Foam::cylindricalCS Foam::arcEdge::calcAngle()
{
vector a = p2_ - p1_;
vector b = p3_ - p1_;
// find centre of arcEdge
scalar asqr = a & a;
scalar bsqr = b & b;
scalar adotb = a & b;
scalar denom = asqr*bsqr - adotb*adotb;
if (mag(denom) < VSMALL)
{
FatalErrorInFunction
<< denom
<< abort(FatalError);
}
scalar fact = 0.5*(bsqr - adotb)/denom;
point centre = 0.5*a + fact*((a ^ b) ^ a);
centre += p1_;
// find position vectors w.r.t. the arcEdge centre
vector r1(p1_ - centre);
vector r2(p2_ - centre);
vector r3(p3_ - centre);
// find angles
angle_ = radToDeg(acos((r3 & r1)/(mag(r3) * mag(r1))));
// check if the vectors define an exterior or an interior arcEdge
if (((r1 ^ r2) & (r1 ^ r3)) < 0.0)
{
angle_ = 360.0 - angle_;
}
vector tempAxis;
if (angle_ <= 180.0)
{
tempAxis = r1 ^ r3;
if (mag(tempAxis)/(mag(r1)*mag(r3)) < 0.001)
{
tempAxis = r1 ^ r2;
}
}
else
{
tempAxis = r3 ^ r1;
}
radius_ = mag(r3);
// set up and return the local coordinate system
return cylindricalCS("arcEdgeCS", centre, tempAxis, r1);
}
Foam::cylindricalCS Foam::arcEdge::calcAngle()
{
vector a = p2_ - p1_;
vector b = p3_ - p1_;
// find centre of arcEdge
scalar asqr = a & a;
scalar bsqr = b & b;
scalar adotb = a & b;
scalar denom = asqr*bsqr - adotb*adotb;
if (mag(denom) < VSMALL)
{
FatalErrorIn("cylindricalCS arcEdge::calcAngle()")
<< "Invalid arc definition - are the points co-linear? Denom ="
<< denom
<< abort(FatalError);
}
scalar fact = 0.5*(bsqr - adotb)/denom;
vector centre = 0.5*a + fact*((a ^ b) ^ a);
centre += p1_;
// find position vectors w.r.t. the arcEdge centre
vector r1(p1_ - centre);
vector r2(p2_ - centre);
vector r3(p3_ - centre);
// find angles
scalar tmp = (r3&r1)/(mag(r3)*mag(r1));
angle_ = acos(tmp)*180.0/mathematicalConstant::pi;
// check if the vectors define an exterior or an interior arcEdge
if (((r1 ^ r2)&(r1 ^ r3)) < 0.0) angle_ = 360 - angle_;
vector tempAxis(0.0,0.0,0.0);
if (angle_ <= 180.0)
{
tempAxis = r1 ^ r3;
if (mag(tempAxis)/(mag(r1)*mag(r3)) < 0.001) tempAxis = r1 ^ r2;
}
else
{
tempAxis = r3 ^ r1;
}
radius_ = mag(r3);
// set up and return the local coordinate system
return cylindricalCS("tmpCS", centre, tempAxis, r1);
}