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root/radiance/ray/src/cv/pabopto2xml.c
Revision: 2.13
Committed: Fri Sep 21 05:17:22 2012 UTC (11 years, 8 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.12: +159 -44 lines
Log Message:
Numerous changes -- still debugging

File Contents

# User Rev Content
1 greg 2.1 #ifndef lint
2 greg 2.13 static const char RCSid[] = "$Id: pabopto2xml.c,v 2.12 2012/09/20 01:23:36 greg Exp $";
3 greg 2.1 #endif
4     /*
5     * Convert PAB-Opto measurements to XML format using tensor tree representation
6     * Employs Bonneel et al. Earth Mover's Distance interpolant.
7     *
8     * G.Ward
9     */
10    
11     #define _USE_MATH_DEFINES
12     #include <stdio.h>
13     #include <stdlib.h>
14     #include <string.h>
15     #include <ctype.h>
16     #include <math.h>
17     #include "bsdf.h"
18    
19 greg 2.10 #define DEBUG 1
20    
21 greg 2.1 #ifndef GRIDRES
22 greg 2.10 #define GRIDRES 200 /* grid resolution per side */
23 greg 2.1 #endif
24    
25 greg 2.3 #define RSCA 2.7 /* radius scaling factor (empirical) */
26 greg 2.2
27 greg 2.6 /* convert to/from coded radians */
28     #define ANG2R(r) (int)((r)*((1<<16)/M_PI))
29 greg 2.2 #define R2ANG(c) (((c)+.5)*(M_PI/(1<<16)))
30 greg 2.1
31     typedef struct {
32 greg 2.5 float vsum; /* DSF sum */
33 greg 2.1 unsigned short nval; /* number of values in sum */
34 greg 2.2 unsigned short crad; /* radius (coded angle) */
35 greg 2.1 } GRIDVAL; /* grid value */
36    
37     typedef struct {
38 greg 2.5 float peak; /* lobe value at peak */
39 greg 2.2 unsigned short crad; /* radius (coded angle) */
40 greg 2.1 unsigned char gx, gy; /* grid position */
41     } RBFVAL; /* radial basis function value */
42    
43 greg 2.7 struct s_rbfnode; /* forward declaration of RBF struct */
44    
45     typedef struct s_migration {
46     struct s_migration *next; /* next in global edge list */
47     struct s_rbfnode *rbfv[2]; /* from,to vertex */
48     struct s_migration *enxt[2]; /* next from,to sibling */
49     float mtx[1]; /* matrix (extends struct) */
50     } MIGRATION; /* migration link (winged edge structure) */
51    
52     typedef struct s_rbfnode {
53     struct s_rbfnode *next; /* next in global RBF list */
54     MIGRATION *ejl; /* edge list for this vertex */
55 greg 2.1 FVECT invec; /* incident vector direction */
56 greg 2.8 double vtotal; /* volume for normalization */
57 greg 2.1 int nrbf; /* number of RBFs */
58     RBFVAL rbfa[1]; /* RBF array (extends struct) */
59 greg 2.10 } RBFNODE; /* RBF representation of DSF @ 1 incidence */
60 greg 2.1
61     /* our loaded grid for this incident angle */
62 greg 2.10 static double theta_in_deg, phi_in_deg;
63     static GRIDVAL dsf_grid[GRIDRES][GRIDRES];
64    
65     /* all incident angles in-plane so far? */
66     static int single_plane_incident = -1;
67    
68     /* input/output orientations */
69     static int input_orient = 0;
70     static int output_orient = 0;
71 greg 2.1
72 greg 2.5 /* processed incident DSF measurements */
73 greg 2.10 static RBFNODE *dsf_list = NULL;
74 greg 2.7
75 greg 2.8 /* RBF-linking matrices (edges) */
76 greg 2.7 static MIGRATION *mig_list = NULL;
77    
78 greg 2.10 /* migration edges drawn in raster fashion */
79     static MIGRATION *mig_grid[GRIDRES][GRIDRES];
80    
81 greg 2.8 #define mtx_nrows(m) ((m)->rbfv[0]->nrbf)
82     #define mtx_ncols(m) ((m)->rbfv[1]->nrbf)
83     #define mtx_ndx(m,i,j) ((i)*mtx_ncols(m) + (j))
84     #define is_src(rbf,m) ((rbf) == (m)->rbfv[0])
85     #define is_dest(rbf,m) ((rbf) == (m)->rbfv[1])
86     #define nextedge(rbf,m) (m)->enxt[is_dest(rbf,m)]
87 greg 2.10 #define opp_rbf(rbf,m) (m)->rbfv[is_src(rbf,m)]
88    
89     #define round(v) (int)((v) + .5 - ((v) < -.5))
90 greg 2.8
91 greg 2.12 char *progname;
92 greg 2.13
93     #ifdef DEBUG /* percentage to cull (<0 to turn off) */
94     int pctcull = -1;
95     #else
96 greg 2.12 int pctcull = 90;
97 greg 2.13 #endif
98     /* sampling order (set by data density) */
99 greg 2.12 int samp_order = 0;
100    
101 greg 2.8 /* Compute volume associated with Gaussian lobe */
102     static double
103     rbf_volume(const RBFVAL *rbfp)
104     {
105     double rad = R2ANG(rbfp->crad);
106    
107     return((2.*M_PI) * rbfp->peak * rad*rad);
108     }
109 greg 2.1
110 greg 2.3 /* Compute outgoing vector from grid position */
111     static void
112 greg 2.10 ovec_from_pos(FVECT vec, int xpos, int ypos)
113 greg 2.1 {
114 greg 2.3 double uv[2];
115     double r2;
116    
117     SDsquare2disk(uv, (1./GRIDRES)*(xpos+.5), (1./GRIDRES)*(ypos+.5));
118     /* uniform hemispherical projection */
119     r2 = uv[0]*uv[0] + uv[1]*uv[1];
120     vec[0] = vec[1] = sqrt(2. - r2);
121     vec[0] *= uv[0];
122     vec[1] *= uv[1];
123 greg 2.10 vec[2] = output_orient*(1. - r2);
124 greg 2.1 }
125    
126 greg 2.10 /* Compute grid position from normalized input/output vector */
127 greg 2.1 static void
128     pos_from_vec(int pos[2], const FVECT vec)
129     {
130     double sq[2]; /* uniform hemispherical projection */
131 greg 2.10 double norm = 1./sqrt(1. + fabs(vec[2]));
132 greg 2.1
133     SDdisk2square(sq, vec[0]*norm, vec[1]*norm);
134    
135     pos[0] = (int)(sq[0]*GRIDRES);
136     pos[1] = (int)(sq[1]*GRIDRES);
137     }
138    
139 greg 2.5 /* Evaluate RBF for DSF at the given normalized outgoing direction */
140 greg 2.1 static double
141 greg 2.10 eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
142 greg 2.1 {
143     double res = .0;
144     const RBFVAL *rbfp;
145     FVECT odir;
146     double sig2;
147     int n;
148    
149 greg 2.12 if (rp == NULL)
150     return(.0);
151 greg 2.1 rbfp = rp->rbfa;
152     for (n = rp->nrbf; n--; rbfp++) {
153 greg 2.10 ovec_from_pos(odir, rbfp->gx, rbfp->gy);
154 greg 2.2 sig2 = R2ANG(rbfp->crad);
155     sig2 = (DOT(odir,outvec) - 1.) / (sig2*sig2);
156 greg 2.1 if (sig2 > -19.)
