| 1 | greg | 1.1 | /* Copyright (c) 1986 Regents of the University of California */ | 
| 2 |  |  |  | 
| 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 |  |  | *  The macro AMBFLUSH (if defined) is the number of ambient values | 
| 11 |  |  | *      to wait before flushing to the ambient file. | 
| 12 |  |  | * | 
| 13 |  |  | *     5/9/86 | 
| 14 |  |  | */ | 
| 15 |  |  |  | 
| 16 |  |  | #include  "ray.h" | 
| 17 |  |  |  | 
| 18 |  |  | #include  "octree.h" | 
| 19 |  |  |  | 
| 20 | greg | 1.8 | #include  "otypes.h" | 
| 21 |  |  |  | 
| 22 | greg | 1.1 | #include  "random.h" | 
| 23 |  |  |  | 
| 24 |  |  | #define  OCTSCALE       0.5     /* ceil((valid rad.)/(cube size)) */ | 
| 25 |  |  |  | 
| 26 |  |  | extern CUBE  thescene;          /* contains space boundaries */ | 
| 27 |  |  |  | 
| 28 |  |  | extern COLOR  ambval;           /* global ambient component */ | 
| 29 |  |  | extern double  ambacc;          /* ambient accuracy */ | 
| 30 |  |  | extern int  ambres;             /* ambient resolution */ | 
| 31 |  |  | extern int  ambdiv;             /* number of divisions for calculation */ | 
| 32 |  |  | extern int  ambssamp;           /* number of super-samples */ | 
| 33 |  |  | extern int  ambounce;           /* number of ambient bounces */ | 
| 34 |  |  | extern char  *amblist[];        /* ambient include/exclude list */ | 
| 35 |  |  | extern int  ambincl;            /* include == 1, exclude == 0 */ | 
| 36 |  |  |  | 
| 37 | greg | 1.8 | OBJECT  ambset[256]={0};        /* ambient include/exclude set */ | 
| 38 | greg | 1.1 |  | 
| 39 |  |  | double  maxarad;                /* maximum ambient radius */ | 
| 40 |  |  | double  minarad;                /* minimum ambient radius */ | 
| 41 |  |  |  | 
| 42 |  |  | typedef struct ambval { | 
| 43 |  |  | FVECT  pos;             /* position in space */ | 
| 44 |  |  | FVECT  dir;             /* normal direction */ | 
| 45 |  |  | int  lvl;               /* recursion level of parent ray */ | 
| 46 |  |  | float  weight;          /* weight of parent ray */ | 
| 47 |  |  | COLOR  val;             /* computed ambient value */ | 
| 48 |  |  | float  rad;             /* validity radius */ | 
| 49 |  |  | struct ambval  *next;   /* next in list */ | 
| 50 |  |  | }  AMBVAL;                      /* ambient value */ | 
| 51 |  |  |  | 
| 52 |  |  | typedef struct ambtree { | 
| 53 |  |  | AMBVAL  *alist;         /* ambient value list */ | 
| 54 |  |  | struct ambtree  *kid;   /* 8 child nodes */ | 
| 55 |  |  | }  AMBTREE;                     /* ambient octree */ | 
| 56 |  |  |  | 
| 57 |  |  | typedef struct { | 
| 58 |  |  | float  k;               /* error contribution per sample */ | 
| 59 |  |  | COLOR  v;               /* ray sum */ | 
