1 |
greg |
1.14 |
/* Copyright (c) 1991 Regents of the University of California */ |
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greg |
1.1 |
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
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/* |
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* ambient.c - routines dealing with ambient (inter-reflected) component. |
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* |
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* The macro AMBFLUSH (if defined) is the number of ambient values |
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* to wait before flushing to the ambient file. |
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* |
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* 5/9/86 |
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*/ |
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#include "ray.h" |
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#include "octree.h" |
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greg |
1.8 |
#include "otypes.h" |
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22 |
greg |
1.14 |
#include "ambient.h" |
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24 |
greg |
1.1 |
#include "random.h" |
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26 |
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#define OCTSCALE 0.5 /* ceil((valid rad.)/(cube size)) */ |
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greg |
1.14 |
typedef struct ambtree { |
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AMBVAL *alist; /* ambient value list */ |
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struct ambtree *kid; /* 8 child nodes */ |
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} AMBTREE; /* ambient octree */ |
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greg |
1.1 |
extern CUBE thescene; /* contains space boundaries */ |
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greg |
1.11 |
#define MAXASET 511 /* maximum number of elements in ambient set */ |
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OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */ |
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greg |
1.1 |
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double maxarad; /* maximum ambient radius */ |
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double minarad; /* minimum ambient radius */ |
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static AMBTREE atrunk; /* our ambient trunk node */ |
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static FILE *ambfp = NULL; /* ambient file pointer */ |
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#define newambval() (AMBVAL *)bmalloc(sizeof(AMBVAL)) |
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#define newambtree() (AMBTREE *)calloc(8, sizeof(AMBTREE)) |
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setambient(afile) /* initialize calculation */ |
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char *afile; |
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{ |
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long ftell(); |
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AMBVAL amb; |
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greg |
1.8 |
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greg |
1.1 |
maxarad = thescene.cusize / 2.0; /* maximum radius */ |
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/* minimum radius */ |
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minarad = ambres > 0 ? thescene.cusize/ambres : 0.0; |
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/* open ambient file */ |
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if (afile != NULL) |
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if ((ambfp = fopen(afile, "r+")) != NULL) { |
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greg |
1.9 |
while (fread((char *)&amb,sizeof(AMBVAL),1,ambfp) == 1) |
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greg |
1.1 |
avinsert(&amb, &atrunk, thescene.cuorg, |
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thescene.cusize); |
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/* align */ |
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fseek(ambfp, -(ftell(ambfp)%sizeof(AMBVAL)), 1); |
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} else if ((ambfp = fopen(afile, "w")) == NULL) { |
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sprintf(errmsg, "cannot open ambient file \"%s\"", |
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afile); |
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error(SYSTEM, errmsg); |
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greg |
1.8 |
} |
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} |
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ambnotify(obj) /* record new modifier */ |
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OBJECT obj; |
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{ |
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greg |
1.11 |
static int hitlimit = 0; |
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greg |
1.8 |
register OBJREC *o = objptr(obj); |
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register char **amblp; |
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greg |
1.11 |
if (hitlimit || !ismodifier(o->otype)) |
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greg |
1.8 |
return; |
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for (amblp = amblist; *amblp != NULL; amblp++) |
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if (!strcmp(o->oname, *amblp)) { |
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greg |
1.11 |
if (ambset[0] >= MAXASET) { |
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error(WARNING, "too many modifiers in ambient list"); |
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hitlimit++; |
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return; /* should this be fatal? */ |
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} |
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greg |
1.8 |
insertelem(ambset, obj); |
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return; |
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greg |
1.1 |
} |
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} |
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ambient(acol, r) /* compute ambient component for ray */ |
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COLOR acol; |
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register RAY *r; |
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{ |
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static int rdepth = 0; /* ambient recursion */ |
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greg |
1.16 |
double d; |
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greg |
1.1 |
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if (ambdiv <= 0) /* no ambient calculation */ |
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goto dumbamb; |
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/* check number of bounces */ |
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greg |
1.16 |
if (rdepth >= ambounce) |
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greg |
1.1 |
goto dumbamb; |
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/* check ambient list */ |
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if (ambincl != -1 && r->ro != NULL && |
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ambincl != inset(ambset, r->ro->omod)) |
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goto dumbamb; |
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if (ambacc <= FTINY) { /* no ambient storage */ |
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greg |
1.16 |
rdepth++; |
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d = doambient(acol, r, r->rweight, NULL, NULL); |
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rdepth--; |
