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root/radiance/ray/src/cv/bsdfinterp.c
Revision: 2.1
Committed: Fri Oct 19 04:14:29 2012 UTC (11 years, 5 months ago) by greg
Content type: text/plain
Branch: MAIN
Log Message:
Broke pabopto2xml into pabopto2bsdf and bsdf2ttree

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id$";
3 #endif
4 /*
5 * Interpolate BSDF data from radial basis functions in advection mesh.
6 *
7 * G. Ward
8 */
9
10 #define _USE_MATH_DEFINES
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <math.h>
15 #include "bsdfrep.h"
16 /* migration edges drawn in raster fashion */
17 MIGRATION *mig_grid[GRIDRES][GRIDRES];
18
19 #ifdef DEBUG
20 #include "random.h"
21 #include "bmpfile.h"
22 /* Hash pointer to byte value (must return 0 for NULL) */
23 static int
24 byte_hash(const void *p)
25 {
26 size_t h = (size_t)p;
27 h ^= (size_t)p >> 8;
28 h ^= (size_t)p >> 16;
29 h ^= (size_t)p >> 24;
30 return(h & 0xff);
31 }
32 /* Write out BMP image showing edges */
33 static void
34 write_edge_image(const char *fname)
35 {
36 BMPHeader *hdr = BMPmappedHeader(GRIDRES, GRIDRES, 0, 256);
37 BMPWriter *wtr;
38 int i, j;
39
40 fprintf(stderr, "Writing incident mesh drawing to '%s'\n", fname);
41 hdr->compr = BI_RLE8;
42 for (i = 256; --i; ) { /* assign random color map */
43 hdr->palette[i].r = random() & 0xff;
44 hdr->palette[i].g = random() & 0xff;
45 hdr->palette[i].b = random() & 0xff;
46 /* reject dark colors */
47 i += (hdr->palette[i].r + hdr->palette[i].g +
48 hdr->palette[i].b < 128);
49 }
50 hdr->palette[0].r = hdr->palette[0].g = hdr->palette[0].b = 0;
51 /* open output */
52 wtr = BMPopenOutputFile(fname, hdr);
53 if (wtr == NULL) {
54 free(hdr);
55 return;
56 }
57 for (i = 0; i < GRIDRES; i++) { /* write scanlines */
58 for (j = 0; j < GRIDRES; j++)
59 wtr->scanline[j] = byte_hash(mig_grid[i][j]);
60 if (BMPwriteScanline(wtr) != BIR_OK)
61 break;
62 }
63 BMPcloseOutput(wtr); /* close & clean up */
64 }
65 #endif
66
67 /* Draw edge list into mig_grid array */
68 void
69 draw_edges(void)
70 {
71 int nnull = 0, ntot = 0;
72 MIGRATION *ej;
73 int p0[2], p1[2];
74
75 memset(mig_grid, 0, sizeof(mig_grid));
76 for (ej = mig_list; ej != NULL; ej = ej->next) {
77 ++ntot;
78 pos_from_vec(p0, ej->rbfv[0]->invec);
79 pos_from_vec(p1, ej->rbfv[1]->invec);
80 if ((p0[0] == p1[0]) & (p0[1] == p1[1])) {
81 ++nnull;
82 mig_grid[p0[0]][p0[1]] = ej;
83 continue;
84 }
85 if (abs(p1[0]-p0[0]) > abs(p1[1]-p0[1])) {
86 const int xstep = 2*(p1[0] > p0[0]) - 1;
87 const double ystep = (double)((p1[1]-p0[1])*xstep) /
88 (double)(p1[0]-p0[0]);
89 int x;
90 double y;
91 for (x = p0[0], y = p0[1]+.5; x != p1[0];
92 x += xstep, y += ystep)
93 mig_grid[x][(int)y] = ej;
94 mig_grid[x][(int)y] = ej;
95 } else {
96 const int ystep = 2*(p1[1] > p0[1]) - 1;
97 const double xstep = (double)((p1[0]-p0[0])*ystep) /
98 (double)(p1[1]-p0[1]);
