private void AnimatedCanvasCtrl_OnDraw(ICanvasAnimatedControl sender, CanvasAnimatedDrawEventArgs args)
{
if (_animatedCompositionMask == null)
{
return;
}
_angle = (float)((_angle + 1) % 360);
var radians = (float)((_angle * Math.PI) / 180);
// Calculate the new geometry based on the angle
var updatedGeometry = _outerGeometry.CombineWith(_combinedGeometry,
Matrix3x2.CreateRotation(radians, new Vector2(_width / 2, _height / 2)),
CanvasGeometryCombine.Exclude);
// Update the geometry in the Composition Mask
_animatedCompositionMask.Redraw(updatedGeometry);
}
/// <summary>
/// Handles the Arrange layout phase
/// </summary>
/// <param name="finalSize">Final Size of the control</param>
/// <returns>Size</returns>
protected override Size ArrangeOverride(Size finalSize)
{
if ((_compositor == null) || (_generator == null))
{
return(base.ArrangeOverride(finalSize));
}
if (Double.IsInfinity(finalSize.Width) || Double.IsInfinity(finalSize.Height) ||
Double.IsNaN(finalSize.Width) || Double.IsNaN(finalSize.Height))
{
return(base.ArrangeOverride(finalSize));
}
// Stop the animations and dispose the previous nodes
// and their animations
if (_isAnimationStarted)
{
for (var i = 0; i < _nodes.Count; i++)
{
_nodes[i].StopAnimation(AnimatedProperty);
_animations[i].Dispose();
_animations[i] = null;
_nodes[i].Dispose();
_nodes[i] = null;
}
_container.StopAnimation(AnimatedProperty);
_containerAnimation.Dispose();
_containerAnimation = null;
_container.Dispose();
_container = null;
_animations.Clear();
_nodes.Clear();
_isAnimationStarted = false;
}
// Validate MaxNodes and ActiveNodes
if ((MaxNodes <= 0) || (ActiveNodes <= 0))
{
return(finalSize);
}
// Coerce ActiveNodes to MaxNodes if ActiveNodes > MaxNodes
if (ActiveNodes > MaxNodes)
{
ActiveNodes = MaxNodes;
}
// Take the smallest of the width or height
var sideLength = (float)Math.Min(finalSize.Width, finalSize.Height);
// Size of the progress ring displayed
_ringSize = new Vector2(sideLength, sideLength);
var sideHalf = sideLength / 2f;
// Radius of each node
_nodeRadius = (float)NodeSizeFactor * sideHalf;
// Size of each node
_nodeSize = new Vector2(_nodeRadius * 2f, _nodeRadius * 2f);
// Radius of the node
_ringRadius = sideHalf - _nodeRadius;
// Each animation will consist of '_maxFrameBlocks' number of
// FrameBlocks. Each FrameBlock will consist of keyframes which allow
// the element being animated to move to the next slot and wait
// at that slot until all other elements have moved to their next slot.
// Each FrameBlock (except the last one) will have '_maxFramesPerBlock'
// number of keyframes. The last keyframe in the last FrameBlock
// will always be (1f, "this.StartingValue + 360")
// Total number of FrameBlocks in each animation
_maxFrameBlocks = ActiveNodes;
// Total keyframes in each FrameBlock
_maxFramesPerBlock = ActiveNodes + 1;
// Total keyframes in each animation
_maxKeyFrames = _maxFrameBlocks * _maxFramesPerBlock;
// Normalized Progress Key unit value for each keyframe
_keyFrameSlice = 1f / _maxKeyFrames;
// ========================================================================
// NOTE:
// gamma * maxNodes = 360
// gamma = alpha + beta
// beta = 2 * Asin(nodeRadius / ringRadius) * (180 / Math.PI)
// invisibleNodes = MaxNodes - ActiveNodes
// phi = (invisibleNodes * gamma)
// theta = phi - beta
// ========================================================================
// gamma is the angle between adjacent nodes when maxNodes number of nodes are arranged in a circle
_gamma = 360f / MaxNodes;
// beta is the angle a node must travel after hitting the adjacent node
_beta = 2f * (float)(Math.Asin(_nodeRadius / _ringRadius) * (180f / Math.PI));
// alpha is the smallest angle a node must travel before hitting the adjacent node
_alpha = _gamma - _beta;
// phi is the angle occupied by (MaxNodes - ActiveNodes) number of nodes
_phi = (MaxNodes - ActiveNodes + 1) * _gamma;
// theta is the largest angle a node must travel before hitting the adjacent node
_theta = _phi - _beta;
// Create the Animations
_animations = CreateAnimations();
// Create the Container
_container = _compositor.CreateContainerVisual();
_container.Size = _ringSize;
_container.Offset = new Vector3(((float)finalSize.Width - sideLength) / 2f,
((float)finalSize.Height - sideLength) / 2f,
0f);
_container.CenterPoint = new Vector3(_ringSize.X / 2f, _ringSize.Y / 2f, 0f);
// Create the Nodes
var offset = new Vector3(_nodeRadius, _ringSize.Y / 2f, 0);
var centerPoint = new Vector3(_ringSize.X / 2f - _nodeRadius, 0, 0);
_nodes = new List <SpriteVisual>();
var geometry = CanvasGeometry.CreateCircle(_generator.Device, new Vector2(_nodeRadius, _nodeRadius), _nodeRadius);
// Create/Update the nodeMask
var color = NodeColor;
if (_nodeMask == null)
{
//Task.Run(async () =>
// {
_nodeMask = _generator.CreateMask(_nodeSize.ToSize(), geometry, color);
// })
//.Wait();
}
else
{
//Task.Run(async () =>
// {
_nodeMask.Redraw(_nodeSize.ToSize(), geometry, color);
// })
//.Wait();
}
// Create the SurfaceBrush for the nodes
var brush = _compositor.CreateSurfaceBrush(_nodeMask.Surface);
var baseAngle = 0f;
// Create the visuals for the nodes
for (var i = 0; i < _maxFramesPerBlock; i++)
{
var node = _compositor.CreateSpriteVisual();
node.Size = _nodeSize;
node.AnchorPoint = new Vector2(0.5f);
node.Offset = offset;
node.CenterPoint = centerPoint;
node.Brush = brush;
node.RotationAngleInDegrees = baseAngle;
if (i == 0)
{
baseAngle += _phi;
}
else if (i == _maxFramesPerBlock - 2)
{
baseAngle = -_beta;
}
else
{
baseAngle += _gamma;
}
_nodes.Add(node);
// Add the visual to the container
_container.Children.InsertAtTop(node);
}
// Add the container to the Visual Tree
ElementCompositionPreview.SetElementChildVisual(this, _container);
// Start Node animations
for (var i = 0; i < _maxFramesPerBlock; i++)
{
_nodes[i].StartAnimation(AnimatedProperty, _animations[i]);
}
// Start container animation
_containerAnimation = _compositor.CreateScalarKeyFrameAnimation();
_containerAnimation.InsertExpressionKeyFrame(1f, "this.StartingValue + 360f", _compositor.CreateLinearEasingFunction());
_containerAnimation.Duration = RingDuration;
_containerAnimation.IterationBehavior = AnimationIterationBehavior.Forever;
_container.StartAnimation(AnimatedProperty, _containerAnimation);
_isAnimationStarted = true;
return(finalSize);
}