| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: bsdfmesh.c,v 2.32 2014/08/21 19:31:23 greg Exp $"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Create BSDF advection mesh from radial basis functions. |
| 6 |
* |
| 7 |
* G. Ward |
| 8 |
*/ |
| 9 |
|
| 10 |
#ifndef _WIN32 |
| 11 |
#include <unistd.h> |
| 12 |
#include <sys/wait.h> |
| 13 |
#include <sys/mman.h> |
| 14 |
#endif |
| 15 |
#define _USE_MATH_DEFINES |
| 16 |
#include <stdio.h> |
| 17 |
#include <stdlib.h> |
| 18 |
#include <string.h> |
| 19 |
#include <math.h> |
| 20 |
#include "bsdfrep.h" |
| 21 |
|
| 22 |
#ifndef NEIGH_FACT2 |
| 23 |
#define NEIGH_FACT2 0.1 /* empirical neighborhood distance weight */ |
| 24 |
#endif |
| 25 |
/* number of processes to run */ |
| 26 |
int nprocs = 1; |
| 27 |
/* number of children (-1 in child) */ |
| 28 |
static int nchild = 0; |
| 29 |
|
| 30 |
/* Compute average DSF value at the given radius from central vector */ |
| 31 |
static double |
| 32 |
eval_DSFsurround(const RBFNODE *rbf, const FVECT outvec, const double rad) |
| 33 |
{ |
| 34 |
const int ninc = 12; |
| 35 |
const double phinc = 2.*M_PI/ninc; |
| 36 |
double sum = 0; |
| 37 |
int n = 0; |
| 38 |
FVECT tvec; |
| 39 |
int i; |
| 40 |
/* compute initial vector */ |
| 41 |
if (output_orient*outvec[2] >= 1.-FTINY) { |
| 42 |
tvec[0] = tvec[2] = 0; |
| 43 |
tvec[1] = 1; |
| 44 |
} else { |
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tvec[0] = tvec[1] = 0; |
| 46 |
tvec[2] = 1; |
| 47 |
} |
| 48 |
geodesic(tvec, outvec, tvec, rad, GEOD_RAD); |
| 49 |
/* average surrounding DSF */ |
| 50 |
for (i = 0; i < ninc; i++) { |
| 51 |
if (i) spinvector(tvec, tvec, outvec, phinc); |
| 52 |
if (tvec[2] > 0 ^ output_orient > 0) |
| 53 |
continue; |
| 54 |
sum += eval_rbfrep(rbf, tvec) * COSF(tvec[2]); |
| 55 |
++n; |
| 56 |
} |
| 57 |
if (n < 2) /* should never happen! */ |
| 58 |
return(sum); |
| 59 |
return(sum/(double)n); |
| 60 |
} |
| 61 |
|
| 62 |
/* Estimate single-lobe radius for DSF at the given outgoing angle */ |
| 63 |
static double |
| 64 |
est_DSFrad(const RBFNODE *rbf, const FVECT outvec) |
| 65 |
{ |
| 66 |
const double rad_epsilon = 0.03; |
| 67 |
const double DSFtarget = 0.60653066 * eval_rbfrep(rbf,outvec) * |
| 68 |
COSF(outvec[2]); |
| 69 |
double inside_rad = rad_epsilon; |
| 70 |
double outside_rad = 0.5; |
| 71 |
double DSFinside = eval_DSFsurround(rbf, outvec, inside_rad); |
| 72 |
double DSFoutside = eval_DSFsurround(rbf, outvec, outside_rad); |
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#define interp_rad inside_rad + (outside_rad-inside_rad) * \ |
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(DSFtarget-DSFinside) / (DSFoutside-DSFinside) |
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/* Newton's method (sort of) */ |
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do { |
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double test_rad = interp_rad; |
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double DSFtest; |
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if (test_rad >= outside_rad) |
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return(test_rad); |
| 81 |
if (test_rad <= inside_rad) |
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return(test_rad*(test_rad>0)); |
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DSFtest = eval_DSFsurround(rbf, outvec, test_rad); |
| 84 |
if (DSFtest > DSFtarget) { |
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inside_rad = test_rad; |
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DSFinside = DSFtest; |
| 87 |
} else { |
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outside_rad = test_rad; |
