private void createButton_Click(object sender, EventArgs e)
{
try
{
int numPoints = int.Parse(numPointsTextBox.Text);
float xmin = Radius;
float ymin = Radius;
float xmax = (pointsPictureBox.ClientSize.Width - Radius) / 3;
float ymax = (pointsPictureBox.ClientSize.Height - Radius) / 3;
for (int i = 0; i < numPoints; i++)
{
float x = xmin + (float)(
(rand.NextDouble() * xmax - xmin) +
(rand.NextDouble() * xmax - xmin) +
(rand.NextDouble() * xmax - xmin));
float y = ymin + (float)(
(rand.NextDouble() * ymax - ymin) +
(rand.NextDouble() * ymax - ymin) +
(rand.NextDouble() * ymax - ymin));
Root.AddPoint(new PointF(x, y));
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
// Redraw.
pointsPictureBox.Refresh();
}
// Add a point to this subtree.
public void AddPoint(PointF newPoint)
{
// See if this quadtree node us full.
if ((Points != null) && (Points.Count + 1 > MaxPoints))
{
// Divide this quadtree node.
float wid = (Area.Right - Area.Left) / 2f;
float hgt = (Area.Bottom - Area.Top) / 2f;
NWchild = new QuadtreeNode(new RectangleF(Area.Left, Area.Top, wid, hgt));
NEchild = new QuadtreeNode(new RectangleF(Area.Left + wid, Area.Top, wid, hgt));
SEchild = new QuadtreeNode(new RectangleF(Area.Left + wid, Area.Top + hgt, wid, hgt));
SWchild = new QuadtreeNode(new RectangleF(Area.Left, Area.Top + hgt, wid, hgt));
// Move the points into the appropriate subtrees.
foreach (PointF pt in Points)
{
if (pt.Y < Ymid)
{
if (pt.X < Xmid)
{
NWchild.AddPoint(pt);
}
else
{
NEchild.AddPoint(pt);
}
}
else
{
if (pt.X < Xmid)
{
SWchild.AddPoint(pt);
}
else
{
SEchild.AddPoint(pt);
}
}
}
// Remove this node's Points list.
Points = null;
}
// Add the point to the appropriate subtree.
if (Points != null)
{
Points.Add(newPoint);
}
else if (newPoint.Y < Ymid)
{
if (newPoint.X < Xmid)
{
NWchild.AddPoint(newPoint);
}
else
{
NEchild.AddPoint(newPoint);
}
}
else
{
if (newPoint.X < Xmid)
{
SWchild.AddPoint(newPoint);
}
else
{
SEchild.AddPoint(newPoint);
}
}
}