99 int y;
100 double x;
101 for (y = p0[1], x = p0[0]+.5; y != p1[1];
102 y += ystep, x += xstep)
103 mig_grid[(int)x][y] = ej;
104 mig_grid[(int)x][y] = ej;
105 }
106 }
107 if (nnull)
108 fprintf(stderr, "Warning: %d of %d edges are null\n",
109 nnull, ntot);
110 #ifdef DEBUG
111 write_edge_image("bsdf_edges.bmp");
112 #endif
113 }
114
115 /* Identify enclosing triangle for this position (flood fill raster check) */
116 static int
117 identify_tri(MIGRATION *miga[3], unsigned char vmap[GRIDRES][(GRIDRES+7)/8],
118 int px, int py)
119 {
120 const int btest = 1<<(py&07);
121
122 if (vmap[px][py>>3] & btest) /* already visited here? */
123 return(1);
124 /* else mark it */
125 vmap[px][py>>3] |= btest;
126
127 if (mig_grid[px][py] != NULL) { /* are we on an edge? */
128 int i;
129 for (i = 0; i < 3; i++) {
130 if (miga[i] == mig_grid[px][py])
131 return(1);
132 if (miga[i] != NULL)
133 continue;
134 miga[i] = mig_grid[px][py];
135 return(1);
136 }
137 return(0); /* outside triangle! */
138 }
139 /* check neighbors (flood) */
140 if (px > 0 && !identify_tri(miga, vmap, px-1, py))
141 return(0);
142 if (px < GRIDRES-1 && !identify_tri(miga, vmap, px+1, py))
143 return(0);
144 if (py > 0 && !identify_tri(miga, vmap, px, py-1))
145 return(0);
146 if (py < GRIDRES-1 && !identify_tri(miga, vmap, px, py+1))
147 return(0);
148 return(1); /* this neighborhood done */
149 }
150
151 /* Insert vertex in ordered list */
152 static void
153 insert_vert(RBFNODE **vlist, RBFNODE *v)
154 {
155 int i, j;
156
157 for (i = 0; vlist[i] != NULL; i++) {
158 if (v == vlist[i])
159 return;
160 if (v->ord < vlist[i]->ord)
161 break;
162 }
163 for (j = i; vlist[j] != NULL; j++)
164 ;
165 while (j > i) {
166 vlist[j] = vlist[j-1];
167 --j;
168 }
169 vlist[i] = v;
170 }
171
172 /* Sort triangle edges in standard order */
173 static int
174 order_triangle(MIGRATION *miga[3])
175 {
176 RBFNODE *vert[7];
177 MIGRATION *ord[3];
178 int i;
179 /* order vertices, first */
180 memset(vert, 0, sizeof(vert));
181 for (i = 3; i--; ) {
182 if (miga[i] == NULL)
183 return(0);
184 insert_vert(vert, miga[i]->rbfv[0]);
185 insert_vert(vert, miga[i]->rbfv[1]);
186 }
187 /* should be just 3 vertices */
188 if ((vert[3] == NULL) | (vert[4] != NULL))
189 return(0);
190 /* identify edge 0 */
191 for (i = 3; i--; )
192 if (miga[i]->rbfv[0] == vert[0] &&
193 miga[i]->rbfv[1] == vert[1]) {
194 ord[0] = miga[i];
195 break;
196 }
197 if (i < 0)
198 return(0);
199 /* identify edge 1 */
200 for (i = 3; i--; )
201 if (miga[i]->rbfv[0] == vert[1] &&
202 miga[i]->rbfv[1] == vert[2]) {
203 ord[1] = miga[i];
204 break;
205 }
206 if (i < 0)
207 return(0);
208 /* identify edge 2 */
209 for (i = 3; i--; )
210 if (miga[i]->rbfv[0] == vert[0] &&
211 miga[i]->rbfv[1] == vert[2]) {
212 ord[2] = miga[i];
213 break;
214 }
215 if (i < 0)
216 return(0);
217 /* reassign order */
218 miga[0] = ord[0]; miga[1] = ord[1]; miga[2] = ord[2];
