/// <summary>
/// Creates the CompositionMask having the given size, geometry & brush
/// </summary>
/// <param name="size">Size of the mask</param>
/// <param name="geometry">Geometry of the mask</param>
/// <param name="brush">Brush to fill the geometry.</param>
/// <returns>ICompositionMask</returns>
public ICompositionMask CreateMask(Size size, CanvasGeometry geometry, ICanvasBrush brush)
{
// Initialize the mask
ICompositionMask mask = new CompositionMask(this, size, geometry, brush);
// Render the mask
mask.Redraw();
return(mask);
}
/// <summary>
/// Creates a CompositionMask having the given size and geometry
/// </summary>
/// <param name="size">Size of the mask</param>
/// <param name="geometry">Geometry of the mask</param>
/// <returns></returns>
public Task <ICompositionMask> CreateMaskAsync(Size size, CanvasGeometry geometry)
{
return(Task.Run(() =>
{
//
// Since the drawing is done asynchronously and multiple threads could
// be trying to get access to the device/surface at the same time, we need
// to do any device/surface work under a lock.
//
lock (_drawingLock)
{
ICompositionMask mask = new CompositionMask(this, size, geometry);
// Render the mask to the surface
using (var session = CanvasComposition.CreateDrawingSession((CompositionDrawingSurface)mask.Surface))
{
// If the geometry is not null then fill the geometry area
// with white. The rest of the area on the surface will be transparent.
// When this mask is applied to a visual, only the area that is white
// will be visible.
if (geometry != null)
{
session.Clear(Colors.Transparent);
session.FillGeometry(geometry, Colors.White);
}
else
{
// If the geometry is null, then the entire mask should be filled white
// so that the masked visual can be seen completely.
session.Clear(Colors.White);
}
}
return mask;
}
}));
}
