/// <summary>
/// Determines one component of a UIElement's location
/// within a Canvas (horizontal or vertical offset)
/// and according to it reletive to which sides it may be relocated
/// </summary>
/// <param name="Left">
/// The value of an offset relative to a Left side of the Canvas
/// </param>
/// <param name="Right">
/// The value of the offset relative to the Right side of the Canvas
/// </param>
/// <param name="Top">
/// The value of an offset relative to a Top side of the Canvas
/// </param>
/// <param name="Bottom">
/// The value of the offset relative to the Bottom side of the Canvas
/// </param>
private ModificationDirection ResolveOffset(double Left, double Right, double Top, double Bottom)
{
// If the Canvas.Left and Canvas.Right attached properties
// are specified for an element, the 'Left' value is honored.
// The 'Top' value is honored if both Canvas.Top and
// Canvas.Bottom are set on the same element. If one
// of those attached properties is not set on an element,
// the default value is Double.NaN.
m_OriginalLefOffset = Left;
m_OriginalRightOffset = Right;
m_OriginalTopOffset = Top;
m_OriginalBottomOffset = Bottom;
ModificationDirection result = ModificationDirection.None;
if (!Double.IsNaN(m_OriginalLefOffset))
{
result |= ModificationDirection.Left;
}
if (!Double.IsNaN(m_OriginalRightOffset))
{
result |= ModificationDirection.Right;
}
if (!Double.IsNaN(m_OriginalTopOffset))
{
result |= ModificationDirection.Top;
}
if (!Double.IsNaN(m_OriginalBottomOffset))
{
result |= ModificationDirection.Bottom;
}
return(result);
}
protected override void OnPreviewMouseLeftButtonDown(MouseButtonEventArgs e)
{
base.OnPreviewMouseLeftButtonDown(e); // call the handler of the base first
m_IsDragInProgress = false;
m_InitialCursorLocation = e.GetPosition(this); // Cache the mouse cursor location
//check if the mouse was clicked on the ScrollBar, in which case let the ScrollBar remain its control.
if (null != GetParentOfType <ScrollBar>(e.OriginalSource as DependencyObject))
{
return;
}
// Walk up the visual tree from the element that was clicked,
// looking for an element that is a direct child of the Canvas
DraggedElement = FindCanvasChild(e.Source as DependencyObject);
if (m_DraggedElement == null)
{
return;
}
m_ModificationDirection = ResolveOffset(Canvas.GetLeft(m_DraggedElement), Canvas.GetRight(m_DraggedElement), Canvas.GetTop(m_DraggedElement), Canvas.GetBottom(m_DraggedElement));
// Set the Handled flag so that a control being dragged
// does not react to the mouse input
e.Handled = true;
if (m_ModificationDirection == ModificationDirection.None)
{
DraggedElement = null;
return;
}
BringToFront(m_DraggedElement as UIElement);
m_IsDragInProgress = true;
}
public void Update(List<DummyObject> selectedObjects, Viewport viewport)
{
if (mControls.LeftPressed.Active)
{
Rectangle mousePixelRectangle = new Rectangle(mControls.MouseState.X, mControls.MouseState.Y, 1, 1);
List<uint> objectIDs = GraphicsManager.GetPickingScreenObjects(mousePixelRectangle);
uint mousePixel = objectIDs.Count > 0 ? objectIDs[0] : 0;
if (mousePixel == mXPickingID || mousePixel == mYPickingID || mousePixel == mZPickingID)
{
mDragMode = Mode;
IsDragging = true;
}
else
{
IsDragging = false;
}
switch (mousePixel)
{
case mXPickingID:
mDragDirection = ModificationDirection.X;
break;
case mYPickingID:
mDragDirection = ModificationDirection.Y;
break;
case mZPickingID:
mDragDirection = ModificationDirection.Z;
break;
}
mStartDragPoint = GetMouseWorldPosition(viewport);
mPreviousDragPoint = mStartDragPoint;
}
else if (mControls.LeftReleased.Active)
{
IsDragging = false;
}
if (IsDragging)
{
Vector3 newDragPoint = GetMouseWorldPosition(viewport);
switch (mDragMode)
{
case ModificationMode.TRANSLATE:
foreach (DummyObject dummyObject in selectedObjects)
{
dummyObject.Position += (newDragPoint - mPreviousDragPoint) * GetDragDirection();
}
break;
case ModificationMode.SCALE:
float scaleMultiplier = (newDragPoint - Position).Length() / (mPreviousDragPoint - Position).Length();
foreach (DummyObject dummyObject in selectedObjects)
{
Vector3 scale = scaleMultiplier * GetDragDirection() + (Vector3.One - GetDragDirection());
dummyObject.ApplyScale(scale);
}
break;
case ModificationMode.ROTATE:
Vector3 axis = GetDragDirection();
Vector3 newDirection = Vector3.Normalize(newDragPoint - Position);
Vector3 previousDirection = Vector3.Normalize(mPreviousDragPoint - Position);
float dot = Math.Min(1.0f, Math.Max(-1.0f, Vector3.Dot(newDirection, previousDirection)));
float angle = (float)Math.Acos(dot);
angle *= Vector3.Dot(Vector3.Cross(newDirection, previousDirection), axis) < 0.0f ? 1.0f : -1.0f;
foreach (DummyObject dummyObject in selectedObjects)
{
Vector3 deltaYawPitchRoll = axis * angle;
dummyObject.ApplyRotation(deltaYawPitchRoll, Position);
}
break;
}
mPreviousDragPoint = newDragPoint;
}
Position = Vector3.Zero;
foreach (DummyObject dummyObject in selectedObjects)
{
Position += dummyObject.Position;
}
if (selectedObjects.Count > 0)
{
mDrawable = true;
Position /= selectedObjects.Count;
}
else
{
mDrawable = false;
}
}