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root/radiance/ray/src/hd/rhd_qtree.c
Revision: 3.12
Committed: Fri Dec 5 16:22:49 1997 UTC (26 years, 10 months ago) by gregl
Content type: text/plain
Branch: MAIN
Changes since 3.11: +15 -12 lines
Log Message:
changed logic so rays just off view are still saved

File Contents

# Content
1 /* Copyright (c) 1997 Silicon Graphics, Inc. */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ SGI";
5 #endif
6
7 /*
8 * Quadtree driver support routines.
9 */
10
11 #include "standard.h"
12 #include "rhd_qtree.h"
13 /* quantity of leaves to free at a time */
14 #ifndef LFREEPCT
15 #define LFREEPCT 25
16 #endif
17 /* maximum allowed angle difference (deg.) */
18 #ifndef MAXANG
19 #define MAXANG 20
20 #endif
21 #if MAXANG>0
22 #define MAXDIFF2 ( MAXANG*MAXANG * (PI*PI/180./180.))
23 #endif
24
25 #define abs(i) ((i) < 0 ? -(i) : (i))
26
27 RTREE qtrunk; /* our quadtree trunk */
28 double qtDepthEps = .05; /* epsilon to compare depths (z fraction) */
29 int qtMinNodesiz = 2; /* minimum node dimension (pixels) */
30 struct rleaves qtL; /* our pile of leaves */
31
32 #define TBUNDLESIZ 409 /* number of twigs in a bundle */
33
34 static RTREE **twigbundle; /* free twig blocks (NULL term.) */
35 static int nexttwig; /* next free twig */
36
37 #define ungetleaf(li) (qtL.tl=(li)) /* dangerous if used improperly */
38
39
40 static RTREE *
41 newtwig() /* allocate a twig */
42 {
43 register int bi;
44
45 if (twigbundle == NULL) { /* initialize */
46 twigbundle = (RTREE **)malloc(sizeof(RTREE *));
47 if (twigbundle == NULL)
48 goto memerr;
49 twigbundle[0] = NULL;
50 }
51 bi = nexttwig / TBUNDLESIZ;
52 if (twigbundle[bi] == NULL) { /* new block */
53 twigbundle = (RTREE **)realloc((char *)twigbundle,
54 (bi+2)*sizeof(RTREE *));
55 if (twigbundle == NULL)
56 goto memerr;
57 twigbundle[bi] = (RTREE *)calloc(TBUNDLESIZ, sizeof(RTREE));
58 if (twigbundle[bi] == NULL)
59 goto memerr;
60 twigbundle[bi+1] = NULL;
61 }
62 /* nexttwig++ % TBUNDLESIZ */
63 return(twigbundle[bi] + (nexttwig++ - bi*TBUNDLESIZ));
64 memerr:
65 error(SYSTEM, "out of memory in newtwig");
66 }
67
68
69 qtFreeTree(really) /* free allocated twigs */
70 int really;
71 {
72 register int i;
73
74 qtrunk.flgs = CH_ANY; /* chop down tree */
75 if (twigbundle == NULL)
76 return;
77 i = (TBUNDLESIZ-1+nexttwig)/TBUNDLESIZ;
78 nexttwig = 0;
79 if (!really) { /* just clear allocated blocks */
80 while (i--)
81 bzero((char *)twigbundle[i], TBUNDLESIZ*sizeof(RTREE));
82 return;
83 }
84 /* else "really" means free up memory */
85 for (i = 0; twigbundle[i] != NULL; i++)
86 free((char *)twigbundle[i]);
87 free((char *)twigbundle);
88 twigbundle = NULL;
89 }
90
91
92 static int
93 newleaf() /* allocate a leaf from our pile */
94 {
95 int li;
96
97 li = qtL.tl++;
98 if (qtL.tl >= qtL.nl) /* get next leaf in ring */
99 qtL.tl = 0;