219 return(1);
220 }
221
222 /* Find edge(s) for interpolating the given vector, applying symmetry */
223 int
224 get_interp(MIGRATION *miga[3], FVECT invec)
225 {
226 miga[0] = miga[1] = miga[2] = NULL;
227 if (single_plane_incident) { /* isotropic BSDF? */
228 RBFNODE *rbf; /* find edge we're on */
229 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
230 if (input_orient*rbf->invec[2] < input_orient*invec[2])
231 break;
232 if (rbf->next != NULL &&
233 input_orient*rbf->next->invec[2] <
234 input_orient*invec[2]) {
235 for (miga[0] = rbf->ejl; miga[0] != NULL;
236 miga[0] = nextedge(rbf,miga[0]))
237 if (opp_rbf(rbf,miga[0]) == rbf->next)
238 return(0);
239 break;
240 }
241 }
242 return(-1); /* outside range! */
243 }
244 { /* else use triangle mesh */
245 const int sym = use_symmetry(invec);
246 unsigned char floodmap[GRIDRES][(GRIDRES+7)/8];
247 int pstart[2];
248 RBFNODE *vother;
249 MIGRATION *ej;
250 int i;
251
252 pos_from_vec(pstart, invec);
253 memset(floodmap, 0, sizeof(floodmap));
254 /* call flooding function */
255 if (!identify_tri(miga, floodmap, pstart[0], pstart[1]))
256 return(-1); /* outside mesh */
257 if ((miga[0] == NULL) | (miga[2] == NULL))
258 return(-1); /* should never happen */
259 if (miga[1] == NULL)
260 return(sym); /* on edge */
261 /* verify triangle */
262 if (!order_triangle(miga)) {
263 #ifdef DEBUG
264 fputs("Munged triangle in get_interp()\n", stderr);
265 #endif
266 vother = NULL; /* find triangle from edge */
267 for (i = 3; i--; ) {
268 RBFNODE *tpair[2];
269 if (get_triangles(tpair, miga[i]) &&
270 (vother = tpair[ is_rev_tri(
271 miga[i]->rbfv[0]->invec,
272 miga[i]->rbfv[1]->invec,
273 invec) ]) != NULL)
274 break;
275 }
276 if (vother == NULL) { /* couldn't find 3rd vertex */
277 #ifdef DEBUG
278 fputs("No triangle in get_interp()\n", stderr);
279 #endif
280 return(-1);
281 }
282 /* reassign other two edges */
283 for (ej = vother->ejl; ej != NULL;
284 ej = nextedge(vother,ej)) {
285 RBFNODE *vorig = opp_rbf(vother,ej);
286 if (vorig == miga[i]->rbfv[0])
287 miga[(i+1)%3] = ej;
288 else if (vorig == miga[i]->rbfv[1])
289 miga[(i+2)%3] = ej;
290 }
291 if (!order_triangle(miga)) {
292 #ifdef DEBUG
293 fputs("Bad triangle in get_interp()\n", stderr);
294 #endif
295 return(-1);
296 }
297 }
298 return(sym); /* return in standard order */
299 }
300 }
301
302 /* Advect and allocate new RBF along edge */
303 static RBFNODE *
304 e_advect_rbf(const MIGRATION *mig, const FVECT invec)
305 {
306 RBFNODE *rbf;
307 int n, i, j;
308 double t, full_dist;
309 /* get relative position */
310 t = acos(DOT(invec, mig->rbfv[0]->invec));
311 if (t < M_PI/GRIDRES) { /* near first DSF */
312 n = sizeof(RBFNODE) + sizeof(RBFVAL)*(mig->rbfv[0]->nrbf-1);
313 rbf = (RBFNODE *)malloc(n);
314 if (rbf == NULL)
315 goto memerr;
316 memcpy(rbf, mig->rbfv[0], n); /* just duplicate */
