//----------------------------------------------------------------------
//
// Private Methods
//
//----------------------------------------------------------------------
#region Private Methods
/// <summary>
/// The compile method transforms the Visual Scene Graph into the Composition Scene Graph.
/// </summary>
private void Compile(DUCE.Channel channel)
{
MediaContext mctx = MediaContext.From(Dispatcher);
Invariant.Assert(_rootVisual.Value != null);
// 1) Check if we have a cached render context.
// 2) Initialize the render context.
// 3) Call to render the scene graph (transforming it into the composition scene graph).
// 4) Deinitalize the render context and cache it if possible.
// ------------------------------------------------------------------------------------
// 1) Get cached render context if possible.
// For performance reasons the render context is cached between frames. Here we check if
// we have a cached one. If we don't we just create a new one. If we do have one, we use
// the render context. Note that we null out the _cachedRenderContext field. This means
// that in failure cases we will always recreate the render context.
RenderContext rc = null;
Invariant.Assert(channel != null);
if (_cachedRenderContext != null)
{
rc = _cachedRenderContext;
_cachedRenderContext = null;
}
else
{
rc = new RenderContext();
}
// ------------------------------------------------------------------------------------
// 2) Prepare the render context.
rc.Initialize(channel, _contentRoot.GetHandle(channel));
// ------------------------------------------------------------------------------------
// 3) Compile the scene.
if (mctx.IsConnected)
{
_rootVisual.Value.Render(rc, 0);
}
// ------------------------------------------------------------------------------------
// 4) Cache the render context.
Debug.Assert(_cachedRenderContext == null);
_cachedRenderContext = rc;
}
/// <summary>
/// AddRefOnChannel
/// </summary>
DUCE.ResourceHandle DUCE.IResource.AddRefOnChannel(DUCE.Channel channel)
{
// reconsider the need for this lock
using (CompositionEngineLock.Acquire())
{
#if DEBUG
// We assume that a multi-channel resource can only be multi-channel
// if it is Frozen and does not have animated properties. In this case we know
// the target resource has at least one animated property so we expect that this
// independently animated property resource will only be added to the channel
// associated with the MediaContext associated with the target object's Dispatcher.
DependencyObject d = (DependencyObject)_dependencyObject.Target;
// I'm not sure how our target animated DependencyObject would get garbage
// collected before we call AddRefOnChannel on one of its animated property
// resources, but if it happens it will be a bad thing.
Debug.Assert(d != null);
// Any animated DependencyObject must be associated with a Dispatcher because the
// AnimationClocks doing the animating must be associated with a Dispatcher.
Debug.Assert(d.Dispatcher != null);
// Make sure the target belongs to this thread
Debug.Assert(d.CheckAccess());
#endif
if (_duceResource.CreateOrAddRefOnChannel(this, channel, ResourceType))
{
_updateResourceHandler = new MediaContext.ResourcesUpdatedHandler(UpdateResource);
UpdateResourceCore(channel);
}
return(_duceResource.GetHandle(channel));
}
}
