static real edge_compatibility(pedge e1, pedge e2){
/* two edges are u1->v1, u2->v2.
return 1 if two edges are exactly the same, 0 if they are very different.
*/
real *u1, *v1, *u2, *v2, *u, dist1, dist2, len1, len2;
int dim = e1->dim, flipped = FALSE;
u1 = e1->x;
v1 = (e1->x)+(e1->npoints)*dim-dim;
u2 = e2->x;
v2 = (e2->x)+(e2->npoints)*dim-dim;
dist1 = sqr_dist(dim, u1, u2) + sqr_dist(dim, v1, v2);
dist2 = sqr_dist(dim, u1, v2) + sqr_dist(dim, v1, u2);
if (dist1 > dist2){
u = u2;
u2 = v2;
v2 = u;
dist1 = dist2;
flipped = TRUE;
}
len1 = dist(dim, u1, v1);
len2 = dist(dim, u2, v2);
//dist1 = MAX(0.1, dist1/(len1+len2+dist1));
dist1 = MAX(0.1, dist1/(len1+len2+0.0001*dist1));
if (flipped){
return -1/dist1;
} else {
return 1/dist1;
}
}
static real edge_compatibility_full(pedge e1, pedge e2){
/* two edges are u1->v1, u2->v2.
return 1 if two edges are exactly the same, 0 if they are very different.
This is based on Holten and van Wijk's paper
*/
real *u1, *v1, *u2, *v2, *u, dist1, dist2, len1, len2, len;
real tmp, ca, cp, cs;
int dim = e1->dim, flipped = FALSE, i;
u1 = e1->x;
v1 = (e1->x)+(e1->npoints)*dim-dim;
u2 = e2->x;
v2 = (e2->x)+(e2->npoints)*dim-dim;
dist1 = sqr_dist(dim, u1, u2) + sqr_dist(dim, v1, v2);
dist2 = sqr_dist(dim, u1, v2) + sqr_dist(dim, v1, u2);
if (dist1 > dist2){
u = u2;
u2 = v2;
v2 = u;
dist1 = dist2;
flipped = TRUE;
}
len1 = MAX(dist(dim, u1, v1), SMALL);
len2 = MAX(dist(dim, u2, v2), SMALL);
len = 0.5*(len1+len2);
/* angle compatibility */
ca = 0;
for (i = 0; i < dim; i++)
ca += (v1[i]-u1[i])*(v2[i]-u2[i]);
ca = ABS(ca/(len1*len2));
assert(ca > -0.001);
/* scale compatibility */
//cs = 2/(len1/len2+len2/len1);
cs = 2/(MAX(len1,len2)/len + len/MIN(len1, len2));
assert(cs > -0.001 && cs < 1.001);
/* position compatibility */
cp = 0;
for (i = 0; i < dim; i++) {
tmp = .5*(v1[i]+u1[i])-.5*(v2[i]+u2[i]);
cp += tmp*tmp;
}
cp = sqrt(cp);
cp = len/(len + cp);
assert(cp > -0.001 && cp < 1.001);
/* visibility compatibility */
//dist1 = MAX(0.1, dist1/(len1+len2+dist1));
dist1 = cp*ca*cs;
if (flipped){
return -dist1;
} else {
return dist1;
}
}
static void edge_attraction_force(real similarity, pedge e1, pedge e2, real *force){
/* attrractive force from x2 applied to x1 */
real *x1 = e1->x, *x2 = e2->x;
int dim = e1->dim;
int np = e1->npoints;
int i, j;
real dist, s, ss;
real edge_length = e1->edge_length;
assert(e1->npoints == e2->npoints);
/* attractive force = 1/d where d = D/||e1|| is the relative distance, D is the distance between e1 and e2.
so the force is norminal and unitless
*/
if (similarity > 0){
s = edge_length;
s = similarity*edge_length;
for (i = 1; i <= np - 2; i++){
dist = sqr_dist(dim, &(x1[i*dim]), &(x2[i*dim]));
if (dist < SMALL) dist = SMALL;
ss = s/(dist+0.1*edge_length*sqrt(dist));
for (j = 0; j < dim; j++) force[i*dim + j] += ss*(x2[i*dim + j] - x1[i*dim + j]);
}
} else {/* clip e2 */
s = -edge_length;
s = -similarity*edge_length;
for (i = 1; i <= np - 2; i++){
dist = sqr_dist(dim, &(x1[i*dim]), &(x2[(np - 1 - i)*dim]));
if (dist < SMALL) dist = SMALL;
ss = s/(dist+0.1*edge_length*sqrt(dist));
for (j = 0; j < dim; j++) force[i*dim + j] += ss*(x2[(np - 1 - i)*dim + j] - x1[i*dim + j]);
}
}
}
double MSLPoint3d::distance(const MSLPoint3d& q) const
{ return sqrt(sqr_dist(q)); }
static real dist(int dim, real *x, real *y){
return sqrt(sqr_dist(dim,x,y));
}
