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root/radiance/ray/src/rt/ambient.c

Comparing ray/src/rt/ambient.c (file contents):
Revision 2.19 by greg, Wed Aug 4 14:22:11 1993 UTC vs.
Revision 2.78 by greg, Thu Apr 24 19:16:52 2014 UTC

#	Line 1 | Line 1
1	–	/* Copyright (c) 1993 Regents of the University of California */
2	–
1		#ifndef lint
2	<	static char SCCSid[] = "$SunId$ LBL";
2	>	static const char       RCSid[] = "$Id$";
3		#endif
6	–
4		/*
5		*  ambient.c - routines dealing with ambient (inter-reflected) component.
6	+	*
7	+	*  Declarations of external symbols in ambient.h
8		*/
9
10	<	#include  "ray.h"
10	>	#include "copyright.h"
11
12	<	#include  "octree.h"
12	>	#include <string.h>
13
14	+	#include  "platform.h"
15	+	#include  "ray.h"
16		#include  "otypes.h"
17	<
17	>	#include  "resolu.h"
18		#include  "ambient.h"
18	–
19		#include  "random.h"
20
21	<	#define  OCTSCALE       0.5     /* ceil((valid rad.)/(cube size)) */
21	>	#ifndef  OCTSCALE
22	>	#define  OCTSCALE       1.0     /* ceil((valid rad.)/(cube size)) */
23	>	#endif
24
25	<	typedef struct ambtree {
24	<	AMBVAL  *alist;         /* ambient value list */
25	<	struct ambtree  *kid;   /* 8 child nodes */
26	<	}  AMBTREE;                     /* ambient octree */
25	>	extern char  *shm_boundary;     /* memory sharing boundary */
26
27	<	extern CUBE  thescene;          /* contains space boundaries */
28	<
29	<	#define  MAXASET        511     /* maximum number of elements in ambient set */
27	>	#ifndef  MAXASET
28	>	#define  MAXASET        4095    /* maximum number of elements in ambient set */
29	>	#endif
30		OBJECT  ambset[MAXASET+1]={0};  /* ambient include/exclude set */
31
32		double  maxarad;                /* maximum ambient radius */
#	Line 38 | Line 37 | static AMBTREE atrunk;         /* our ambient trunk node */
37		static FILE  *ambfp = NULL;     /* ambient file pointer */
38		static int  nunflshed = 0;      /* number of unflushed ambient values */
39
40	+	#ifndef SORT_THRESH
41	+	#ifdef SMLMEM
42	+	#define SORT_THRESH     ((16L<<20)/sizeof(AMBVAL))
43	+	#else
44	+	#define SORT_THRESH     ((64L<<20)/sizeof(AMBVAL))
45	+	#endif
46	+	#endif
47	+	#ifndef SORT_INTVL
48	+	#define SORT_INTVL      (SORT_THRESH<<1)
49	+	#endif
50	+	#ifndef MAX_SORT_INTVL
51	+	#define MAX_SORT_INTVL  (SORT_INTVL<<6)
52	+	#endif
53	+
54	+
55	+	static double  qambacc = 0.;            /* ambient accuracy to the 1/4 power */
56	+	static double  avsum = 0.;              /* computed ambient value sum (log) */
57	+	static unsigned int  navsum = 0;        /* number of values in avsum */
58	+	static unsigned int  nambvals = 0;      /* total number of indirect values */
59	+	static unsigned int  nambshare = 0;     /* number of values from file */
60	+	static unsigned long  ambclock = 0;     /* ambient access clock */
61	+	static unsigned long  lastsort = 0;     /* time of last value sort */
62	+	static long  sortintvl = SORT_INTVL;    /* time until next sort */
63	+	static FILE  *ambinp = NULL;            /* auxiliary file for input */
64	+	static long  lastpos = -1;              /* last flush position */
65	+
66	+	#define MAXACLOCK       (1L<<30)        /* clock turnover value */
67	+	/*
68	+	* Track access times unless we are sharing ambient values
69	+	* through memory on a multiprocessor, when we want to avoid
70	+	* claiming our own memory (copy on write).  Go ahead anyway
71	+	* if more than two thirds of our values are unshared.
72	+	* Compile with -Dtracktime=0 to turn this code off.
73	+	*/
74	+	#ifndef tracktime
75	+	#define tracktime       (shm_boundary == NULL || nambvals > 3*nambshare)
76	+	#endif
77	+
78		#define  AMBFLUSH       (BUFSIZ/AMBVALSIZ)
79
80	<	#define  newambval()    (AMBVAL *)bmalloc(sizeof(AMBVAL))
80	>	#define  newambval()    (AMBVAL *)malloc(sizeof(AMBVAL))
81	>	#define  freeav(av)     free((void *)av);
82
83	<	#define  newambtree()   (AMBTREE *)calloc(8, sizeof(AMBTREE))
83	>	static void initambfile(int creat);
84	>	static void avsave(AMBVAL *av);
85	>	static AMBVAL *avstore(AMBVAL  *aval);
86	>	static AMBTREE *newambtree(void);
87	>	static void freeambtree(AMBTREE  *atp);
88
89	<	extern long  ftell(), lseek();
90	<	static int  initambfile(), avsave(), avinsert();
89	>	typedef void unloadtf_t(AMBVAL *);
90	>	static unloadtf_t avinsert;
91	>	static unloadtf_t av2list;
92	>	static unloadtf_t avfree;
93	>	static void unloadatree(AMBTREE  *at, unloadtf_t *f);
94	>
95	>	static int aposcmp(const void *avp1, const void *avp2);
96	>	static int avlmemi(AMBVAL *avaddr);
97	>	static void sortambvals(int always);
98	>
99		#ifdef  F_SETLKW
100	<	static  aflock();
100	>	static void aflock(int  typ);
101		#endif
102
103
104	<	setambres(ar)                           /* set ambient resolution */
105	<	int  ar;
104	>	void
105	>	setambres(                              /* set ambient resolution */
106	>	int  ar
107	>	)
108		{
109	+	ambres = ar < 0 ? 0 : ar;               /* may be done already */
110		/* set min & max radii */
111		if (ar <= 0) {
112	<	minarad = 0.0;
112	>	minarad = 0;
113		maxarad = thescene.cusize / 2.0;
114		} else {
115		minarad = thescene.cusize / ar;
116	<	maxarad = 16.0 * minarad;               /* heuristic */
116	>	maxarad = 64 * minarad;                 /* heuristic */
117		if (maxarad > thescene.cusize / 2.0)
118		maxarad = thescene.cusize / 2.0;
119		}
120	<	if (maxarad <= FTINY)
121	<	maxarad = .001;
120	>	if (minarad <= FTINY)
121	>	minarad = 10*FTINY;
122	>	if (maxarad <= minarad)
123	>	maxarad = 64 * minarad;
124		}
