/// <summary>
/// returns the Convex Hull of a list of points
/// </summary>
/// <param name="points"></param>
/// <returns>Convex Hull</returns>
private static List <Point> ConvexHull(List <Point> points)
{
var vertices = new Vertex[points.Count];
for (var i = 0; i < points.Count; i++)
{
vertices[i] = new Vertex(points[i].X, points[i].Y);
}
ConvexHullCreationResult <Vertex, DefaultConvexFace <Vertex> > convexHull = MIConvexHull.ConvexHull.Create(vertices);
if (convexHull.Result == null)
{
throw new ArgumentOutOfRangeException("Could not create convex hull, check your points are not co-linear.");
}
var hullPoints = convexHull.Result.Points.ToList();
var convexHullPoints = new List <Point>();
foreach (Vertex vertex in hullPoints)
{
convexHullPoints.Add(Point.ByCoordinates(vertex.Position[0], vertex.Position[1]));
}
return(convexHullPoints);
}
public static RectangleOriented FindMbrBoxByArea(List <PointD> list_of_points)
{
if (list_of_points.Count <= 1)
{
return(new RectangleOriented(new PointD(0, 0), 0, 0, 0));
}
ConvexHullCreationResult <DefaultVertex2D> hull = ConvexHull.Create2D(list_of_points.Select(x => new double[2] {
x.X, x.Y
}).ToList());
double[,] hull_array = new double[hull.Result.Count, 2];
for (int i = 0; i < hull.Result.Count; i++)
{
hull_array[i, 0] = hull.Result[i].X;
hull_array[i, 1] = hull.Result[i].Y;
}
Matrix <double> hull_matrix = DenseMatrix.OfArray(hull_array);
List <double> edge_angles = Rotating_Caliper(hull_array);
double? min_area = null;
RectangleOriented best_rectangle = new RectangleOriented();
/// Test each angle to find bounding box with smallest area
foreach (double angle in edge_angles)
{
RectangleOriented rectangle = FindMinimumBoundingRectangle(hull_matrix, angle);
double area = rectangle.Width * rectangle.Lenght;
if (area < min_area || min_area == null)
{
min_area = area;
best_rectangle = rectangle;
}
}
return(best_rectangle);
}
public static RectangleOriented FindMbrBoxByOverlap(List <PointD> list_of_points)
{
ConvexHullCreationResult <DefaultVertex2D> hull = ConvexHull.Create2D(list_of_points.Select(x => new double[2] {
x.X, x.Y
}).ToList());
double[,] hull_array = new double[hull.Result.Count, 2];
for (int i = 0; i < hull.Result.Count; i++)
{
hull_array[i, 0] = hull.Result[i].X;
hull_array[i, 1] = hull.Result[i].Y;
}
Matrix <double> hull_matrix = DenseMatrix.OfArray(hull_array);
List <double> edge_angles = Rotating_Caliper(hull_array);
int?max_overlap = null;
RectangleOriented best_rectangle = new RectangleOriented();
/// Test each angle to find bounding box with smallest area
foreach (double angle in edge_angles)
{
RectangleOriented rectangle = FindMinimumBoundingRectangle(hull_matrix, angle);
int overlap = FindAllBorderPoints(list_of_points, rectangle, 0.05).Count;
if (overlap > max_overlap || max_overlap == null)
{
max_overlap = overlap;
best_rectangle = rectangle;
}
}
return(best_rectangle);
}
