private void ReccursiveDrawWithClipping(UIElement element)
{
// if the element is not visible, we also remove all its children
if (!element.IsVisible)
{
return;
}
var renderer = rendererManager.GetRenderer(element);
renderingContext.DepthBias = element.DepthBias;
// render the clipping region of the element
if (element.ClipToBounds)
{
// flush current elements
batch.End();
// render the clipping region
batch.Begin(ref uiSystem.ViewProjectionInternal, GraphicsDevice.BlendStates.ColorDisabled, uiSystem.IncreaseStencilValueState, renderingContext.StencilTestReferenceValue);
renderer.RenderClipping(element, renderingContext);
batch.End();
// update context and restart the batch
renderingContext.StencilTestReferenceValue += 1;
batch.Begin(ref uiSystem.ViewProjectionInternal, GraphicsDevice.BlendStates.AlphaBlend, uiSystem.KeepStencilValueState, renderingContext.StencilTestReferenceValue);
}
// render the design of the element
renderer.RenderColor(element, renderingContext);
// render the children
foreach (var child in element.VisualChildrenCollection)
{
ReccursiveDrawWithClipping(child);
}
// clear the element clipping region from the stencil buffer
if (element.ClipToBounds)
{
// flush current elements
batch.End();
renderingContext.DepthBias = element.MaxChildrenDepthBias;
// render the clipping region
batch.Begin(ref uiSystem.ViewProjectionInternal, GraphicsDevice.BlendStates.ColorDisabled, uiSystem.DecreaseStencilValueState, renderingContext.StencilTestReferenceValue);
renderer.RenderClipping(element, renderingContext);
batch.End();
// update context and restart the batch
renderingContext.StencilTestReferenceValue -= 1;
batch.Begin(ref uiSystem.ViewProjectionInternal, GraphicsDevice.BlendStates.AlphaBlend, uiSystem.KeepStencilValueState, renderingContext.StencilTestReferenceValue);
}
}