125
126
127	<	setambient(afile)                       /* initialize calculation */
128	<	char  *afile;
127	>	void
128	>	setambacc(                              /* set ambient accuracy */
129	>	double  newa
130	>	)
131		{
132	<	long  headlen;
132	>	double  ambdiff;
133	>
134	>	if (newa < 0.0)
135	>	newa = 0.0;
136	>	ambdiff = fabs(newa - ambacc);
137	>	if (ambdiff >= .01 && (ambacc = newa) > FTINY) {
138	>	qambacc = sqrt(sqrt(ambacc));
139	>	if (nambvals > 0)
140	>	sortambvals(1);         /* rebuild tree */
141	>	}
142	>	}
143	>
144	>
145	>	void
146	>	setambient(void)                                /* initialize calculation */
147	>	{
148	>	int     readonly = 0;
149	>	long    flen;
150		AMBVAL  amb;
151	+	/* make sure we're fresh */
152	+	ambdone();
153		/* init ambient limits */
154		setambres(ambres);
155	<	if (afile == NULL)
155	>	qambacc = sqrt(sqrt(ambacc *= (ambacc > FTINY)));
156	>	if (ambfile == NULL || !ambfile[0])
157		return;
158	+	if (ambacc <= FTINY) {
159	+	sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
160	+	ambfile);
161	+	error(WARNING, errmsg);
162	+	return;
163	+	}
164		/* open ambient file */
165	<	if ((ambfp = fopen(afile, "r+")) != NULL) {
166	<	initambfile(0);
167	<	headlen = ftell(ambfp);
165	>	if ((ambfp = fopen(ambfile, "r+")) == NULL)
166	>	readonly = (ambfp = fopen(ambfile, "r")) != NULL;
167	>	if (ambfp != NULL) {
168	>	initambfile(0);                 /* file exists */
169	>	lastpos = ftell(ambfp);
170		while (readambval(&amb, ambfp))
171	<	avinsert(&amb, &atrunk, thescene.cuorg,
172	<	thescene.cusize);
173	<	/* align */
174	<	fseek(ambfp, -((ftell(ambfp)-headlen)%AMBVALSIZ), 1);
175	<	} else if ((ambfp = fopen(afile, "w+")) != NULL)
176	<	initambfile(1);
177	<	else {
178	<	sprintf(errmsg, "cannot open ambient file \"%s\"", afile);
171	>	avinsert(avstore(&amb));
172	>	nambshare = nambvals;           /* share loaded values */
173	>	if (readonly) {
174	>	sprintf(errmsg,
175	>	"loaded %u values from read-only ambient file",
176	>	nambvals);
177	>	error(WARNING, errmsg);
178	>	fclose(ambfp);          /* close file so no writes */
179	>	ambfp = NULL;
180	>	return;                 /* avoid ambsync() */
181	>	}
182	>	/* align file pointer */
183	>	lastpos += (long)nambvals*AMBVALSIZ;
184	>	flen = lseek(fileno(ambfp), (off_t)0, SEEK_END);
185	>	if (flen != lastpos) {
186	>	sprintf(errmsg,
187	>	"ignoring last %ld values in ambient file (corrupted)",
188	>	(flen - lastpos)/AMBVALSIZ);
189	>	error(WARNING, errmsg);
190	>	fseek(ambfp, lastpos, SEEK_SET);
191	>	#ifndef _WIN32 /* XXX we need a replacement for that one */
192	>	ftruncate(fileno(ambfp), (off_t)lastpos);
193	>	#endif
194	>	}
195	>	} else if ((ambfp = fopen(ambfile, "w+")) != NULL) {
196	>	initambfile(1);                 /* else create new file */
197	>	fflush(ambfp);
198	>	lastpos = ftell(ambfp);
199	>	} else {
200	>	sprintf(errmsg, "cannot open ambient file \"%s\"", ambfile);
201		error(SYSTEM, errmsg);
202		}
203	<	nunflshed++;    /* lie */
204	<	ambsync();
203	>	#ifdef getc_unlocked
204	>	flockfile(ambfp);                       /* application-level lock */
205	>	#endif
206	>	#ifdef  F_SETLKW
207	>	aflock(F_UNLCK);                        /* release file */
208	>	#endif
209		}
210
211
212	<	ambnotify(obj)                  /* record new modifier */
213	<	OBJECT  obj;
212	>	void
213	>	ambdone(void)                   /* close ambient file and free memory */
214		{
215	+	if (ambfp != NULL) {            /* close ambient file */
216	+	ambsync();
217	+	fclose(ambfp);
218	+	ambfp = NULL;
219	+	if (ambinp != NULL) {
220	+	fclose(ambinp);
221	+	ambinp = NULL;
222	+	}
223	+	lastpos = -1;
224	+	}
225	+	/* free ambient tree */
226	+	unloadatree(&atrunk, &avfree);
227	+	/* reset state variables */
228	+	avsum = 0.;
229	+	navsum = 0;
230	+	nambvals = 0;
231	+	nambshare = 0;
232	+	ambclock = 0;
233	+	lastsort = 0;
234	+	sortintvl = SORT_INTVL;
235	+	}
236	+
237	+
238	+	void
239	+	ambnotify(                      /* record new modifier */
240	+	OBJECT  obj
241	+	)
242	+	{
243		static int  hitlimit = 0;
244	<	register OBJREC  *o = objptr(obj);
245	<	register char  **amblp;
244	>	OBJREC   *o;
245	>	char  **amblp;
246
247	+	if (obj == OVOID) {             /* starting over */
248	+	ambset[0] = 0;
249	+	hitlimit = 0;
250	+	return;
251	+	}
252	+	o = objptr(obj);
253		if (hitlimit || !ismodifier(o->otype))
254		return;
255		for (amblp = amblist; *amblp != NULL; amblp++)
#	Line 119 | Line 264 | OBJECT obj;
264		}
265		}
266
267	+	/************ THE FOLLOWING ROUTINES DIFFER BETWEEN NEW & OLD ***************/
268
269	<	ambient(acol, r)                /* compute ambient component for ray */
270	<	COLOR  acol;
271	<	register RAY  *r;
269	>	#ifdef NEWAMB
270	>
271	>	#define tfunc(lwr, x, upr)      (((x)-(lwr))/((upr)-(lwr)))
272	>
273	>	static double   sumambient(COLOR acol, RAY *r, FVECT rn, int al,
274	>	AMBTREE *at, FVECT c0, double s);
275	>	static int      makeambient(COLOR acol, RAY *r, FVECT rn, int al);
276	>	static void     extambient(COLOR cr, AMBVAL *ap, FVECT pv, FVECT nv,
277	>	FVECT uvw[3]);
278	>
279	>	void
280	>	multambient(            /* compute ambient component & multiply by coef. */
281	>	COLOR  aval,
282	>	RAY  *r,
283	>	FVECT  nrm
284	>	)
285		{
286		static int  rdepth = 0;                 /* ambient recursion */
287	<	double  d;
287	>	COLOR   acol;
288	>	int     ok;
289	>	double  d, l;
290
291		if (ambdiv <= 0)                        /* no ambient calculation */
292		goto dumbamb;
#	Line 138 | Line 299 | register RAY  *r;
299		goto dumbamb;
