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#include <math.h> |
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#include "bsdfrep.h" |
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|
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#ifndef RSCA |
18 |
< |
#define RSCA 2.7 /* radius scaling factor (empirical) */ |
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> |
#ifndef MINRSCA |
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> |
#define MINRSCA 0.15 /* minimum radius scaling factor */ |
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#endif |
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#ifndef MAXRSCA |
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#define MAXRSCA 2.7 /* maximum radius scaling factor */ |
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#endif |
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#ifndef MAXFRAC |
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#define MAXFRAC 0.5 /* maximum contribution to neighbor */ |
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#endif |
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#ifndef NNEIGH |
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#define NNEIGH 10 /* number of neighbors to consider */ |
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#endif |
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/* our loaded grid for this incident angle */ |
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GRIDVAL dsf_grid[GRIDRES][GRIDRES]; |
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|
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ovec[1] = sin((M_PI/180.)*phi_out) * ovec[2]; |
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ovec[2] = sqrt(1. - ovec[2]*ovec[2]); |
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|
60 |
< |
if (!isDSF) |
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if (val <= 0) /* truncate to zero */ |
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val = 0; |
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else if (!isDSF) |
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val *= ovec[2]; /* convert from BSDF to DSF */ |
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|
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/* update BSDF histogram */ |
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if (val < BSDF2BIG*ovec[2] && val > BSDF2SML*ovec[2]) |
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++bsdf_hist[histndx(val/ovec[2])]; |
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|
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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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} |
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|
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/* Compute radii for non-empty bins */ |
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/* (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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{ |
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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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double ang2, lastang2; |
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int r, i, j, jn, ii, jj, inear, jnear; |
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|
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for (i = 0; i < GRIDRES; i++) /* initialize minimum radii */ |
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for (j = 0; j < GRIDRES; j++) |
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if (dsf_grid[i][j].nval) |
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dsf_grid[i][j].crad = cradmin; |
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|
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r = GRIDRES/2; /* proceed in zig-zag */ |
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for (i = 0; i < GRIDRES; i++) |
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for (jn = 0; jn < GRIDRES; jn++) { |
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memset(fill_cnt, 0, sizeof(fill_cnt)); |
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for (i = 0; i < GRIDRES; i++) |
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for (j = 0; j < GRIDRES; j++) { |
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if (!dsf_grid[i][j].crad) |
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continue; /* missing distance */ |
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r = R2ANG(dsf_grid[i][j].crad)*(2.*RSCA*GRIDRES/M_PI); |
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if (!dsf_grid[i][j].nval) |
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continue; /* not part of this */ |
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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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if (ii < 0) continue; |
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if (ii >= GRIDRES) break; |
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for (jj = j-r; jj <= j+r; jj++) { |
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if ((ii == i) & (jj == j)) |
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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; |