157 greg 2.5 res += rbfp->peak * exp(sig2);
158 greg 2.1 }
159     return(res);
160     }
161    
162 greg 2.10 /* Insert a new directional scattering function in our global list */
163     static void
164     insert_dsf(RBFNODE *newrbf)
165     {
166     RBFNODE *rbf, *rbf_last;
167     /* keep in ascending theta order */
168     for (rbf_last = NULL, rbf = dsf_list;
169     single_plane_incident & (rbf != NULL);
170     rbf_last = rbf, rbf = rbf->next)
171     if (input_orient*rbf->invec[2] < input_orient*newrbf->invec[2])
172     break;
173     if (rbf_last == NULL) {
174     newrbf->next = dsf_list;
175     dsf_list = newrbf;
176     return;
177     }
178     newrbf->next = rbf;
179     rbf_last->next = newrbf;
180     }
181    
182 greg 2.3 /* Count up filled nodes and build RBF representation from current grid */
183 greg 2.10 static RBFNODE *
184 greg 2.3 make_rbfrep(void)
185     {
186 greg 2.6 int niter = 16;
187 greg 2.12 int minrad = ANG2R(pow(2., 1.-samp_order));
188 greg 2.6 double lastVar, thisVar = 100.;
189 greg 2.3 int nn;
190 greg 2.10 RBFNODE *newnode;
191 greg 2.3 int i, j;
192    
193     nn = 0; /* count selected bins */
194     for (i = 0; i < GRIDRES; i++)
195     for (j = 0; j < GRIDRES; j++)
196 greg 2.6 nn += dsf_grid[i][j].nval;
197 greg 2.3 /* allocate RBF array */
198 greg 2.10 newnode = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(nn-1));
199 greg 2.3 if (newnode == NULL) {
200 greg 2.8 fputs("Out of memory in make_rbfrep()\n", stderr);
201 greg 2.3 exit(1);
202     }
203     newnode->next = NULL;
204 greg 2.7 newnode->ejl = NULL;
205 greg 2.3 newnode->invec[2] = sin(M_PI/180.*theta_in_deg);
206     newnode->invec[0] = cos(M_PI/180.*phi_in_deg)*newnode->invec[2];
207     newnode->invec[1] = sin(M_PI/180.*phi_in_deg)*newnode->invec[2];
208 greg 2.10 newnode->invec[2] = input_orient*sqrt(1. - newnode->invec[2]*newnode->invec[2]);
209 greg 2.8 newnode->vtotal = 0;
210 greg 2.3 newnode->nrbf = nn;
211     nn = 0; /* fill RBF array */
212     for (i = 0; i < GRIDRES; i++)
213     for (j = 0; j < GRIDRES; j++)
214 greg 2.5 if (dsf_grid[i][j].nval) {
215 greg 2.6 newnode->rbfa[nn].peak = dsf_grid[i][j].vsum;
216 greg 2.5 newnode->rbfa[nn].crad = RSCA*dsf_grid[i][j].crad + .5;
217 greg 2.3 newnode->rbfa[nn].gx = i;
218     newnode->rbfa[nn].gy = j;
219 greg 2.12 if (newnode->rbfa[nn].crad < minrad)
220     minrad = newnode->rbfa[nn].crad;
221 greg 2.3 ++nn;
222     }
223 greg 2.6 /* iterate to improve interpolation accuracy */
224     do {
225 greg 2.13 double dsum = 0, dsum2 = 0;
226 greg 2.3 nn = 0;
227     for (i = 0; i < GRIDRES; i++)
228     for (j = 0; j < GRIDRES; j++)
229 greg 2.5 if (dsf_grid[i][j].nval) {
230 greg 2.3 FVECT odir;
231 greg 2.6 double corr;
232 greg 2.10 ovec_from_pos(odir, i, j);
233 greg 2.6 newnode->rbfa[nn++].peak *= corr =
234 greg 2.5 dsf_grid[i][j].vsum /
235 greg 2.3 eval_rbfrep(newnode, odir);
236 greg 2.4 dsum += corr - 1.;
237     dsum2 += (corr-1.)*(corr-1.);
238 greg 2.3 }
239 greg 2.6 lastVar = thisVar;
240     thisVar = dsum2/(double)nn;
241 greg 2.10 #ifdef DEBUG
242 greg 2.4 fprintf(stderr, "Avg., RMS error: %.1f%% %.1f%%\n",
243     100.*dsum/(double)nn,
244 greg 2.6 100.*sqrt(thisVar));
245 greg 2.10 #endif
246 greg 2.6 } while (--niter > 0 && lastVar-thisVar > 0.02*lastVar);
247    
248 greg 2.8 nn = 0; /* compute sum for normalization */
249     while (nn < newnode->nrbf)
250     newnode->vtotal += rbf_volume(&newnode->rbfa[nn++]);
251    
252 greg 2.10 insert_dsf(newnode);
253 greg 2.12 /* adjust sampling resolution */
254 greg 2.13 samp_order = log(2./R2ANG(minrad))/M_LN2 + .5;
255 greg 2.12
256 greg 2.10 return(newnode);
257 greg 2.3 }
258    
259 greg 2.1 /* Load a set of measurements corresponding to a particular incident angle */
260     static int
261 greg 2.10 load_pabopto_meas(const char *fname)
262 greg 2.1 {
263     FILE *fp = fopen(fname, "r");
264     int inp_is_DSF = -1;
265 greg 2.10 double new_phi, theta_out, phi_out, val;
266 greg 2.1 char buf[2048];
267     int n, c;
268    
269     if (fp == NULL) {
270     fputs(fname, stderr);
271     fputs(": cannot open\n", stderr);
272     return(0);
273     }
274 greg 2.5 memset(dsf_grid, 0, sizeof(dsf_grid));
275 greg 2.10 #ifdef DEBUG
276     fprintf(stderr, "Loading measurement file '%s'...\n", fname);
277     #endif
278 greg 2.1 /* read header information */
279     while ((c = getc(fp)) == '#' || c == EOF) {
280     if (fgets(buf, sizeof(buf), fp) == NULL) {
281     fputs(fname, stderr);
282     fputs(": unexpected EOF\n", stderr);
283     fclose(fp);
284     return(0);
285     }
286     if (!strcmp(buf, "format: theta phi DSF\n")) {
287     inp_is_DSF = 1;
288     continue;
289     }
290     if (!strcmp(buf, "format: theta phi BSDF\n")) {
291     inp_is_DSF = 0;
292     continue;
293     }
294     if (sscanf(buf, "intheta %lf", &theta_in_deg) == 1)
295     continue;
296 greg 2.10 if (sscanf(buf, "inphi %lf", &new_phi) == 1)
297 greg 2.1 continue;
298     if (sscanf(buf, "incident_angle %lf %lf",
299 greg 2.10 &theta_in_deg, &new_phi) == 2)
300 greg 2.1 continue;
301     }
302     if (inp_is_DSF < 0) {
303     fputs(fname, stderr);
304     fputs(": unknown format\n", stderr);
305     fclose(fp);
306     return(0);
307     }
308 greg 2.10 if (!input_orient) /* check input orientation */
309     input_orient = 1 - 2*(theta_in_deg > 90.);
310     else if (input_orient > 0 ^ theta_in_deg < 90.) {
311     fputs("Cannot handle input angles on both sides of surface\n",
312     stderr);
313     exit(1);
314     }
315     if (single_plane_incident > 0) /* check if still in plane */
316     single_plane_incident = (round(new_phi) == round(phi_in_deg));
317     else if (single_plane_incident < 0)
318     single_plane_incident = 1;
319     phi_in_deg = new_phi;
320     ungetc(c, fp); /* read actual data */
321 greg 2.1 while (fscanf(fp, "%lf %lf %lf\n", &theta_out, &phi_out, &val) == 3) {
322     FVECT ovec;
323     int pos[2];
324    
325 greg 2.10 if (!output_orient) /* check output orientation */
326     output_orient = 1 - 2*(theta_out > 90.);
327     else if (output_orient > 0 ^ theta_out < 90.) {
328     fputs("Cannot handle output angles on both sides of surface\n",
329     stderr);
330     exit(1);
331     }
332 greg 2.1 ovec[2] = sin(M_PI/180.*theta_out);
333     ovec[0] = cos(M_PI/180.*phi_out) * ovec[2];
334     ovec[1] = sin(M_PI/180.*phi_out) * ovec[2];
335     ovec[2] = sqrt(1. - ovec[2]*ovec[2]);
336    
337 greg 2.5 if (!inp_is_DSF)
338     val *= ovec[2]; /* convert from BSDF to DSF */
339 greg 2.1
340     pos_from_vec(pos, ovec);
341    
342 greg 2.5 dsf_grid[pos[0]][pos[1]].vsum += val;
343     dsf_grid[pos[0]][pos[1]].nval++;
344 greg 2.1 }
345     n = 0;
346     while ((c = getc(fp)) != EOF)
347     n += !isspace(c);
348     if (n)
349     fprintf(stderr,
350     "%s: warning: %d unexpected characters past EOD\n",
351     fname, n);
352     fclose(fp);
353     return(1);
354     }
355    
356     /* Compute radii for non-empty bins */
357     /* (distance to furthest empty bin for which non-empty bin is the closest) */
358     static void
359     compute_radii(void)
360     {
361 greg 2.4 unsigned int fill_grid[GRIDRES][GRIDRES];
362     unsigned short fill_cnt[GRIDRES][GRIDRES];
363 greg 2.2 FVECT ovec0, ovec1;
364     double ang2, lastang2;
365     int r, i, j, jn, ii, jj, inear, jnear;
366    
367     r = GRIDRES/2; /* proceed in zig-zag */
368 greg 2.1 for (i = 0; i < GRIDRES; i++)
369     for (jn = 0; jn < GRIDRES; jn++) {
370     j = (i&1) ? jn : GRIDRES-1-jn;
371 greg 2.5 if (dsf_grid[i][j].nval) /* find empty grid pos. */
372 greg 2.1 continue;
373 greg 2.10 ovec_from_pos(ovec0, i, j);
374 greg 2.1 inear = jnear = -1; /* find nearest non-empty */
375 greg 2.2 lastang2 = M_PI*M_PI;
376 greg 2.1 for (ii = i-r; ii <= i+r; ii++) {
377     if (ii < 0) continue;
378     if (ii >= GRIDRES) break;
379     for (jj = j-r; jj <= j+r; jj++) {
380     if (jj < 0) continue;
381     if (jj >= GRIDRES) break;