| 60 |  |  | int  n;                 /* number of samples */ | 
| 61 |  |  | short  t, p;            /* theta, phi indices */ | 
| 62 |  |  | }  AMBSAMP;                     /* ambient sample */ | 
| 63 |  |  |  | 
| 64 |  |  | static AMBTREE  atrunk;         /* our ambient trunk node */ | 
| 65 |  |  |  | 
| 66 |  |  | static FILE  *ambfp = NULL;     /* ambient file pointer */ | 
| 67 |  |  |  | 
| 68 |  |  | #define  newambval()    (AMBVAL *)bmalloc(sizeof(AMBVAL)) | 
| 69 |  |  |  | 
| 70 |  |  | #define  newambtree()   (AMBTREE *)calloc(8, sizeof(AMBTREE)) | 
| 71 |  |  |  | 
| 72 |  |  | double  sumambient(), doambient(), makeambient(); | 
| 73 |  |  |  | 
| 74 |  |  |  | 
| 75 |  |  | setambient(afile)                       /* initialize calculation */ | 
| 76 |  |  | char  *afile; | 
| 77 |  |  | { | 
| 78 |  |  | long  ftell(); | 
| 79 |  |  | OBJECT  obj; | 
| 80 |  |  | AMBVAL  amb; | 
| 81 | greg | 1.8 |  | 
| 82 | greg | 1.1 | maxarad = thescene.cusize / 2.0;                /* maximum radius */ | 
| 83 |  |  | /* minimum radius */ | 
| 84 |  |  | minarad = ambres > 0 ? thescene.cusize/ambres : 0.0; | 
| 85 |  |  |  | 
| 86 |  |  | /* open ambient file */ | 
| 87 |  |  | if (afile != NULL) | 
| 88 |  |  | if ((ambfp = fopen(afile, "r+")) != NULL) { | 
| 89 | greg | 1.9 | while (fread((char *)&amb,sizeof(AMBVAL),1,ambfp) == 1) | 
| 90 | greg | 1.1 | avinsert(&amb, &atrunk, thescene.cuorg, | 
| 91 |  |  | thescene.cusize); | 
| 92 |  |  | /* align */ | 
| 93 |  |  | fseek(ambfp, -(ftell(ambfp)%sizeof(AMBVAL)), 1); | 
| 94 |  |  | } else if ((ambfp = fopen(afile, "w")) == NULL) { | 
| 95 |  |  | sprintf(errmsg, "cannot open ambient file \"%s\"", | 
| 96 |  |  | afile); | 
| 97 |  |  | error(SYSTEM, errmsg); | 
| 98 | greg | 1.8 | } | 
| 99 |  |  | } | 
| 100 |  |  |  | 
| 101 |  |  |  | 
| 102 |  |  | ambnotify(obj)                  /* record new modifier */ | 
| 103 |  |  | OBJECT  obj; | 
| 104 |  |  | { | 
| 105 |  |  | register OBJREC  *o = objptr(obj); | 
| 106 |  |  | register char  **amblp; | 
| 107 |  |  |  | 
| 108 |  |  | if (!ismodifier(o->otype)) | 
| 109 |  |  | return; | 
| 110 |  |  | for (amblp = amblist; *amblp != NULL; amblp++) | 
| 111 |  |  | if (!strcmp(o->oname, *amblp)) { | 
| 112 |  |  | insertelem(ambset, obj); | 
| 113 |  |  | return; | 
| 114 | greg | 1.1 | } | 
| 115 |  |  | } | 
| 116 |  |  |  | 
| 117 |  |  |  | 
| 118 |  |  | ambient(acol, r)                /* compute ambient component for ray */ | 
| 119 |  |  | COLOR  acol; | 
| 120 |  |  | register RAY  *r; | 
| 121 |  |  | { | 
| 122 |  |  | static int  rdepth = 0;                 /* ambient recursion */ | 
| 123 |  |  | double  wsum; | 
| 124 |  |  |  | 
| 125 |  |  | rdepth++;                               /* increment level */ | 
| 126 |  |  |  | 