300
301		if (ambacc <= FTINY) {                  /* no ambient storage */
302	+	copycolor(acol, aval);
303		rdepth++;
304	<	d = doambient(acol, r, r->rweight, NULL, NULL);
304	>	ok = doambient(acol, r, r->rweight, NULL, NULL, NULL, NULL);
305		rdepth--;
306	<	if (d == 0.0)
306	>	if (!ok)
307		goto dumbamb;
308	+	copycolor(aval, acol);
309		return;
310		}
311	<	/* get ambient value */
311	>
312	>	if (tracktime)                          /* sort to minimize thrashing */
313	>	sortambvals(0);
314	>	/* interpolate ambient value */
315		setcolor(acol, 0.0, 0.0, 0.0);
316	<	d = sumambient(acol, r, rdepth,
316	>	d = sumambient(acol, r, nrm, rdepth,
317		&atrunk, thescene.cuorg, thescene.cusize);
318	<	if (d > FTINY)
319	<	scalecolor(acol, 1.0/d);
320	<	else {
321	<	d = makeambient(acol, r, rdepth++);
322	<	rdepth--;
318	>	if (d > FTINY) {
319	>	d = 1.0/d;
320	>	scalecolor(acol, d);
321	>	multcolor(aval, acol);
322	>	return;
323		}
324	<	if (d > FTINY)
324	>	rdepth++;                               /* need to cache new value */
325	>	ok = makeambient(acol, r, nrm, rdepth-1);
326	>	rdepth--;
327	>	if (ok) {
328	>	multcolor(aval, acol);          /* computed new value */
329		return;
330	+	}
331		dumbamb:                                        /* return global value */
332	<	copycolor(acol, ambval);
332	>	if ((ambvwt <= 0) | (navsum == 0)) {
333	>	multcolor(aval, ambval);
334	>	return;
335	>	}
336	>	l = bright(ambval);                     /* average in computations */
337	>	if (l > FTINY) {
338	>	d = (log(l)*(double)ambvwt + avsum) /
339	>	(double)(ambvwt + navsum);
340	>	d = exp(d) / l;
341	>	scalecolor(aval, d);
342	>	multcolor(aval, ambval);        /* apply color of ambval */
343	>	} else {
344	>	d = exp( avsum / (double)navsum );
345	>	scalecolor(aval, d);            /* neutral color */
346	>	}
347		}
348
349
350		double
351	<	sumambient(acol, r, al, at, c0, s)      /* get interpolated ambient value */
352	<	COLOR  acol;
353	<	register RAY  *r;
354	<	int  al;
355	<	AMBTREE  *at;
356	<	FVECT  c0;
357	<	double  s;
351	>	sumambient(             /* get interpolated ambient value */
352	>	COLOR  acol,
353	>	RAY  *r,
354	>	FVECT  rn,
355	>	int  al,
356	>	AMBTREE  *at,
357	>	FVECT  c0,
358	>	double  s
359	>	)
360	>	{                                       /* initial limit is ambacc radians */
361	>	const double    maxangle = (ambacc-PI/2.)*pow(r->rweight,0.13) + PI/2.;
362	>	double          wsum = 0.0;
363	>	FVECT           ck0;
364	>	int             i, j;
365	>	AMBVAL          *av;
366	>	/* sum this node */
367	>	for (av = at->alist; av != NULL; av = av->next) {
368	>	double  d, delta_r2, delta_t2;
369	>	COLOR   ct;
370	>	FVECT   uvw[3];
371	>	/* record access */
372	>	if (tracktime)
373	>	av->latick = ambclock;
374	>	/*
375	>	*  Ambient level test
376	>	*/
377	>	if (av->lvl > al)       /* list sorted, so this works */
378	>	break;
379	>	if (av->weight < 0.9*r->rweight)
380	>	continue;
381	>	/*
382	>	*  Direction test using unperturbed normal
383	>	*/
384	>	decodedir(uvw[2], av->ndir);
385	>	d = DOT(uvw[2], r->ron);
386	>	if (d <= 0.0)           /* >= 90 degrees */
387	>	continue;
388	>	delta_r2 = 2.0 - 2.0*d; /* approx. radians^2 */
389	>	if (delta_r2 >= maxangle*maxangle)
390	>	continue;
391	>	/*
392	>	*  Elliptical radii test based on Hessian
393	>	*/
394	>	decodedir(uvw[0], av->udir);
395	>	VCROSS(uvw[1], uvw[2], uvw[0]);
396	>	VSUB(ck0, av->pos, r->rop);
397	>	d = DOT(ck0, uvw[0]) / av->rad[0];
398	>	delta_t2 = d*d;
399	>	d = DOT(ck0, uvw[1]) / av->rad[1];
400	>	delta_t2 += d*d;
401	>	if (delta_t2 >= qambacc*qambacc)
402	>	continue;
403	>	/*
404	>	*  Intersection behind test
405	>	*/
406	>	d = 0.0;
407	>	for (j = 0; j < 3; j++)
408	>	d += (r->rop[j] - av->pos[j])*(uvw[2][j] + r->ron[j]);
409	>	if (d*0.5 < -minarad*qambacc-.001)
410	>	continue;
411	>	/*
412	>	*  Extrapolate value and compute final weight (hat function)
413	>	*/
414	>	extambient(ct, av, r->rop, rn, uvw);
415	>	d = tfunc(maxangle, sqrt(delta_r2), 0.0) *
416	>	tfunc(qambacc, sqrt(delta_t2), 0.0);
417	>	scalecolor(ct, d);
418	>	addcolor(acol, ct);
419	>	wsum += d;
420	>	}
421	>	if (at->kid == NULL)
422	>	return(wsum);
423	>	/* sum children */
424	>	s *= 0.5;
425	>	for (i = 0; i < 8; i++) {
426	>	for (j = 0; j < 3; j++) {
427	>	ck0[j] = c0[j];
428	>	if (1<<j & i)
429	>	ck0[j] += s;
430	>	if (r->rop[j] < ck0[j] - OCTSCALE*s)
431	>	break;
432	>	if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
433	>	break;
434	>	}
435	>	if (j == 3)
436	>	wsum += sumambient(acol, r, rn, al,
437	>	at->kid+i, ck0, s);
438	>	}
439	>	return(wsum);
440	>	}
441	>
442	>
443	>	int
444	>	makeambient(            /* make a new ambient value for storage */
445	>	COLOR  acol,
446	>	RAY  *r,
447	>	FVECT  rn,
448	>	int  al
449	>	)
450		{
451	+	AMBVAL  amb;
452	+	FVECT   uvw[3];
453	+	int     i;
454	+
455	+	amb.weight = 1.0;                       /* compute weight */
456	+	for (i = al; i-- > 0; )
457	+	amb.weight *= AVGREFL;
458	+	if (r->rweight < 0.1*amb.weight)        /* heuristic override */
459	+	amb.weight = 1.25*r->rweight;
460	+	setcolor(acol, AVGREFL, AVGREFL, AVGREFL);
461	+	/* compute ambient */
462	+	i = doambient(acol, r, amb.weight, uvw, amb.rad, amb.gpos, amb.gdir);
463	+	scalecolor(acol, 1./AVGREFL);           /* undo assumed reflectance */
464	+	if (i <= 0 || amb.rad[0] <= FTINY)      /* no Hessian or zero radius */
465	+	return(i);
466	+	/* store value */
467	+	VCOPY(amb.pos, r->rop);
468	+	amb.ndir = encodedir(r->ron);
469	+	amb.udir = encodedir(uvw[0]);