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DSFoutside = DSFtest; |
| 90 |
} |
| 91 |
if (DSFoutside >= DSFinside) |
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return(test_rad); |
| 93 |
} while (outside_rad-inside_rad > rad_epsilon); |
| 94 |
return(interp_rad); |
| 95 |
#undef interp_rad |
| 96 |
} |
| 97 |
|
| 98 |
/* Compute average BSDF peak from current DSF's */ |
| 99 |
static void |
| 100 |
comp_bsdf_spec(void) |
| 101 |
{ |
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double peak_sum = 0; |
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double rad_sum = 0; |
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int n = 0; |
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RBFNODE *rbf; |
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FVECT sdv; |
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|
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if (dsf_list == NULL) { |
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bsdf_spec_peak = 0; |
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bsdf_spec_rad = 0; |
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return; |
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} |
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for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) { |
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sdv[0] = -rbf->invec[0]; |
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sdv[1] = -rbf->invec[1]; |
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sdv[2] = rbf->invec[2]*(2*(input_orient==output_orient) - 1); |
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peak_sum += eval_rbfrep(rbf, sdv); |
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rad_sum += est_DSFrad(rbf, sdv); |
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++n; |
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} |
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bsdf_spec_peak = peak_sum/(double)n; |
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bsdf_spec_rad = rad_sum/(double)n; |
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} |
| 124 |
|
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/* Create a new migration holder (sharing memory for multiprocessing) */ |
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static MIGRATION * |
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new_migration(RBFNODE *from_rbf, RBFNODE *to_rbf) |
| 128 |
{ |
| 129 |
size_t memlen = sizeof(MIGRATION) + |
| 130 |
sizeof(float)*(from_rbf->nrbf*to_rbf->nrbf - 1); |
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MIGRATION *newmig; |
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#ifdef _WIN32 |
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if (nprocs > 1) |
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fprintf(stderr, "%s: warning - multiprocessing not supported\n", |
| 135 |
progname); |
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nprocs = 1; |
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newmig = (MIGRATION *)malloc(memlen); |
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#else |
| 139 |
if (nprocs <= 1) { /* single process? */ |
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newmig = (MIGRATION *)malloc(memlen); |
| 141 |
} else { /* else need to share memory */ |
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newmig = (MIGRATION *)mmap(NULL, memlen, PROT_READ|PROT_WRITE, |
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MAP_ANON|MAP_SHARED, -1, 0); |
| 144 |
if ((void *)newmig == MAP_FAILED) |
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newmig = NULL; |
