14 |
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#include <math.h> |
15 |
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#include "bsdfrep.h" |
16 |
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|
17 |
< |
#ifndef RSCA |
18 |
< |
#define RSCA 2.7 /* radius scaling factor (empirical) */ |
17 |
> |
#ifndef MINRSCA |
18 |
> |
#define MINRSCA 0.5 /* minimum radius scaling factor */ |
19 |
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#endif |
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+ |
#ifndef MAXRSCA |
21 |
+ |
#define MAXRSCA 2.7 /* maximum radius scaling factor */ |
22 |
+ |
#endif |
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+ |
#ifndef DIFFTHRESH |
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+ |
#define DIFFTHRESH 0.2 /* culling difference threshold */ |
25 |
+ |
#endif |
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+ |
#ifndef MAXFRAC |
27 |
+ |
#define MAXFRAC 0.5 /* maximum contribution to neighbor */ |
28 |
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#endif |
29 |
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#ifndef NNEIGH |
30 |
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#define NNEIGH 10 /* number of neighbors to consider */ |
31 |
+ |
#endif |
32 |
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/* our loaded grid for this incident angle */ |
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GRIDVAL dsf_grid[GRIDRES][GRIDRES]; |
34 |
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|
60 |
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ovec[1] = sin((M_PI/180.)*phi_out) * ovec[2]; |
61 |
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ovec[2] = sqrt(1. - ovec[2]*ovec[2]); |
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|
63 |
< |
if (!isDSF) |
63 |
> |
if (val <= 0) /* truncate to zero */ |
64 |
> |
val = 0; |
65 |
> |
else if (!isDSF) |
66 |
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val *= ovec[2]; /* convert from BSDF to DSF */ |
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|
68 |
+ |
/* update BSDF histogram */ |
69 |
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if (val < BSDF2BIG*ovec[2] && val > BSDF2SML*ovec[2]) |
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+ |
++bsdf_hist[histndx(val/ovec[2])]; |
71 |
+ |
|
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pos_from_vec(pos, ovec); |
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|
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dsf_grid[pos[0]][pos[1]].vsum += val; |
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dsf_grid[pos[0]][pos[1]].nval++; |
76 |
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} |
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|
78 |
+ |
/* Check if the two DSF values are significantly different */ |
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+ |
static int |
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+ |
big_diff(double ref, double tst) |
81 |
+ |
{ |
82 |
+ |
if (ref > 0) { |
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+ |
tst = tst/ref - 1.; |
84 |
+ |
if (tst < 0) tst = -tst; |
85 |
+ |
} else |
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tst *= 50.; |
87 |
+ |
return(tst > DIFFTHRESH); |
88 |
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} |
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+ |
|
90 |
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/* Compute radii for non-empty bins */ |
91 |
< |
/* (distance to furthest empty bin for which non-empty bin is the closest) */ |
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> |
/* (distance to furthest empty bin for which non-empty test bin is closest) */ |
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static void |
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compute_radii(void) |
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{ |
95 |
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const int cradmin = ANG2R(.5*M_PI/GRIDRES); |
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unsigned int fill_grid[GRIDRES][GRIDRES]; |
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unsigned short fill_cnt[GRIDRES][GRIDRES]; |
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FVECT ovec0, ovec1; |
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/* next search radius */ |
