/// <summary>
/// Retrieves a Vector4 value of the property defined in
/// the CompositionPropertySet using the given key
/// </summary>
/// <param name="propertySet">CompositionPropertySet</param>
/// <param name="key">Key of the object to retrieve</param>
/// <returns>Vector4</returns>
public static Vector4 GetVector4(this CompositionPropertySet propertySet, string key)
{
return(propertySet.Get <Vector4>(key));
}
/// <summary>
/// Retrieves a Boolean value of the property defined in
/// the CompositionPropertySet using the given key
/// </summary>
/// <param name="propertySet">CompositionPropertySet</param>
/// <param name="key">Key of the object to retrieve</param>
/// <returns>Boolean</returns>
public static bool GetBoolean(this CompositionPropertySet propertySet, string key)
{
return(propertySet.Get <bool>(key));
}
/// <summary>
/// Retrieves a Scalar value of the property defined in
/// the CompositionPropertySet using the given key
/// </summary>
/// <param name="propertySet">CompositionPropertySet</param>
/// <param name="key">Key of the object to retrieve</param>
/// <returns>Scalar</returns>
public static float GetScalar(this CompositionPropertySet propertySet, string key)
{
return(propertySet.Get <float>(key));
}
/// <summary>
/// Retrieves a Quaternion value of the property defined in
/// the CompositionPropertySet using the given key
/// </summary>
/// <param name="propertySet">CompositionPropertySet</param>
/// <param name="key">Key of the object to retrieve</param>
/// <returns>Quaternion</returns>
public static Quaternion GetQuaternion(this CompositionPropertySet propertySet, string key)
{
return(propertySet.Get <Quaternion>(key));
}
/// <summary>
/// Retrieves a Matrix4x4 value of the property defined in
/// the CompositionPropertySet using the given key
/// </summary>
/// <param name="propertySet">CompositionPropertySet</param>
/// <param name="key">Key of the object to retrieve</param>
/// <returns>Matrix4x4</returns>
public static Matrix4x4 GetMatrix4x4(this CompositionPropertySet propertySet, string key)
{
return(propertySet.Get <Matrix4x4>(key));
}
/// <summary>
/// Retrieves a Color value of the property defined in
/// the CompositionPropertySet using the given key
/// </summary>
/// <param name="propertySet">CompositionPropertySet</param>
/// <param name="key">Key of the object to retrieve</param>
/// <returns>Color</returns>
public static Color GetColor(this CompositionPropertySet propertySet, string key)
{
return(propertySet.Get <Color>(key));
}
private async void OnPageLoaded(object sender, RoutedEventArgs e)
{
_compositor = Window.Current.Compositor;
_generator = _compositor.CreateCompositionGenerator();
var gridSize = new Vector2((float)RootGrid.ActualWidth, (float)RootGrid.ActualHeight);
var anim = _compositor.CreatePathKeyFrameAnimation();
_rootVisual = _compositor.CreateSpriteVisual();
_rootVisual.Size = gridSize;
// Create the surface brush from the image
var imageSurface = await _generator.CreateImageSurfaceAsync(
new Uri("ms-appx:///Assets/Images/Cat.png"),
new Size(400, 400),
ImageSurfaceOptions.Default);
var imageBrush = _compositor.CreateSurfaceBrush(imageSurface);
// Create the clipped visuals
for (var i = 0; i < 145; i++)
{
var visual = _compositor.CreateSpriteVisual();
visual.Offset = new Vector3(400, 400, 0);
visual.Size = new Vector2(400, 400);
visual.Brush = imageBrush;
visual.AnchorPoint = new Vector2(0.5f);
var radius = 290 - (i * 2);
// Create the GeometricClip for this visual
var clipGeometry = CanvasGeometry.CreateCircle(null, new Vector2(200, 200), radius);
visual.Clip = _compositor.CreateGeometricClip(clipGeometry);
_rootVisual.Children.InsertAtTop(visual);
_visuals.Add(visual);
}
// Display the rootVisual
ElementCompositionPreview.SetElementChildVisual(RootGrid, _rootVisual);
// Reverse the visuals list so that the items in the list are now sorted
// in z-order from top to bottom
_visuals.Reverse();
// The topmost visual would track the pointer position
_dragVisual = _visuals.First();
// Get the CompositionPropertySet which tracks the pointer position on the RootGrid
_pointerTrackerSet = ElementCompositionPreview.GetPointerPositionPropertySet(RootGrid);
// Animate the topmost visual so that it tracks and follows the pointer position
_pointerTrackerAnimation = _compositor.GenerateVector3KeyFrameAnimation()
.HavingDuration(PointerTrackerAnimationDuration)
.RepeatsForever();
_pointerTrackerAnimation.InsertExpressionKeyFrame(0f, c => new VisualTarget().Offset);
_pointerTrackerAnimation.InsertExpressionKeyFrame(
1f,
c => c.Lerp(new VisualTarget().Offset, _pointerTrackerSet.Get <Vector3>("Position"), DefaultLerpAmount),
_compositor.CreateEaseOutQuinticEasingFunction());
// Animate the remaining visuals in such a way that each visual tracks and follows the
// position of the visual above it.
var prevChild = _dragVisual;
foreach (var child in _visuals.Skip(1))
{
var offsetAnimation = _compositor.GenerateVector3KeyFrameAnimation()
.HavingDuration(ChildOffsetAnimationDuration)
.RepeatsForever();
offsetAnimation.InsertExpressionKeyFrame(0f, c => new VisualTarget().Offset);
offsetAnimation.InsertExpressionKeyFrame(
1f,
c => c.Lerp(new VisualTarget().Offset, prevChild.Offset, DefaultLerpAmount),
_compositor.CreateEaseOutQuinticEasingFunction());
child.StartAnimation(() => child.Offset, offsetAnimation);
prevChild = child;
}
}
