_MdcGeomSvc_impl Namespace Reference

Functions
void	tangents (CLHEP::Hep2Vector c, double r1, double r2, vector< MdcGeomSvc::AdjCandiTgtLine2D > &ans)
	find tangent. should have returned optional<line>, but ok..
vector< MdcGeomSvc::AdjCandiTgtLine2D >	tangents (CLHEP::Hep2Vector a, CLHEP::Hep2Vector b, double ra, double rb)
	find all tangents of 2 circles given as point and radius. may return 0,1,2,3,4 lines

Variables
const double	EPS = 1E-9

Function Documentation

tangents() [1/2]

vector< MdcGeomSvc::AdjCandiTgtLine2D > _MdcGeomSvc_impl::tangents	(	CLHEP::Hep2Vector	a,
		CLHEP::Hep2Vector	b,
		double	ra,
		double	rb )

find all tangents of 2 circles given as point and radius. may return 0,1,2,3,4 lines

Parameters

a
b
ra
rb

Returns

vector<MdcGeomSvc::AdjCandiTgtLine2D>

Definition at line 1562 of file MdcGeomSvc-00-01-42/src/MdcGeomSvc.cxx.

                                                                                                              {
        vector<MdcGeomSvc::AdjCandiTgtLine2D> ans;
        for (int i=-1; i<=1; i+=2)
            for (int j=-1; j<=1; j+=2)
                tangents (b-a, ra*i, rb*j, ans);
        for (size_t i=0; i<ans.size(); ++i)
            ans[i].c -= ans[i].a * a.x() + ans[i].b * a.y();
        return ans;
    }

tangents() [2/2]

void _MdcGeomSvc_impl::tangents	(	CLHEP::Hep2Vector	c,
		double	r1,
		double	r2,
		vector< MdcGeomSvc::AdjCandiTgtLine2D > &	ans )

find tangent. should have returned optional<line>, but ok..

Parameters

c
r1
r2
ans

Definition at line 1540 of file MdcGeomSvc-00-01-42/src/MdcGeomSvc.cxx.

                                                                                                       {
        double r = r2 - r1;
        double z = squared(c.x()) + squared(c.y());
        double d = z - squared(r);
        if (d < -EPS)  return;
        d = sqrt (abs (d));
        MdcGeomSvc::AdjCandiTgtLine2D l;
        l.a = (c.x() * r + c.y() * d) / z;
        l.b = (c.y() * r - c.x() * d) / z;
        l.c = r1;
        ans.push_back (l);
    }

Referenced by MdcGeomSvc::getAdjacentCandidateWithDriftCircle(), and tangents().

Variable Documentation

EPS

const double _MdcGeomSvc_impl::EPS = 1E-9

Definition at line 1531 of file MdcGeomSvc-00-01-42/src/MdcGeomSvc.cxx.

Referenced by tangents().