382 greg 2.5 if (!dsf_grid[ii][jj].nval)
383 greg 2.1 continue;
384 greg 2.10 ovec_from_pos(ovec1, ii, jj);
385 greg 2.2 ang2 = 2. - 2.*DOT(ovec0,ovec1);
386     if (ang2 >= lastang2)
387 greg 2.1 continue;
388 greg 2.2 lastang2 = ang2;
389 greg 2.1 inear = ii; jnear = jj;
390     }
391     }
392 greg 2.2 if (inear < 0) {
393     fputs("Could not find non-empty neighbor!\n", stderr);
394     exit(1);
395     }
396     ang2 = sqrt(lastang2);
397     r = ANG2R(ang2); /* record if > previous */
398 greg 2.5 if (r > dsf_grid[inear][jnear].crad)
399     dsf_grid[inear][jnear].crad = r;
400 greg 2.2 /* next search radius */
401 greg 2.10 r = ang2*(2.*GRIDRES/M_PI) + 3;
402 greg 2.1 }
403 greg 2.4 /* blur radii over hemisphere */
404 greg 2.1 memset(fill_grid, 0, sizeof(fill_grid));
405 greg 2.4 memset(fill_cnt, 0, sizeof(fill_cnt));
406 greg 2.1 for (i = 0; i < GRIDRES; i++)
407     for (j = 0; j < GRIDRES; j++) {
408 greg 2.5 if (!dsf_grid[i][j].crad)
409 greg 2.4 continue; /* missing distance */
410 greg 2.5 r = R2ANG(dsf_grid[i][j].crad)*(2.*RSCA*GRIDRES/M_PI);
411 greg 2.1 for (ii = i-r; ii <= i+r; ii++) {
412     if (ii < 0) continue;
413     if (ii >= GRIDRES) break;
414     for (jj = j-r; jj <= j+r; jj++) {
415     if (jj < 0) continue;
416     if (jj >= GRIDRES) break;
417 greg 2.4 if ((ii-i)*(ii-i) + (jj-j)*(jj-j) > r*r)
418 greg 2.1 continue;
419 greg 2.5 fill_grid[ii][jj] += dsf_grid[i][j].crad;
420 greg 2.4 fill_cnt[ii][jj]++;
421 greg 2.1 }
422     }
423     }
424 greg 2.6 /* copy back blurred radii */
425 greg 2.1 for (i = 0; i < GRIDRES; i++)
426     for (j = 0; j < GRIDRES; j++)
427 greg 2.4 if (fill_cnt[i][j])
428 greg 2.5 dsf_grid[i][j].crad = fill_grid[i][j]/fill_cnt[i][j];
429 greg 2.1 }
430    
431 greg 2.6 /* Cull points for more uniform distribution, leave all nval 0 or 1 */
432 greg 2.1 static void
433     cull_values(void)
434     {
435 greg 2.2 FVECT ovec0, ovec1;
436     double maxang, maxang2;
437     int i, j, ii, jj, r;
438 greg 2.1 /* simple greedy algorithm */
439     for (i = 0; i < GRIDRES; i++)
440     for (j = 0; j < GRIDRES; j++) {
441 greg 2.5 if (!dsf_grid[i][j].nval)
442 greg 2.1 continue;
443 greg 2.5 if (!dsf_grid[i][j].crad)
444 greg 2.2 continue; /* shouldn't happen */
445 greg 2.10 ovec_from_pos(ovec0, i, j);
446 greg 2.5 maxang = 2.*R2ANG(dsf_grid[i][j].crad);
447 greg 2.2 if (maxang > ovec0[2]) /* clamp near horizon */
448     maxang = ovec0[2];
449     r = maxang*(2.*GRIDRES/M_PI) + 1;
450     maxang2 = maxang*maxang;
451 greg 2.1 for (ii = i-r; ii <= i+r; ii++) {
452     if (ii < 0) continue;
453     if (ii >= GRIDRES) break;
454     for (jj = j-r; jj <= j+r; jj++) {
455     if (jj < 0) continue;
456     if (jj >= GRIDRES) break;
457 greg 2.5 if (!dsf_grid[ii][jj].nval)
458 greg 2.1 continue;
459 greg 2.2 if ((ii == i) & (jj == j))
460     continue; /* don't get self-absorbed */
461 greg 2.10 ovec_from_pos(ovec1, ii, jj);
462 greg 2.2 if (2. - 2.*DOT(ovec0,ovec1) >= maxang2)
463 greg 2.1 continue;
464 greg 2.2 /* absorb sum */
465 greg 2.5 dsf_grid[i][j].vsum += dsf_grid[ii][jj].vsum;
466     dsf_grid[i][j].nval += dsf_grid[ii][jj].nval;
467 greg 2.2 /* keep value, though */
468 greg 2.6 dsf_grid[ii][jj].vsum /= (float)dsf_grid[ii][jj].nval;
469 greg 2.5 dsf_grid[ii][jj].nval = 0;
470 greg 2.1 }
471     }
472     }
473 greg 2.6 /* final averaging pass */
474     for (i = 0; i < GRIDRES; i++)
475     for (j = 0; j < GRIDRES; j++)
476     if (dsf_grid[i][j].nval > 1) {
477     dsf_grid[i][j].vsum /= (float)dsf_grid[i][j].nval;
478     dsf_grid[i][j].nval = 1;
479     }
480 greg 2.1 }
481    
482 greg 2.8 /* Compute (and allocate) migration price matrix for optimization */
483     static float *
484 greg 2.10 price_routes(const RBFNODE *from_rbf, const RBFNODE *to_rbf)
485 greg 2.8 {
486     float *pmtx = (float *)malloc(sizeof(float) *
487     from_rbf->nrbf * to_rbf->nrbf);
488     FVECT *vto = (FVECT *)malloc(sizeof(FVECT) * to_rbf->nrbf);
489     int i, j;
490    
491     if ((pmtx == NULL) | (vto == NULL)) {
492     fputs("Out of memory in migration_costs()\n", stderr);
493     exit(1);
494     }
495     for (j = to_rbf->nrbf; j--; ) /* save repetitive ops. */
496 greg 2.10 ovec_from_pos(vto[j], to_rbf->rbfa[j].gx, to_rbf->rbfa[j].gy);
497 greg 2.8
498     for (i = from_rbf->nrbf; i--; ) {
499     const double from_ang = R2ANG(from_rbf->rbfa[i].crad);
500     FVECT vfrom;
501 greg 2.10 ovec_from_pos(vfrom, from_rbf->rbfa[i].gx, from_rbf->rbfa[i].gy);
502 greg 2.8 for (j = to_rbf->nrbf; j--; )
503     pmtx[i*to_rbf->nrbf + j] = acos(DOT(vfrom, vto[j])) +
504     fabs(R2ANG(to_rbf->rbfa[j].crad) - from_ang);
505     }
506     free(vto);
507     return(pmtx);
508     }
509    
510     /* Comparison routine needed for sorting price row */
511     static const float *price_arr;
512     static int
513     msrt_cmp(const void *p1, const void *p2)
514     {
515     float c1 = price_arr[*(const int *)p1];
516     float c2 = price_arr[*(const int *)p2];
517    
518     if (c1 > c2) return(1);
519     if (c1 < c2) return(-1);
520     return(0);
521     }
522    
523     /* Compute minimum (optimistic) cost for moving the given source material */
524     static double
525     min_cost(double amt2move, const double *avail, const float *price, int n)
526     {
527     static int *price_sort = NULL;
528     static int n_alloc = 0;
529     double total_cost = 0;
530     int i;
531    
532     if (amt2move <= FTINY) /* pre-emptive check */
533     return(0.);
534     if (n > n_alloc) { /* (re)allocate sort array */
535     if (n_alloc) free(price_sort);
536     price_sort = (int *)malloc(sizeof(int)*n);
537     if (price_sort == NULL) {
538     fputs("Out of memory in min_cost()\n", stderr);
539     exit(1);
540     }
541     n_alloc = n;
542     }
543     for (i = n; i--; )
544     price_sort[i] = i;
545     price_arr = price;
546     qsort(price_sort, n, sizeof(int), &msrt_cmp);
547     /* move cheapest first */
548     for (i = 0; i < n && amt2move > FTINY; i++) {
549     int d = price_sort[i];
550     double amt = (amt2move < avail[d]) ? amt2move : avail[d];
551    
552     total_cost += amt * price[d];
553     amt2move -= amt;
554     }
555     return(total_cost);
556     }
557    
558     /* Take a step in migration by choosing optimal bucket to transfer */
559     static double
560     migration_step(MIGRATION *mig, double *src_rem, double *dst_rem, const float *pmtx)
561     {
562     static double *src_cost = NULL;
563     int n_alloc = 0;
564 greg 2.9 const double maxamt = 2./(mtx_nrows(mig)*mtx_ncols(mig));
565 greg 2.8 double amt = 0;
566     struct {
567     int s, d; /* source and destination */
568     double price; /* price estimate per amount moved */
569     double amt; /* amount we can move */
570     } cur, best;
571     int i;
572    
573     if (mtx_nrows(mig) > n_alloc) { /* allocate cost array */
574     if (n_alloc)
575     free(src_cost);
576     src_cost = (double *)malloc(sizeof(double)*mtx_nrows(mig));
577     if (src_cost == NULL) {
578     fputs("Out of memory in migration_step()\n", stderr);
579     exit(1);
580     }
581     n_alloc = mtx_nrows(mig);
582     }
583     for (i = mtx_nrows(mig); i--; ) /* starting costs for diff. */
584     src_cost[i] = min_cost(src_rem[i], dst_rem,
585     pmtx+i*mtx_ncols(mig), mtx_ncols(mig));
586    
587     /* find best source & dest. */
588     best.s = best.d = -1; best.price = FHUGE; best.amt = 0;
589     for (cur.s = mtx_nrows(mig); cur.s--; ) {
590     const float *price = pmtx + cur.s*mtx_ncols(mig);
591     double cost_others = 0;
592     if (src_rem[cur.s] <= FTINY)
593     continue;
594     cur.d = -1; /* examine cheapest dest. */
595     for (i = mtx_ncols(mig); i--; )
596     if (dst_rem[i] > FTINY &&
597     (cur.d < 0 || price[i] < price[cur.d]))
598     cur.d = i;
599     if (cur.d < 0)
600     return(.0);
601     if ((cur.price = price[cur.d]) >= best.price)
602     continue; /* no point checking further */
603     cur.amt = (src_rem[cur.s] < dst_rem[cur.d]) ?