| 127 |  |  | if (ambdiv <= 0)                        /* no ambient calculation */ | 
| 128 |  |  | goto dumbamb; | 
| 129 |  |  | /* check number of bounces */ | 
| 130 |  |  | if (rdepth > ambounce) | 
| 131 |  |  | goto dumbamb; | 
| 132 |  |  | /* check ambient list */ | 
| 133 |  |  | if (ambincl != -1 && r->ro != NULL && | 
| 134 |  |  | ambincl != inset(ambset, r->ro->omod)) | 
| 135 |  |  | goto dumbamb; | 
| 136 |  |  |  | 
| 137 |  |  | if (ambacc <= FTINY) {                  /* no ambient storage */ | 
| 138 |  |  | if (doambient(acol, r) == 0.0) | 
| 139 |  |  | goto dumbamb; | 
| 140 |  |  | goto done; | 
| 141 |  |  | } | 
| 142 |  |  | /* get ambient value */ | 
| 143 |  |  | setcolor(acol, 0.0, 0.0, 0.0); | 
| 144 |  |  | wsum = sumambient(acol, r, &atrunk, thescene.cuorg, thescene.cusize); | 
| 145 |  |  | if (wsum > FTINY) | 
| 146 |  |  | scalecolor(acol, 1.0/wsum); | 
| 147 |  |  | else if (makeambient(acol, r) == 0.0) | 
| 148 |  |  | goto dumbamb; | 
| 149 |  |  | goto done; | 
| 150 |  |  |  | 
| 151 |  |  | dumbamb:                                        /* return global value */ | 
| 152 |  |  | copycolor(acol, ambval); | 
| 153 |  |  | done:                                           /* must finish here! */ | 
| 154 |  |  | rdepth--; | 
| 155 |  |  | } | 
| 156 |  |  |  | 
| 157 |  |  |  | 
| 158 |  |  | double | 
| 159 |  |  | sumambient(acol, r, at, c0, s)          /* get interpolated ambient value */ | 
| 160 |  |  | COLOR  acol; | 
| 161 |  |  | register RAY  *r; | 
| 162 |  |  | AMBTREE  *at; | 
| 163 |  |  | FVECT  c0; | 
| 164 |  |  | double  s; | 
| 165 |  |  | { | 
| 166 |  |  | extern double  sqrt(); | 
| 167 |  |  | double  d, e1, e2, wt, wsum; | 
| 168 |  |  | COLOR  ct; | 
| 169 |  |  | FVECT  ck0; | 
| 170 |  |  | int  i; | 
| 171 |  |  | register int  j; | 
| 172 |  |  | register AMBVAL  *av; | 
| 173 | greg | 1.7 | /* do this node */ | 
| 174 | greg | 1.1 | wsum = 0.0; | 
| 175 |  |  | for (av = at->alist; av != NULL; av = av->next) { | 
| 176 |  |  | /* | 
| 177 |  |  | *  Ray strength test. | 
| 178 |  |  | */ | 
| 179 |  |  | if (av->lvl > r->rlvl || av->weight < r->rweight-FTINY) | 
| 180 |  |  | continue; | 
| 181 |  |  | /* | 
| 182 |  |  | *  Ambient radius test. | 
| 183 |  |  | */ | 
| 184 |  |  | e1 = 0.0; | 
| 185 |  |  | for (j = 0; j < 3; j++) { | 
| 186 |  |  | d = av->pos[j] - r->rop[j]; | 
| 187 |  |  | e1 += d * d; | 
| 188 |  |  | } | 
| 189 |  |  | e1 /= av->rad * av->rad; | 
| 190 |  |  | if (e1 > ambacc*ambacc*1.21) | 
| 191 |  |  | continue; | 
| 192 |  |  | /* | 
| 193 |  |  | *  Normal direction test. | 
| 194 |  |  | */ | 
| 195 |  |  | e2 = (1.0 - DOT(av->dir, r->ron)) * r->rweight; | 
| 196 |  |  | if (e2 < 0.0) e2 = 0.0; | 
| 197 |  |  | if (e1 + e2 > ambacc*ambacc*1.21) | 