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} |
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#endif |
| 148 |
if (newmig == NULL) { |
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fprintf(stderr, "%s: cannot allocate new migration\n", progname); |
| 150 |
exit(1); |
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} |
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newmig->rbfv[0] = from_rbf; |
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newmig->rbfv[1] = to_rbf; |
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/* insert in edge lists */ |
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newmig->enxt[0] = from_rbf->ejl; |
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from_rbf->ejl = newmig; |
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newmig->enxt[1] = to_rbf->ejl; |
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to_rbf->ejl = newmig; |
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newmig->next = mig_list; /* push onto global list */ |
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return(mig_list = newmig); |
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} |
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|
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#ifdef _WIN32 |
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#define await_children(n) (void)(n) |
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#define run_subprocess() 0 |
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#define end_subprocess() (void)0 |
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#else |
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|
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/* Wait for the specified number of child processes to complete */ |
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static void |
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await_children(int n) |
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{ |
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int exit_status = 0; |
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|
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if (n > nchild) |
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n = nchild; |
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while (n-- > 0) { |
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int status; |
| 179 |
if (wait(&status) < 0) { |
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fprintf(stderr, "%s: missing child(ren)!\n", progname); |
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nchild = 0; |
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break; |
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} |
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--nchild; |
| 185 |
if (status) { /* something wrong */ |
| 186 |
if ((status = WEXITSTATUS(status))) |
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exit_status = status; |
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else |
| 189 |
exit_status += !exit_status; |
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fprintf(stderr, "%s: subprocess died\n", progname); |
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n = nchild; /* wait for the rest */ |
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} |
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} |
| 194 |
if (exit_status) |
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exit(exit_status); |
| 196 |
} |
| 197 |
|
| 198 |
/* Start child process if multiprocessing selected */ |
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static pid_t |
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run_subprocess(void) |
