/// <summary>
/// Searches the nearest StatusHelperElement from the given Point
/// </summary>
/// <param name="point">The Point to search a StatusHelperElement for</param>
/// <returns>The nearest StatusHelperElement that is positioned left of the Poin</returns>
internal StatusHelperElement SearchLeft(PolygonPoint point)
{
// The found StatusHelperElement and the Distance Variables
StatusHelperElement result = null;
var dist = Double.PositiveInfinity;
// Search for the right StatusHelperElement
foreach (var she in this.EdgesHelpers)
{
// Calculate the x-Coordinate of the Intersection between
// a horizontal Line from the Point to the Left and the Edge of the StatusHelperElement
Double xValue = Double.NaN;
if (point.Y == she.Edge.PointOne.Y)
{
xValue = she.Edge.PointOne.X;
}
else if (point.Y == she.Edge.PointTwo.Y)
{
xValue = she.Edge.PointTwo.X;
}
else
{
xValue = she.Edge.PointOne.X + ((point.Y - she.Edge.PointOne.Y) / (she.Edge.PointTwo.Y - she.Edge.PointOne.Y)) * (she.Edge.PointTwo.X - she.Edge.PointOne.X);
}
// If the xValue is smaller than or equal to the Point's x-Coordinate
// (i.e. it lies on the left Side of it - allows a small Error)
if (xValue <= (point.X + SweepLinePolygonTriangulator.Epsilon))
{
// Calculate the Distance
var sheDist = point.X - xValue;
// Update, if the Distance is smaller than a previously found Result
if (sheDist < dist)
{
dist = sheDist;
result = she;
}
}
}
// Return the nearest found StatusHelperElement
return(result);
}
/// <summary>
/// Constructor that takes both Points of the Edge
/// </summary>
/// <param name="one">The Startpoint</param>
/// <param name="two">The Endpoint</param>
internal PolygonEdge(PolygonPoint one, PolygonPoint two)
{
this.mPointOne = one;
this.mPointTwo = two;
}
/// <summary>
/// Constructor taking an Edge and a Helper
/// </summary>
/// <param name="edge">The Edge of the StatusHelperElement</param>
/// <param name="point">The Helper for the Edge of the StatusHelperElement</param>
internal StatusHelperElement(PolygonEdge edge, PolygonPoint point)
{
this.Edge = edge;
this.Helper = point;
}