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if (d == 0.0) |
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greg |
1.1 |
goto dumbamb; |
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greg |
1.16 |
return; |
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greg |
1.1 |
} |
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/* get ambient value */ |
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setcolor(acol, 0.0, 0.0, 0.0); |
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greg |
1.16 |
d = sumambient(acol, r, rdepth, |
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&atrunk, thescene.cuorg, thescene.cusize); |
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if (d > FTINY) |
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scalecolor(acol, 1.0/d); |
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else { |
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d = makeambient(acol, r, rdepth++); |
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rdepth--; |
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} |
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if (d > FTINY) |
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return; |
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greg |
1.1 |
dumbamb: /* return global value */ |
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copycolor(acol, ambval); |
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} |
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double |
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greg |
1.16 |
sumambient(acol, r, al, at, c0, s) /* get interpolated ambient value */ |
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greg |
1.1 |
COLOR acol; |
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register RAY *r; |
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greg |
1.16 |
int al; |
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greg |
1.1 |
AMBTREE *at; |
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FVECT c0; |
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double s; |
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{ |
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extern double sqrt(); |
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double d, e1, e2, wt, wsum; |
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COLOR ct; |
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FVECT ck0; |
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int i; |
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register int j; |
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register AMBVAL *av; |
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greg |
1.7 |
/* do this node */ |
157 |
greg |
1.1 |
wsum = 0.0; |
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for (av = at->alist; av != NULL; av = av->next) { |
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/* |
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greg |
1.16 |
* Ambient level test. |
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greg |
1.1 |
*/ |
162 |
greg |
1.16 |
if (av->lvl > al || av->weight < r->rweight-FTINY) |
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greg |
1.1 |
continue; |
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/* |
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* Ambient radius test. |
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*/ |
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e1 = 0.0; |
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for (j = 0; j < 3; j++) { |
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d = av->pos[j] - r->rop[j]; |
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e1 += d * d; |
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} |
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e1 /= av->rad * av->rad; |
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if (e1 > ambacc*ambacc*1.21) |
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continue; |
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/* |
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* Normal direction test. |
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*/ |
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e2 = (1.0 - DOT(av->dir, r->ron)) * r->rweight; |
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if (e2 < 0.0) e2 = 0.0; |
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if (e1 + e2 > ambacc*ambacc*1.21) |
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continue; |
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/* |
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* Ray behind test. |
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*/ |
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d = 0.0; |
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for (j = 0; j < 3; j++) |
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d += (r->rop[j] - av->pos[j]) * |
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(av->dir[j] + r->ron[j]); |
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greg |
1.18 |
if (d*0.5 < -minarad*ambacc-.001) |
190 |
greg |
1.1 |
continue; |
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/* |
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* Jittering final test reduces image artifacts. |
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*/ |
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wt = sqrt(e1) + sqrt(e2); |
195 |
greg |
2.2 |
wt *= .9 + .2*urand(9015+samplendx); |
196 |
greg |
1.6 |
if (wt > ambacc) |
197 |
greg |
1.1 |
continue; |
198 |
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if (wt <= 1e-3) |
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wt = 1e3; |
200 |
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else |
201 |
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wt = 1.0 / wt; |
202 |
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wsum += wt; |
203 |
greg |
1.15 |
extambient(ct, av, r->rop, r->ron); |
204 |
greg |
1.1 |
scalecolor(ct, wt); |
205 |
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addcolor(acol, ct); |
206 |
greg |
1.7 |
} |
207 |
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if (at->kid == NULL) |
208 |
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return(wsum); |
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/* do children */ |
210 |
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s *= 0.5; |
211 |
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for (i = 0; i < 8; i++) { |
212 |
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for (j = 0; j < 3; j++) { |
213 |
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ck0[j] = c0[j]; |
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if (1<<j & i) |
215 |
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ck0[j] += s; |
216 |
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if (r->rop[j] < ck0[j] - OCTSCALE*s) |
217 |
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break; |
218 |
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if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s) |
219 |
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break; |
220 |
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} |
221 |
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if (j == 3) |
222 |
greg |
1.16 |
wsum += sumambient(acol, r, al, at->kid+i, ck0, s); |
223 |
greg |
1.1 |
} |
224 |
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return(wsum); |
225 |
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} |
226 |
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227 |
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228 |
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double |
229 |
greg |
1.16 |
makeambient(acol, r, al) /* make a new ambient value */ |
230 |
greg |
1.1 |
COLOR acol; |
231 |
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register RAY *r; |
232 |
greg |
1.16 |
int al; |
233 |
greg |
1.1 |