100 if (qtL.tl == qtL.bl) /* need to shake some free */
101 qtCompost(LFREEPCT);
102 return(li);
103 }
104
105
106 #define LEAFSIZ (3*sizeof(float)+sizeof(int4)+\
107 sizeof(TMbright)+6*sizeof(BYTE))
108
109 int
110 qtAllocLeaves(n) /* allocate space for n leaves */
111 register int n;
112 {
113 unsigned nbytes;
114 register unsigned i;
115
116 qtFreeTree(0); /* make sure tree is empty */
117 if (n <= 0)
118 return(0);
119 if (qtL.nl >= n)
120 return(qtL.nl);
121 else if (qtL.nl > 0)
122 free(qtL.base);
123 /* round space up to nearest power of 2 */
124 nbytes = n*LEAFSIZ + 8;
125 for (i = 1024; nbytes > i; i <<= 1)
126 ;
127 n = (i - 8) / LEAFSIZ; /* should we make sure n is even? */
128 qtL.base = (char *)malloc(n*LEAFSIZ);
129 if (qtL.base == NULL)
130 return(0);
131 /* assign larger alignment types earlier */
132 qtL.wp = (float (*)[3])qtL.base;
133 qtL.wd = (int4 *)(qtL.wp + n);
134 qtL.brt = (TMbright *)(qtL.wd + n);
135 qtL.chr = (BYTE (*)[3])(qtL.brt + n);
136 qtL.rgb = (BYTE (*)[3])(qtL.chr + n);
137 qtL.nl = n;
138 qtL.tml = qtL.bl = qtL.tl = 0;
139 return(n);
140 }
141
142 #undef LEAFSIZ
143
144
145 qtFreeLeaves() /* free our allocated leaves and twigs */
146 {
147 qtFreeTree(1); /* free tree also */
148 if (qtL.nl <= 0)
149 return;
150 free(qtL.base);
151 qtL.base = NULL;
152 qtL.nl = 0;
153 }
154
155
156 static
157 shaketree(tp) /* shake dead leaves from tree */
158 register RTREE *tp;
159 {
160 register int i, li;
161
162 for (i = 0; i < 4; i++)
163 if (tp->flgs & BRF(i)) {
164 shaketree(tp->k[i].b);
165 if (is_stump(tp->k[i].b))
166 tp->flgs &= ~BRF(i);
167 } else if (tp->flgs & LFF(i)) {
168 li = tp->k[i].li;
169 if (qtL.bl < qtL.tl ?
170 (li < qtL.bl || li >= qtL.tl) :
171 (li < qtL.bl && li >= qtL.tl))
172 tp->flgs &= ~LFF(i);
173 }
174 }
175
176
177 int
178 qtCompost(pct) /* free up some leaves */
179 int pct;
180 {
181 int nused, nclear, nmapped;
182
183 /* figure out how many leaves to clear */
184 nclear = qtL.nl * pct / 100;
185 nused = qtL.tl - qtL.bl;
186 if (nused <= 0) nused += qtL.nl;
187 nclear -= qtL.nl - nused;
188 if (nclear <= 0)
189 return(0);
190 if (nclear >= nused) { /* clear them all */
191 qtFreeTree(0);
192 qtL.tml = qtL.bl = qtL.tl = 0;
193 return(nused);
194 }
195 /* else clear leaves from bottom */
196 nmapped = qtL.tml - qtL.bl;
197 if (nmapped < 0) nmapped += qtL.nl;
198 qtL.bl += nclear;
199 if (qtL.bl >= qtL.nl) qtL.bl -= qtL.nl;
200 if (nmapped <= nclear) qtL.tml = qtL.bl;
201 shaketree(&qtrunk);
202 return(nclear);
203 }
204
205
206 #define DCSCALE 11585.2 /* (1<<13)*sqrt(2) */
207 #define FXNEG 01
208 #define FYNEG 02
209 #define FZNEG 04
210 #define F1X 010
211 #define F2Z 020
212 #define F1SFT 5
213 #define F2SFT 18
214 #define FMASK 0x1fff
215
216 static int4
217 encodedir(dv) /* encode a normalized direction vector */
218 FVECT dv;
219 {
220 register int4 dc = 0;
221 int cd[3], cm;
222 register int i;