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r = ang2*(2.*GRIDRES/M_PI) + 3; |
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} |
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for (i = 0; i < GRIDRES; i++) /* grow radii where uniform */ |
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for (j = 0; j < GRIDRES; j++) { |
142 |
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double midmean; |
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+ |
if (!dsf_grid[i][j].nval) |
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continue; |
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+ |
midmean = dsf_grid[i][j].vsum / (double)dsf_grid[i][j].nval; |
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+ |
r = R2ANG(dsf_grid[i][j].crad)*(MAXRSCA*GRIDRES/M_PI); |
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while (++r < GRIDRES) { /* attempt to grow perimeter */ |
148 |
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for (ii = i-r; ii <= i+r; ii++) { |
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int jstep = 1; |
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if (ii < 0) continue; |
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if (ii >= GRIDRES) break; |
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if ((i-r < ii) & (ii < i+r)) |
153 |
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jstep = r<<1; |
154 |
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for (jj = j-r; jj <= j+r; jj += jstep) { |
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if (jj < 0) continue; |
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if (jj >= GRIDRES) break; |
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+ |
if (dsf_grid[ii][jj].nval && big_diff(midmean, |
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dsf_grid[ii][jj].vsum / |
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+ |
(double)dsf_grid[ii][jj].nval)) |
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goto hit_diff; |
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} |
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} |
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+ |
} |
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+ |
hit_diff: --r; |
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+ |
dsf_grid[i][j].crad = ANG2R(r*(M_PI/MAXRSCA/GRIDRES)); |
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+ |
if (dsf_grid[i][j].crad < cradmin) |
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dsf_grid[i][j].crad = cradmin; |
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} |
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/* blur radii over hemisphere */ |
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memset(fill_grid, 0, sizeof(fill_grid)); |
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memset(fill_cnt, 0, sizeof(fill_cnt)); |
172 |
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for (i = 0; i < GRIDRES; i++) |
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for (j = 0; j < GRIDRES; j++) { |
174 |
< |
if (!dsf_grid[i][j].crad) |
175 |
< |
continue; /* missing distance */ |
176 |
< |
r = R2ANG(dsf_grid[i][j].crad)*(2.*RSCA*GRIDRES/M_PI); |
174 |
> |
if (!dsf_grid[i][j].nval) |
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> |
continue; /* not part of this */ |
176 |
> |
r = R2ANG(dsf_grid[i][j].crad)*(2.*MAXRSCA*GRIDRES/M_PI); |
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for (ii = i-r; ii <= i+r; ii++) { |
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if (ii < 0) continue; |
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if (ii >= GRIDRES) break; |
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continue; /* shouldn't happen */ |
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ovec_from_pos(ovec0, i, j); |
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maxang = 2.*R2ANG(dsf_grid[i][j].crad); |
213 |
< |
if (maxang > ovec0[2]) /* clamp near horizon */ |
214 |
< |
maxang = ovec0[2]; |
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> |
/* clamp near horizon */ |
214 |
> |
if (maxang > output_orient*ovec0[2]) |
215 |
> |
maxang = output_orient*ovec0[2]; |
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r = maxang*(2.*GRIDRES/M_PI) + 1; |
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maxang2 = maxang*maxang; |