| 198 |  |  | continue; | 
| 199 |  |  | /* | 
| 200 |  |  | *  Ray behind test. | 
| 201 |  |  | */ | 
| 202 |  |  | d = 0.0; | 
| 203 |  |  | for (j = 0; j < 3; j++) | 
| 204 |  |  | d += (r->rop[j] - av->pos[j]) * | 
| 205 |  |  | (av->dir[j] + r->ron[j]); | 
| 206 |  |  | if (d < -minarad) | 
| 207 |  |  | continue; | 
| 208 |  |  | /* | 
| 209 |  |  | *  Jittering final test reduces image artifacts. | 
| 210 |  |  | */ | 
| 211 |  |  | wt = sqrt(e1) + sqrt(e2); | 
| 212 | greg | 1.7 | wt *= .9 + .2*frandom(); | 
| 213 | greg | 1.6 | if (wt > ambacc) | 
| 214 | greg | 1.1 | continue; | 
| 215 |  |  | if (wt <= 1e-3) | 
| 216 |  |  | wt = 1e3; | 
| 217 |  |  | else | 
| 218 |  |  | wt = 1.0 / wt; | 
| 219 |  |  | wsum += wt; | 
| 220 |  |  | copycolor(ct, av->val); | 
| 221 |  |  | scalecolor(ct, wt); | 
| 222 |  |  | addcolor(acol, ct); | 
| 223 | greg | 1.7 | } | 
| 224 |  |  | if (at->kid == NULL) | 
| 225 |  |  | return(wsum); | 
| 226 |  |  | /* do children */ | 
| 227 |  |  | s *= 0.5; | 
| 228 |  |  | for (i = 0; i < 8; i++) { | 
| 229 |  |  | for (j = 0; j < 3; j++) { | 
| 230 |  |  | ck0[j] = c0[j]; | 
| 231 |  |  | if (1<<j & i) | 
| 232 |  |  | ck0[j] += s; | 
| 233 |  |  | if (r->rop[j] < ck0[j] - OCTSCALE*s) | 
| 234 |  |  | break; | 
| 235 |  |  | if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s) | 
| 236 |  |  | break; | 
| 237 |  |  | } | 
| 238 |  |  | if (j == 3) | 
| 239 |  |  | wsum += sumambient(acol, r, at->kid+i, ck0, s); | 
| 240 | greg | 1.1 | } | 
| 241 |  |  | return(wsum); | 
| 242 |  |  | } | 
| 243 |  |  |  | 
| 244 |  |  |  | 
| 245 |  |  | double | 
| 246 |  |  | makeambient(acol, r)            /* make a new ambient value */ | 
| 247 |  |  | COLOR  acol; | 
| 248 |  |  | register RAY  *r; | 
| 249 |  |  | { | 
| 250 |  |  | AMBVAL  amb; | 
| 251 |  |  |  | 
| 252 |  |  | amb.rad = doambient(acol, r);           /* compute ambient */ | 
| 253 |  |  | if (amb.rad == 0.0) | 
| 254 |  |  | return(0.0); | 
| 255 |  |  | /* store it */ | 
| 256 |  |  | VCOPY(amb.pos, r->rop); | 
| 257 |  |  | VCOPY(amb.dir, r->ron); | 
| 258 |  |  | amb.lvl = r->rlvl; | 
| 259 |  |  | amb.weight = r->rweight; | 
| 260 |  |  | copycolor(amb.val, acol); | 
| 261 |  |  | /* insert into tree */ | 
| 262 |  |  | avinsert(&amb, &atrunk, thescene.cuorg, thescene.cusize); | 
| 263 |  |  | avsave(&amb);                           /* write to file */ | 
| 264 |  |  | return(amb.rad); | 
| 265 |  |  | } | 
| 266 |  |  |  | 
| 267 |  |  |  | 
| 268 |  |  | double | 
| 269 |  |  | doambient(acol, r)                      /* compute ambient component */ | 
| 270 |  |  | COLOR  acol; | 
| 271 |  |  | register RAY  *r; | 
| 272 |  |  | { | 
| 273 |  |  | extern int  ambcmp(); | 
| 274 |  |  | extern double  sin(), cos(), sqrt(); | 