604     src_rem[cur.s] : dst_rem[cur.d];
605     if (cur.amt > maxamt) cur.amt = maxamt;
606     dst_rem[cur.d] -= cur.amt; /* add up differential costs */
607     for (i = mtx_nrows(mig); i--; ) {
608     if (i == cur.s) continue;
609     cost_others += min_cost(src_rem[i], dst_rem, price, mtx_ncols(mig))
610     - src_cost[i];
611     }
612     dst_rem[cur.d] += cur.amt; /* undo trial move */
613     cur.price += cost_others/cur.amt; /* adjust effective price */
614     if (cur.price < best.price) /* are we better than best? */
615     best = cur;
616     }
617     if ((best.s < 0) | (best.d < 0))
618     return(.0);
619     /* make the actual move */
620     mig->mtx[mtx_ndx(mig,best.s,best.d)] += best.amt;
621     src_rem[best.s] -= best.amt;
622     dst_rem[best.d] -= best.amt;
623     return(best.amt);
624     }
625    
626     /* Compute (and insert) migration along directed edge */
627     static MIGRATION *
628 greg 2.10 make_migration(RBFNODE *from_rbf, RBFNODE *to_rbf)
629 greg 2.8 {
630     const double end_thresh = 0.02/(from_rbf->nrbf*to_rbf->nrbf);
631     float *pmtx = price_routes(from_rbf, to_rbf);
632     MIGRATION *newmig = (MIGRATION *)malloc(sizeof(MIGRATION) +
633     sizeof(float) *
634     (from_rbf->nrbf*to_rbf->nrbf - 1));
635     double *src_rem = (double *)malloc(sizeof(double)*from_rbf->nrbf);
636     double *dst_rem = (double *)malloc(sizeof(double)*to_rbf->nrbf);
637     double total_rem = 1.;
638     int i;
639    
640     if ((newmig == NULL) | (src_rem == NULL) | (dst_rem == NULL)) {
641     fputs("Out of memory in make_migration()\n", stderr);
642     exit(1);
643     }
644 greg 2.10 #ifdef DEBUG
645     {
646     double theta, phi;
647     theta = acos(from_rbf->invec[2])*(180./M_PI);
648     phi = atan2(from_rbf->invec[1],from_rbf->invec[0])*(180./M_PI);
649     fprintf(stderr, "Building path from (theta,phi) (%d,%d) to ",
650     round(theta), round(phi));
651     theta = acos(to_rbf->invec[2])*(180./M_PI);
652     phi = atan2(to_rbf->invec[1],to_rbf->invec[0])*(180./M_PI);
653 greg 2.13 fprintf(stderr, "(%d,%d)", round(theta), round(phi));
654 greg 2.10 }
655     #endif
656 greg 2.8 newmig->next = NULL;
657     newmig->rbfv[0] = from_rbf;
658     newmig->rbfv[1] = to_rbf;
659     newmig->enxt[0] = newmig->enxt[1] = NULL;
660     memset(newmig->mtx, 0, sizeof(float)*from_rbf->nrbf*to_rbf->nrbf);
661     /* starting quantities */
662     for (i = from_rbf->nrbf; i--; )
663     src_rem[i] = rbf_volume(&from_rbf->rbfa[i]) / from_rbf->vtotal;
664     for (i = to_rbf->nrbf; i--; )
665     dst_rem[i] = rbf_volume(&to_rbf->rbfa[i]) / to_rbf->vtotal;
666     /* move a bit at a time */
667 greg 2.13 while (total_rem > end_thresh) {
668 greg 2.8 total_rem -= migration_step(newmig, src_rem, dst_rem, pmtx);
669 greg 2.13 #ifdef DEBUG
670     fputc('.', stderr);
671     /*XXX*/break;
672     #endif
673     }
674     #ifdef DEBUG
675     fputs("done.\n", stderr);
676     #endif
677 greg 2.8
678     free(pmtx); /* free working arrays */
679     free(src_rem);
680     free(dst_rem);
681     for (i = from_rbf->nrbf; i--; ) { /* normalize final matrix */
682     float nf = rbf_volume(&from_rbf->rbfa[i]);
683     int j;
684     if (nf <= FTINY) continue;
685     nf = from_rbf->vtotal / nf;
686     for (j = to_rbf->nrbf; j--; )
687     newmig->mtx[mtx_ndx(newmig,i,j)] *= nf;
688     }
689     /* insert in edge lists */
690     newmig->enxt[0] = from_rbf->ejl;
691     from_rbf->ejl = newmig;
692     newmig->enxt[1] = to_rbf->ejl;
693     to_rbf->ejl = newmig;
694     newmig->next = mig_list;
695     return(mig_list = newmig);
696     }
697    
698 greg 2.10 /* Get triangle surface orientation (unnormalized) */
699     static void
700     tri_orient(FVECT vres, const FVECT v1, const FVECT v2, const FVECT v3)
701     {
702     FVECT v2minus1, v3minus2;
703    
704     VSUB(v2minus1, v2, v1);
705     VSUB(v3minus2, v3, v2);
706     VCROSS(vres, v2minus1, v3minus2);
707     }
708    
709     /* Determine if vertex order is reversed (inward normal) */
710     static int
711     is_rev_tri(const FVECT v1, const FVECT v2, const FVECT v3)
712     {
713     FVECT tor;
714    
715     tri_orient(tor, v1, v2, v3);
716    
717     return(DOT(tor, v2) < 0.);
718     }
719    
720     /* Find vertices completing triangles on either side of the given edge */
721     static int
722     get_triangles(RBFNODE *rbfv[2], const MIGRATION *mig)
723     {
724     const MIGRATION *ej, *ej2;
725     RBFNODE *tv;
726    
727     rbfv[0] = rbfv[1] = NULL;
728 greg 2.13 if (mig == NULL)
729     return(0);
730 greg 2.10 for (ej = mig->rbfv[0]->ejl; ej != NULL;
731     ej = nextedge(mig->rbfv[0],ej)) {
732     if (ej == mig)
733     continue;
734     tv = opp_rbf(mig->rbfv[0],ej);
735     for (ej2 = tv->ejl; ej2 != NULL; ej2 = nextedge(tv,ej2))
736     if (opp_rbf(tv,ej2) == mig->rbfv[1]) {
737     rbfv[is_rev_tri(mig->rbfv[0]->invec,
738     mig->rbfv[1]->invec,
739     tv->invec)] = tv;
740     break;
741     }
742     }
743     return((rbfv[0] != NULL) + (rbfv[1] != NULL));
744     }
745    
746 greg 2.13 /* Check if prospective vertex would create overlapping triangle */
747     static int
748     overlaps_tri(const RBFNODE *bv0, const RBFNODE *bv1, const RBFNODE *pv)
749     {
750     const MIGRATION *ej;
751     RBFNODE *vother[2];
752     int im_rev;
753     /* find shared edge in mesh */
754     for (ej = pv->ejl; ej != NULL; ej = nextedge(pv,ej)) {
755     const RBFNODE *tv = opp_rbf(pv,ej);
756     if (tv == bv0) {
757     im_rev = is_rev_tri(ej->rbfv[0]->invec,
758     ej->rbfv[1]->invec, bv1->invec);
759     break;
760     }
761     if (tv == bv1) {
762     im_rev = is_rev_tri(ej->rbfv[0]->invec,
763     ej->rbfv[1]->invec, bv0->invec);
764     break;
765     }
766     }
767     if (!get_triangles(vother, ej))
768     return(0);
769     return(vother[im_rev] != NULL);
770     }
771    
772 greg 2.10 /* Find context hull vertex to complete triangle (oriented call) */
773     static RBFNODE *
774     find_chull_vert(const RBFNODE *rbf0, const RBFNODE *rbf1)
775 greg 2.8 {
776 greg 2.10 FVECT vmid, vor;
777     RBFNODE *rbf, *rbfbest = NULL;
778 greg 2.13 double dprod2, area2, bestarea2 = FHUGE, bestdprod2 = 0.5;
779 greg 2.10
780     VADD(vmid, rbf0->invec, rbf1->invec);
