//get the radius line perpendicular to the tangent at ptTo
public void get_RTo(StraightLine rTo)
{
StraightLine TangTo = new StraightLine();
GetTangTo(TangTo);
//zhang revised
if (TangTo.bVerticalLine == false)
{
if (TangTo.k == 0)
{
rTo.xIntercept = ptTo.X;
rTo.bVerticalLine = true;
}
else
{
rTo.k = -1 / TangTo.k;
rTo.b = ptTo.Y + ptTo.X / TangTo.k;
rTo.bVerticalLine = false;
}
}
else//true
{
rTo.k = 0;
rTo.b = ptTo.Y;
rTo.bVerticalLine = false;
}
}
public static String GetPointIntersection(StraightLine line1, StraightLine line2, IPoint PI)
{
if (line1.bVerticalLine == false && line2.bVerticalLine == false)
{
PI.X = (line2.b - line1.b) / (line1.k - line2.k);
PI.Y = line1.k * PI.X + line1.b;
return(null);
}
else if (line1.bVerticalLine == false && line2.bVerticalLine == true)
{
PI.X = line2.b;
PI.Y = line1.k * line2.b + line1.b;
return(null);
}
else if (line1.bVerticalLine == true && line2.bVerticalLine == false)
{
PI.X = line1.b;
PI.Y = line2.k * line1.b + line2.b;
return(null);
}
else if (line1.bVerticalLine == true && line2.bVerticalLine == true)
{
//int i = 0;
return("Bad Roadway Network!");
//MessageBox.Show("Bad Roadway Network!");
}
else
{
return(null);
}
}
//Internal methods
//get the radius line perpendicular to the tangent at ptFrom
public void get_RFrom(StraightLine rFrom)
{
StraightLine TangFrom = new StraightLine();
GetTangFrom(TangFrom);
if (TangFrom.bVerticalLine == false)
{
if (TangFrom.k == 0)
{
rFrom.bVerticalLine = true;
rFrom.xIntercept = ptFrom.X;
}
else
{
rFrom.bVerticalLine = false;
rFrom.k = -1 / TangFrom.k;
rFrom.b = ptFrom.Y + ptFrom.X / TangFrom.k;
}
}
else
{
rFrom.k = 0;
rFrom.b = ptFrom.Y;
rFrom.bVerticalLine = false;
}
}
//point of intersection
public void GetPI(IPoint PI)
{
StraightLine TangFrom = new StraightLine();
GetTangFrom(TangFrom);
StraightLine TangTo = new StraightLine();
GetTangTo(TangTo);
StraightLine.GetPointIntersection(TangFrom, TangTo, PI);
}
//the tangent line at ptTo
public void GetTangTo(StraightLine tangTo)
{
StraightLine slTemp = new StraightLine(ptAfterTo, ptTo);
if (slTemp.bVerticalLine == false)
{
tangTo.k = slTemp.k;
tangTo.b = slTemp.b;
}
else
{
tangTo.xIntercept = slTemp.xIntercept;
}
}
//Center Point
public void GetCenterPT(IPoint ptCenter)
{
//debug zli
if (lCurveID == 27)
{
//int i = 0;
}
StraightLine rFrom = new StraightLine();
StraightLine rTo = new StraightLine();
get_RFrom(rFrom);
get_RTo(rTo);
StraightLine.GetPointIntersection(rFrom, rTo, ptCenter);
}
//Public Methods
//the tangent line at ptFrom
public void GetTangFrom(StraightLine tangFrom)
{
StraightLine slTemp = new StraightLine(ptBeforeFrom, ptFrom);
//zhang revised
if (slTemp.bVerticalLine == false)
{
tangFrom.k = slTemp.k;
tangFrom.b = slTemp.b;
}
else
{
tangFrom.xIntercept = slTemp.xIntercept;
}
}