| 17 |
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#ifndef RSCA |
| 18 |
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#define RSCA 2.7 /* radius scaling factor (empirical) */ |
| 19 |
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#endif |
| 20 |
+ |
#ifndef MAXFRAC |
| 21 |
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#define MAXFRAC 0.5 /* maximum contribution to neighbor */ |
| 22 |
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#endif |
| 23 |
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#ifndef NNEIGH |
| 24 |
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#define NNEIGH 10 /* number of neighbors to consider */ |
| 25 |
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#endif |
| 26 |
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/* our loaded grid for this incident angle */ |
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GRIDVAL dsf_grid[GRIDRES][GRIDRES]; |
| 28 |
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|
| 57 |
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if (!isDSF) |
| 58 |
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val *= ovec[2]; /* convert from BSDF to DSF */ |
| 59 |
|
|
| 60 |
+ |
/* update BSDF histogram */ |
| 61 |
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if (val < BSDF2BIG*ovec[2] && val > BSDF2SML*ovec[2]) |
| 62 |
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++bsdf_hist[histndx(val/ovec[2])]; |
| 63 |
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|
| 64 |
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pos_from_vec(pos, ovec); |
| 65 |
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|
| 66 |
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dsf_grid[pos[0]][pos[1]].vsum += val; |
| 195 |
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} |
| 196 |
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} |
| 197 |
|
|
| 198 |
+ |
/* Compute minimum BSDF from histogram and clear it */ |
| 199 |
+ |
static void |
| 200 |
+ |
comp_bsdf_min() |
| 201 |
+ |
{ |
| 202 |
+ |
int cnt; |
| 203 |
+ |
int i, target; |
| 204 |
+ |
|
| 205 |
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cnt = 0; |
| 206 |
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for (i = HISTLEN; i--; ) |
| 207 |
+ |
cnt += bsdf_hist[i]; |
| 208 |
+ |
if (!cnt) { /* shouldn't happen */ |
| 209 |
+ |
bsdf_min = 0; |
| 210 |
+ |
return; |
| 211 |
+ |
} |
| 212 |
+ |
target = cnt/100; /* ignore bottom 1% */ |
| 213 |
+ |
cnt = 0; |
| 214 |
+ |
for (i = 0; cnt <= target; i++) |
| 215 |
+ |
cnt += bsdf_hist[i]; |
| 216 |
+ |
bsdf_min = histval(i-1); |
| 217 |
+ |
memset(bsdf_hist, 0, sizeof(bsdf_hist)); |
| 218 |
+ |
} |
| 219 |
+ |
|
| 220 |
+ |
/* Find n nearest sub-sampled neighbors to the given grid position */ |
| 221 |
+ |
static int |
| 222 |
+ |
get_neighbors(int neigh[][2], int n, const int i, const int j) |
| 223 |
+ |
{ |
| 224 |
+ |
int k = 0; |
| 225 |
+ |
int r; |
| 226 |
+ |
/* search concentric squares */ |
| 227 |
+ |
for (r = 1; r < GRIDRES; r++) { |
| 228 |
+ |
int ii, jj; |
| 229 |
+ |
for (ii = i-r; ii <= i+r; ii++) { |
| 230 |
+ |
int jstep = 1; |
| 231 |
+ |
if (ii < 0) continue; |