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{ |
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int status; |
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pid_t pid; |
| 204 |
|
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if (nprocs <= 1) /* any children requested? */ |
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return(0); |
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await_children(nchild + 1 - nprocs); /* free up child process */ |
| 208 |
if ((pid = fork())) { |
| 209 |
if (pid < 0) { |
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fprintf(stderr, "%s: cannot fork subprocess\n", |
| 211 |
progname); |
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await_children(nchild); |
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exit(1); |
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} |
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++nchild; /* subprocess started */ |
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return(pid); |
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} |
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nchild = -1; |
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return(0); /* put child to work */ |
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} |
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|
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/* If we are in subprocess, call exit */ |
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#define end_subprocess() if (nchild < 0) _exit(0); else |
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|
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#endif /* ! _WIN32 */ |
| 226 |
|
| 227 |
/* Compute normalized distribution scattering functions for comparison */ |
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static void |
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compute_nDSFs(const RBFNODE *rbf0, const RBFNODE *rbf1) |
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{ |
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const double nf0 = (GRIDRES*GRIDRES) / rbf0->vtotal; |
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const double nf1 = (GRIDRES*GRIDRES) / rbf1->vtotal; |
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int x, y; |
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FVECT dv; |
| 235 |
|
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for (x = GRIDRES; x--; ) |
| 237 |
for (y = GRIDRES; y--; ) { |
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ovec_from_pos(dv, x, y); /* cube root (brightness) */ |
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dsf_grid[x][y].val[0] = pow(nf0*eval_rbfrep(rbf0, dv), .3333); |
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dsf_grid[x][y].val[1] = pow(nf1*eval_rbfrep(rbf1, dv), .3333); |
| 241 |
} |
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} |
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|
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/* Compute neighborhood distance-squared (dissimilarity) */ |
| 245 |
static double |
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neighborhood_dist2(int x0, int y0, int x1, int y1) |
| 247 |
{ |
| 248 |
int rad = GRIDRES>>5; |
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double sum2 = 0.; |
| 250 |
double d; |
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int p[4]; |
| 252 |
int i, j; |
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/* check radius */ |
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p[0] = x0; p[1] = y0; p[2] = x1; p[3] = y1; |
| 255 |
for (i = 4; i--; ) { |
| 256 |
if (p[i] < rad) rad = p[i]; |