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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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} |
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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() |
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{ |
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int cnt; |
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int i, target; |
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|
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cnt = 0; |
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for (i = HISTLEN; i--; ) |
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cnt += bsdf_hist[i]; |
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if (!cnt) { /* shouldn't happen */ |
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bsdf_min = 0; |
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return; |
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} |
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target = cnt/100; /* ignore bottom 1% */ |
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cnt = 0; |
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for (i = 0; cnt <= target; i++) |
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cnt += bsdf_hist[i]; |
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bsdf_min = histval(i-1); |
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memset(bsdf_hist, 0, sizeof(bsdf_hist)); |
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} |
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|
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/* Find n nearest sub-sampled neighbors to the given grid position */ |
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static int |
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get_neighbors(int neigh[][2], int n, const int i, const int j) |
234 |
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{ |
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int k = 0; |
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int r; |
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/* search concentric squares */ |
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for (r = 1; r < GRIDRES; r++) { |
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int ii, jj; |
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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)) |
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jstep = r<<1; |
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for (jj = j-r; jj <= j+r; jj += jstep) { |
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if (jj < 0) continue; |
248 |
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if (jj >= GRIDRES) break; |
249 |
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if (dsf_grid[ii][jj].nval) { |
250 |
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neigh[k][0] = ii; |
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neigh[k][1] = jj; |
252 |
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if (++k >= n) |
253 |
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return(n); |
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} |
255 |
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} |
256 |
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} |
257 |
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} |
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return(k); |
259 |
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} |
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|
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/* Adjust coded radius for the given grid position based on neighborhood */ |
262 |
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static int |
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adj_coded_radius(const int i, const int j) |
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{ |
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const double rad0 = R2ANG(dsf_grid[i][j].crad); |
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const double minrad = MINRSCA * rad0; |
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double currad = MAXRSCA * rad0; |
268 |
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int neigh[NNEIGH][2]; |
269 |
+ |
int n; |
270 |
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FVECT our_dir; |
271 |
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|
272 |
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ovec_from_pos(our_dir, i, j); |
273 |
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n = get_neighbors(neigh, NNEIGH, i, j); |
274 |
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while (n--) { |
275 |
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FVECT their_dir; |
276 |
+ |
double max_ratio, rad_ok2; |
277 |
+ |
/* check our value at neighbor */ |
278 |
+ |
ovec_from_pos(their_dir, neigh[n][0], neigh[n][1]); |
279 |
+ |
max_ratio = MAXFRAC * dsf_grid[neigh[n][0]][neigh[n][1]].vsum |
280 |
+ |
/ dsf_grid[i][j].vsum; |
281 |
+ |
if (max_ratio >= 1) |
282 |
+ |
continue; |
283 |
+ |
rad_ok2 = (DOT(their_dir,our_dir) - 1.)/log(max_ratio); |
284 |
+ |
if (rad_ok2 >= currad*currad) |
285 |
+ |
continue; /* value fraction OK */ |
286 |
+ |
currad = sqrt(rad_ok2); /* else reduce lobe radius */ |
