private void OnTimerTick(object sender, EventArgs args)
{
if (_division == null)
{
return;
}
// clear current selections, if any
if (_nearestEdge >= 0)
{
SetNearestEdge(null, 0);
}
if (_selectedEdge >= 0)
{
SetSelectedEdge(-1);
}
if (_selectedVertex >= 0)
{
SetSelectedVertex(-1);
}
// check if mouse cursor is over subdivision
Point cursor = Mouse.GetPosition(OutputBox);
if (cursor.X < 0 || cursor.X >= OutputBox.Width ||
cursor.Y < 0 || cursor.Y >= OutputBox.Height)
{
return;
}
// show nearest half-edge, if any
PointD q = cursor.ToPointD();
double distance;
SubdivisionEdge edge = _division.FindNearestEdge(q, out distance);
if (edge != null)
{
SetNearestEdge(edge, distance);
if (distance <= 30)
{
SetSelectedEdge(edge.Key);
}
}
// show nearest vertex, if any
var vertices = _division.Vertices;
if (vertices.Count > 0)
{
var vertexComparer = (PointDComparerY)vertices.Comparer;
int index = vertexComparer.FindNearest(vertices.Keys, q);
SetSelectedVertex(index);
}
}