| 257 |
if (GRIDRES-1-p[i] < rad) rad = GRIDRES-1-p[i]; |
| 258 |
} |
| 259 |
for (i = -rad; i <= rad; i++) |
| 260 |
for (j = -rad; j <= rad; j++) { |
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d = dsf_grid[x0+i][y0+j].val[0] - |
| 262 |
dsf_grid[x1+i][y1+j].val[1]; |
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sum2 += d*d; |
| 264 |
} |
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return(sum2 / (4*rad*(rad+1) + 1)); |
| 266 |
} |
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|
| 268 |
/* Compute distance between two RBF lobes */ |
| 269 |
double |
| 270 |
lobe_distance(RBFVAL *rbf1, RBFVAL *rbf2) |
| 271 |
{ |
| 272 |
FVECT vfrom, vto; |
| 273 |
double d, res; |
| 274 |
/* quadratic cost function */ |
| 275 |
ovec_from_pos(vfrom, rbf1->gx, rbf1->gy); |
| 276 |
ovec_from_pos(vto, rbf2->gx, rbf2->gy); |
| 277 |
d = Acos(DOT(vfrom, vto)); |
| 278 |
res = d*d; |
| 279 |
d = R2ANG(rbf2->crad) - R2ANG(rbf1->crad); |
| 280 |
res += d*d; |
| 281 |
/* neighborhood difference */ |
| 282 |
res += NEIGH_FACT2 * neighborhood_dist2( rbf1->gx, rbf1->gy, |
| 283 |
rbf2->gx, rbf2->gy ); |
| 284 |
return(res); |
| 285 |
} |
| 286 |
|
| 287 |
|
| 288 |
/* Compute and insert migration along directed edge (may fork child) */ |
| 289 |
static MIGRATION * |
| 290 |
create_migration(RBFNODE *from_rbf, RBFNODE *to_rbf) |
| 291 |
{ |
| 292 |
MIGRATION *newmig; |
| 293 |
int i, j; |
| 294 |
/* check if exists already */ |
| 295 |
for (newmig = from_rbf->ejl; newmig != NULL; |
| 296 |
newmig = nextedge(from_rbf,newmig)) |
| 297 |
if (newmig->rbfv[1] == to_rbf) |
| 298 |
return(NULL); |
| 299 |
/* else allocate */ |
| 300 |
#ifdef DEBUG |
| 301 |
fprintf(stderr, "Building path from (theta,phi) (%.1f,%.1f) ", |
| 302 |
get_theta180(from_rbf->invec), |
| 303 |
get_phi360(from_rbf->invec)); |
| 304 |
fprintf(stderr, "to (%.1f,%.1f) with %d x %d matrix\n", |
| 305 |
get_theta180(to_rbf->invec), |
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get_phi360(to_rbf->invec), |
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from_rbf->nrbf, to_rbf->nrbf); |
| 308 |
#endif |
| 309 |
newmig = new_migration(from_rbf, to_rbf); |
| 310 |
if (run_subprocess()) |
| 311 |
return(newmig); /* child continues */ |
| 312 |
|
| 313 |
/* compute transport plan */ |
| 314 |
compute_nDSFs(from_rbf, to_rbf); |
| 315 |
plan_transport(newmig); |
| 316 |
|
| 317 |
for (i = from_rbf->nrbf; i--; ) { /* normalize final matrix */ |
| 318 |
double nf = rbf_volume(&from_rbf->rbfa[i]); |
| 319 |
if (nf <= FTINY) continue; |
| 320 |
nf = from_rbf->vtotal / nf; |
| 321 |
for (j = to_rbf->nrbf; j--; ) |
| 322 |
mtx_coef(newmig,i,j) *= nf; /* row now sums to 1.0 */ |
| 323 |
} |
| 324 |
end_subprocess(); /* exit here if subprocess */ |
| 325 |
return(newmig); |
| 326 |
} |
| 327 |
|
| 328 |
/* Check if prospective vertex would create overlapping triangle */ |
| 329 |
static int |
| 330 |
overlaps_tri(const RBFNODE *bv0, const RBFNODE *bv1, const RBFNODE *pv) |
| 331 |
{ |
| 332 |
const MIGRATION *ej; |
| 333 |
RBFNODE *vother[2]; |
| 334 |
int im_rev; |
| 335 |
/* find shared edge in mesh */ |
| 336 |
for (ej = pv->ejl; ej != NULL; ej = nextedge(pv,ej)) { |
| 337 |
const RBFNODE *tv = opp_rbf(pv,ej); |
| 338 |
if (tv == bv0) { |
| 339 |
im_rev = is_rev_tri(ej->rbfv[0]->invec, |
| 340 |
ej->rbfv[1]->invec, bv1->invec); |
| 341 |
break; |
| 342 |
} |
| 343 |
if (tv == bv1) { |
| 344 |
im_rev = is_rev_tri(ej->rbfv[0]->invec, |
| 345 |
ej->rbfv[1]->invec, bv0->invec); |
| 346 |
break; |
| 347 |
} |
| 348 |
} |
| 349 |
if (!get_triangles(vother, ej)) /* triangle on same side? */ |
| 350 |
return(0); |
| 351 |
return(vother[im_rev] != NULL); |