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for (ii = i-r; ii <= i+r; ii++) { |
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if (ii < 0) continue; |
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if (ii >= GRIDRES) break; |
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for (jj = j-r; jj <= j+r; jj++) { |
222 |
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if ((ii == i) & (jj == j)) |
223 |
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continue; /* don't get self-absorbed */ |
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if (jj < 0) continue; |
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if (jj >= GRIDRES) break; |
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if (!dsf_grid[ii][jj].nval) |
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continue; |
165 |
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if ((ii == i) & (jj == j)) |
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continue; /* don't get self-absorbed */ |
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ovec_from_pos(ovec1, ii, jj); |
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if (2. - 2.*DOT(ovec0,ovec1) >= maxang2) |
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continue; |
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} |
247 |
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} |
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|
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+ |
/* Compute minimum BSDF from histogram and clear it */ |
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+ |
static void |
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+ |
comp_bsdf_min() |
252 |
+ |
{ |
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+ |
int cnt; |
254 |
+ |
int i, target; |
255 |
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|
256 |
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cnt = 0; |
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for (i = HISTLEN; i--; ) |
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cnt += bsdf_hist[i]; |
259 |
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if (!cnt) { /* shouldn't happen */ |
260 |
+ |
bsdf_min = 0; |
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+ |
return; |
262 |
+ |
} |
263 |
+ |
target = cnt/100; /* ignore bottom 1% */ |
264 |
+ |
cnt = 0; |
265 |
+ |
for (i = 0; cnt <= target; i++) |
266 |
+ |
cnt += bsdf_hist[i]; |
267 |
+ |
bsdf_min = histval(i-1); |
268 |
+ |
memset(bsdf_hist, 0, sizeof(bsdf_hist)); |
269 |
+ |
} |
270 |
+ |
|
271 |
+ |
/* Find n nearest sub-sampled neighbors to the given grid position */ |
272 |
+ |
static int |
273 |
+ |
get_neighbors(int neigh[][2], int n, const int i, const int j) |
274 |
+ |
{ |
275 |
+ |
int k = 0; |
276 |
+ |
int r; |
277 |
+ |
/* search concentric squares */ |
278 |
+ |
for (r = 1; r < GRIDRES; r++) { |
279 |
+ |
int ii, jj; |
280 |
+ |
for (ii = i-r; ii <= i+r; ii++) { |
281 |
+ |
int jstep = 1; |
282 |
+ |
if (ii < 0) continue; |
283 |
+ |
if (ii >= GRIDRES) break; |
284 |
+ |
if ((i-r < ii) & (ii < i+r)) |
285 |
+ |
jstep = r<<1; |
286 |
+ |
for (jj = j-r; jj <= j+r; jj += jstep) { |
287 |
+ |
if (jj < 0) continue; |
288 |
+ |
if (jj >= GRIDRES) break; |
289 |
+ |
if (dsf_grid[ii][jj].nval) { |
290 |
+ |
neigh[k][0] = ii; |
291 |
+ |
neigh[k][1] = jj; |
292 |
+ |
if (++k >= n) |
293 |
+ |
return(n); |
294 |
+ |
} |
295 |
+ |
} |
296 |
+ |
} |
297 |
+ |
} |
298 |
+ |
return(k); |
299 |
+ |
} |
300 |
+ |
|
301 |
+ |
/* Adjust coded radius for the given grid position based on neighborhood */ |
302 |
+ |
static int |
303 |
+ |
adj_coded_radius(const int i, const int j) |
304 |
+ |
{ |
305 |
+ |
const double rad0 = R2ANG(dsf_grid[i][j].crad); |
306 |
+ |
const double minrad = MINRSCA * rad0; |
307 |
+ |
double currad = MAXRSCA * rad0; |
308 |
+ |
int neigh[NNEIGH][2]; |
309 |
+ |
int n; |
310 |
+ |
FVECT our_dir; |
311 |
+ |
|
312 |
+ |
ovec_from_pos(our_dir, i, j); |
313 |
+ |
n = get_neighbors(neigh, NNEIGH, i, j); |
314 |
+ |
while (n--) { |
315 |
+ |
FVECT their_dir; |
316 |
+ |
double max_ratio, rad_ok2; |
317 |
+ |
/* check our value at neighbor */ |
318 |
+ |
ovec_from_pos(their_dir, neigh[n][0], neigh[n][1]); |
319 |
+ |
max_ratio = MAXFRAC * dsf_grid[neigh[n][0]][neigh[n][1]].vsum |
320 |
+ |
/ dsf_grid[i][j].vsum; |
321 |
+ |
if (max_ratio >= 1) |
322 |
+ |
continue; |
323 |
+ |
