CompositionMaskBrush Class

Definition

public ref class CompositionMaskBrush sealed : CompositionBrush

/// [Windows.Foundation.Metadata.ContractVersion(Microsoft.Foundation.LiftedContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class CompositionMaskBrush final : CompositionBrush

/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
/// [Windows.Foundation.Metadata.ContractVersion(Microsoft.Foundation.WindowsAppSDKContract, 65536)]
class CompositionMaskBrush final : CompositionBrush

[Windows.Foundation.Metadata.ContractVersion(typeof(Microsoft.Foundation.LiftedContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public sealed class CompositionMaskBrush : CompositionBrush

[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
[Windows.Foundation.Metadata.ContractVersion(typeof(Microsoft.Foundation.WindowsAppSDKContract), 65536)]
public sealed class CompositionMaskBrush : CompositionBrush

Public NotInheritable Class CompositionMaskBrush
Inherits CompositionBrush

Inheritance

Object Platform::Object IInspectable CompositionObject CompositionBrush CompositionMaskBrush

Attributes

ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Examples

Apply a star-shaped mask to an image.

private SpriteVisual CreateCircleImage(ICompositionSurface myImageSurface, ICompositionSurface myStarMaskSurface) 
{ 
 // Create SurfaceBrush with image surface and specify stretch and alignment 
 CompositionSurfaceBrush imageBrush = _compositor.CreateSurfaceBrush(myImageSurface); 
 imageBrush.HorizontalAlignmentRatio = 0.5f; 
 imageBrush.VerticalAlignmentRatio = 0.5f; 
 imageBrush.Stretch = CompositionStretch.UniformToFill; 

 // Create surface brush with opacity mask surface and specify stretch and alignment 
 CompositionSurfaceBrush starMaskBrush = _compositor.CreateSurfaceBrush(myStarMaskSurface); 
 starMaskBrush.Stretch = CompositionStretch.Uniform; 

 // SpriteVisual to be painted with masked content 
 SpriteVisual imageVisual = _compositor.CreateSpriteVisual(); 
 imageVisual.Size = new Vector2(200, 200); 

 // Create MaskBrush 
 CompositionMaskBrush maskBrush = _compositor.CreateMaskBrush(); 
 maskBrush.Source = imageBrush; // Set source to content that is to be masked 
 maskBrush.Mask = starMaskBrush; // Set mask to content that is the opacity mask 

 imageVisual.Brush = maskBrush; // Paint SpriteVisual with MaskBrush 

 return imageVisual; 
} 

Applying an opacity mask to solid color fill to create a shape; animate the transform property on the opacity mask CompositionSurfaceBrush to create a color bloom animation

private void CreateCircleMaskSprite(ICompositionSurface myCircleMaskSurface, ICompositionSurface myImageSurface)
{
 // SpriteVisual to be painted by MaskBrush
 _circleVisual = _compositor.CreateSpriteVisual();
 _circleVisual.Size = MyContainerGrid.RenderSize.ToVector2();

 // SurfaceBrush w/ image as MaskBrush.Source
 CompositionSurfaceBrush imageBrush = _compositor.CreateSurfaceBrush(myImageSurface);
 imageBrush.Stretch = CompositionStretch.UniformToFill;

 // SurfaceBrush w/ opacity mask surface as MaskBrush.Mask
 CompositionSurfaceBrush circleBrush = _compositor.CreateSurfaceBrush(myCircleMaskSurface);

 // Specify stretch and transform properties to scale and position brush for initial state
 circleBrush.Stretch = CompositionStretch.Uniform;
 circleBrush.CenterPoint = _circleVisual.Size / 2;
 circleBrush.Scale = new Vector2(0.5f);

 // Create MaskBrush
 CompositionMaskBrush maskBrush = _compositor.CreateMaskBrush();
 maskBrush.Source = imageBrush;
 maskBrush.Mask = circleBrush;
 _circleVisual.Brush = maskBrush;

 // Set SpriteVisual as child of XAML Grid
 ElementCompositionPreview.SetElementChildVisual(MyContainerGrid, _circleVisual);
}

private void BloomAnimation()
{
 // Create KeyFrame Animation to target Scale transform on SurfaceBrush 
 Vector2KeyFrameAnimation scaleAnimation = _compositor.CreateVector2KeyFrameAnimation();
 scaleAnimation.InsertKeyFrame(1.0f, new Vector2(2));
 scaleAnimation.Duration = TimeSpan.FromMilliseconds(500);

 var maskBrush = (CompositionMaskBrush)_circleVisual.Brush;
 var surfaceBrush = (CompositionSurfaceBrush) maskBrush.Mask;

 // Animate the Scale on the circle opacity mask
 surfaceBrush.StartAnimation("Scale", scaleAnimation); 
}

Applying a rounded rectangle mask to create a solid color rounded rectangle whose corner radius does not increase upon resizing (use CompositionNineGridBrush as input to a CompositionMaskBrush ).

private SpriteVisual CreateMaskedRoundedRectVisual(ICompositionSurface myRoundedRectMaskSurface)
{
 // ColorBrush to be set as MaskBrush.Source
 CompositionColorBrush colorBrush = _compositor.CreateColorBrush(Colors.Blue);

 // SurfaceBrush w/ opacity mask surface
 CompositionSurfaceBrush roundedRectBrush = _compositor.CreateSurfaceBrush(myRoundedRectMaskSurface);
 roundedRectBrush.Stretch = CompositionStretch.Fill; // stretch for center of nine-grid

 // NineGridBrush w/ insets on opacity mask surface
 CompositionNineGridBrush ninegridBrush = _compositor.CreateNineGridBrush();
 ninegridBrush.Source = roundedRectBrush;
 ninegridBrush.SetInsets(_cornerRadius); // the radius, in pixels, of the corner as specified on my opacity mask surface 

 // Create MaskBrush
 CompositionMaskBrush maskBrush = _compositor.CreateMaskBrush();
 maskBrush.Source = colorBrush;
 maskBrush.Mask = ninegridBrush;

 // Paint SpriteVisual with MaskBrush
 SpriteVisual sprite = _compositor.CreateSpriteVisual();
 sprite.Size = new Vector2(300, 200);
 sprite.Brush = maskBrush;
 return sprite;

}

Remarks

CompositionMaskBrush can not be set as the source parameter to a CompositionEffectBrush. If you wish to apply an IGraphicsEffect to your masked content, use a CompositionEffectBrush with the Composite effect instead.

See also

• CompositionBrush
• IClosable