{ |
234 |
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AMBVAL amb; |
235 |
greg |
1.14 |
FVECT gp, gd; |
236 |
greg |
1.16 |
/* compute weight */ |
237 |
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amb.weight = pow(AVGREFL, (double)al); |
238 |
greg |
1.17 |
if (r->rweight < 0.2*amb.weight) /* heuristic */ |
239 |
greg |
1.16 |
amb.weight = r->rweight; |
240 |
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/* compute ambient */ |
241 |
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amb.rad = doambient(acol, r, amb.weight, gp, gd); |
242 |
greg |
1.1 |
if (amb.rad == 0.0) |
243 |
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return(0.0); |
244 |
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/* store it */ |
245 |
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VCOPY(amb.pos, r->rop); |
246 |
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VCOPY(amb.dir, r->ron); |
247 |
greg |
1.16 |
amb.lvl = al; |
248 |
greg |
1.1 |
copycolor(amb.val, acol); |
249 |
greg |
1.14 |
VCOPY(amb.gpos, gp); |
250 |
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VCOPY(amb.gdir, gd); |
251 |
greg |
1.1 |
/* insert into tree */ |
252 |
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avinsert(&amb, &atrunk, thescene.cuorg, thescene.cusize); |
253 |
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avsave(&amb); /* write to file */ |
254 |
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return(amb.rad); |
255 |
greg |
1.15 |
} |
256 |
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257 |
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258 |
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extambient(cr, ap, pv, nv) /* extrapolate value at pv, nv */ |
259 |
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COLOR cr; |
260 |
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register AMBVAL *ap; |
261 |
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FVECT pv, nv; |
262 |
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{ |
263 |
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FVECT v1, v2; |
264 |
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register int i; |
265 |
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double d; |
266 |
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267 |
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d = 1.0; /* zeroeth order */ |
268 |
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/* gradient due to translation */ |
269 |
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for (i = 0; i < 3; i++) |
270 |
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d += ap->gpos[i]*(pv[i]-ap->pos[i]); |
271 |
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/* gradient due to rotation */ |
272 |
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VCOPY(v1, ap->dir); |
273 |
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fcross(v2, v1, nv); |
274 |
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d += DOT(ap->gdir, v2); |
275 |
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if (d <= 0.0) { |
276 |
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setcolor(cr, 0.0, 0.0, 0.0); |
277 |
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return; |
278 |
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} |
279 |
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copycolor(cr, ap->val); |
280 |
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scalecolor(cr, d); |
281 |
greg |
1.1 |
} |
282 |
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283 |
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284 |
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static |
285 |
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avsave(av) /* save an ambient value */ |
286 |
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AMBVAL *av; |
287 |
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{ |
288 |
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#ifdef AMBFLUSH |
289 |
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static int nunflshed = 0; |
290 |
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#endif |
291 |
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if (ambfp == NULL) |
292 |
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return; |
293 |
greg |
1.9 |
if (fwrite((char *)av, sizeof(AMBVAL), 1, ambfp) != 1) |
294 |
greg |
1.1 |
goto writerr; |
295 |
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#ifdef AMBFLUSH |
296 |
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if (++nunflshed >= AMBFLUSH) { |
297 |
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if (fflush(ambfp) == EOF) |
298 |
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goto writerr; |
299 |
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nunflshed = 0; |
300 |
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} |
301 |
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#endif |
302 |
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return; |
303 |
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writerr: |
304 |
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error(SYSTEM, "error writing ambient file"); |
305 |
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} |
306 |
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307 |
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308 |
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static |
309 |
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avinsert(aval, at, c0, s) /* insert ambient value in a tree */ |
310 |
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AMBVAL *aval; |
311 |
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register AMBTREE *at; |
312 |
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FVECT c0; |
313 |
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double s; |
314 |
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{ |
315 |
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FVECT ck0; |
316 |
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int branch; |
317 |
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register AMBVAL *av; |
318 |
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register int i; |
319 |
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320 |
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if ((av = newambval()) == NULL) |
321 |
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goto memerr; |
322 |
greg |
1.9 |
copystruct(av, aval); |
323 |
greg |
1.1 |
VCOPY(ck0, c0); |
324 |
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while (s*(OCTSCALE/2) > av->rad*ambacc) { |
325 |
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if (at->kid == NULL) |
326 |
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if ((at->kid = newambtree()) == NULL) |
327 |
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goto memerr; |
328 |
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s *= 0.5; |
329 |
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branch = 0; |
330 |
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for (i = 0; i < 3; i++) |
331 |
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if (av->pos[i] > ck0[i] + s) { |
332 |
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ck0[i] += s; |
333 |
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branch |= 1 << i; |
334 |
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} |
335 |
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at = at->kid + branch; |
336 |
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} |
337 |
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av->next = at->alist; |
338 |
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at->alist = av; |
339 |
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return; |
340 |
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memerr: |
341 |
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error(SYSTEM, "out of memory in avinsert"); |
342 |
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} |