470	+	amb.lvl = al;
471	+	copycolor(amb.val, acol);
472	+	/* insert into tree */
473	+	avsave(&amb);                           /* and save to file */
474	+	if (rn != r->ron) {                     /* texture */
475	+	VCOPY(uvw[2], r->ron);
476	+	extambient(acol, &amb, r->rop, rn, uvw);
477	+	}
478	+	return(1);
479	+	}
480	+
481	+
482	+	void
483	+	extambient(             /* extrapolate value at pv, nv */
484	+	COLOR  cr,
485	+	AMBVAL   *ap,
486	+	FVECT  pv,
487	+	FVECT  nv,
488	+	FVECT  uvw[3]
489	+	)
490	+	{
491	+	static FVECT    my_uvw[3];
492	+	FVECT           v1;
493	+	int             i;
494	+	double          d = 1.0;        /* zeroeth order */
495	+
496	+	if (uvw == NULL) {              /* need local coordinates? */
497	+	decodedir(my_uvw[2], ap->ndir);
498	+	decodedir(my_uvw[0], ap->udir);
499	+	VCROSS(my_uvw[1], my_uvw[2], my_uvw[0]);
500	+	uvw = my_uvw;
501	+	}
502	+	for (i = 3; i--; )              /* gradient due to translation */
503	+	d += (pv[i] - ap->pos[i]) *
504	+	(ap->gpos[0]*uvw[0][i] + ap->gpos[1]*uvw[1][i]);
505	+
506	+	VCROSS(v1, uvw[2], nv);         /* gradient due to rotation */
507	+	for (i = 3; i--; )
508	+	d += v1[i] * (ap->gdir[0]*uvw[0][i] + ap->gdir[1]*uvw[1][i]);
509	+
510	+	if (d <= 0.0) {
511	+	setcolor(cr, 0.0, 0.0, 0.0);
512	+	return;
513	+	}
514	+	copycolor(cr, ap->val);
515	+	scalecolor(cr, d);
516	+	}
517	+
518	+
519	+	static void
520	+	avinsert(                               /* insert ambient value in our tree */
521	+	AMBVAL *av
522	+	)
523	+	{
524	+	AMBTREE  *at;
525	+	AMBVAL  *ap;
526	+	AMBVAL  avh;
527	+	FVECT  ck0;
528	+	double  s;
529	+	int  branch;
530	+	int  i;
531	+
532	+	if (av->rad[0] <= FTINY)
533	+	error(CONSISTENCY, "zero ambient radius in avinsert");
534	+	at = &atrunk;
535	+	VCOPY(ck0, thescene.cuorg);
536	+	s = thescene.cusize;
537	+	while (s*(OCTSCALE/2) > av->rad[1]*qambacc) {
538	+	if (at->kid == NULL)
539	+	if ((at->kid = newambtree()) == NULL)
540	+	error(SYSTEM, "out of memory in avinsert");
541	+	s *= 0.5;
542	+	branch = 0;
543	+	for (i = 0; i < 3; i++)
544	+	if (av->pos[i] > ck0[i] + s) {
545	+	ck0[i] += s;
546	+	branch |= 1 << i;
547	+	}
548	+	at = at->kid + branch;
549	+	}
550	+	avh.next = at->alist;           /* order by increasing level */
551	+	for (ap = &avh; ap->next != NULL; ap = ap->next)
552	+	if (ap->next->lvl >= av->lvl)
553	+	break;
554	+	av->next = ap->next;
555	+	ap->next = (AMBVAL*)av;
556	+	at->alist = avh.next;
557	+	}
558	+
559	+
560	+	#else /* ! NEWAMB */
561	+
562	+	static double   sumambient(COLOR acol, RAY *r, FVECT rn, int al,
563	+	AMBTREE *at, FVECT c0, double s);
564	+	static double   makeambient(COLOR acol, RAY *r, FVECT rn, int al);
565	+	static void     extambient(COLOR cr, AMBVAL *ap, FVECT pv, FVECT nv);
566	+
567	+
568	+	void
569	+	multambient(            /* compute ambient component & multiply by coef. */
570	+	COLOR  aval,
571	+	RAY  *r,
572	+	FVECT  nrm
573	+	)
574	+	{
575	+	static int  rdepth = 0;                 /* ambient recursion */
576	+	COLOR   acol;
577	+	double  d, l;
578	+
579	+	if (ambdiv <= 0)                        /* no ambient calculation */
580	+	goto dumbamb;
581	+	/* check number of bounces */
582	+	if (rdepth >= ambounce)
583	+	goto dumbamb;
584	+	/* check ambient list */
585	+	if (ambincl != -1 && r->ro != NULL &&
586	+	ambincl != inset(ambset, r->ro->omod))
587	+	goto dumbamb;
588	+
589	+	if (ambacc <= FTINY) {                  /* no ambient storage */
590	+	copycolor(acol, aval);
591	+	rdepth++;
592	+	d = doambient(acol, r, r->rweight, NULL, NULL);
593	+	rdepth--;
594	+	if (d <= FTINY)
595	+	goto dumbamb;
596	+	copycolor(aval, acol);
597	+	return;
598	+	}
599	+
600	+	if (tracktime)                          /* sort to minimize thrashing */
601	+	sortambvals(0);
602	+	/* interpolate ambient value */
603	+	setcolor(acol, 0.0, 0.0, 0.0);
604	+	d = sumambient(acol, r, nrm, rdepth,
605	+	&atrunk, thescene.cuorg, thescene.cusize);
606	+	if (d > FTINY) {
607	+	d = 1.0/d;
608	+	scalecolor(acol, d);
609	+	multcolor(aval, acol);
610	+	return;
611	+	}
612	+	rdepth++;                               /* need to cache new value */
613	+	d = makeambient(acol, r, nrm, rdepth-1);
614	+	rdepth--;
615	+	if (d > FTINY) {
616	+	multcolor(aval, acol);          /* got new value */
617	+	return;
618	+	}
619	+	dumbamb:                                        /* return global value */
620	+	if ((ambvwt <= 0) | (navsum == 0)) {
621	+	multcolor(aval, ambval);
622	+	return;
623	+	}
624	+	l = bright(ambval);                     /* average in computations */
625	+	if (l > FTINY) {
626	+	d = (log(l)*(double)ambvwt + avsum) /
627	+	(double)(ambvwt + navsum);
628	+	d = exp(d) / l;
629	+	scalecolor(aval, d);
630	+	multcolor(aval, ambval);        /* apply color of ambval */
631	+	} else {
632	+	d = exp( avsum / (double)navsum );
633	+	scalecolor(aval, d);            /* neutral color */
634	+	}
635	+	}
636	+
637	+
638	+	static double
639	+	sumambient(     /* get interpolated ambient value */
640	+	COLOR  acol,
641	+	RAY  *r,
642	+	FVECT  rn,
643	+	int  al,
644	+	AMBTREE  *at,
645	+	FVECT  c0,
646	+	double  s
647	+	)
648	+	{
649		double  d, e1, e2, wt, wsum;
650		COLOR  ct;
651		FVECT  ck0;
652		int  i;
653	<	register int  j;
654	<	register AMBVAL  *av;
655	<	/* do this node */
653	>	int  j;
654	>	AMBVAL   *av;
655	>
656		wsum = 0.0;
657	+	/* do this node */
658		for (av = at->alist; av != NULL; av = av->next) {
659	+	double  rn_dot = -2.0;
660	+	if (tracktime)
661	+	av->latick = ambclock;
662		/*
663		*  Ambient level test.