| 352 |
} |
| 353 |
|
| 354 |
/* Find convex hull vertex to complete triangle (oriented call) */ |
| 355 |
static RBFNODE * |
| 356 |
find_chull_vert(const RBFNODE *rbf0, const RBFNODE *rbf1) |
| 357 |
{ |
| 358 |
FVECT vmid, vejn, vp; |
| 359 |
RBFNODE *rbf, *rbfbest = NULL; |
| 360 |
double dprod, area2, bestarea2 = FHUGE, bestdprod = -.5; |
| 361 |
|
| 362 |
VSUB(vejn, rbf1->invec, rbf0->invec); |
| 363 |
VADD(vmid, rbf0->invec, rbf1->invec); |
| 364 |
if (normalize(vejn) == 0 || normalize(vmid) == 0) |
| 365 |
return(NULL); |
| 366 |
/* XXX exhaustive search */ |
| 367 |
/* Find triangle with minimum rotation from perpendicular */ |
| 368 |
for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) { |
| 369 |
if ((rbf == rbf0) | (rbf == rbf1)) |
| 370 |
continue; |
| 371 |
tri_orient(vp, rbf0->invec, rbf1->invec, rbf->invec); |
| 372 |
if (DOT(vp, vmid) <= FTINY) |
| 373 |
continue; /* wrong orientation */ |
| 374 |
area2 = .25*DOT(vp,vp); |
| 375 |
VSUB(vp, rbf->invec, vmid); |
| 376 |
dprod = -DOT(vp, vejn); |
| 377 |
VSUM(vp, vp, vejn, dprod); /* above guarantees non-zero */ |
| 378 |
dprod = DOT(vp, vmid) / VLEN(vp); |
| 379 |
if (dprod <= bestdprod + FTINY*(1 - 2*(area2 < bestarea2))) |
| 380 |
continue; /* found better already */ |
| 381 |
if (overlaps_tri(rbf0, rbf1, rbf)) |
| 382 |
continue; /* overlaps another triangle */ |
| 383 |
rbfbest = rbf; |
| 384 |
bestdprod = dprod; /* new one to beat */ |
| 385 |
bestarea2 = area2; |
| 386 |
} |
| 387 |
return(rbfbest); |
| 388 |
} |
| 389 |
|
| 390 |
/* Create new migration edge and grow mesh recursively around it */ |
| 391 |
static void |
| 392 |
mesh_from_edge(MIGRATION *edge) |
| 393 |
{ |
| 394 |
MIGRATION *ej0, *ej1; |
| 395 |
RBFNODE *tvert[2]; |
| 396 |
|
| 397 |
if (edge == NULL) |
| 398 |
return; |
| 399 |
/* triangle on either side? */ |
| 400 |
get_triangles(tvert, edge); |
| 401 |
if (tvert[0] == NULL) { /* grow mesh on right */ |
| 402 |
tvert[0] = find_chull_vert(edge->rbfv[0], edge->rbfv[1]); |
| 403 |
if (tvert[0] != NULL) { |
| 404 |
if (tvert[0]->ord > edge->rbfv[0]->ord) |
| 405 |
ej0 = create_migration(edge->rbfv[0], tvert[0]); |
| 406 |
else |
| 407 |
ej0 = create_migration(tvert[0], edge->rbfv[0]); |
| 408 |
if (tvert[0]->ord > edge->rbfv[1]->ord) |
| 409 |
ej1 = create_migration(edge->rbfv[1], tvert[0]); |
| 410 |
else |
| 411 |
ej1 = create_migration(tvert[0], edge->rbfv[1]); |
| 412 |
mesh_from_edge(ej0); |
| 413 |
mesh_from_edge(ej1); |
| 414 |
return; |
| 415 |
} |
| 416 |
} |
| 417 |
if (tvert[1] == NULL) { /* grow mesh on left */ |
| 418 |
tvert[1] = find_chull_vert(edge->rbfv[1], edge->rbfv[0]); |
| 419 |
if (tvert[1] != NULL) { |
| 420 |
if (tvert[1]->ord > edge->rbfv[0]->ord) |
| 421 |
ej0 = create_migration(edge->rbfv[0], tvert[1]); |
| 422 |
else |
| 423 |
ej0 = create_migration(tvert[1], edge->rbfv[0]); |
| 424 |
if (tvert[1]->ord > edge->rbfv[1]->ord) |
| 425 |
ej1 = create_migration(edge->rbfv[1], tvert[1]); |
| 426 |
else |
| 427 |
ej1 = create_migration(tvert[1], edge->rbfv[1]); |
| 428 |
mesh_from_edge(ej0); |
| 429 |
mesh_from_edge(ej1); |
| 430 |
} |
| 431 |
} |
| 432 |
} |
| 433 |
|
| 434 |
/* Add normal direction if missing */ |
| 435 |
static void |
| 436 |
check_normal_incidence(void) |
| 437 |
{ |
| 438 |
static FVECT norm_vec = {.0, .0, 1.}; |
| 439 |
const int saved_nprocs = nprocs; |
| 440 |
RBFNODE *near_rbf, *mir_rbf, *rbf; |
| 441 |
double bestd; |
| 442 |
int n; |
| 443 |
|
| 444 |
if (dsf_list == NULL) |
| 445 |
return; /* XXX should be error? */ |
| 446 |
near_rbf = dsf_list; |
| 447 |
bestd = input_orient*near_rbf->invec[2]; |
| 448 |
if (single_plane_incident) { /* ordered plane incidence? */ |
