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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
//
using MS.Internal;
using System;
using System.IO;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Diagnostics;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Media;
using System.Windows.Markup;
using System.Windows.Media.Animation;
using System.Windows.Media.Composition;
namespace System.Windows.Media.Animation
{
/// <summary>
/// This animation can be used inside of a MatrixAnimationCollection to move
/// a visual object along a path.
/// </summary>
public class MatrixAnimationUsingPath : MatrixAnimationBase
{
#region Data
private bool _isValid;
/// <summary>
/// If IsCumulative is set to true, these values represents the values
/// that are accumulated with each repeat. They are the end values of
/// the path.
/// </summary>
private Vector _accumulatingOffset = new Vector();
private double _accumulatingAngle;
#endregion
#region Constructors
/// <summary>
/// Creates a new PathMatrixAnimation class.
/// </summary>
/// <remarks>
/// There is no default PathGeometry so the user must specify one.
/// </remarks>
public MatrixAnimationUsingPath()
: base()
{
}
#endregion
#region Freezable
/// <summary>
/// Creates a copy of this PathMatrixAnimation.
/// </summary>
/// <returns>The copy.</returns>
public new MatrixAnimationUsingPath Clone()
{
return (MatrixAnimationUsingPath)base.Clone();
}
/// <summary>
/// Implementation of <see cref="System.Windows.Freezable.CreateInstanceCore">Freezable.CreateInstanceCore</see>.
/// </summary>
/// <returns>The new Freezable.</returns>
protected override Freezable CreateInstanceCore()
{
return new MatrixAnimationUsingPath();
}
/// <summary>
/// Implementation of <see cref="System.Windows.Freezable.OnChanged">Freezable.OnChanged</see>.
/// </summary>
protected override void OnChanged()
{
_isValid = false;
base.OnChanged();
}
#endregion
#region Public
/// <summary>
/// DoesRotateWithTangent Property
/// </summary>
public static readonly DependencyProperty DoesRotateWithTangentProperty =
DependencyProperty.Register(
"DoesRotateWithTangent",
typeof(bool),
typeof(MatrixAnimationUsingPath),
new PropertyMetadata(false));
/// <summary>
/// If this is set to true, the object will rotate along with the
/// tangent to the path.
/// </summary>
public bool DoesRotateWithTangent
{
get
{
return (bool)GetValue(DoesRotateWithTangentProperty);
}
set
{
SetValue(DoesRotateWithTangentProperty, value);
}
}
/// <summary>
/// IsAdditive
/// </summary>
public bool IsAdditive
{
get
{
return (bool)GetValue(IsAdditiveProperty);
}
set
{
SetValue(IsAdditiveProperty, value);
}
}
/// <summary>
/// IsAngleCumulative Property
/// </summary>
public static readonly DependencyProperty IsAngleCumulativeProperty =
DependencyProperty.Register(
"IsAngleCumulative",
typeof(bool),
typeof(MatrixAnimationUsingPath),
new PropertyMetadata(false));
/// <summary>
/// If this property is set to true, the rotation angle of the animated matrix
/// will accumulate over repeats of the animation. For instance if
/// your path is a small arc a cumulative angle will cause your object
/// to continuously rotate with each repeat instead of restarting the
/// rotation. When combined with IsOffsetCumulative, your object may
/// appear to tumble while it bounces depending on your path.
/// See <seealso cref="System.Windows.Media.Animation.MatrixAnimationUsingPath.IsOffsetCumulative">PathMatrixAnimation.IsOffsetCumulative</seealso>
/// for related information.
/// </summary>
/// <value>default value: false</value>
public bool IsAngleCumulative
{
get
{
return (bool)GetValue(IsAngleCumulativeProperty);
}
set
{
SetValue(IsAngleCumulativeProperty, value);
}
}
/// <summary>
/// IsOffsetCumulative Property
/// </summary>
public static readonly DependencyProperty IsOffsetCumulativeProperty =
DependencyProperty.Register(
"IsOffsetCumulative",
typeof(bool),
typeof(MatrixAnimationUsingPath),
new PropertyMetadata(false));
/// <summary>
/// If this property is set to true, the offset of the animated matrix
/// will accumulate over repeats of the animation. For instance if
/// your path is a small arc a cumulative offset will cause your object
/// to appear to bounce once for each repeat.
/// See <seealso cref="System.Windows.Media.Animation.MatrixAnimationUsingPath.IsAngleCumulative">PathMatrixAnimation.IsAngleCumulative</seealso>
/// for related information.
