/// <summary>
/// The sort children.
/// </summary>
private void SortChildren()
{
var vp = Visual3DHelper.GetViewport3D(this);
if (vp == null)
{
return;
}
var cam = vp.Camera as ProjectionCamera;
if (cam == null)
{
return;
}
var cameraPos = cam.Position;
var transform = new MatrixTransform3D(Visual3DHelper.GetTransform(this));
IList <Visual3D> transparentChildren = new List <Visual3D>();
IList <Visual3D> opaqueChildren = new List <Visual3D>();
if (this.CheckForOpaqueVisuals)
{
foreach (var child in this.Children)
{
if (this.IsVisualTransparent(child))
{
transparentChildren.Add(child);
}
else
{
opaqueChildren.Add(child);
}
}
}
else
{
transparentChildren = this.Children;
}
// sort the children by distance from camera (note that OrderBy is a stable sort algorithm)
var sortedTransparentChildren =
transparentChildren.OrderBy(item => - this.GetCameraDistance(item, cameraPos, transform)).ToList();
this.Children.Clear();
// add the opaque children
foreach (var c in opaqueChildren)
{
this.Children.Add(c);
}
// add the sorted transparent children
foreach (var c in sortedTransparentChildren)
{
this.Children.Add(c);
}
}
/// <summary>
/// Updates the clipping object.
/// </summary>
private void UpdateClipping()
{
var vp = Visual3DHelper.GetViewport3D(this);
if (vp == null)
{
return;
}
this.Clipping = new CohenSutherlandClipping(10, vp.ActualWidth - 20, 10, vp.ActualHeight - 20);
}
/// <summary>
/// Invoked when an unhandled <see cref="E:System.Windows.Input.Mouse.MouseDown" /> attached event reaches an element in its route that is derived from this class. Implement this method to add class handling for this event.
/// </summary>
/// <param name="e">The <see cref="T:System.Windows.Input.MouseButtonEventArgs" /> that contains the event data. This event data reports details about the mouse button that was pressed and the handled state.</param>
protected override void OnMouseDown(MouseButtonEventArgs e)
{
base.OnMouseDown(e);
this.ParentViewport = Visual3DHelper.GetViewport3D(this);
this.Camera = this.ParentViewport.Camera as ProjectionCamera;
var projectionCamera = this.Camera;
if (projectionCamera != null)
{
this.HitPlaneNormal = projectionCamera.LookDirection;
}
this.CaptureMouse();
}
/// <summary>
/// The sort children.
/// </summary>
private void SortChildren()
{
var vp = Visual3DHelper.GetViewport3D(this);
if (vp == null)
{
return;
}
var cam = vp.Camera as ProjectionCamera;
if (cam == null)
{
return;
}
var cameraPos = cam.Position;
var transform = new MatrixTransform3D(Visual3DHelper.GetTransform(this));
IList <Visual3D> transparentChildren = new List <Visual3D>();
IList <Visual3D> opaqueChildren = new List <Visual3D>();
if (this.CheckForOpaqueVisuals)
{
foreach (var child in this.Children)
{
if (this.IsVisualTransparent(child))
{
transparentChildren.Add(child);
}
else
{
opaqueChildren.Add(child);
}
}
}
else
{
transparentChildren = this.Children;
}
// sort the children by distance from camera (note that OrderBy is a stable sort algorithm)
var sortedTransparentChildren =
transparentChildren.OrderBy(item => - this.GetCameraDistance(item, cameraPos, transform)).ToList();
// Now that opaqueChildren and sortedTransparentChildren describe our desired ordering, we need sort the current children in the new order.
// To optimize the efficiency of this procedure we want to change the children list as little as possible.
// Unfortunatally the Visual3DCollection does not have a swap method and we always need to remove an item before we can add it again as
// temporary duplicates result in exceptions in the visual tree.
// Due to this set of considerations we use selection sort to sort the current Children. (if we could swap without removal, cycle sort might be a small improvement)
for (int desiredIndex = 0; desiredIndex < opaqueChildren.Count; desiredIndex++)
{
Visual3D currentChild = opaqueChildren[desiredIndex];
int currentIndex = Children.IndexOf(currentChild);
//Insert in the proper spot if not contained:
if (currentIndex == -1)
{
Children.Insert(desiredIndex, currentChild);
continue;
}
//Do nothing if it is in the correct spot;
//The order of the opaque children does not matter as long as they are before the transparent children:
if (currentIndex < opaqueChildren.Count)
{
continue;
}
//remove from old spot and insert to the new correct spot:
Children.RemoveAt(currentIndex);
Children.Insert(desiredIndex, currentChild);
}
for (int desiredIndex = opaqueChildren.Count; desiredIndex < opaqueChildren.Count + sortedTransparentChildren.Count; desiredIndex++)
{
Visual3D currentChild = sortedTransparentChildren[desiredIndex - opaqueChildren.Count];
int currentIndex = Children.IndexOf(currentChild);
//Insert in the proper spot if not contained:
if (currentIndex == -1)
{
Children.Insert(desiredIndex, currentChild);
continue;
}
//Do nothing if it is in the correct spot:
if (currentIndex == desiredIndex)
{
continue;
}
//remove from old spot and insert to the new correct spot:
Children.RemoveAt(currentIndex);
Children.Insert(desiredIndex, currentChild);
}
}