| 449 |
if (bestd >= 1.-2.*FTINY) |
| 450 |
return; /* already have normal */ |
| 451 |
} else { |
| 452 |
switch (inp_coverage) { |
| 453 |
case INP_QUAD1: |
| 454 |
case INP_QUAD2: |
| 455 |
case INP_QUAD3: |
| 456 |
case INP_QUAD4: |
| 457 |
break; /* quadrilateral symmetry? */ |
| 458 |
default: |
| 459 |
return; /* else we can interpolate */ |
| 460 |
} |
| 461 |
for (rbf = near_rbf->next; rbf != NULL; rbf = rbf->next) { |
| 462 |
const double d = input_orient*rbf->invec[2]; |
| 463 |
if (d >= 1.-2.*FTINY) |
| 464 |
return; /* seems we have normal */ |
| 465 |
if (d > bestd) { |
| 466 |
near_rbf = rbf; |
| 467 |
bestd = d; |
| 468 |
} |
| 469 |
} |
| 470 |
} |
| 471 |
if (mig_list != NULL) { /* need to be called first */ |
| 472 |
fprintf(stderr, "%s: Late call to check_normal_incidence()\n", |
| 473 |
progname); |
| 474 |
exit(1); |
| 475 |
} |
| 476 |
#ifdef DEBUG |
| 477 |
fprintf(stderr, "Interpolating normal incidence by mirroring (%.1f,%.1f)\n", |
| 478 |
get_theta180(near_rbf->invec), get_phi360(near_rbf->invec)); |
| 479 |
#endif |
| 480 |
/* mirror nearest incidence */ |
| 481 |
n = sizeof(RBFNODE) + sizeof(RBFVAL)*(near_rbf->nrbf-1); |
| 482 |
mir_rbf = (RBFNODE *)malloc(n); |
| 483 |
if (mir_rbf == NULL) |
| 484 |
goto memerr; |
| 485 |
memcpy(mir_rbf, near_rbf, n); |
| 486 |
mir_rbf->ord = near_rbf->ord - 1; /* not used, I think */ |
| 487 |
mir_rbf->next = NULL; |
| 488 |
mir_rbf->ejl = NULL; |
| 489 |
rev_rbf_symmetry(mir_rbf, MIRROR_X|MIRROR_Y); |
| 490 |
nprocs = 1; /* compute migration matrix */ |
| 491 |
if (create_migration(mir_rbf, near_rbf) == NULL) |
| 492 |
exit(1); /* XXX should never happen! */ |
| 493 |
norm_vec[2] = input_orient; /* interpolate normal dist. */ |
| 494 |
rbf = e_advect_rbf(mig_list, norm_vec, 0); |
| 495 |
nprocs = saved_nprocs; /* final clean-up */ |
| 496 |
free(mir_rbf); |
| 497 |
free(mig_list); |
| 498 |
mig_list = near_rbf->ejl = NULL; |
| 499 |
insert_dsf(rbf); /* insert interpolated normal */ |
| 500 |
return; |
| 501 |
memerr: |
| 502 |
fprintf(stderr, "%s: Out of memory in check_normal_incidence()\n", |
| 503 |
progname); |
| 504 |
exit(1); |
| 505 |
} |
| 506 |
|
| 507 |
/* Build our triangle mesh from recorded RBFs */ |
| 508 |
void |
| 509 |
build_mesh(void) |
| 510 |
{ |
| 511 |
double best2 = M_PI*M_PI; |
| 512 |
RBFNODE *shrt_edj[2]; |
| 513 |
RBFNODE *rbf0, *rbf1; |
| 514 |
/* average specular peak */ |
| 515 |
comp_bsdf_spec(); |
| 516 |
/* add normal if needed */ |
| 517 |
check_normal_incidence(); |
| 518 |
/* check if isotropic */ |
| 519 |
if (single_plane_incident) { |
| 520 |
for (rbf0 = dsf_list; rbf0 != NULL; rbf0 = rbf0->next) |
| 521 |
if (rbf0->next != NULL) |
| 522 |
create_migration(rbf0, rbf0->next); |
| 523 |
await_children(nchild); |
| 524 |
return; |
| 525 |
} |
| 526 |
shrt_edj[0] = shrt_edj[1] = NULL; /* start w/ shortest edge */ |
| 527 |
for (rbf0 = dsf_list; rbf0 != NULL; rbf0 = rbf0->next) |
| 528 |
for (rbf1 = rbf0->next; rbf1 != NULL; rbf1 = rbf1->next) { |
| 529 |
double dist2 = 2. - 2.*DOT(rbf0->invec,rbf1->invec); |
| 530 |
if (dist2 < best2) { |
| 531 |
shrt_edj[0] = rbf0; |
| 532 |
shrt_edj[1] = rbf1; |
| 533 |
best2 = dist2; |
| 534 |
} |
| 535 |
} |
| 536 |
if (shrt_edj[0] == NULL) { |
| 537 |
fprintf(stderr, "%s: Cannot find shortest edge\n", progname); |
| 538 |
exit(1); |
| 539 |
} |
| 540 |
/* build mesh from this edge */ |
| 541 |
if (shrt_edj[0]->ord < shrt_edj[1]->ord) |
| 542 |
mesh_from_edge(create_migration(shrt_edj[0], shrt_edj[1])); |
| 543 |
else |
| 544 |
mesh_from_edge(create_migration(shrt_edj[1], shrt_edj[0])); |
| 545 |
/* complete migrations */ |
| 546 |
await_children(nchild); |
| 547 |
} |