664		*/
665	<	if (av->lvl > al || av->weight < r->rweight-FTINY)
665	>	if (av->lvl > al)       /* list sorted, so this works */
666	>	break;
667	>	if (av->weight < 0.9*r->rweight)
668		continue;
669		/*
670		*  Ambient radius test.
671		*/
672	<	e1 = 0.0;
673	<	for (j = 0; j < 3; j++) {
193	<	d = av->pos[j] - r->rop[j];
194	<	e1 += d * d;
195	<	}
196	<	e1 /= av->rad * av->rad;
672	>	VSUB(ck0, av->pos, r->rop);
673	>	e1 = DOT(ck0, ck0) / (av->rad * av->rad);
674		if (e1 > ambacc*ambacc*1.21)
675		continue;
676		/*
677	<	*  Normal direction test.
677	>	*  Direction test using closest normal.
678		*/
679	<	e2 = (1.0 - DOT(av->dir, r->ron)) * r->rweight;
680	<	if (e2 < 0.0) e2 = 0.0;
681	<	if (e1 + e2 > ambacc*ambacc*1.21)
679	>	d = DOT(av->dir, r->ron);
680	>	if (rn != r->ron) {
681	>	rn_dot = DOT(av->dir, rn);
682	>	if (rn_dot > 1.0-FTINY)
683	>	rn_dot = 1.0-FTINY;
684	>	if (rn_dot >= d-FTINY) {
685	>	d = rn_dot;
686	>	rn_dot = -2.0;
687	>	}
688	>	}
689	>	e2 = (1.0 - d) * r->rweight;
690	>	if (e2 < 0.0)
691	>	e2 = 0.0;
692	>	else if (e1 + e2 > ambacc*ambacc*1.21)
693		continue;
694		/*
695		*  Ray behind test.
#	Line 215 | Line 703 | double s;
703		/*
704		*  Jittering final test reduces image artifacts.
705		*/
706	<	wt = sqrt(e1) + sqrt(e2);
707	<	wt *= .9 + .2*urand(9015+samplendx);
708	<	if (wt > ambacc)
706	>	e1 = sqrt(e1);
707	>	e2 = sqrt(e2);
708	>	wt = e1 + e2;
709	>	if (wt > ambacc*(.9+.2*urand(9015+samplendx)))
710		continue;
711	+	/*
712	+	*  Recompute directional error using perturbed normal
713	+	*/
714	+	if (rn_dot > 0.0) {
715	+	e2 = sqrt((1.0 - rn_dot)*r->rweight);
716	+	wt = e1 + e2;
717	+	}
718		if (wt <= 1e-3)
719		wt = 1e3;
720		else
721		wt = 1.0 / wt;
722		wsum += wt;
723	<	extambient(ct, av, r->rop, r->ron);
723	>	extambient(ct, av, r->rop, rn);
724		scalecolor(ct, wt);
725		addcolor(acol, ct);
726		}
#	Line 243 | Line 739 | double s;
739		break;
740		}
741		if (j == 3)
742	<	wsum += sumambient(acol, r, al, at->kid+i, ck0, s);
742	>	wsum += sumambient(acol, r, rn, al,
743	>	at->kid+i, ck0, s);
744		}
745		return(wsum);
746		}
747
748
749	<	double
750	<	makeambient(acol, r, al)        /* make a new ambient value */
751	<	COLOR  acol;
752	<	register RAY  *r;
753	<	int  al;
749	>	static double
750	>	makeambient(            /* make a new ambient value for storage */
751	>	COLOR  acol,
752	>	RAY  *r,
753	>	FVECT  rn,
754	>	int  al
755	>	)
756		{
757		AMBVAL  amb;
758		FVECT   gp, gd;
759	<	/* compute weight */
760	<	amb.weight = pow(AVGREFL, (double)al);
761	<	if (r->rweight < 0.2*amb.weight)        /* heuristic */
762	<	amb.weight = r->rweight;
759	>	int     i;
760	>
761	>	amb.weight = 1.0;                       /* compute weight */
762	>	for (i = al; i-- > 0; )
763	>	amb.weight *= AVGREFL;
764	>	if (r->rweight < 0.1*amb.weight)        /* heuristic override */
765	>	amb.weight = 1.25*r->rweight;
766	>	setcolor(acol, AVGREFL, AVGREFL, AVGREFL);
767		/* compute ambient */
768		amb.rad = doambient(acol, r, amb.weight, gp, gd);
769	<	if (amb.rad == 0.0)
769	>	if (amb.rad <= FTINY) {
770	>	setcolor(acol, 0.0, 0.0, 0.0);
771		return(0.0);
772	<	/* store it */
772	>	}
773	>	scalecolor(acol, 1./AVGREFL);           /* undo assumed reflectance */
774	>	/* store value */
775		VCOPY(amb.pos, r->rop);
776		VCOPY(amb.dir, r->ron);
777		amb.lvl = al;
#	Line 274 | Line 780 | int  al;
780		VCOPY(amb.gdir, gd);
781		/* insert into tree */
782		avsave(&amb);                           /* and save to file */
783	+	if (rn != r->ron)
784	+	extambient(acol, &amb, r->rop, rn);     /* texture */
785		return(amb.rad);
786		}
787
788
789	<	extambient(cr, ap, pv, nv)              /* extrapolate value at pv, nv */
790	<	COLOR  cr;
791	<	register AMBVAL  *ap;
792	<	FVECT  pv, nv;
789	>	static void
790	>	extambient(             /* extrapolate value at pv, nv */
791	>	COLOR  cr,
792	>	AMBVAL   *ap,
793	>	FVECT  pv,
794	>	FVECT  nv
795	>	)
796		{
797	<	FVECT  v1, v2;
798	<	register int  i;
797	>	FVECT  v1;
798	>	int  i;
799		double  d;
800
801		d = 1.0;                        /* zeroeth order */
#	Line 292 | Line 803 | FVECT  pv, nv;
803		for (i = 0; i < 3; i++)
804		d += ap->gpos[i]*(pv[i]-ap->pos[i]);
805		/* gradient due to rotation */
806	<	VCOPY(v1, ap->dir);
807	<	fcross(v2, v1, nv);
297	<	d += DOT(ap->gdir, v2);
806	>	VCROSS(v1, ap->dir, nv);
807	>	d += DOT(ap->gdir, v1);
808		if (d <= 0.0) {
809		setcolor(cr, 0.0, 0.0, 0.0);
810		return;
#	Line 304 | Line 814 | FVECT  pv, nv;
814		}
815
816
817	<	static
818	<	initambfile(creat)              /* initialize ambient file */
819	<	int  creat;
817	>	static void
818	>	avinsert(                               /* insert ambient value in our tree */
819	>	AMBVAL *av
820	>	)
821		{
822	<	extern char  *progname, *octname, VersionID[];
822	>	AMBTREE  *at;
823	>	AMBVAL  *ap;
824	>	AMBVAL  avh;
825	>	FVECT  ck0;
826	>	double  s;
827	>	int  branch;
828	>	int  i;
829
830	+	if (av->rad <= FTINY)
831	+	error(CONSISTENCY, "zero ambient radius in avinsert");
832	+	at = &atrunk;
833	+	VCOPY(ck0, thescene.cuorg);