287 |
+ |
if (currad <= minrad) /* limit how small we'll go */ |
288 |
+ |
return(ANG2R(minrad)); |
289 |
+ |
} |
290 |
+ |
return(ANG2R(currad)); /* encode selected radius */ |
291 |
+ |
} |
292 |
+ |
|
293 |
|
/* Count up filled nodes and build RBF representation from current grid */ |
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RBFNODE * |
295 |
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make_rbfrep(void) |
296 |
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{ |
297 |
+ |
long cradsum = 0, ocradsum = 0; |
298 |
|
int niter = 16; |
299 |
|
double lastVar, thisVar = 100.; |
300 |
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int nn; |
301 |
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RBFNODE *newnode; |
302 |
+ |
RBFVAL *itera; |
303 |
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int i, j; |
304 |
+ |
|
305 |
+ |
#ifdef DEBUG |
306 |
+ |
{ |
307 |
+ |
int maxcnt = 0, nempty = 0; |
308 |
+ |
long cntsum = 0; |
309 |
+ |
for (i = 0; i < GRIDRES; i++) |
310 |
+ |
for (j = 0; j < GRIDRES; j++) |
311 |
+ |
if (!dsf_grid[i][j].nval) { |
312 |
+ |
++nempty; |
313 |
+ |
} else { |
314 |
+ |
if (dsf_grid[i][j].nval > maxcnt) |
315 |
+ |
maxcnt = dsf_grid[i][j].nval; |
316 |
+ |
cntsum += dsf_grid[i][j].nval; |
317 |
+ |
} |
318 |
+ |
fprintf(stderr, "Average, maximum bin count: %d, %d (%.1f%% empty)\n", |
319 |
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(int)(cntsum/((GRIDRES*GRIDRES)-nempty)), maxcnt, |
320 |
+ |
100./(GRIDRES*GRIDRES)*nempty); |
321 |
+ |
} |
322 |
+ |
#endif |
323 |
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/* compute RBF radii */ |
324 |
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compute_radii(); |
325 |
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/* coagulate lobes */ |
328 |
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for (i = 0; i < GRIDRES; i++) |
329 |
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for (j = 0; j < GRIDRES; j++) |
330 |
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nn += dsf_grid[i][j].nval; |
331 |
+ |
/* compute minimum BSDF */ |
332 |
+ |
comp_bsdf_min(); |
333 |
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/* allocate RBF array */ |
334 |
|
newnode = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(nn-1)); |
335 |
< |
if (newnode == NULL) { |
336 |
< |
fprintf(stderr, "%s: Out of memory in make_rbfrep()\n", progname); |
209 |
< |
exit(1); |
210 |
< |
} |
335 |
> |
if (newnode == NULL) |
336 |
> |
goto memerr; |
337 |
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newnode->ord = -1; |
338 |
|
newnode->next = NULL; |
339 |
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newnode->ejl = NULL; |
348 |
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for (j = 0; j < GRIDRES; j++) |
349 |
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if (dsf_grid[i][j].nval) { |
350 |
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newnode->rbfa[nn].peak = dsf_grid[i][j].vsum; |
351 |
< |
newnode->rbfa[nn].crad = RSCA*dsf_grid[i][j].crad + .5; |
351 |
> |
ocradsum += dsf_grid[i][j].crad; |
352 |
> |
cradsum += |
353 |
> |
newnode->rbfa[nn].crad = adj_coded_radius(i, j); |
354 |
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newnode->rbfa[nn].gx = i; |
355 |
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newnode->rbfa[nn].gy = j; |
356 |
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++nn; |
357 |
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} |
358 |
+ |
#ifdef DEBUG |
359 |
+ |
fprintf(stderr, |
360 |
+ |
"Average radius reduced from %.2f to %.2f degrees for %d lobes\n", |
361 |
+ |
180./M_PI*MAXRSCA*R2ANG(ocradsum/newnode->nrbf), |
362 |
+ |
180./M_PI*R2ANG(cradsum/newnode->nrbf), newnode->nrbf); |
363 |
+ |
#endif |
364 |
|
/* iterate to improve interpolation accuracy */ |
365 |
+ |
itera = (RBFVAL *)malloc(sizeof(RBFVAL)*newnode->nrbf); |
366 |
+ |
if (itera == NULL) |
367 |
+ |
goto memerr; |
368 |
+ |
memcpy(itera, newnode->rbfa, sizeof(RBFVAL)*newnode->nrbf); |
369 |
|
do { |
370 |
|
double dsum = 0, dsum2 = 0; |
371 |
|
nn = 0; |
375 |
|
FVECT odir; |
376 |
|
double corr; |
377 |
|
ovec_from_pos(odir, i, j); |
378 |
< |
newnode->rbfa[nn++].peak *= corr = |
378 |
> |
itera[nn++].peak *= corr = |
379 |
|
dsf_grid[i][j].vsum / |
380 |
|
eval_rbfrep(newnode, odir); |
381 |
< |
dsum += corr - 1.; |
382 |
< |
dsum2 += (corr-1.)*(corr-1.); |
381 |
> |
dsum += 1. - corr; |
382 |
> |
dsum2 += (1.-corr)*(1.-corr); |
383 |
|
} |
384 |
+ |
memcpy(newnode->rbfa, itera, sizeof(RBFVAL)*newnode->nrbf); |
385 |
|
lastVar = thisVar; |
386 |
|
thisVar = dsum2/(double)nn; |
387 |
|
#ifdef DEBUG |
391 |
|
#endif |
392 |
|
} while (--niter > 0 && lastVar-thisVar > 0.02*lastVar); |
393 |
|
|
394 |
+ |
free(itera); |
395 |
|
nn = 0; /* compute sum for normalization */ |
396 |
|
while (nn < newnode->nrbf) |
397 |
|
newnode->vtotal += rbf_volume(&newnode->rbfa[nn++]); |
398 |
< |
|
398 |
> |
#ifdef DEBUG |
399 |
> |
fprintf(stderr, "Integrated DSF at (%.1f,%.1f) deg. is %.2f\n", |
400 |
> |
get_theta180(newnode->invec), get_phi360(newnode->invec), |
401 |
> |
newnode->vtotal); |
402 |
> |
#endif |
403 |
|
insert_dsf(newnode); |
404 |
|
|
405 |
|
return(newnode); |
406 |
+ |
memerr: |
407 |
+ |
fprintf(stderr, "%s: Out of memory in make_rbfrep()\n", progname); |
408 |
+ |
exit(1); |
409 |
|
} |