Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Core / CSharp / System / Windows / Media / Animation / BounceEase.cs / 1305600 / BounceEase.cs
//------------------------------------------------------------------------------ // Copyright (c) Microsoft Corporation, 2008 // // File: BounceEase.cs //----------------------------------------------------------------------------- using MS.Internal; namespace System.Windows.Media.Animation { ////// This class implements an easing function that can be used to simulate bouncing /// public class BounceEase : EasingFunctionBase { public BounceEase() { } ////// Bounces Property /// public static readonly DependencyProperty BouncesProperty = DependencyProperty.Register( "Bounces", typeof(int), typeof(BounceEase), new PropertyMetadata(3)); ////// Specifies the number of bounces. This does not include the final half bounce. /// public int Bounces { get { return (int)GetValue(BouncesProperty); } set { SetValueInternal(BouncesProperty, value); } } ////// Bounciness Property /// public static readonly DependencyProperty BouncinessProperty = DependencyProperty.Register( "Bounciness", typeof(double), typeof(BounceEase), new PropertyMetadata(2.0)); ////// Specifies the amount of bounciness. This corresponds to the scale difference between a bounce and the next bounce. /// For example, Bounciness = 2.0 correspondes to the next bounce being twices as high and taking twice as long. /// public double Bounciness { get { return (double)GetValue(BouncinessProperty); } set { SetValueInternal(BouncinessProperty, value); } } protected override double EaseInCore(double normalizedTime) { // The math below is complicated because we have a few requirements to get the correct look for bounce: // 1) The bounces should be symetrical // 2) Bounciness should control both the amplitude and the period of the bounces // 3) Bounces should control the number of bounces without including the final half bounce to get you back to 1.0 // // Note: Simply modulating a expo or power curve with a abs(sin(...)) wont work because it violates 1) above. // // Constants double bounces = Math.Max(0.0, (double)Bounces); double bounciness = Bounciness; // Clamp the bounciness so we dont hit a divide by zero if (bounciness < 1.0 || DoubleUtil.IsOne(bounciness)) { // Make it just over one. In practice, this will look like 1.0 but avoid divide by zeros. bounciness = 1.001; } double pow = Math.Pow(bounciness, bounces); double oneMinusBounciness = 1.0 - bounciness; // 'unit' space calculations. // Our bounces grow in the x axis exponentially. we define the first bounce as having a 'unit' width of 1.0 and compute // the total number of 'units' using a geometric series. // We then compute which 'unit' the current time is in. double sumOfUnits = (1.0 - pow) / oneMinusBounciness + pow * 0.5; // geometric series with only half the last sum double unitAtT = normalizedTime * sumOfUnits; // 'bounce' space calculations. // Now that we know which 'unit' the current time is in, we can determine which bounce we're in by solving the geometric equation: // unitAtT = (1 - bounciness^bounce) / (1 - bounciness), for bounce. double bounceAtT = Math.Log(-unitAtT * (1.0-bounciness) + 1.0, bounciness); double start = Math.Floor(bounceAtT); double end = start + 1.0; // 'time' space calculations. // We then project the start and end of the bounce into 'time' space double startTime = (1.0 - Math.Pow(bounciness, start)) / (oneMinusBounciness * sumOfUnits); double endTime = (1.0 - Math.Pow(bounciness, end)) / (oneMinusBounciness * sumOfUnits); // Curve fitting for bounce. double midTime = (startTime + endTime) * 0.5; double timeRelativeToPeak = normalizedTime - midTime; double radius = midTime - startTime; double amplitude = Math.Pow(1.0 / bounciness, (bounces - start)); // Evaluate a quadratic that hits (startTime,0), (endTime, 0), and peaks at amplitude. return (-amplitude / (radius * radius)) * (timeRelativeToPeak - radius) * (timeRelativeToPeak + radius); } protected override Freezable CreateInstanceCore() { return new BounceEase(); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- TraversalRequest.cs
- GACMembershipCondition.cs
- DbDataAdapter.cs
- DbXmlEnabledProviderManifest.cs
- UriWriter.cs
- GrammarBuilderBase.cs
- ProviderException.cs
- CloseCollectionAsyncResult.cs
- ErrorEventArgs.cs
- FormsAuthenticationUserCollection.cs
- ApplicationHost.cs
- InputScopeNameConverter.cs
- AnimationTimeline.cs
- SchemaTypeEmitter.cs
- DictionarySectionHandler.cs
- ChtmlTextWriter.cs
- ProgressBar.cs
- FileUtil.cs
- WebPartMovingEventArgs.cs
- oledbmetadatacolumnnames.cs
- TaskFormBase.cs
- UniqueConstraint.cs
- GenericIdentity.cs
- Attributes.cs
- HotSpot.cs
- ModelChangedEventArgsImpl.cs
- ProxyGenerator.cs
- NativeRecognizer.cs
- TextFormatterContext.cs
- Tokenizer.cs
- ToolStripControlHost.cs
- SystemInfo.cs
- Transform.cs
- EventWaitHandle.cs
- HttpModuleActionCollection.cs
- UTF7Encoding.cs
- ThreadNeutralSemaphore.cs
- HwndMouseInputProvider.cs
- InArgument.cs
- TypeConverterHelper.cs
- ViewStateException.cs
- WebPageTraceListener.cs
- CapabilitiesAssignment.cs
- MouseGestureValueSerializer.cs
- StretchValidation.cs
- BookmarkResumptionRecord.cs
- SamlSubjectStatement.cs
- EditorZoneBase.cs
- PasswordTextNavigator.cs
- BaseCollection.cs
- XmlSchemaExporter.cs
- MsmqTransportReceiveParameters.cs
- Color.cs
- CodeGeneratorOptions.cs
- NonVisualControlAttribute.cs
- HtmlTableRow.cs
- Size3D.cs
- ApplicationServiceHelper.cs
- QueuePathEditor.cs
- EncoderBestFitFallback.cs
- RemotingAttributes.cs
- ExpressionEditor.cs
- GetPageNumberCompletedEventArgs.cs
- JavaScriptString.cs
- XmlDownloadManager.cs
- VirtualPathProvider.cs
- FamilyTypeface.cs
- SQLByteStorage.cs
- tibetanshape.cs
- DataGridViewCellStateChangedEventArgs.cs
- VerificationException.cs
- MediaCommands.cs
- PathData.cs
- ObjectDataSourceSelectingEventArgs.cs
- ToolStripOverflow.cs
- XmlDataImplementation.cs
- SettingsBase.cs
- DesignerRegionMouseEventArgs.cs
- EdmToObjectNamespaceMap.cs
- Rectangle.cs
- TagMapInfo.cs
- messageonlyhwndwrapper.cs
- FrameworkContentElement.cs
- ValueTable.cs
- DataSet.cs
- RegexNode.cs
- TypefaceMap.cs
- QueryConverter.cs
- ComponentEvent.cs
- HttpProtocolReflector.cs
- UIElementParaClient.cs
- ReflectTypeDescriptionProvider.cs
- ButtonBaseDesigner.cs
- ListViewUpdatedEventArgs.cs
- SortKey.cs
- HttpCookiesSection.cs
- HuffModule.cs
- DependencyPropertyHelper.cs
- ParallelDesigner.xaml.cs
- ConditionCollection.cs