223
224 for (i = 0; i < 3; i++)
225 if (dv[i] < 0.) {
226 cd[i] = dv[i] * -DCSCALE;
227 dc |= 1<<i;
228 } else
229 cd[i] = dv[i] * DCSCALE;
230 if (cd[0] <= cd[1]) {
231 dc |= F1X | cd[0] << F1SFT;
232 cm = cd[1];
233 } else {
234 dc |= cd[1] << F1SFT;
235 cm = cd[0];
236 }
237 if (cd[2] <= cm)
238 dc |= F2Z | cd[2] << F2SFT;
239 else
240 dc |= cm << F2SFT;
241 return(dc);
242 }
243
244
245 static
246 decodedir(dv, dc) /* decode a normalized direction vector */
247 register FVECT dv; /* returned */
248 register int4 dc;
249 {
250 double d1, d2, der;
251
252 d1 = ((dc>>F1SFT & FMASK)+.5)/DCSCALE;
253 d2 = ((dc>>F2SFT & FMASK)+.5)/DCSCALE;
254 der = sqrt(1. - d1*d1 - d2*d2);
255 if (dc & F1X) {
256 dv[0] = d1;
257 if (dc & F2Z) { dv[1] = der; dv[2] = d2; }
258 else { dv[1] = d2; dv[2] = der; }
259 } else {
260 dv[1] = d1;
261 if (dc & F2Z) { dv[0] = der; dv[2] = d2; }
262 else { dv[0] = d2; dv[2] = der; }
263 }
264 if (dc & FXNEG) dv[0] = -dv[0];
265 if (dc & FYNEG) dv[1] = -dv[1];
266 if (dc & FZNEG) dv[2] = -dv[2];
267 }
268
269
270 static double
271 dir2diff(dc1, dc2) /* relative radians^2 between directions */
272 int4 dc1, dc2;
273 {
274 FVECT v1, v2;
275
276 decodedir(v1, dc1);
277 decodedir(v2, dc2);
278
279 return(2. - 2.*DOT(v1,v2));
280 }
281
282
283 static double
284 fdir2diff(dc1, v2) /* relative radians^2 between directions */
285 int4 dc1;
286 register FVECT v2;
287 {
288 FVECT v1;
289
290 decodedir(v1, dc1);
291
292 return(2. - 2.*DOT(v1,v2));
293 }
294
295
296 int
297 qtFindLeaf(x, y) /* find closest leaf to (x,y) */
298 int x, y;
299 {
300 register RTREE *tp = &qtrunk;
301 int li = -1;
302 int x0=0, y0=0, x1=odev.hres, y1=odev.vres;
303 int mx, my;
304 register int q;
305 /* check limits */
306 if (x < 0 || x >= odev.hres || y < 0 || y >= odev.vres)
307 return(-1);
308 /* find nearby leaf in our tree */
309 for ( ; ; ) {
310 for (q = 0; q < 4; q++) /* find any leaf this level */
311 if (tp->flgs & LFF(q)) {
312 li = tp->k[q].li;
313 break;
314 }
315 q = 0; /* which quadrant are we? */
316 mx = (x0 + x1) >> 1;
317 my = (y0 + y1) >> 1;
318 if (x < mx) x1 = mx;
319 else {x0 = mx; q |= 01;}
320 if (y < my) y1 = my;
321 else {y0 = my; q |= 02;}
322 if (tp->flgs & BRF(q)) { /* branch down if not a leaf */
323 tp = tp->k[q].b;
324 continue;
325 }
326 if (tp->flgs & LFF(q)) /* good shot! */
327 return(tp->k[q].li);
328 return(li); /* else return what we have */
329 }
330 }
331
332
333 static
334 addleaf(li) /* add a leaf to our tree */
335 int li;
336 {
337 register RTREE *tp = &qtrunk;
338 int x0=0, y0=0, x1=odev.hres, y1=odev.vres;
339 int lo = -1;
340 double d2;
341 int x, y, mx, my;
342 double z;
343 FVECT ip, wp, vd;
344 register int q;
345 /* compute leaf location in view */
346 VCOPY(wp, qtL.wp[li]);
347 viewloc(ip, &odev.v, wp);
348 if (ip[2] <= 0. || ip[0] < 0. || ip[0] >= 1.
349 || ip[1] < 0. || ip[1] >= 1.)