834	+	s = thescene.cusize;
835	+	while (s*(OCTSCALE/2) > av->rad*ambacc) {
836	+	if (at->kid == NULL)
837	+	if ((at->kid = newambtree()) == NULL)
838	+	error(SYSTEM, "out of memory in avinsert");
839	+	s *= 0.5;
840	+	branch = 0;
841	+	for (i = 0; i < 3; i++)
842	+	if (av->pos[i] > ck0[i] + s) {
843	+	ck0[i] += s;
844	+	branch |= 1 << i;
845	+	}
846	+	at = at->kid + branch;
847	+	}
848	+	avh.next = at->alist;           /* order by increasing level */
849	+	for (ap = &avh; ap->next != NULL; ap = ap->next)
850	+	if (ap->next->lvl >= av->lvl)
851	+	break;
852	+	av->next = ap->next;
853	+	ap->next = (AMBVAL*)av;
854	+	at->alist = avh.next;
855	+	}
856	+
857	+	#endif  /* ! NEWAMB */
858	+
859	+	/************* FOLLOWING ROUTINES SAME FOR NEW & OLD METHODS ***************/
860	+
861	+	static void
862	+	initambfile(            /* initialize ambient file */
863	+	int  cre8
864	+	)
865	+	{
866	+	extern char  *progname, *octname;
867	+	static char  *mybuf = NULL;
868	+
869		#ifdef  F_SETLKW
870	<	aflock(creat ? F_WRLCK : F_RDLCK);
870	>	aflock(cre8 ? F_WRLCK : F_RDLCK);
871		#endif
872	<	#ifdef MSDOS
873	<	setmode(fileno(ambfp), O_BINARY);
874	<	#endif
875	<	setbuf(ambfp, bmalloc(BUFSIZ));
876	<	if (creat) {                    /* new file */
877	<	fprintf(ambfp, "%s -av %g %g %g -ab %d -aa %g ",
872	>	SET_FILE_BINARY(ambfp);
873	>	if (mybuf == NULL)
874	>	mybuf = (char *)bmalloc(BUFSIZ+8);
875	>	setbuf(ambfp, mybuf);
876	>	if (cre8) {                     /* new file */
877	>	newheader("RADIANCE", ambfp);
878	>	fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
879		progname, colval(ambval,RED),
880		colval(ambval,GRN), colval(ambval,BLU),
881	<	ambounce, ambacc);
882	<	fprintf(ambfp, "-ad %d -as %d -ar %d %s\n",
883	<	ambdiv, ambssamp, ambres,
884	<	octname==NULL ? "" : octname);
881	>	ambvwt, ambounce, ambacc);
882	>	fprintf(ambfp, "-ad %d -as %d -ar %d ",
883	>	ambdiv, ambssamp, ambres);
884	>	if (octname != NULL)
885	>	fputs(octname, ambfp);
886	>	fputc('\n', ambfp);
887		fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
888	+	fputnow(ambfp);
889		fputformat(AMBFMT, ambfp);
890	<	putc('\n', ambfp);
890	>	fputc('\n', ambfp);
891		putambmagic(ambfp);
892		} else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
893		error(USER, "bad ambient file");
894		}
895
896
897	<	static
898	<	avsave(av)                              /* insert and save an ambient value */
899	<	AMBVAL  *av;
897	>	static void
898	>	avsave(                         /* insert and save an ambient value */
899	>	AMBVAL  *av
900	>	)
901		{
902	<	avinsert(av, &atrunk, thescene.cuorg, thescene.cusize);
902	>	avinsert(avstore(av));
903		if (ambfp == NULL)
904		return;
905		if (writambval(av, ambfp) < 0)
#	Line 348 | Line 909 | AMBVAL *av;
909		goto writerr;
910		return;
911		writerr:
912	<	error(SYSTEM, "error writing ambient file");
912	>	error(SYSTEM, "error writing to ambient file");
913		}
914
915
916	<	static
917	<	avinsert(aval, at, c0, s)               /* insert ambient value in a tree */
918	<	AMBVAL  *aval;
919	<	register AMBTREE  *at;
359	<	FVECT  c0;
360	<	double  s;
916	>	static AMBVAL *
917	>	avstore(                                /* allocate memory and store aval */
918	>	AMBVAL  *aval
919	>	)
920		{
921	<	FVECT  ck0;
922	<	int  branch;
364	<	register AMBVAL  *av;
365	<	register int  i;
921	>	AMBVAL  *av;
922	>	double  d;
923
924		if ((av = newambval()) == NULL)
925	<	goto memerr;
926	<	copystruct(av, aval);
927	<	VCOPY(ck0, c0);
928	<	while (s*(OCTSCALE/2) > av->rad*ambacc) {
929	<	if (at->kid == NULL)
930	<	if ((at->kid = newambtree()) == NULL)
931	<	goto memerr;
932	<	s *= 0.5;
933	<	branch = 0;
934	<	for (i = 0; i < 3; i++)
935	<	if (av->pos[i] > ck0[i] + s) {
936	<	ck0[i] += s;
937	<	branch |= 1 << i;
925	>	error(SYSTEM, "out of memory in avstore");
926	>	*av = *aval;
927	>	av->latick = ambclock;
928	>	av->next = NULL;
929	>	nambvals++;
930	>	d = bright(av->val);
931	>	if (d > FTINY) {                /* add to log sum for averaging */
932	>	avsum += log(d);
933	>	navsum++;
934	>	}
935	>	return(av);
936	>	}
937	>
938	>
939	>	#define ATALLOCSZ       512             /* #/8 trees to allocate at once */
940	>
941	>	static AMBTREE  *atfreelist = NULL;     /* free ambient tree structures */
942	>
943	>
944	>	static AMBTREE *
945	>	newambtree(void)                                /* allocate 8 ambient tree structs */
946	>	{
947	>	AMBTREE  *atp, *upperlim;
948	>
949	>	if (atfreelist == NULL) {       /* get more nodes */
950	>	atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
951	>	if (atfreelist == NULL)
952	>	return(NULL);
953	>	/* link new free list */
954	>	upperlim = atfreelist + 8*(ATALLOCSZ-1);
955	>	for (atp = atfreelist; atp < upperlim; atp += 8)
956	>	atp->kid = atp + 8;
957	>	atp->kid = NULL;
958	>	}
959	>	atp = atfreelist;
960	>	atfreelist = atp->kid;
961	>	memset((char *)atp, '\0', 8*sizeof(AMBTREE));
962	>	return(atp);
963	>	}
964	>
965	>
966	>	static void
967	>	freeambtree(                    /* free 8 ambient tree structs */
968	>	AMBTREE  *atp