781     if (normalize(vmid) == 0)
782     return(NULL);
783     /* XXX exhaustive search */
784     for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
785     if ((rbf == rbf0) | (rbf == rbf1))
786     continue;
787     tri_orient(vor, rbf0->invec, rbf1->invec, rbf->invec);
788     dprod2 = DOT(vor, vmid);
789     if (dprod2 <= FTINY)
790     continue; /* wrong orientation */
791 greg 2.13 area2 = DOT(vor, vor);
792     dprod2 *= dprod2 / area2;
793     if (dprod2 > bestdprod2 +
794     FTINY*(1 - 2*(area2 < bestarea2)) &&
795     !overlaps_tri(rbf0, rbf1, rbf)) {
796 greg 2.10 rbfbest = rbf;
797     bestdprod2 = dprod2;
798 greg 2.13 bestarea2 = area2;
799 greg 2.10 }
800     }
801 greg 2.13 return(rbfbest);
802 greg 2.10 }
803    
804     /* Create new migration edge and grow mesh recursively around it */
805     static void
806 greg 2.13 mesh_from_edge(MIGRATION *edge)
807 greg 2.10 {
808 greg 2.13 MIGRATION *ej0, *ej1;
809 greg 2.10 RBFNODE *tvert[2];
810     /* triangle on either side? */
811 greg 2.13 get_triangles(tvert, edge);
812     if (tvert[0] == NULL) { /* grow mesh on right */
813     tvert[0] = find_chull_vert(edge->rbfv[0], edge->rbfv[1]);
814 greg 2.10 if (tvert[0] != NULL) {
815 greg 2.13 if (tvert[0] > edge->rbfv[0])
816     ej0 = make_migration(edge->rbfv[0], tvert[0]);
817     else
818     ej0 = make_migration(tvert[0], edge->rbfv[0]);
819     if (tvert[0] > edge->rbfv[1])
820     ej1 = make_migration(edge->rbfv[1], tvert[0]);
821     else
822     ej1 = make_migration(tvert[0], edge->rbfv[1]);
823     mesh_from_edge(ej0);
824     mesh_from_edge(ej1);
825 greg 2.10 }
826     }
827 greg 2.13 if (tvert[1] == NULL) { /* grow mesh on left */
828     tvert[1] = find_chull_vert(edge->rbfv[1], edge->rbfv[0]);
829 greg 2.10 if (tvert[1] != NULL) {
830 greg 2.13 if (tvert[1] > edge->rbfv[0])
831     ej0 = make_migration(edge->rbfv[0], tvert[1]);
832     else
833     ej0 = make_migration(tvert[1], edge->rbfv[0]);
834     if (tvert[1] > edge->rbfv[1])
835     ej1 = make_migration(edge->rbfv[1], tvert[1]);
836     else
837     ej1 = make_migration(tvert[1], edge->rbfv[1]);
838     mesh_from_edge(ej0);
839     mesh_from_edge(ej1);
840 greg 2.10 }
841     }
842     }
843 greg 2.8
844 greg 2.13 #ifdef DEBUG
845     #include "random.h"
846     #include "bmpfile.h"
847     /* Hash pointer to byte value */
848     static int
849     byte_hash(const void *p)
850     {
851     size_t h = (size_t)p;
852     h ^= (size_t)p >> 8;
853     h ^= (size_t)p >> 16;
854     h ^= (size_t)p >> 24;
855     return(h & 0xff);
856     }
857     /* Write out BMP image showing edges */
858     static void
859     write_edge_image(const char *fname)
860     {
861     BMPHeader *hdr = BMPmappedHeader(GRIDRES, GRIDRES, 0, 256);
862     BMPWriter *wtr;
863     int i, j;
864    
865     fprintf(stderr, "Writing incident mesh drawing to '%s'\n", fname);
866     hdr->compr = BI_RLE8;
867     for (i = 256; --i; ) { /* assign random color map */
868     hdr->palette[i].r = random() & 0xff;
869     hdr->palette[i].r = random() & 0xff;
870     hdr->palette[i].r = random() & 0xff;
871     }
872     hdr->palette[0].r = hdr->palette[0].g = hdr->palette[0].b = 0;
873     /* open output */
874     wtr = BMPopenOutputFile(fname, hdr);
875     if (wtr == NULL) {
876     free(hdr);
877     return;
878     }
879     for (i = 0; i < GRIDRES; i++) { /* write scanlines */
880     for (j = 0; j < GRIDRES; j++)
881     wtr->scanline[j] = byte_hash(mig_grid[i][j]);
882     if (BMPwriteScanline(wtr) != BIR_OK)
883     break;
884     }
885     BMPcloseOutput(wtr); /* close & clean up */
886     }
887     #endif
888    
889 greg 2.10 /* Draw edge list into mig_grid array */
890     static void
891     draw_edges()
892     {
893     int nnull = 0, ntot = 0;
894     MIGRATION *ej;
895     int p0[2], p1[2];
896    
897     /* memset(mig_grid, 0, sizeof(mig_grid)); */
898     for (ej = mig_list; ej != NULL; ej = ej->next) {
899     ++ntot;
900     pos_from_vec(p0, ej->rbfv[0]->invec);
901     pos_from_vec(p1, ej->rbfv[1]->invec);
902     if ((p0[0] == p1[0]) & (p0[1] == p1[1])) {
903     ++nnull;
904     mig_grid[p0[0]][p0[1]] = ej;
905     continue;
906     }
907     if (abs(p1[0]-p0[0]) > abs(p1[1]-p0[1])) {
908     const int xstep = 2*(p1[0] > p0[0]) - 1;
909     const double ystep = (double)((p1[1]-p0[1])*xstep) /
910     (double)(p1[0]-p0[0]);
911     int x;
912     double y;
913     for (x = p0[0], y = p0[1]+.5; x != p1[0];
914     x += xstep, y += ystep)
915     mig_grid[x][(int)y] = ej;
916     mig_grid[x][(int)y] = ej;
917     } else {
918     const int ystep = 2*(p1[1] > p0[1]) - 1;
919     const double xstep = (double)((p1[0]-p0[0])*ystep) /
920     (double)(p1[1]-p0[1]);
921     int y;
922     double x;
923     for (y = p0[1], x = p0[0]+.5; y != p1[1];
924     y += ystep, x += xstep)
925     mig_grid[(int)x][y] = ej;
926     mig_grid[(int)x][y] = ej;
927     }
928     }
929     if (nnull)
930     fprintf(stderr, "Warning: %d of %d edges are null\n",
931     nnull, ntot);
932 greg 2.13 #ifdef DEBUG
933     write_edge_image("bsdf_edges.bmp");
934     #endif
935 greg 2.10 }
936    
937     /* Build our triangle mesh from recorded RBFs */
938     static void
939     build_mesh()
940     {
941     double best2 = M_PI*M_PI;
942 greg 2.13 RBFNODE *shrt_edj[2];
943     RBFNODE *rbf0, *rbf1;
944 greg 2.10 /* check if isotropic */
945     if (single_plane_incident) {
946 greg 2.13 for (rbf0 = dsf_list; rbf0 != NULL; rbf0 = rbf0->next)
947     if (rbf0->next != NULL)
948     make_migration(rbf0, rbf0->next);
949 greg 2.10 return;
950     }
951 greg 2.13 /* start w/ shortest edge */
952     shrt_edj[0] = shrt_edj[1] = NULL;
953     for (rbf0 = dsf_list; rbf0 != NULL; rbf0 = rbf0->next)
954     for (rbf1 = rbf0->next; rbf1 != NULL; rbf1 = rbf1->next) {
955     double dist2 = 2. - 2.*DOT(rbf0->invec,rbf1->invec);
956 greg 2.10 if (dist2 < best2) {
957 greg 2.13 shrt_edj[0] = rbf0;
958     shrt_edj[1] = rbf1;
959 greg 2.10 best2 = dist2;
960     }
961     }
962 greg 2.13 if (shrt_edj[0] == NULL) {
963     fputs("Cannot find shortest edge\n", stderr);
964 greg 2.8 exit(1);
965     }
966 greg 2.10 /* build mesh from this edge */
967 greg 2.13 if (shrt_edj[0] < shrt_edj[1])