350 return(-1); /* behind or outside view */
351 #ifdef DEBUG
352 if (odev.v.type == VT_PAR | odev.v.vfore > FTINY)
353 error(INTERNAL, "bad view assumption in addleaf");
354 #endif
355 for (q = 0; q < 3; q++)
356 vd[q] = (wp[q] - odev.v.vp[q])/ip[2];
357 d2 = fdir2diff(qtL.wd[li], vd);
358 #ifdef MAXDIFF2
359 if (d2 > MAXDIFF2)
360 return(0); /* leaf dir. too far off */
361 #endif
362 x = ip[0] * odev.hres;
363 y = ip[1] * odev.vres;
364 z = ip[2];
365 /* find the place for it */
366 for ( ; ; ) {
367 q = 0; /* which quadrant? */
368 mx = (x0 + x1) >> 1;
369 my = (y0 + y1) >> 1;
370 if (x < mx) x1 = mx;
371 else {x0 = mx; q |= 01;}
372 if (y < my) y1 = my;
373 else {y0 = my; q |= 02;}
374 if (tp->flgs & BRF(q)) { /* move to next branch */
375 tp->flgs |= CHF(q); /* not sure; guess */
376 tp = tp->k[q].b;
377 continue;
378 }
379 if (!(tp->flgs & LFF(q))) { /* found stem for leaf */
380 tp->k[q].li = li;
381 tp->flgs |= CHLFF(q);
382 break;
383 }
384 if (lo != tp->k[q].li) { /* check old leaf */
385 lo = tp->k[q].li;
386 VCOPY(wp, qtL.wp[lo]);
387 viewloc(ip, &odev.v, wp);
388 }
389 /* is node minimum size? */
390 if (y1-y0 <= qtMinNodesiz || x1-x0 <= qtMinNodesiz) {
391 if (z > (1.+qtDepthEps)*ip[2])
392 return(0); /* old one closer */
393 if (z >= (1.-qtDepthEps)*ip[2] &&
394 fdir2diff(qtL.wd[lo], vd) < d2)
395 return(0); /* old one better */
396 tp->k[q].li = li; /* else new one is */
397 tp->flgs |= CHF(q);
398 break;
399 }
400 tp->flgs &= ~LFF(q); /* else grow tree */
401 tp->flgs |= CHBRF(q);
402 tp = tp->k[q].b = newtwig();
403 q = 0; /* old leaf -> new branch */
404 mx = ip[0] * odev.hres;
405 my = ip[1] * odev.vres;
406 if (mx >= (x0 + x1) >> 1) q |= 01;
407 if (my >= (y0 + y1) >> 1) q |= 02;
408 tp->flgs = CH_ANY|LFF(q); /* all new */
409 tp->k[q].li = lo;
410 }
411 return(1); /* done */
412 }
413
414
415 dev_value(c, p, v) /* add a pixel value to our quadtree */
416 COLR c;
417 FVECT p, v;
418 {
419 register int li;
420
421 li = newleaf();
422 VCOPY(qtL.wp[li], p);
423 qtL.wd[li] = encodedir(v);
424 tmCvColrs(&qtL.brt[li], qtL.chr[li], c, 1);
425 if (!addleaf(li))
426 ungetleaf(li);
427 }
428
429
430 qtReplant() /* replant our tree using new view */
431 {
432 register int i;
433 /* anything to replant? */
434 if (qtL.bl == qtL.tl)
435 return;
436 qtFreeTree(0); /* blow the old tree away */
437 /* regrow it in new place */
438 for (i = qtL.bl; i != qtL.tl; ) {
439 addleaf(i);
440 if (++i >= qtL.nl) i = 0;
441 }
442 }
443
444
445 qtMapLeaves(redo) /* map our leaves to RGB */
446 int redo;
447 {
448 int aorg, alen, borg, blen;
449 /* recompute mapping? */
450 if (redo)
451 qtL.tml = qtL.bl;
452 /* already done? */
453 if (qtL.tml == qtL.tl)
454 return(1);
455 /* compute segments */
456 aorg = qtL.tml;
457 if (qtL.tl >= aorg) {
458 alen = qtL.tl - aorg;
459 blen = 0;
460 } else {
461 alen = qtL.nl - aorg;
462 borg = 0;
463 blen = qtL.tl;
464 }
465 /* (re)compute tone mapping? */
466 if (qtL.tml == qtL.bl) {
467 tmClearHisto();
468 tmAddHisto(qtL.brt+aorg, alen, 1);
469 if (blen > 0)
470 tmAddHisto(qtL.brt+borg, blen, 1);
471 if (tmComputeMapping(0., 0., 0.) != TM_E_OK)
472 return(0);
473 }
474 if (tmMapPixels(qtL.rgb+aorg, qtL.brt+aorg,
475 qtL.chr+aorg, alen) != TM_E_OK)
476 return(0);
477 if (blen > 0)
478 tmMapPixels(qtL.rgb+borg, qtL.brt+borg,
479 qtL.chr+borg, blen);
480 qtL.tml = qtL.tl;
481 return(1);
482 }