317 return(rbf);
318 }
319 full_dist = acos(DOT(mig->rbfv[0]->invec, mig->rbfv[1]->invec));
320 if (t > full_dist-M_PI/GRIDRES) { /* near second DSF */
321 n = sizeof(RBFNODE) + sizeof(RBFVAL)*(mig->rbfv[1]->nrbf-1);
322 rbf = (RBFNODE *)malloc(n);
323 if (rbf == NULL)
324 goto memerr;
325 memcpy(rbf, mig->rbfv[1], n); /* just duplicate */
326 return(rbf);
327 }
328 t /= full_dist;
329 n = 0; /* count migrating particles */
330 for (i = 0; i < mtx_nrows(mig); i++)
331 for (j = 0; j < mtx_ncols(mig); j++)
332 n += (mig->mtx[mtx_ndx(mig,i,j)] > FTINY);
333 #ifdef DEBUG
334 fprintf(stderr, "Input RBFs have %d, %d nodes -> output has %d\n",
335 mig->rbfv[0]->nrbf, mig->rbfv[1]->nrbf, n);
336 #endif
337 rbf = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(n-1));
338 if (rbf == NULL)
339 goto memerr;
340 rbf->next = NULL; rbf->ejl = NULL;
341 VCOPY(rbf->invec, invec);
342 rbf->nrbf = n;
343 rbf->vtotal = 1.-t + t*mig->rbfv[1]->vtotal/mig->rbfv[0]->vtotal;
344 n = 0; /* advect RBF lobes */
345 for (i = 0; i < mtx_nrows(mig); i++) {
346 const RBFVAL *rbf0i = &mig->rbfv[0]->rbfa[i];
347 const float peak0 = rbf0i->peak;
348 const double rad0 = R2ANG(rbf0i->crad);
349 FVECT v0;
350 float mv;
351 ovec_from_pos(v0, rbf0i->gx, rbf0i->gy);
352 for (j = 0; j < mtx_ncols(mig); j++)
353 if ((mv = mig->mtx[mtx_ndx(mig,i,j)]) > FTINY) {
354 const RBFVAL *rbf1j = &mig->rbfv[1]->rbfa[j];
355 double rad1 = R2ANG(rbf1j->crad);
356 FVECT v;
357 int pos[2];
358 rbf->rbfa[n].peak = peak0 * mv * rbf->vtotal;
359 rbf->rbfa[n].crad = ANG2R(sqrt(rad0*rad0*(1.-t) +
360 rad1*rad1*t));
361 ovec_from_pos(v, rbf1j->gx, rbf1j->gy);
362 geodesic(v, v0, v, t, GEOD_REL);
363 pos_from_vec(pos, v);
364 rbf->rbfa[n].gx = pos[0];
365 rbf->rbfa[n].gy = pos[1];
366 ++n;
367 }
368 }
369 rbf->vtotal *= mig->rbfv[0]->vtotal; /* turn ratio into actual */
370 return(rbf);
371 memerr:
372 fprintf(stderr, "%s: Out of memory in e_advect_rbf()\n", progname);
373 exit(1);
374 return(NULL); /* pro forma return */
375 }
376
377 /* Partially advect between recorded incident angles and allocate new RBF */
378 RBFNODE *
379 advect_rbf(const FVECT invec)
380 {
381 FVECT sivec;
382 MIGRATION *miga[3];
383 RBFNODE *rbf;
384 int sym;
385 float mbfact, mcfact;
386 int n, i, j, k;
387 FVECT v0, v1, v2;
388 double s, t;
389
390 VCOPY(sivec, invec); /* find triangle/edge */
391 sym = get_interp(miga, sivec);
392 if (sym < 0) /* can't interpolate? */
393 return(NULL);
394 if (miga[1] == NULL) { /* advect along edge? */
395 rbf = e_advect_rbf(miga[0], sivec);
396 rev_rbf_symmetry(rbf, sym);
397 return(rbf);
398 }
399 #ifdef DEBUG
400 if (miga[0]->rbfv[0] != miga[2]->rbfv[0] |
401 miga[0]->rbfv[1] != miga[1]->rbfv[0] |
402 miga[1]->rbfv[1] != miga[2]->rbfv[1]) {
403 fprintf(stderr, "%s: Triangle vertex screw-up!\n", progname);
404 exit(1);
405 }
406 #endif
407 /* figure out position */
