/// <summary>
/// Animates a point light and it's distance.
/// </summary>
/// <param name="animationSet">The animation set.</param>
/// <param name="distance">The distance of the light.</param>
/// <param name="duration">The duration in milliseconds.</param>
/// <param name="delay">The delay. (ignored if duration == 0)</param>
/// <seealso cref="IsLightingSupported" />
/// <returns>
/// An Animation Set.
/// </returns>
public static AnimationSet Light(
this AnimationSet animationSet,
double distance = 0d,
double duration = 500d,
double delay = 0d)
{
if (!IsLightingSupported)
{
return(null);
}
if (animationSet == null)
{
return(null);
}
var visual = animationSet.Visual;
var associatedObject = animationSet.Element as FrameworkElement;
if (associatedObject == null)
{
return(animationSet);
}
var compositor = visual?.Compositor;
if (compositor == null)
{
return(null);
}
var task = new AnimationTask();
task.AnimationSet = animationSet;
task.Task = DispatcherHelper.ExecuteOnUIThreadAsync(
() =>
{
const string sceneName = "PointLightScene";
PointLight pointLight;
CompositionDrawingSurface normalMap = null;
if (!pointLights.ContainsKey(visual))
{
SurfaceLoader.Initialize(compositor);
normalMap = SurfaceLoader.LoadText(string.Empty, new Windows.Foundation.Size(512, 512), new Graphics.Canvas.Text.CanvasTextFormat(), Colors.Transparent, Colors.Transparent);
}
if (pointLights.ContainsKey(visual))
{
pointLight = pointLights[visual];
}
else
{
pointLight = compositor.CreatePointLight();
var normalBrush = compositor.CreateSurfaceBrush(normalMap);
normalBrush.Stretch = CompositionStretch.Fill;
// check to see if the visual already has a point light applied.
var spriteVisual = ElementCompositionPreview.GetElementChildVisual(associatedObject) as SpriteVisual;
var normalsBrush = spriteVisual?.Brush as CompositionEffectBrush;
if (normalsBrush == null || normalsBrush.Comment != sceneName)
{
var lightEffect = new CompositeEffect()
{
Mode = CanvasComposite.Add,
Sources =
{
new CompositionEffectSourceParameter("ImageSource"),
new SceneLightingEffect()
{
Name = sceneName,
AmbientAmount = 0,
DiffuseAmount = 0.5f,
SpecularAmount = 0,
NormalMapSource = new CompositionEffectSourceParameter("NormalMap"),
}
}
};
var effectFactory = compositor.CreateEffectFactory(lightEffect);
var brush = effectFactory.CreateBrush();
brush.SetSourceParameter("NormalMap", normalBrush);
var sprite = compositor.CreateSpriteVisual();
sprite.Size = visual.Size;
sprite.Brush = brush;
sprite.Comment = sceneName;
ElementCompositionPreview.SetElementChildVisual(task.AnimationSet.Element, sprite);
pointLight.CoordinateSpace = visual;
pointLight.Targets.Add(visual);
}
}
var delayTime = task.Delay != null ? task.Delay.Value : TimeSpan.FromMilliseconds(delay);
var durationTime = task.Duration != null ? task.Duration.Value : TimeSpan.FromMilliseconds(duration);
if (durationTime.TotalMilliseconds <= 0)
{
task.AnimationSet.AddEffectDirectPropertyChange(pointLight, (float)distance, nameof(pointLight.Offset));
}
else
{
var diffuseAnimation = compositor.CreateVector3KeyFrameAnimation();
diffuseAnimation.InsertKeyFrame(1f, new System.Numerics.Vector3(visual.Size.X / 2, visual.Size.Y / 2, (float)distance));
diffuseAnimation.Duration = durationTime;
diffuseAnimation.DelayTime = delayTime;
task.AnimationSet.AddCompositionEffectAnimation(pointLight, diffuseAnimation, nameof(pointLight.Offset));
}
pointLights[visual] = pointLight;
}, Windows.UI.Core.CoreDispatcherPriority.Normal);
animationSet.AddAnimationThroughTask(task);
return(animationSet);
}
/// <summary>
/// Adds a <see cref="AnimationTask"/> to the AnimationSet that
/// will run add an animation once completed. Usefull when an animation
/// needs to do asyncronous initialization before running
/// </summary>
/// <param name="animationTask">The <see cref="AnimationTask"/> to be added</param>
internal void AddAnimationThroughTask(AnimationTask animationTask)
{
_animationTasks.Add(animationTask);
}