/** @return */
public double getFaceArea() {
if (_halfedge == null) {
return 0;
}
final WB_Coord n = getFaceNormal();
if (WB_Vector.getLength3D(n) < 0.5) {
return 0;
}
final double x = WB_Math.fastAbs(n.xd());
final double y = WB_Math.fastAbs(n.yd());
final double z = WB_Math.fastAbs(n.zd());
double area = 0;
int coord = 3;
if ((x >= y) && (x >= z)) {
coord = 1;
} else if ((y >= x) && (y >= z)) {
coord = 2;
}
HE_Halfedge he = _halfedge;
do {
switch (coord) {
case 1:
area +=
(he.getVertex().yd()
* (he.getNextInFace().getVertex().zd() - he.getPrevInFace().getVertex().zd()));
break;
case 2:
area +=
(he.getVertex().xd()
* (he.getNextInFace().getVertex().zd() - he.getPrevInFace().getVertex().zd()));
break;
case 3:
area +=
(he.getVertex().xd()
* (he.getNextInFace().getVertex().yd() - he.getPrevInFace().getVertex().yd()));
break;
}
he = he.getNextInFace();
} while (he != _halfedge);
switch (coord) {
case 1:
area *= (0.5 / x);
break;
case 2:
area *= (0.5 / y);
break;
case 3:
area *= (0.5 / z);
}
return WB_Math.fastAbs(area);
}
public double findSmallestSpanAroundStrut(final int i) {
final int n = struts.size();
if ((i < 0) || (i >= n)) {
throw new IllegalArgumentException("Index beyond strut range.");
}
final ArrayList<WB_FrameNode> nnodes = getNeighbors();
if (n == 1) {
return 2 * Math.PI;
} else if (n == 2) {
final WB_Vector u = nnodes.get(0).subToVector(this);
final WB_Vector w = nnodes.get(1).subToVector(this);
u._normalizeSelf();
w._normalizeSelf();
final double udw = WB_Math.clamp(u.dot(w), -1, 1);
if (udw < WB_Epsilon.EPSILON - 1) {
return Math.PI;
} else {
return Math.acos(udw);
}
} else {
double minAngle = Double.MAX_VALUE;
final WB_Vector u = nnodes.get(i).subToVector(this);
u._normalizeSelf();
for (int j = 0; j < n; j++) {
if (i != j) {
final WB_Vector w = nnodes.get(j).subToVector(this);
w._normalizeSelf();
final double a = Math.acos(u.dot(w));
minAngle = WB_Math.min(minAngle, a);
}
}
return minAngle;
}
}