969	>	)
970	>	{
971	>	atp->kid = atfreelist;
972	>	atfreelist = atp;
973	>	}
974	>
975	>
976	>	static void
977	>	unloadatree(                    /* unload an ambient value tree */
978	>	AMBTREE  *at,
979	>	unloadtf_t *f
980	>	)
981	>	{
982	>	AMBVAL  *av;
983	>	int  i;
984	>	/* transfer values at this node */
985	>	for (av = at->alist; av != NULL; av = at->alist) {
986	>	at->alist = av->next;
987	>	(*f)(av);
988	>	}
989	>	if (at->kid == NULL)
990	>	return;
991	>	for (i = 0; i < 8; i++)         /* transfer and free children */
992	>	unloadatree(at->kid+i, f);
993	>	freeambtree(at->kid);
994	>	at->kid = NULL;
995	>	}
996	>
997	>
998	>	static struct avl {
999	>	AMBVAL  *p;
1000	>	unsigned long   t;
1001	>	}       *avlist1;                       /* ambient value list with ticks */
1002	>	static AMBVAL   **avlist2;              /* memory positions for sorting */
1003	>	static int      i_avlist;               /* index for lists */
1004	>
1005	>	static int alatcmp(const void *av1, const void *av2);
1006	>
1007	>	static void
1008	>	avfree(AMBVAL *av)
1009	>	{
1010	>	free(av);
1011	>	}
1012	>
1013	>	static void
1014	>	av2list(
1015	>	AMBVAL *av
1016	>	)
1017	>	{
1018	>	#ifdef DEBUG
1019	>	if (i_avlist >= nambvals)
1020	>	error(CONSISTENCY, "too many ambient values in av2list1");
1021	>	#endif
1022	>	avlist1[i_avlist].p = avlist2[i_avlist] = (AMBVAL*)av;
1023	>	avlist1[i_avlist++].t = av->latick;
1024	>	}
1025	>
1026	>
1027	>	static int
1028	>	alatcmp(                        /* compare ambient values for MRA */
1029	>	const void *av1,
1030	>	const void *av2
1031	>	)
1032	>	{
1033	>	long  lc = ((struct avl *)av2)->t - ((struct avl *)av1)->t;
1034	>	return(lc<0 ? -1 : lc>0 ? 1 : 0);
1035	>	}
1036	>
1037	>
1038	>	/* GW NOTE 2002/10/3:
1039	>	* I used to compare AMBVAL pointers, but found that this was the
1040	>	* cause of a serious consistency error with gcc, since the optimizer
1041	>	* uses some dangerous trick in pointer subtraction that
1042	>	* assumes pointers differ by exact struct size increments.
1043	>	*/
1044	>	static int
1045	>	aposcmp(                        /* compare ambient value positions */
1046	>	const void      *avp1,
1047	>	const void      *avp2
1048	>	)
1049	>	{
1050	>	long    diff = *(char * const *)avp1 - *(char * const *)avp2;
1051	>	if (diff < 0)
1052	>	return(-1);
1053	>	return(diff > 0);
1054	>	}
1055	>
1056	>
1057	>	static int
1058	>	avlmemi(                                /* find list position from address */
1059	>	AMBVAL  *avaddr
1060	>	)
1061	>	{
1062	>	AMBVAL  **avlpp;
1063	>
1064	>	avlpp = (AMBVAL **)bsearch((char *)&avaddr, (char *)avlist2,
1065	>	nambvals, sizeof(AMBVAL *), &aposcmp);
1066	>	if (avlpp == NULL)
1067	>	error(CONSISTENCY, "address not found in avlmemi");
1068	>	return(avlpp - avlist2);
1069	>	}
1070	>
1071	>
1072	>	static void
1073	>	sortambvals(                    /* resort ambient values */
1074	>	int     always
1075	>	)
1076	>	{
1077	>	AMBTREE  oldatrunk;
1078	>	AMBVAL  tav, *tap, *pnext;
1079	>	int     i, j;
1080	>	/* see if it's time yet */
1081	>	if (!always && (ambclock++ < lastsort+sortintvl ||
1082	>	nambvals < SORT_THRESH))
1083	>	return;
1084	>	/*
1085	>	* The idea here is to minimize memory thrashing
1086	>	* in VM systems by improving reference locality.
1087	>	* We do this by periodically sorting our stored ambient
1088	>	* values in memory in order of most recently to least
1089	>	* recently accessed.  This ordering was chosen so that new
1090	>	* ambient values (which tend to be less important) go into
1091	>	* higher memory with the infrequently accessed values.
1092	>	*      Since we expect our values to need sorting less
1093	>	* frequently as the process continues, we double our
1094	>	* waiting interval after each call.
1095	>	*      This routine is also called by setambacc() with
1096	>	* the "always" parameter set to 1 so that the ambient
1097	>	* tree will be rebuilt with the new accuracy parameter.
1098	>	*/
1099	>	if (tracktime) {                /* allocate pointer arrays to sort */
1100	>	avlist2 = (AMBVAL **)malloc(nambvals*sizeof(AMBVAL *));
1101	>	avlist1 = (struct avl *)malloc(nambvals*sizeof(struct avl));
1102	>	} else {
1103	>	avlist2 = NULL;
1104	>	avlist1 = NULL;
1105	>	}
1106	>	if (avlist1 == NULL) {          /* no time tracking -- rebuild tree? */
1107	>	if (avlist2 != NULL)
1108	>	free((void *)avlist2);
1109	>	if (always) {           /* rebuild without sorting */
1110	>	oldatrunk = atrunk;
1111	>	atrunk.alist = NULL;
1112	>	atrunk.kid = NULL;
1113	>	unloadatree(&oldatrunk, &avinsert);
1114	>	}
1115	>	} else {                        /* sort memory by last access time */
1116	>	/*
1117	>	* Sorting memory is tricky because it isn't contiguous.
1118	>	* We have to sort an array of pointers by MRA and also
1119	>	* by memory position.  We then copy values in "loops"
1120	>	* to minimize memory hits.  Nevertheless, we will visit
1121	>	* everyone at least twice, and this is an expensive process
1122	>	* when we're thrashing, which is when we need to do it.