408 fcross(v0, miga[2]->rbfv[0]->invec, miga[2]->rbfv[1]->invec);
409 normalize(v0);
410 fcross(v2, miga[1]->rbfv[0]->invec, miga[1]->rbfv[1]->invec);
411 normalize(v2);
412 fcross(v1, sivec, miga[1]->rbfv[1]->invec);
413 normalize(v1);
414 s = acos(DOT(v0,v1)) / acos(DOT(v0,v2));
415 geodesic(v1, miga[0]->rbfv[0]->invec, miga[0]->rbfv[1]->invec,
416 s, GEOD_REL);
417 t = acos(DOT(v1,sivec)) / acos(DOT(v1,miga[1]->rbfv[1]->invec));
418 n = 0; /* count migrating particles */
419 for (i = 0; i < mtx_nrows(miga[0]); i++)
420 for (j = 0; j < mtx_ncols(miga[0]); j++)
421 for (k = (miga[0]->mtx[mtx_ndx(miga[0],i,j)] > FTINY) *
422 mtx_ncols(miga[2]); k--; )
423 n += (miga[2]->mtx[mtx_ndx(miga[2],i,k)] > FTINY &&
424 miga[1]->mtx[mtx_ndx(miga[1],j,k)] > FTINY);
425 #ifdef DEBUG
426 fprintf(stderr, "Input RBFs have %d, %d, %d nodes -> output has %d\n",
427 miga[0]->rbfv[0]->nrbf, miga[0]->rbfv[1]->nrbf,
428 miga[2]->rbfv[1]->nrbf, n);
429 #endif
430 rbf = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(n-1));
431 if (rbf == NULL) {
432 fprintf(stderr, "%s: Out of memory in advect_rbf()\n", progname);
433 exit(1);
434 }
435 rbf->next = NULL; rbf->ejl = NULL;
436 VCOPY(rbf->invec, sivec);
437 rbf->nrbf = n;
438 n = 0; /* compute RBF lobes */
439 mbfact = s * miga[0]->rbfv[1]->vtotal/miga[0]->rbfv[0]->vtotal *
440 (1.-t + t*miga[1]->rbfv[1]->vtotal/miga[1]->rbfv[0]->vtotal);
441 mcfact = (1.-s) *
442 (1.-t + t*miga[2]->rbfv[1]->vtotal/miga[2]->rbfv[0]->vtotal);
443 for (i = 0; i < mtx_nrows(miga[0]); i++) {
444 const RBFVAL *rbf0i = &miga[0]->rbfv[0]->rbfa[i];
445 const float w0i = rbf0i->peak;
446 const double rad0i = R2ANG(rbf0i->crad);
447 ovec_from_pos(v0, rbf0i->gx, rbf0i->gy);
448 for (j = 0; j < mtx_ncols(miga[0]); j++) {
449 const float ma = miga[0]->mtx[mtx_ndx(miga[0],i,j)];
450 const RBFVAL *rbf1j;
451 double rad1j, srad2;
452 if (ma <= FTINY)
453 continue;
454 rbf1j = &miga[0]->rbfv[1]->rbfa[j];
455 rad1j = R2ANG(rbf1j->crad);
456 srad2 = (1.-s)*(1.-t)*rad0i*rad0i + s*(1.-t)*rad1j*rad1j;
457 ovec_from_pos(v1, rbf1j->gx, rbf1j->gy);
458 geodesic(v1, v0, v1, s, GEOD_REL);
459 for (k = 0; k < mtx_ncols(miga[2]); k++) {
460 float mb = miga[1]->mtx[mtx_ndx(miga[1],j,k)];
461 float mc = miga[2]->mtx[mtx_ndx(miga[2],i,k)];
462 const RBFVAL *rbf2k;
463 double rad2k;
464 FVECT vout;
465 int pos[2];
466 if ((mb <= FTINY) | (mc <= FTINY))
467 continue;
468 rbf2k = &miga[2]->rbfv[1]->rbfa[k];
469 rbf->rbfa[n].peak = w0i * ma * (mb*mbfact + mc*mcfact);
470 rad2k = R2ANG(rbf2k->crad);
471 rbf->rbfa[n].crad = ANG2R(sqrt(srad2 + t*rad2k*rad2k));
472 ovec_from_pos(v2, rbf2k->gx, rbf2k->gy);
473 geodesic(vout, v1, v2, t, GEOD_REL);
474 pos_from_vec(pos, vout);
475 rbf->rbfa[n].gx = pos[0];
476 rbf->rbfa[n].gy = pos[1];
477 ++n;
478 }
479 }
480 }
481 rbf->vtotal = miga[0]->rbfv[0]->vtotal * (mbfact + mcfact);
482 rev_rbf_symmetry(rbf, sym);
483 return(rbf);
484 }