/** @return */
public WB_Plane getPlane() {
WB_Coord fn = getFaceNormal();
if (WB_Vector.getSqLength3D(fn) < 0.5) {
if (WB_Epsilon.isEqualAbs(_halfedge.getVertex().xd(), _halfedge.getEndVertex().xd())) {
fn = new WB_Vector(1, 0, 0);
} else {
fn = new WB_Vector(0, 0, 1);
}
}
return new WB_Plane(getFaceCenter(), fn);
}
/** @return */
public WB_Coord getNonNormFaceNormal() {
if (_halfedge == null) {
return null;
}
// calculate normal with Newell's method
HE_Halfedge he = _halfedge;
final WB_Vector _normal = new WB_Vector();
HE_Vertex p0;
HE_Vertex p1;
do {
p0 = he.getVertex();
p1 = he.getNextInFace().getVertex();
_normal.addSelf(
(p0.yd() - p1.yd()) * (p0.zd() + p1.zd()),
(p0.zd() - p1.zd()) * (p0.xd() + p1.xd()),
(p0.xd() - p1.xd()) * (p0.yd() + p1.yd()));
he = he.getNextInFace();
} while (he != _halfedge);
return _normal;
}
/** @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);
}
/** @return */
public boolean isDegenerate() {
return WB_Vector.getLength3D(getFaceNormal()) < 0.5;
}