/// </summary>
/// <value>default value: false</value>
public bool IsOffsetCumulative
{
get
{
return (bool)GetValue(IsOffsetCumulativeProperty);
}
set
{
SetValue(IsOffsetCumulativeProperty, value);
}
}
/// <summary>
/// PathGeometry Property
/// </summary>
public static readonly DependencyProperty PathGeometryProperty =
DependencyProperty.Register(
"PathGeometry",
typeof(PathGeometry),
typeof(MatrixAnimationUsingPath),
new PropertyMetadata(
(PathGeometry)null));
/// <summary>
/// This geometry specifies the path.
/// </summary>
public PathGeometry PathGeometry
{
get
{
return (PathGeometry)GetValue(PathGeometryProperty);
}
set
{
SetValue(PathGeometryProperty, value);
}
}
#endregion
#region MatrixAnimationBase
/// <summary>
/// Calculates the value this animation believes should be the current value for the property.
/// </summary>
/// <param name="defaultOriginValue">
/// This value is the suggested origin value provided to the animation
/// to be used if the animation does not have its own concept of a
/// start value. If this animation is the first in a composition chain
/// this value will be the snapshot value if one is available or the
/// base property value if it is not; otherise this value will be the
/// value returned by the previous animation in the chain with an
/// animationClock that is not Stopped.
/// </param>
/// <param name="defaultDestinationValue">
/// This value is the suggested destination value provided to the animation
/// to be used if the animation does not have its own concept of an
/// end value. This value will be the base value if the animation is
/// in the first composition layer of animations on a property;
/// otherwise this value will be the output value from the previous
/// composition layer of animations for the property.
/// </param>
/// <param name="animationClock">
/// This is the animationClock which can generate the CurrentTime or
/// CurrentProgress value to be used by the animation to generate its
/// output value.
/// </param>
/// <returns>
/// The value this animation believes should be the current value for the property.
/// </returns>
protected override Matrix GetCurrentValueCore(Matrix defaultOriginValue, Matrix defaultDestinationValue, AnimationClock animationClock)
{
Debug.Assert(animationClock.CurrentState != ClockState.Stopped);
PathGeometry pathGeometry = PathGeometry;
if (pathGeometry == null)
{
return defaultDestinationValue;
}
if (!_isValid)
{
Validate();
}
Point pathPoint;
Point pathTangent;
pathGeometry.GetPointAtFractionLength(animationClock.CurrentProgress.Value, out pathPoint, out pathTangent);
double angle = 0.0;
if (DoesRotateWithTangent)
{
angle = DoubleAnimationUsingPath.CalculateAngleFromTangentVector(pathTangent.X, pathTangent.Y);
}
Matrix matrix = new Matrix();
double currentRepeat = (double)(animationClock.CurrentIteration - 1);
if (currentRepeat > 0)
{
if (IsOffsetCumulative)
{
pathPoint = pathPoint + (_accumulatingOffset * currentRepeat);
}
if ( DoesRotateWithTangent
&& IsAngleCumulative)
{
angle = angle + (_accumulatingAngle * currentRepeat);
}
}
matrix.Rotate(angle);
matrix.Translate(pathPoint.X, pathPoint.Y);
if (IsAdditive)
{
return Matrix.Multiply(matrix, defaultOriginValue);
}
else
{
return matrix;
}
}
#endregion
#region Private Methods
private void Validate()
{
Debug.Assert(!_isValid);
if ( IsOffsetCumulative
|| IsAngleCumulative)
{
Point startPoint;
Point startTangent;
Point endPoint;
Point endTangent;
PathGeometry pathGeometry = PathGeometry;
// Get values at the beginning of the path.
pathGeometry.GetPointAtFractionLength(0.0, out startPoint, out startTangent);
// Get values at the end of the path.
pathGeometry.GetPointAtFractionLength(1.0, out endPoint, out endTangent);
// Calculate difference.
_accumulatingAngle = DoubleAnimationUsingPath.CalculateAngleFromTangentVector(endTangent.X, endTangent.Y)
- DoubleAnimationUsingPath.CalculateAngleFromTangentVector(startTangent.X, startTangent.Y);
_accumulatingOffset.X = endPoint.X - startPoint.X;
_accumulatingOffset.Y = endPoint.Y - startPoint.Y;
}
_isValid = true;
}
#endregion
}
}
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