968     mesh_from_edge(make_migration(shrt_edj[0], shrt_edj[1]));
969     else
970     mesh_from_edge(make_migration(shrt_edj[1], shrt_edj[0]));
971 greg 2.10 /* draw edge list into grid */
972     draw_edges();
973     }
974    
975     /* Identify enclosing triangle for this position (flood fill raster check) */
976     static int
977     identify_tri(MIGRATION *miga[3], unsigned char vmap[GRIDRES][(GRIDRES+7)/8],
978     int px, int py)
979     {
980     const int btest = 1<<(py&07);
981    
982     if (vmap[px][py>>3] & btest) /* already visited here? */
983     return(1);
984     /* else mark it */
985     vmap[px][py>>3] |= btest;
986    
987     if (mig_grid[px][py] != NULL) { /* are we on an edge? */
988     int i;
989     for (i = 0; i < 3; i++) {
990     if (miga[i] == mig_grid[px][py])
991     return(1);
992     if (miga[i] != NULL)
993     continue;
994     miga[i] = mig_grid[px][py];
995     return(1);
996     }
997     return(0); /* outside triangle! */
998     }
999     /* check neighbors (flood) */
1000     if (px > 0 && !identify_tri(miga, vmap, px-1, py))
1001     return(0);
1002     if (px < GRIDRES-1 && !identify_tri(miga, vmap, px+1, py))
1003     return(0);
1004     if (py > 0 && !identify_tri(miga, vmap, px, py-1))
1005     return(0);
1006     if (py < GRIDRES-1 && !identify_tri(miga, vmap, px, py+1))
1007     return(0);
1008     return(1); /* this neighborhood done */
1009     }
1010    
1011     /* Find edge(s) for interpolating the given incident vector */
1012     static int
1013     get_interp(MIGRATION *miga[3], const FVECT invec)
1014     {
1015     miga[0] = miga[1] = miga[2] = NULL;
1016     if (single_plane_incident) { /* isotropic BSDF? */
1017     RBFNODE *rbf; /* find edge we're on */
1018     for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
1019     if (input_orient*rbf->invec[2] < input_orient*invec[2])
1020     break;
1021     if (rbf->next != NULL &&
1022     input_orient*rbf->next->invec[2] <
1023     input_orient*invec[2]) {
1024     for (miga[0] = rbf->ejl; miga[0] != NULL;
1025     miga[0] = nextedge(rbf,miga[0]))
1026     if (opp_rbf(rbf,miga[0]) == rbf->next)
1027     return(1);
1028     break;
1029     }
1030     }
1031     return(0); /* outside range! */
1032     }
1033 greg 2.12 { /* else use triangle mesh */
1034 greg 2.10 unsigned char floodmap[GRIDRES][(GRIDRES+7)/8];
1035     int pstart[2];
1036    
1037     pos_from_vec(pstart, invec);
1038     memset(floodmap, 0, sizeof(floodmap));
1039     /* call flooding function */
1040     if (!identify_tri(miga, floodmap, pstart[0], pstart[1]))
1041     return(0); /* outside mesh */
1042     if ((miga[0] == NULL) | (miga[2] == NULL))
1043     return(0); /* should never happen */
1044     if (miga[1] == NULL)
1045     return(1); /* on edge */
1046     return(3); /* else in triangle */
1047     }
1048     }
1049    
1050     /* Advect and allocate new RBF along edge */
1051     static RBFNODE *
1052     e_advect_rbf(const MIGRATION *mig, const FVECT invec)
1053     {
1054     RBFNODE *rbf;
1055     int n, i, j;
1056     double t, full_dist;
1057     /* get relative position */
1058     t = acos(DOT(invec, mig->rbfv[0]->invec));
1059     if (t < M_PI/GRIDRES) { /* near first DSF */
1060     n = sizeof(RBFNODE) + sizeof(RBFVAL)*(mig->rbfv[0]->nrbf-1);
1061     rbf = (RBFNODE *)malloc(n);
1062     if (rbf == NULL)
1063     goto memerr;
1064     memcpy(rbf, mig->rbfv[0], n); /* just duplicate */
1065     return(rbf);
1066     }
1067     full_dist = acos(DOT(mig->rbfv[0]->invec, mig->rbfv[1]->invec));
1068     if (t > full_dist-M_PI/GRIDRES) { /* near second DSF */
1069     n = sizeof(RBFNODE) + sizeof(RBFVAL)*(mig->rbfv[1]->nrbf-1);
1070     rbf = (RBFNODE *)malloc(n);
1071     if (rbf == NULL)
1072     goto memerr;
1073     memcpy(rbf, mig->rbfv[1], n); /* just duplicate */
1074     return(rbf);
1075     }
1076     t /= full_dist;
1077     n = 0; /* count migrating particles */
1078     for (i = 0; i < mtx_nrows(mig); i++)
1079     for (j = 0; j < mtx_ncols(mig); j++)
1080     n += (mig->mtx[mtx_ndx(mig,i,j)] > FTINY);
1081 greg 2.12 #ifdef DEBUG
1082     fprintf(stderr, "Input RBFs have %d, %d nodes -> output has %d\n",
1083     mig->rbfv[0]->nrbf, mig->rbfv[1]->nrbf, n);
1084     #endif
1085 greg 2.10 rbf = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(n-1));
1086     if (rbf == NULL)
1087     goto memerr;
1088     rbf->next = NULL; rbf->ejl = NULL;
1089     VCOPY(rbf->invec, invec);
1090     rbf->nrbf = n;
1091     rbf->vtotal = 1.-t + t*mig->rbfv[1]->vtotal/mig->rbfv[0]->vtotal;
1092     n = 0; /* advect RBF lobes */
1093     for (i = 0; i < mtx_nrows(mig); i++) {
1094     const RBFVAL *rbf0i = &mig->rbfv[0]->rbfa[i];
1095     const float peak0 = rbf0i->peak;
1096     const double rad0 = R2ANG(rbf0i->crad);
1097     FVECT v0;
1098     float mv;
1099     ovec_from_pos(v0, rbf0i->gx, rbf0i->gy);
1100     for (j = 0; j < mtx_ncols(mig); j++)
1101     if ((mv = mig->mtx[mtx_ndx(mig,i,j)]) > FTINY) {
1102     const RBFVAL *rbf1j = &mig->rbfv[1]->rbfa[j];
1103     double rad1 = R2ANG(rbf1j->crad);
1104     FVECT v;
1105     int pos[2];
1106     rbf->rbfa[n].peak = peak0 * mv * rbf->vtotal;
1107     rbf->rbfa[n].crad = ANG2R(sqrt(rad0*rad0*(1.-t) +
1108     rad1*rad1*t));
1109     ovec_from_pos(v, rbf1j->gx, rbf1j->gy);
1110     geodesic(v, v0, v, t, GEOD_REL);
1111     pos_from_vec(pos, v);
1112     rbf->rbfa[n].gx = pos[0];
1113     rbf->rbfa[n].gy = pos[1];
1114     ++n;
1115     }
1116     }
1117     rbf->vtotal *= mig->rbfv[0]->vtotal; /* turn ratio into actual */
1118     return(rbf);
1119     memerr:
1120     fputs("Out of memory in e_advect_rbf()\n", stderr);
1121     exit(1);
1122     return(NULL); /* pro forma return */
1123     }
1124    
1125 greg 2.11 /* Insert vertex in ordered list */
1126     static void
1127     insert_vert(RBFNODE **vlist, RBFNODE *v)
1128     {
1129     int i, j;
1130    
1131     for (i = 0; vlist[i] != NULL; i++) {
1132     if (v == vlist[i])
1133     return;
1134     if (v < vlist[i])
1135     break;
1136     }
1137     for (j = i; vlist[j] != NULL; j++)
1138     ;
1139     while (j > i) {
1140     vlist[j] = vlist[j-1];
1141     --j;
1142     }
1143     vlist[i] = v;
1144     }
1145    
1146     /* Sort triangle edges in standard order */