rad_ok2 = (DOT(their_dir,our_dir) - 1.)/log(max_ratio); |
324 |
+ |
if (rad_ok2 >= currad*currad) |
325 |
+ |
continue; /* value fraction OK */ |
326 |
+ |
currad = sqrt(rad_ok2); /* else reduce lobe radius */ |
327 |
+ |
if (currad <= minrad) /* limit how small we'll go */ |
328 |
+ |
return(ANG2R(minrad)); |
329 |
+ |
} |
330 |
+ |
return(ANG2R(currad)); /* encode selected radius */ |
331 |
+ |
} |
332 |
+ |
|
333 |
|
/* Count up filled nodes and build RBF representation from current grid */ |
334 |
|
RBFNODE * |
335 |
|
make_rbfrep(void) |
336 |
|
{ |
337 |
+ |
long cradsum = 0, ocradsum = 0; |
338 |
|
int niter = 16; |
339 |
|
double lastVar, thisVar = 100.; |
340 |
|
int nn; |
341 |
|
RBFNODE *newnode; |
342 |
+ |
RBFVAL *itera; |
343 |
|
int i, j; |
344 |
+ |
|
345 |
+ |
#ifdef DEBUG |
346 |
+ |
{ |
347 |
+ |
int maxcnt = 0, nempty = 0; |
348 |
+ |
long cntsum = 0; |
349 |
+ |
for (i = 0; i < GRIDRES; i++) |
350 |
+ |
for (j = 0; j < GRIDRES; j++) |
351 |
+ |
if (!dsf_grid[i][j].nval) { |
352 |
+ |
++nempty; |
353 |
+ |
} else { |
354 |
+ |
if (dsf_grid[i][j].nval > maxcnt) |
355 |
+ |
maxcnt = dsf_grid[i][j].nval; |
356 |
+ |
cntsum += dsf_grid[i][j].nval; |
357 |
+ |
} |
358 |
+ |
fprintf(stderr, "Average, maximum bin count: %d, %d (%.1f%% empty)\n", |
359 |
+ |
(int)(cntsum/((GRIDRES*GRIDRES)-nempty)), maxcnt, |
360 |
+ |
100./(GRIDRES*GRIDRES)*nempty); |
361 |
+ |
} |
362 |
+ |
#endif |
363 |
|
/* compute RBF radii */ |
364 |
|
compute_radii(); |
365 |
|
/* coagulate lobes */ |
368 |
|
for (i = 0; i < GRIDRES; i++) |
369 |
|
for (j = 0; j < GRIDRES; j++) |
370 |
|
nn += dsf_grid[i][j].nval; |
371 |
+ |
/* compute minimum BSDF */ |
372 |
+ |
comp_bsdf_min(); |
373 |
|
/* allocate RBF array */ |
374 |
|
newnode = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(nn-1)); |
375 |
< |
if (newnode == NULL) { |
376 |
< |
fprintf(stderr, "%s: Out of memory in make_rbfrep()\n", progname); |
209 |
< |
exit(1); |
210 |
< |
} |
375 |
> |
if (newnode == NULL) |
376 |
> |
goto memerr; |
377 |
|
newnode->ord = -1; |
378 |
|
newnode->next = NULL; |
379 |
|
newnode->ejl = NULL; |
388 |
|
for (j = 0; j < GRIDRES; j++) |
389 |
|
if (dsf_grid[i][j].nval) { |
390 |
|
newnode->rbfa[nn].peak = dsf_grid[i][j].vsum; |
391 |
< |
newnode->rbfa[nn].crad = RSCA*dsf_grid[i][j].crad + .5; |
391 |
> |
ocradsum += dsf_grid[i][j].crad; |
392 |
> |
cradsum += |
393 |
> |
newnode->rbfa[nn].crad = adj_coded_radius(i, j); |
394 |
|
newnode->rbfa[nn].gx = i; |
395 |
|
newnode->rbfa[nn].gy = j; |
396 |
|
++nn; |
397 |
|
} |
398 |
+ |
#ifdef DEBUG |
399 |
+ |
fprintf(stderr, |
400 |
+ |
"Average radius reduced from %.2f to %.2f degrees for %d lobes\n", |
401 |
+ |
180./M_PI*MAXRSCA*R2ANG(ocradsum/newnode->nrbf), |
402 |
+ |
180./M_PI*R2ANG(cradsum/newnode->nrbf), newnode->nrbf); |
403 |
+ |
#endif |
404 |
|
/* iterate to improve interpolation accuracy */ |
405 |
+ |
itera = (RBFVAL *)malloc(sizeof(RBFVAL)*newnode->nrbf); |
406 |
+ |
if (itera == NULL) |
407 |
+ |
goto memerr; |
408 |
+ |
memcpy(itera, newnode->rbfa, sizeof(RBFVAL)*newnode->nrbf); |
409 |
|
do { |
410 |
|
double dsum = 0, dsum2 = 0; |
411 |
|
nn = 0; |
415 |
|
FVECT odir; |
416 |
|
double corr; |
417 |
|
ovec_from_pos(odir, i, j); |
418 |
< |
newnode->rbfa[nn++].peak *= corr = |
418 |
> |
itera[nn++].peak *= corr = |
419 |
|
dsf_grid[i][j].vsum / |
420 |
|
eval_rbfrep(newnode, odir); |
421 |
< |
dsum += corr - 1.; |
422 |
< |
dsum2 += (corr-1.)*(corr-1.); |
421 |
> |
dsum += 1. - corr; |
422 |
> |
dsum2 += (1.-corr)*(1.-corr); |
423 |
|
} |
424 |
+ |
memcpy(newnode->rbfa, itera, sizeof(RBFVAL)*newnode->nrbf); |
425 |
|
lastVar = thisVar; |
426 |
|
thisVar = dsum2/(double)nn; |
427 |
|
#ifdef DEBUG |
431 |
|
#endif |
432 |
|
} while (--niter > 0 && lastVar-thisVar > 0.02*lastVar); |
433 |
|
|
434 |
+ |
free(itera); |
435 |
|
nn = 0; /* compute sum for normalization */ |
436 |
|
while (nn < newnode->nrbf) |
437 |
|
newnode->vtotal += rbf_volume(&newnode->rbfa[nn++]); |
438 |
< |
|
438 |
> |
#ifdef DEBUG |
439 |
> |
fprintf(stderr, "Integrated DSF at (%.1f,%.1f) deg. is %.2f\n", |
440 |
> |
get_theta180(newnode->invec), get_phi360(newnode->invec), |
441 |
> |
newnode->vtotal); |
442 |
> |
#endif |
443 |
|
insert_dsf(newnode); |
444 |
|
|
445 |
|
return(newnode); |
446 |
+ |
memerr: |
447 |
+ |
fprintf(stderr, "%s: Out of memory in make_rbfrep()\n", progname); |
448 |
+ |
exit(1); |
449 |
|
} |