| 232 |
+ |
if (ii >= GRIDRES) break; |
| 233 |
+ |
if ((i-r < ii) & (ii < i+r)) |
| 234 |
+ |
jstep = r<<1; |
| 235 |
+ |
for (jj = j-r; jj <= j+r; jj += jstep) { |
| 236 |
+ |
if (jj < 0) continue; |
| 237 |
+ |
if (jj >= GRIDRES) break; |
| 238 |
+ |
if (dsf_grid[ii][jj].nval) { |
| 239 |
+ |
neigh[k][0] = ii; |
| 240 |
+ |
neigh[k][1] = jj; |
| 241 |
+ |
if (++k >= n) |
| 242 |
+ |
return(n); |
| 243 |
+ |
} |
| 244 |
+ |
} |
| 245 |
+ |
} |
| 246 |
+ |
} |
| 247 |
+ |
return(k); |
| 248 |
+ |
} |
| 249 |
+ |
|
| 250 |
+ |
/* Adjust coded radius for the given grid position based on neighborhood */ |
| 251 |
+ |
static int |
| 252 |
+ |
adj_coded_radius(const int i, const int j) |
| 253 |
+ |
{ |
| 254 |
+ |
const double rad0 = R2ANG(dsf_grid[i][j].crad); |
| 255 |
+ |
double currad = RSCA * rad0; |
| 256 |
+ |
int neigh[NNEIGH][2]; |
| 257 |
+ |
int n; |
| 258 |
+ |
FVECT our_dir; |
| 259 |
+ |
|
| 260 |
+ |
ovec_from_pos(our_dir, i, j); |
| 261 |
+ |
n = get_neighbors(neigh, NNEIGH, i, j); |
| 262 |
+ |
while (n--) { |
| 263 |
+ |
FVECT their_dir; |
| 264 |
+ |
double max_ratio, rad_ok2; |
| 265 |
+ |
/* check our value at neighbor */ |
| 266 |
+ |
ovec_from_pos(their_dir, neigh[n][0], neigh[n][1]); |
| 267 |
+ |
max_ratio = MAXFRAC * dsf_grid[neigh[n][0]][neigh[n][1]].vsum |
| 268 |
+ |
/ dsf_grid[i][j].vsum; |
| 269 |
+ |
if (max_ratio >= 1) |
| 270 |
+ |
continue; |
| 271 |
+ |
rad_ok2 = (DOT(their_dir,our_dir) - 1.)/log(max_ratio); |
| 272 |
+ |
if (rad_ok2 >= currad*currad) |
| 273 |
+ |
continue; /* value fraction OK */ |
| 274 |
+ |
currad = sqrt(rad_ok2); /* else reduce lobe radius */ |
| 275 |
+ |
if (currad <= rad0) /* limit how small we'll go */ |
| 276 |
+ |
return(dsf_grid[i][j].crad); |
| 277 |
+ |
} |
| 278 |
+ |
return(ANG2R(currad)); /* encode selected radius */ |
| 279 |
+ |
} |
| 280 |
+ |
|
| 281 |
|
/* Count up filled nodes and build RBF representation from current grid */ |
| 282 |
|
RBFNODE * |
| 283 |
|
make_rbfrep(void) |
| 296 |
|
for (i = 0; i < GRIDRES; i++) |
| 297 |
|
for (j = 0; j < GRIDRES; j++) |
| 298 |
|
nn += dsf_grid[i][j].nval; |
| 299 |
+ |
/* compute minimum BSDF */ |
| 300 |
+ |
comp_bsdf_min(); |
| 301 |
|
/* allocate RBF array */ |
| 302 |
|
newnode = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(nn-1)); |
| 303 |
|
if (newnode == NULL) |
| 316 |
|
for (j = 0; j < GRIDRES; j++) |
| 317 |
|
if (dsf_grid[i][j].nval) { |
| 318 |
|
newnode->rbfa[nn].peak = dsf_grid[i][j].vsum; |
| 319 |
< |
newnode->rbfa[nn].crad = RSCA*dsf_grid[i][j].crad + .5; |
| 319 |
> |
newnode->rbfa[nn].crad = adj_coded_radius(i, j); |
| 320 |
|
newnode->rbfa[nn].gx = i; |
| 321 |
|
newnode->rbfa[nn].gy = j; |
| 322 |
|
++nn; |
| 355 |
|
nn = 0; /* compute sum for normalization */ |
| 356 |
|
while (nn < newnode->nrbf) |
| 357 |
|
newnode->vtotal += rbf_volume(&newnode->rbfa[nn++]); |
| 358 |
< |
|
| 358 |
> |
#ifdef DEBUG |
| 359 |
> |
fprintf(stderr, "Integrated DSF at (%.1f,%.1f) deg. is %.2f\n", |
| 360 |
> |
get_theta180(newnode->invec), get_phi360(newnode->invec), |
| 361 |
> |
newnode->vtotal); |
| 362 |
> |
#endif |
| 363 |
|
insert_dsf(newnode); |
| 364 |
|
|
| 365 |
|
return(newnode); |