| 275 |  |  | double  phi, xd, yd, zd; | 
| 276 | greg | 1.3 | double  b, b2; | 
| 277 | greg | 1.1 | register AMBSAMP  *div; | 
| 278 |  |  | AMBSAMP  dnew; | 
| 279 |  |  | RAY  ar; | 
| 280 |  |  | FVECT  ux, uy; | 
| 281 |  |  | double  arad; | 
| 282 |  |  | int  ndivs, nt, np, ns, ne, i, j; | 
| 283 |  |  | register int  k; | 
| 284 |  |  |  | 
| 285 |  |  | setcolor(acol, 0.0, 0.0, 0.0); | 
| 286 |  |  | /* set number of divisions */ | 
| 287 |  |  | nt = sqrt(ambdiv * r->rweight * 0.5) + 0.5; | 
| 288 |  |  | np = 2 * nt; | 
| 289 |  |  | ndivs = nt * np; | 
| 290 |  |  | /* check first */ | 
| 291 |  |  | if (ndivs == 0 || rayorigin(&ar, r, AMBIENT, 0.5) < 0) | 
| 292 |  |  | return(0.0); | 
| 293 |  |  | /* set number of super-samples */ | 
| 294 |  |  | ns = ambssamp * r->rweight + 0.5; | 
| 295 |  |  | if (ns > 0) { | 
| 296 |  |  | div = (AMBSAMP *)malloc(ndivs*sizeof(AMBSAMP)); | 
| 297 |  |  | if (div == NULL) | 
| 298 |  |  | error(SYSTEM, "out of memory in doambient"); | 
| 299 |  |  | } | 
| 300 |  |  | /* make axes */ | 
| 301 |  |  | uy[0] = uy[1] = uy[2] = 0.0; | 
| 302 |  |  | for (k = 0; k < 3; k++) | 
| 303 |  |  | if (r->ron[k] < 0.6 && r->ron[k] > -0.6) | 
| 304 |  |  | break; | 
| 305 |  |  | uy[k] = 1.0; | 
| 306 |  |  | fcross(ux, r->ron, uy); | 
| 307 |  |  | normalize(ux); | 
| 308 |  |  | fcross(uy, ux, r->ron); | 
| 309 |  |  | /* sample divisions */ | 
| 310 |  |  | arad = 0.0; | 
| 311 |  |  | ne = 0; | 
| 312 |  |  | for (i = 0; i < nt; i++) | 
| 313 |  |  | for (j = 0; j < np; j++) { | 
| 314 |  |  | rayorigin(&ar, r, AMBIENT, 0.5);        /* pretested */ | 
| 315 |  |  | zd = sqrt((i+frandom())/nt); | 
| 316 |  |  | phi = 2.0*PI * (j+frandom())/np; | 
| 317 |  |  | xd = cos(phi) * zd; | 
| 318 |  |  | yd = sin(phi) * zd; | 
| 319 |  |  | zd = sqrt(1.0 - zd*zd); | 
| 320 |  |  | for (k = 0; k < 3; k++) | 
| 321 |  |  | ar.rdir[k] = xd*ux[k]+yd*uy[k]+zd*r->ron[k]; | 
| 322 |  |  | rayvalue(&ar); | 
| 323 |  |  | if (ar.rot < FHUGE) | 
| 324 |  |  | arad += 1.0 / ar.rot; | 
| 325 |  |  | if (ns > 0) {                   /* save division */ | 
| 326 |  |  | div[ne].k = 0.0; | 
| 327 |  |  | copycolor(div[ne].v, ar.rcol); | 
| 328 |  |  | div[ne].n = 0; | 
| 329 |  |  | div[ne].t = i; div[ne].p = j; | 
| 330 |  |  | /* sum errors */ | 
| 331 | greg | 1.3 | b = bright(ar.rcol); | 
| 332 | greg | 1.1 | if (i > 0) {            /* from above */ | 
| 333 | greg | 1.3 | b2 = bright(div[ne-np].v) - b; | 
| 334 |  |  | b2 *= b2 * 0.25; | 
| 335 |  |  | div[ne].k += b2; | 
| 336 | greg | 1.1 | div[ne].n++; | 
| 337 | greg | 1.3 | div[ne-np].k += b2; | 
| 338 | greg | 1.1 | div[ne-np].n++; | 
| 339 |  |  | } | 
| 340 |  |  | if (j > 0) {            /* from behind */ | 
| 341 | greg | 1.3 | b2 = bright(div[ne-1].v) - b; | 
