public CLine(CPoint2D point1, CPoint2D point2) { try { if (CPoint2D.SamePoints(point1, point2)) { string errMsg = "The input points are the same"; Exception ex = new Exception(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); }