/// <summary>
/// Splits the path by the supplied by line
/// </summary>
/// <param name="path">Path to split</param>
/// <param name="cutter">Cutter to cut the path by</param>
/// <returns>An enumeration of parts, or a single part if not split occurred</returns>
public static IEnumerable <ILucidLine> Split(IEnumerable <IPoint> path, ILucidLine cutter)
{
var current = new LucidLine();
current.AddVertex(path.First());
foreach (var vertices in path.SlidingWindow(2))
{
var line = new AlgebraicLine(vertices);
var lineExtent = CalculateExtent(line);
foreach (var cutterLine in cutter.Vertices.SlidingWindow(2))
{
var byLine = new AlgebraicLine(cutterLine);
var intersection = Intersection(line, byLine);
if (intersection != null && Intersects(intersection, lineExtent) &&
Intersects(intersection, CalculateExtent(byLine)))
{
current.AddVertex(intersection);
yield return(current);
current = new LucidLine();
current.AddVertex(intersection);
break;
}
}
current.AddVertex(line.End);
}
yield return(current);
}
/// <summary>
/// Splits the path at the given point if the point lies on the path.
/// </summary>
/// <param name="path">Path to split</param>
/// <param name="splitPoint">Point at which to cut the path</param>
/// <returns>An enumeration of parts, or a single part if no split occurred</returns>
public static IEnumerable <ILucidLine> Split(IEnumerable <IPoint> path, IPoint splitPoint)
{
var current = new LucidLine();
current.AddVertex(path.First());
foreach (var vertices in path.SlidingWindow(2))
{
var line = new AlgebraicLine(vertices);
var lineExtent = CalculateExtent(line);
if (Intersects(splitPoint, lineExtent))
{
current.AddVertex(splitPoint);
yield return(current);
current = new LucidLine();
current.AddVertex(splitPoint);
}
current.AddVertex(line.End);
}
yield return(current);
}
/// <summary>
/// Returns the point of intersection or null if they are parallel
/// </summary>
public static IPoint Intersection(AlgebraicLine first, AlgebraicLine second)
{
var delta = (first.DeltaY * second.DeltaX) - (second.DeltaY * first.DeltaX);
if (delta == 0)
{
return(null);
}
double x = (second.DeltaX * first.C - first.DeltaX * second.C) / delta;
double y = (first.DeltaY * second.C - second.DeltaY * first.C) / delta;
return(new LucidVertex()
{
X = x,
Y = y
});
}