| 342 |  |  | b2 *= b2 * 0.25; | 
| 343 |  |  | div[ne].k += b2; | 
| 344 | greg | 1.1 | div[ne].n++; | 
| 345 | greg | 1.3 | div[ne-1].k += b2; | 
| 346 | greg | 1.1 | div[ne-1].n++; | 
| 347 |  |  | } | 
| 348 |  |  | if (j == np-1) {        /* around */ | 
| 349 | greg | 1.3 | b2 = bright(div[ne-(np-1)].v) - b; | 
| 350 |  |  | b2 *= b2 * 0.25; | 
| 351 |  |  | div[ne].k += b2; | 
| 352 | greg | 1.1 | div[ne].n++; | 
| 353 | greg | 1.3 | div[ne-(np-1)].k += b2; | 
| 354 | greg | 1.1 | div[ne-(np-1)].n++; | 
| 355 |  |  | } | 
| 356 |  |  | ne++; | 
| 357 |  |  | } else | 
| 358 |  |  | addcolor(acol, ar.rcol); | 
| 359 |  |  | } | 
| 360 |  |  | for (k = 0; k < ne; k++) {              /* compute errors */ | 
| 361 |  |  | if (div[k].n > 1) | 
| 362 |  |  | div[k].k /= div[k].n; | 
| 363 |  |  | div[k].n = 1; | 
| 364 |  |  | } | 
| 365 |  |  | /* sort the divisions */ | 
| 366 |  |  | qsort(div, ne, sizeof(AMBSAMP), ambcmp); | 
| 367 |  |  | /* skim excess */ | 
| 368 |  |  | while (ne > ns) { | 
| 369 |  |  | ne--; | 
| 370 |  |  | addcolor(acol, div[ne].v); | 
| 371 |  |  | } | 
| 372 |  |  | /* super-sample */ | 
| 373 |  |  | for (i = ns; i > 0; i--) { | 
| 374 |  |  | rayorigin(&ar, r, AMBIENT, 0.5);        /* pretested */ | 
| 375 |  |  | zd = sqrt((div[0].t+frandom())/nt); | 
| 376 |  |  | phi = 2.0*PI * (div[0].p+frandom())/np; | 
| 377 |  |  | xd = cos(phi) * zd; | 
| 378 |  |  | yd = sin(phi) * zd; | 
| 379 |  |  | zd = sqrt(1.0 - zd*zd); | 
| 380 |  |  | for (k = 0; k < 3; k++) | 
| 381 |  |  | ar.rdir[k] = xd*ux[k]+yd*uy[k]+zd*r->ron[k]; | 
| 382 |  |  | rayvalue(&ar); | 
| 383 |  |  | if (ar.rot < FHUGE) | 
| 384 |  |  | arad += 1.0 / ar.rot; | 
| 385 |  |  | /* recompute error */ | 
| 386 |  |  | copycolor(dnew.v, div[0].v); | 
| 387 |  |  | addcolor(dnew.v, ar.rcol); | 
| 388 |  |  | dnew.n = div[0].n + 1; | 
| 389 |  |  | dnew.t = div[0].t; dnew.p = div[0].p; | 
| 390 | greg | 1.3 | b2 = bright(dnew.v)/dnew.n - bright(ar.rcol); | 
| 391 | greg | 1.5 | b2 = b2*b2 + div[0].k*(div[0].n*div[0].n); | 
| 392 |  |  | dnew.k = b2/(dnew.n*dnew.n); | 
| 393 | greg | 1.1 | /* reinsert */ | 
| 394 |  |  | for (k = 0; k < ne-1 && dnew.k < div[k+1].k; k++) | 
| 395 | greg | 1.9 | copystruct(&div[k], &div[k+1]); | 
| 396 |  |  | copystruct(&div[k], &dnew); | 
| 397 | greg | 1.1 |  | 
| 398 |  |  | if (ne >= i) {          /* extract darkest division */ | 
| 399 |  |  | ne--; | 
| 400 |  |  | if (div[ne].n > 1) | 
| 401 |  |  | scalecolor(div[ne].v, 1.0/div[ne].n); | 
| 402 |  |  | addcolor(acol, div[ne].v); | 
| 403 |  |  | } | 
| 404 |  |  | } | 
| 405 |  |  | scalecolor(acol, 1.0/ndivs); | 
| 406 |  |  | if (arad <= FTINY) | 
| 407 |  |  | arad = FHUGE; | 
| 408 |  |  | else | 
| 409 |  |  | arad = (ndivs+ns) / arad / sqrt(r->rweight); | 
