public CLine(CPoint2D point1, CPoint2D point2)
{
try
{
if (CPoint2D.SamePoints(point1, point2))
{
string errMsg = "The input points are the same";
InvalidInputGeometryDataException ex = new
InvalidInputGeometryDataException(errMsg);
throw ex;
}
//Point1 and Point2 are different points:
if (Math.Abs(point1.X - point2.X)
< ConstantValue.SmallValue) //vertical line
{
Initialize(Math.PI / 2, point1);
}
else if (Math.Abs(point1.Y - point2.Y)
< ConstantValue.SmallValue) //Horizontal line
{
Initialize(0, point1);
}
else //normal line
{
double m = (point2.Y - point1.Y) / (point2.X - point1.X);
double alphaInRad = Math.Atan(m);
Initialize(alphaInRad, point1);
}
}
catch (Exception e)
{
System.Diagnostics.Trace.WriteLine(e.Message + e.StackTrace);
}
}
/***********************************
* From a given point, get its vertex index.
* If the given point is not a polygon vertex,
* it will return -1
***********************************/
public int VertexIndex(CPoint2D vertex)
{
int nIndex = -1;
int nNumPts = m_aVertices.Length;
for (int i = 0; i < nNumPts; i++) //each vertex
{
if (CPoint2D.SamePoints(m_aVertices[i], vertex))
{
nIndex = i;
}
}
return(nIndex);
}