1147     static void
1148     order_triangle(MIGRATION *miga[3])
1149     {
1150     RBFNODE *vert[4];
1151     MIGRATION *ord[3];
1152     int i;
1153     /* order vertices, first */
1154     memset(vert, 0, sizeof(vert));
1155     for (i = 0; i < 3; i++) {
1156     insert_vert(vert, miga[i]->rbfv[0]);
1157     insert_vert(vert, miga[i]->rbfv[1]);
1158     }
1159     /* identify edge 0 */
1160     for (i = 0; i < 3; i++)
1161     if (miga[i]->rbfv[0] == vert[0] &&
1162     miga[i]->rbfv[1] == vert[1]) {
1163     ord[0] = miga[i];
1164     break;
1165     }
1166     /* identify edge 1 */
1167     for (i = 0; i < 3; i++)
1168     if (miga[i]->rbfv[0] == vert[1] &&
1169     miga[i]->rbfv[1] == vert[2]) {
1170     ord[1] = miga[i];
1171     break;
1172     }
1173     /* identify edge 2 */
1174     for (i = 0; i < 3; i++)
1175     if (miga[i]->rbfv[0] == vert[0] &&
1176     miga[i]->rbfv[1] == vert[2]) {
1177     ord[2] = miga[i];
1178     break;
1179     }
1180     miga[0] = ord[0]; miga[1] = ord[1]; miga[2] = ord[2];
1181     }
1182    
1183 greg 2.10 /* Partially advect between recorded incident angles and allocate new RBF */
1184     static RBFNODE *
1185     advect_rbf(const FVECT invec)
1186     {
1187     MIGRATION *miga[3];
1188     RBFNODE *rbf;
1189 greg 2.11 float mbfact, mcfact;
1190     int n, i, j, k;
1191     FVECT v0, v1, v2;
1192 greg 2.10 double s, t;
1193    
1194     if (!get_interp(miga, invec)) /* can't interpolate? */
1195     return(NULL);
1196 greg 2.13 if (miga[1] == NULL) /* advect along edge? */
1197 greg 2.10 return(e_advect_rbf(miga[0], invec));
1198 greg 2.11 /* put in standard order */
1199     order_triangle(miga);
1200 greg 2.12 #ifdef DEBUG
1201     if (miga[0]->rbfv[0] != miga[2]->rbfv[0] |
1202     miga[0]->rbfv[1] != miga[1]->rbfv[0] |
1203     miga[1]->rbfv[1] != miga[2]->rbfv[1]) {
1204     fputs("Triangle vertex screw-up!\n", stderr);
1205     exit(1);
1206     }
1207     #endif
1208 greg 2.10 /* figure out position */
1209 greg 2.11 fcross(v0, miga[2]->rbfv[0]->invec, miga[2]->rbfv[1]->invec);
1210     normalize(v0);
1211     fcross(v2, miga[1]->rbfv[0]->invec, miga[1]->rbfv[1]->invec);
1212     normalize(v2);
1213     fcross(v1, invec, miga[1]->rbfv[1]->invec);
1214     normalize(v1);
1215     s = acos(DOT(v0,v1)) / acos(DOT(v0,v2));
1216     geodesic(v1, miga[0]->rbfv[0]->invec, miga[0]->rbfv[1]->invec,
1217     s, GEOD_REL);
1218     t = acos(DOT(v1,invec)) / acos(DOT(v1,miga[1]->rbfv[1]->invec));
1219     n = 0; /* count migrating particles */
1220     for (i = 0; i < mtx_nrows(miga[0]); i++)
1221     for (j = 0; j < mtx_ncols(miga[0]); j++)
1222     for (k = (miga[0]->mtx[mtx_ndx(miga[0],i,j)] > FTINY) *
1223     mtx_ncols(miga[2]); k--; )
1224     n += (miga[2]->mtx[mtx_ndx(miga[2],i,k)] > FTINY &&
1225     miga[1]->mtx[mtx_ndx(miga[1],j,k)] > FTINY);
1226 greg 2.12 #ifdef DEBUG
1227     fprintf(stderr, "Input RBFs have %d, %d, %d nodes -> output has %d\n",
1228     miga[0]->rbfv[0]->nrbf, miga[0]->rbfv[1]->nrbf,
1229     miga[2]->rbfv[1]->nrbf, n);
1230     #endif
1231 greg 2.10 rbf = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(n-1));
1232 greg 2.8 if (rbf == NULL) {
1233     fputs("Out of memory in advect_rbf()\n", stderr);
1234     exit(1);
1235     }
1236     rbf->next = NULL; rbf->ejl = NULL;
1237     VCOPY(rbf->invec, invec);
1238 greg 2.10 rbf->nrbf = n;
1239 greg 2.11 n = 0; /* compute RBF lobes */
1240     mbfact = s * miga[0]->rbfv[1]->vtotal/miga[0]->rbfv[0]->vtotal *
1241     (1.-t + t*miga[1]->rbfv[1]->vtotal/miga[1]->rbfv[0]->vtotal);
1242     mcfact = (1.-s) *
1243     (1.-t + t*miga[2]->rbfv[1]->vtotal/miga[2]->rbfv[0]->vtotal);
1244     for (i = 0; i < mtx_nrows(miga[0]); i++) {
1245     const RBFVAL *rbf0i = &miga[0]->rbfv[0]->rbfa[i];
1246     const float w0i = rbf0i->peak;
1247     const double rad0i = R2ANG(rbf0i->crad);
1248     ovec_from_pos(v0, rbf0i->gx, rbf0i->gy);
1249     for (j = 0; j < mtx_ncols(miga[0]); j++) {
1250     const float ma = miga[0]->mtx[mtx_ndx(miga[0],i,j)];
1251     const RBFVAL *rbf1j;
1252     double rad1j, srad2;
1253     if (ma <= FTINY)
1254     continue;
1255     rbf1j = &miga[0]->rbfv[1]->rbfa[j];
1256     rad1j = R2ANG(rbf1j->crad);
1257     srad2 = (1.-s)*(1.-t)*rad0i*rad0i + s*(1.-t)*rad1j*rad1j;
1258     ovec_from_pos(v1, rbf1j->gx, rbf1j->gy);
1259     geodesic(v1, v0, v1, s, GEOD_REL);
1260     for (k = 0; k < mtx_ncols(miga[2]); k++) {
1261     float mb = miga[1]->mtx[mtx_ndx(miga[1],j,k)];
1262     float mc = miga[2]->mtx[mtx_ndx(miga[2],i,k)];
1263     const RBFVAL *rbf2k;
1264     double rad2k;
1265     FVECT vout;
1266     int pos[2];
1267     if ((mb <= FTINY) | (mc <= FTINY))
1268     continue;
1269     rbf2k = &miga[2]->rbfv[1]->rbfa[k];
1270     rbf->rbfa[n].peak = w0i * ma * (mb*mbfact + mc*mcfact);
1271     rad2k = R2ANG(rbf2k->crad);
1272 greg 2.12 rbf->rbfa[n].crad = ANG2R(sqrt(srad2 + t*rad2k*rad2k));
1273 greg 2.11 ovec_from_pos(v2, rbf2k->gx, rbf2k->gy);
1274     geodesic(vout, v1, v2, t, GEOD_REL);
1275     pos_from_vec(pos, vout);
1276     rbf->rbfa[n].gx = pos[0];
1277     rbf->rbfa[n].gy = pos[1];
1278     ++n;
1279     }
1280     }
1281     }
1282     rbf->vtotal = miga[0]->rbfv[0]->vtotal * (mbfact + mcfact);
1283 greg 2.10 return(rbf);
1284 greg 2.8 }
1285 greg 2.1
1286 greg 2.12 /* Interpolate and output isotropic BSDF data */
1287     static void
1288     interp_isotropic()
1289     {
1290     const int sqres = 1<<samp_order;
1291     FILE *ofp = NULL;
1292     char cmd[128];
1293     int ix, ox, oy;
1294     FVECT ivec, ovec;
1295     double bsdf;
1296 greg 2.13 #if DEBUG
1297     fprintf(stderr, "Writing isotropic order %d ", samp_order);
1298     if (pctcull >= 0) fprintf(stderr, "data with %d%% culling\n", pctcull);
1299     else fputs("raw data\n", stderr);
1300     #endif
1301 greg 2.12 if (pctcull >= 0) { /* begin output */
1302     sprintf(cmd, "rttree_reduce -h -a -fd -r 3 -t %d -g %d",
1303     pctcull, samp_order);
1304     fflush(stdout);
1305     ofp = popen(cmd, "w");
1306     if (ofp == NULL) {
1307     fputs("Cannot create pipe for rttree_reduce\n", stderr);
1308     exit(1);
1309     }
1310     } else
1311     fputs("{\n", stdout);
1312     /* run through directions */
1313     for (ix = 0; ix < sqres/2; ix++) {