| 410 |  |  | if (arad > maxarad) | 
| 411 |  |  | arad = maxarad; | 
| 412 |  |  | else if (arad < minarad) | 
| 413 |  |  | arad = minarad; | 
| 414 |  |  | if (ns > 0) | 
| 415 |  |  | free((char *)div); | 
| 416 |  |  | return(arad); | 
| 417 |  |  | } | 
| 418 |  |  |  | 
| 419 |  |  |  | 
| 420 |  |  | static int | 
| 421 |  |  | ambcmp(d1, d2)                          /* decreasing order */ | 
| 422 |  |  | AMBSAMP  *d1, *d2; | 
| 423 |  |  | { | 
| 424 |  |  | if (d1->k < d2->k) | 
| 425 |  |  | return(1); | 
| 426 |  |  | if (d1->k > d2->k) | 
| 427 |  |  | return(-1); | 
| 428 |  |  | return(0); | 
| 429 |  |  | } | 
| 430 |  |  |  | 
| 431 |  |  |  | 
| 432 |  |  | static | 
| 433 |  |  | avsave(av)                              /* save an ambient value */ | 
| 434 |  |  | AMBVAL  *av; | 
| 435 |  |  | { | 
| 436 |  |  | #ifdef  AMBFLUSH | 
| 437 |  |  | static int  nunflshed = 0; | 
| 438 |  |  | #endif | 
| 439 |  |  | if (ambfp == NULL) | 
| 440 |  |  | return; | 
| 441 | greg | 1.9 | if (fwrite((char *)av, sizeof(AMBVAL), 1, ambfp) != 1) | 
| 442 | greg | 1.1 | goto writerr; | 
| 443 |  |  | #ifdef  AMBFLUSH | 
| 444 |  |  | if (++nunflshed >= AMBFLUSH) { | 
| 445 |  |  | if (fflush(ambfp) == EOF) | 
| 446 |  |  | goto writerr; | 
| 447 |  |  | nunflshed = 0; | 
| 448 |  |  | } | 
| 449 |  |  | #endif | 
| 450 |  |  | return; | 
| 451 |  |  | writerr: | 
| 452 |  |  | error(SYSTEM, "error writing ambient file"); | 
| 453 |  |  | } | 
| 454 |  |  |  | 
| 455 |  |  |  | 
| 456 |  |  | static | 
| 457 |  |  | avinsert(aval, at, c0, s)               /* insert ambient value in a tree */ | 
| 458 |  |  | AMBVAL  *aval; | 
| 459 |  |  | register AMBTREE  *at; | 
| 460 |  |  | FVECT  c0; | 
| 461 |  |  | double  s; | 
| 462 |  |  | { | 
| 463 |  |  | FVECT  ck0; | 
| 464 |  |  | int  branch; | 
| 465 |  |  | register AMBVAL  *av; | 
| 466 |  |  | register int  i; | 
| 467 |  |  |  | 
| 468 |  |  | if ((av = newambval()) == NULL) | 
| 469 |  |  | goto memerr; | 
| 470 | greg | 1.9 | copystruct(av, aval); | 
| 471 | greg | 1.1 | VCOPY(ck0, c0); | 
| 472 |  |  | while (s*(OCTSCALE/2) > av->rad*ambacc) { | 
| 473 |  |  | if (at->kid == NULL) | 
| 474 |  |  | if ((at->kid = newambtree()) == NULL) | 
| 475 |  |  | goto memerr; | 
| 476 |  |  | s *= 0.5; | 
| 477 |  |  | branch = 0; | 
| 478 |  |  | for (i = 0; i < 3; i++) | 
| 479 |  |  | if (av->pos[i] > ck0[i] + s) { | 
| 480 |  |  | ck0[i] += s; | 
| 481 |  |  | branch |= 1 << i; | 
| 482 |  |  | } | 
| 483 |  |  | at = at->kid + branch; | 
| 484 |  |  | } | 
| 485 |  |  | av->next = at->alist; | 
| 486 |  |  | at->alist = av; | 
| 487 |  |  | return; | 
| 488 |  |  | memerr: | 
| 489 |  |  | error(SYSTEM, "out of memory in avinsert"); | 
| 490 |  |  | } |