allocate memory and store aval */
393			register AMBVAL *aval;
394			{
395			register AMBVAL *av;
396
397			if ((av = newambval()) == NULL)
398			error(SYSTEM, "out of memory in avstore");
399			copystruct(av, aval);
400			return(av);
401			}
402
403
404	greg	1.1	static
405	greg	2.21	avinsert(av) /* insert ambient value in our tree */
406	greg	2.20	register AMBVAL *av;
407	greg	1.1	{
408	greg	2.21	register AMBTREE *at;
409	greg	2.23	register AMBVAL *ap;
410			AMBVAL avh;
411	greg	1.1	FVECT ck0;
412	greg	2.21	double s;
413	greg	1.1	int branch;
414			register int i;
415
416	greg	2.20	if (av->rad <= FTINY)
417			error(CONSISTENCY, "zero ambient radius in avinsert");
418	greg	2.21	at = &atrunk;
419			VCOPY(ck0, thescene.cuorg);
420			s = thescene.cusize;
421	greg	1.1	while (s(OCTSCALE/2) > av->radambacc) {
422			if (at->kid == NULL)
423			if ((at->kid = newambtree()) == NULL)
424	greg	2.20	error(SYSTEM, "out of memory in avinsert");
425	greg	1.1	s *= 0.5;
426			branch = 0;
427			for (i = 0; i < 3; i++)
428			if (av->pos[i] > ck0[i] + s) {
429			ck0[i] += s;
430			branch \|= 1 << i;
431			}
432			at = at->kid + branch;
433			}
434	greg	2.23	avh.next = at->alist; /* order by increasing level */
435			for (ap = &avh; ap->next != NULL; ap = ap->next)
436			if (ap->next->lvl >= av->lvl)
437			break;
438			av->next = ap->next;
439			ap->next = av;
440			at->alist = avh.next;
441	greg	2.7	}
442
443
444	greg	2.20	static
445	greg	2.21	loadatree(at) /* move tree to main store */
446	greg	2.20	register AMBTREE *at;
447			{
448			register AMBVAL *av;
449			register int i;
450			/* transfer values at this node */
451			for (av = at->alist; av != NULL; av = at->alist) {
452			at->alist = av->next;
453	greg	2.21	avinsert(av);
454	greg	2.20	}
455	greg	2.21	if (at->kid == NULL)
456			return;
457	greg	2.20	for (i = 0; i < 8; i++) /* transfer and free children */
458	greg	2.21	loadatree(at->kid+i);
459	greg	2.20	freeambtree(at->kid);
460			}
461
462
463	greg	2.18	#ifdef F_SETLKW
464	greg	2.10
465	greg	2.19	static
466			aflock(typ) /* lock/unlock ambient file */
467			int typ;
468			{
469			static struct flock fls; /* static so initialized to zeroes */
470
471			fls.l_type = typ;
472			if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
473			error(SYSTEM, "cannot (un)lock ambient file");
474			}
475
476
477	greg	2.16	int
478	greg	2.7	ambsync() /* synchronize ambient file */
479			{
480			static FILE *ambinp = NULL;
481	greg	2.15	static long lastpos = -1;
482			long flen;
483	greg	2.12	AMBVAL avs;
484	greg	2.7	register int n;
485	greg	2.16
486			if (nunflshed == 0)
487			return(0);
488	greg	2.19	if (lastpos < 0) /* initializing (locked in initambfile) */
489			goto syncend;
490	greg	2.7	/* gain exclusive access */
491	greg	2.19	aflock(F_WRLCK);
492	greg	2.7	/* see if file has grown */
493	greg	2.15	if ((flen = lseek(fileno(ambfp), 0L, 2)) < 0)
494	greg	2.21	goto seekerr;
495	greg	2.15	if (n = flen - lastpos) { /* file has grown */
496	greg	2.17	if (ambinp == NULL) { /* use duplicate filedes */
497			ambinp = fdopen(dup(fileno(ambfp)), "r");
498	greg	2.14	if (ambinp == NULL)
499	greg	2.17	error(SYSTEM, "fdopen failed in ambsync");
500	greg	2.14	}
501	greg	2.15	if (fseek(ambinp, lastpos, 0) < 0)
502	greg	2.21	goto seekerr;
503	greg	2.15	while (n >= AMBVALSIZ) { /* load contributed values */
504	greg	2.7	readambval(&avs, ambinp);
505	greg	2.21	avinsert(avstore(&avs));
506	greg	2.15	n -= AMBVALSIZ;
507			}
508	greg	2.22	/*** seek always as safety measure
509			if (n) **/ / alignment */
510	greg	2.21	if (lseek(fileno(ambfp), flen-n, 0) < 0)
511			goto seekerr;
512	greg	2.7	}
513	greg	2.21	#ifdef DEBUG
514			if (ambfp->_ptr - ambfp->_base != nunflshed*AMBVALSIZ) {
515			sprintf(errmsg, "ambient file buffer at %d rather than %d",
516			ambfp->_ptr - ambfp->_base,
517			nunflshed*AMBVALSIZ);
518			error(CONSISTENCY, errmsg);
519			}
520			#endif
521	greg	2.15	syncend:
522	greg	2.7	n = fflush(ambfp); /* calls write() at last */
523	greg	2.21	if ((lastpos = lseek(fileno(ambfp), 0L, 1)) < 0)
524			goto seekerr;
525	greg	2.19	aflock(F_UNLCK); /* release file */
526	greg	2.16	nunflshed = 0;
527	greg	2.7	return(n);
528	greg	2.21	seekerr:
529			error(SYSTEM, "seek failed in ambsync");
530	greg	2.18	}
531
532			#else
533
534			int
535			ambsync() /* flush ambient file */
536			{
537			if (nunflshed == 0)
538			return(0);
539			nunflshed = 0;
540			return(fflush(ambfp));
541	greg	1.1	}
542	greg	2.10
543			#endif