1314     RBFNODE *rbf;
1315     SDsquare2disk(ivec, (ix+.5)/sqres, .5);
1316     ivec[2] = input_orient *
1317     sqrt(1. - ivec[0]*ivec[0] - ivec[1]*ivec[1]);
1318     rbf = advect_rbf(ivec);
1319     for (ox = 0; ox < sqres; ox++)
1320     for (oy = 0; oy < sqres; oy++) {
1321     SDsquare2disk(ovec, (ox+.5)/sqres, (oy+.5)/sqres);
1322     ovec[2] = output_orient *
1323     sqrt(1. - ovec[0]*ovec[0] - ovec[1]*ovec[1]);
1324     bsdf = eval_rbfrep(rbf, ovec) / fabs(ovec[2]);
1325     if (pctcull >= 0)
1326     fwrite(&bsdf, sizeof(bsdf), 1, ofp);
1327     else
1328     printf("\t%.3e\n", bsdf);
1329     }
1330     free(rbf);
1331     }
1332     if (pctcull >= 0) { /* finish output */
1333     if (pclose(ofp)) {
1334     fprintf(stderr, "Error running '%s'\n", cmd);
1335     exit(1);
1336     }
1337     } else {
1338     for (ix = sqres*sqres*sqres/2; ix--; )
1339     fputs("\t0\n", stdout);
1340     fputs("}\n", stdout);
1341     }
1342     }
1343    
1344     /* Interpolate and output anisotropic BSDF data */
1345     static void
1346     interp_anisotropic()
1347     {
1348     const int sqres = 1<<samp_order;
1349     FILE *ofp = NULL;
1350     char cmd[128];
1351     int ix, iy, ox, oy;
1352     FVECT ivec, ovec;
1353     double bsdf;
1354 greg 2.13 #if DEBUG
1355     fprintf(stderr, "Writing anisotropic order %d ", samp_order);
1356     if (pctcull >= 0) fprintf(stderr, "data with %d%% culling\n", pctcull);
1357     else fputs("raw data\n", stderr);
1358     #endif
1359 greg 2.12 if (pctcull >= 0) { /* begin output */
1360     sprintf(cmd, "rttree_reduce -h -a -fd -r 4 -t %d -g %d",
1361     pctcull, samp_order);
1362     fflush(stdout);
1363     ofp = popen(cmd, "w");
1364     if (ofp == NULL) {
1365     fputs("Cannot create pipe for rttree_reduce\n", stderr);
1366     exit(1);
1367     }
1368     } else
1369     fputs("{\n", stdout);
1370     /* run through directions */
1371     for (ix = 0; ix < sqres; ix++)
1372     for (iy = 0; iy < sqres; iy++) {
1373     RBFNODE *rbf;
1374     SDsquare2disk(ivec, (ix+.5)/sqres, (iy+.5)/sqres);
1375     ivec[2] = input_orient *
1376     sqrt(1. - ivec[0]*ivec[0] - ivec[1]*ivec[1]);
1377     rbf = advect_rbf(ivec);
1378     for (ox = 0; ox < sqres; ox++)
1379     for (oy = 0; oy < sqres; oy++) {
1380     SDsquare2disk(ovec, (ox+.5)/sqres, (oy+.5)/sqres);
1381     ovec[2] = output_orient *
1382     sqrt(1. - ovec[0]*ovec[0] - ovec[1]*ovec[1]);
1383     bsdf = eval_rbfrep(rbf, ovec) / fabs(ovec[2]);
1384     if (pctcull >= 0)
1385     fwrite(&bsdf, sizeof(bsdf), 1, ofp);
1386     else
1387     printf("\t%.3e\n", bsdf);
1388     }
1389     free(rbf);
1390     }
1391     if (pctcull >= 0) { /* finish output */
1392     if (pclose(ofp)) {
1393     fprintf(stderr, "Error running '%s'\n", cmd);
1394     exit(1);
1395     }
1396     } else
1397     fputs("}\n", stdout);
1398     }
1399    
1400 greg 2.1 #if 1
1401 greg 2.12 /* Read in BSDF files and interpolate as tensor tree representation */
1402     int
1403     main(int argc, char *argv[])
1404     {
1405     RBFNODE *rbf;
1406     double bsdf;
1407     int i;
1408    
1409     progname = argv[0];
1410     if (argc > 2 && !strcmp(argv[1], "-t")) {
1411     pctcull = atoi(argv[2]);
1412     argv += 2; argc -= 2;
1413     }
1414     if (argc < 3) {
1415     fprintf(stderr,
1416     "Usage: %s [-t pctcull] meas1.dat meas2.dat .. > bsdf.xml\n",
1417     progname);
1418     return(1);
1419     }
1420     for (i = 1; i < argc; i++) { /* compile measurements */
1421     if (!load_pabopto_meas(argv[i]))
1422     return(1);
1423     compute_radii();
1424     cull_values();
1425     make_rbfrep();
1426     }
1427     build_mesh(); /* create interpolation */
1428     /* xml_prologue(); /* start XML output */
1429     if (single_plane_incident) /* resample dist. */
1430     interp_isotropic();
1431     else
1432     interp_anisotropic();
1433     /* xml_epilogue(); /* finish XML output */
1434     return(0);
1435     }
1436     #else
1437 greg 2.1 /* Test main produces a Radiance model from the given input file */
1438     int
1439     main(int argc, char *argv[])
1440     {
1441     char buf[128];
1442     FILE *pfp;
1443     double bsdf;
1444     FVECT dir;
1445     int i, j, n;
1446    
1447     if (argc != 2) {
1448     fprintf(stderr, "Usage: %s input.dat > output.rad\n", argv[0]);
1449     return(1);
1450     }
1451 greg 2.10 if (!load_pabopto_meas(argv[1]))
1452 greg 2.1 return(1);
1453    
1454     compute_radii();
1455     cull_values();
1456 greg 2.3 make_rbfrep();
1457     /* produce spheres at meas. */
1458     puts("void plastic yellow\n0\n0\n5 .6 .4 .01 .04 .08\n");
1459 greg 2.1 puts("void plastic pink\n0\n0\n5 .5 .05 .9 .04 .08\n");
1460     n = 0;
1461     for (i = 0; i < GRIDRES; i++)
1462     for (j = 0; j < GRIDRES; j++)
1463 greg 2.5 if (dsf_grid[i][j].vsum > .0f) {
1464 greg 2.10 ovec_from_pos(dir, i, j);
1465 greg 2.5 bsdf = dsf_grid[i][j].vsum / dir[2];
1466     if (dsf_grid[i][j].nval) {
1467 greg 2.3 printf("pink cone c%04d\n0\n0\n8\n", ++n);
1468     printf("\t%.6g %.6g %.6g\n",
1469 greg 2.1 dir[0]*bsdf, dir[1]*bsdf, dir[2]*bsdf);
1470 greg 2.3 printf("\t%.6g %.6g %.6g\n",
1471 greg 2.1 dir[0]*(bsdf+.005), dir[1]*(bsdf+.005),
1472     dir[2]*(bsdf+.005));
1473 greg 2.3 puts("\t.003\t0\n");
1474     } else {
1475 greg 2.10 ovec_from_pos(dir, i, j);
1476 greg 2.3 printf("yellow sphere s%04d\n0\n0\n", ++n);
1477     printf("4 %.6g %.6g %.6g .0015\n\n",
1478     dir[0]*bsdf, dir[1]*bsdf, dir[2]*bsdf);
1479     }
1480 greg 2.1 }
1481     /* output continuous surface */
1482     puts("void trans tgreen\n0\n0\n7 .7 1 .7 .04 .04 .9 .9\n");
1483     fflush(stdout);
1484 greg 2.5 sprintf(buf, "gensurf tgreen bsdf - - - %d %d", GRIDRES-1, GRIDRES-1);
1485 greg 2.1 pfp = popen(buf, "w");
1486     if (pfp == NULL) {
1487     fputs(buf, stderr);
1488     fputs(": cannot start command\n", stderr);
1489     return(1);
1490     }
1491     for (i = 0; i < GRIDRES; i++)
1492     for (j = 0; j < GRIDRES; j++) {
1493 greg 2.10 ovec_from_pos(dir, i, j);
1494 greg 2.5 bsdf = eval_rbfrep(dsf_list, dir) / dir[2];
1495 greg 2.1 fprintf(pfp, "%.8e %.8e %.8e\n",
1496     dir[0]*bsdf, dir[1]*bsdf, dir[2]*bsdf);
1497     }
1498     return(pclose(pfp)==0 ? 0 : 1);
1499     }
1500     #endif