1123	>	*/
1124	>	#ifdef DEBUG
1125	>	sprintf(errmsg, "sorting %u ambient values at ambclock=%lu...",
1126	>	nambvals, ambclock);
1127	>	eputs(errmsg);
1128	>	#endif
1129	>	i_avlist = 0;
1130	>	unloadatree(&atrunk, &av2list); /* empty current tree */
1131	>	#ifdef DEBUG
1132	>	if (i_avlist < nambvals)
1133	>	error(CONSISTENCY, "missing ambient values in sortambvals");
1134	>	#endif
1135	>	qsort((char *)avlist1, nambvals, sizeof(struct avl), &alatcmp);
1136	>	qsort((char *)avlist2, nambvals, sizeof(AMBVAL *), &aposcmp);
1137	>	for (i = 0; i < nambvals; i++) {
1138	>	if (avlist1[i].p == NULL)
1139	>	continue;
1140	>	tap = avlist2[i];
1141	>	tav = *tap;
1142	>	for (j = i; (pnext = avlist1[j].p) != tap;
1143	>	j = avlmemi(pnext)) {
1144	>	*(avlist2[j]) = *pnext;
1145	>	avinsert(avlist2[j]);
1146	>	avlist1[j].p = NULL;
1147		}
1148	<	at = at->kid + branch;
1148	>	*(avlist2[j]) = tav;
1149	>	avinsert(avlist2[j]);
1150	>	avlist1[j].p = NULL;
1151	>	}
1152	>	free((void *)avlist1);
1153	>	free((void *)avlist2);
1154	>	/* compute new sort interval */
1155	>	sortintvl = ambclock - lastsort;
1156	>	if (sortintvl >= MAX_SORT_INTVL/2)
1157	>	sortintvl = MAX_SORT_INTVL;
1158	>	else
1159	>	sortintvl <<= 1;        /* wait twice as long next */
1160	>	#ifdef DEBUG
1161	>	eputs("done\n");
1162	>	#endif
1163		}
1164	<	av->next = at->alist;
1165	<	at->alist = av;
1166	<	return;
387	<	memerr:
388	<	error(SYSTEM, "out of memory in avinsert");
1164	>	if (ambclock >= MAXACLOCK)
1165	>	ambclock = MAXACLOCK/2;
1166	>	lastsort = ambclock;
1167		}
1168
1169
1170		#ifdef  F_SETLKW
1171
1172	<	static
1173	<	aflock(typ)                     /* lock/unlock ambient file */
1174	<	int  typ;
1172	>	static void
1173	>	aflock(                 /* lock/unlock ambient file */
1174	>	int  typ
1175	>	)
1176		{
1177		static struct flock  fls;       /* static so initialized to zeroes */
1178
1179	+	if (typ == fls.l_type)          /* already called? */
1180	+	return;
1181		fls.l_type = typ;
1182		if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
1183		error(SYSTEM, "cannot (un)lock ambient file");
#	Line 404 | Line 1185 | int  typ;
1185
1186
1187		int
1188	<	ambsync()                       /* synchronize ambient file */
1188	>	ambsync(void)                   /* synchronize ambient file */
1189		{
409	–	static FILE  *ambinp = NULL;
410	–	static long  lastpos = -1;
1190		long  flen;
1191		AMBVAL  avs;
1192	<	register int  n;
1192	>	int  n;
1193
1194	<	if (nunflshed == 0)
1194	>	if (ambfp == NULL)      /* no ambient file? */
1195		return(0);
1196	<	if (lastpos < 0)        /* initializing (locked in initambfile) */
1197	<	goto syncend;
419	<	/* gain exclusive access */
420	<	aflock(F_WRLCK);
1196	>	/* gain appropriate access */
1197	>	aflock(nunflshed ? F_WRLCK : F_RDLCK);
1198		/* see if file has grown */
1199	<	if ((flen = lseek(fileno(ambfp), 0L, 2)) < 0)
1200	<	error(SYSTEM, "cannot seek on ambient file");
1201	<	if (n = flen - lastpos) {               /* file has grown */
1199	>	if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
1200	>	goto seekerr;
1201	>	if ((n = flen - lastpos) > 0) {         /* file has grown */
1202		if (ambinp == NULL) {           /* use duplicate filedes */
1203		ambinp = fdopen(dup(fileno(ambfp)), "r");
1204		if (ambinp == NULL)
1205		error(SYSTEM, "fdopen failed in ambsync");
1206		}
1207	<	if (fseek(ambinp, lastpos, 0) < 0)
1208	<	error(SYSTEM, "fseek failed in ambsync");
1207	>	if (fseek(ambinp, lastpos, SEEK_SET) < 0)
1208	>	goto seekerr;
1209		while (n >= AMBVALSIZ) {        /* load contributed values */
1210	<	readambval(&avs, ambinp);
1211	<	avinsert(&avs,&atrunk,thescene.cuorg,thescene.cusize);
1210	>	if (!readambval(&avs, ambinp)) {
1211	>	sprintf(errmsg,
1212	>	"ambient file \"%s\" corrupted near character %ld",
1213	>	ambfile, flen - n);
1214	>	error(WARNING, errmsg);
1215	>	break;
1216	>	}
1217	>	avinsert(avstore(&avs));
1218		n -= AMBVALSIZ;
1219		}
1220	<	if (n)                          /* alignment */
1221	<	lseek(fileno(ambfp), flen-n, 0);
1220	>	lastpos = flen - n;
1221	>	/*** seek always as safety measure
1222	>	if (n) ***/                     /* alignment */
1223	>	if (lseek(fileno(ambfp), (off_t)lastpos, SEEK_SET) < 0)
1224	>	goto seekerr;
1225		}
440	–	syncend:
1226		n = fflush(ambfp);                      /* calls write() at last */
1227	<	lastpos = lseek(fileno(ambfp), 0L, 1);
1227	>	if (n != EOF)
1228	>	lastpos += (long)nunflshed*AMBVALSIZ;
1229	>	else if ((lastpos = lseek(fileno(ambfp), (off_t)0, SEEK_CUR)) < 0)
1230	>	goto seekerr;
1231	>
1232		aflock(F_UNLCK);                        /* release file */
1233		nunflshed = 0;
1234		return(n);
1235	+	seekerr:
1236	+	error(SYSTEM, "seek failed in ambsync");
1237	+	return -1; /* pro forma return */
1238		}
1239
1240	<	#else
1240	>	#else   /* ! F_SETLKW */
1241
1242		int
1243	<	ambsync()                       /* flush ambient file */
1243	>	ambsync(void)                   /* flush ambient file */
1244		{
1245	<	if (nunflshed == 0)
1245	>	if (ambfp == NULL)
1246		return(0);
1247		nunflshed = 0;
1248		return(fflush(ambfp));
1249		}
1250
1251	<	#endif
1251	>	#endif  /* ! F_SETLKW */

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