EventDispatcher.fr

//Distance Between Point A and M (A and B with the ratio you want : _nPosition)
var nMidNorme:Number = Point.distance(new Point(cur1.x, cur1.y),new Point(cur2.x, cur2.y))*_nPosition;
//Position of Point B with Point A for origin
var pCur2:Point = new Point(cur2.x, cur2.y).subtract(new Point(cur1.x, cur1.y));
//Distance between A and D with Pythagoras theorem
var nHypo:Number = Math.sqrt(Math.pow(nMidNorme,2) + Math.pow(_nRadius,2));
//Angle between AM (or AB) with hypothenuse in triangle AMD.
//MD is the opposite angle or the radius of the circle.
var nAngle:Number = Math.atan2(_nRadius, nMidNorme);
//Angle between AC and AB -> CÂB
var nCurAngle:Number = (Math.atan2(pCur2.y, pCur2.x));
//New matrix to handle place of the body
var pMatrix:Matrix = new Matrix();
//We translate the point with the distance AD (along the AC segment)
pMatrix.translate(nHypo, 0);
//Angle between AC and AD -> CÂD (CÂB + BÂD)
var nTotalAngle:Number = -nAngle + nCurAngle;
//Rotate point of CÂD angle
pMatrix.rotate(nTotalAngle);

_mcCircle.x = cur1.x + pMatrix.tx,
_mcCircle.y = cur1.y + pMatrix.ty;