protected internal override void internal_draw(RenderPass pass, RenderPassDrawMode mode)
{
First.internal_draw(pass, mode);
Second.internal_draw(pass, mode.Invert());
}
protected internal override void internal_draw(RenderPass pass, RenderPassDrawMode mode)
{
Union.internal_draw(pass, mode);
Overlap.internal_draw(pass, mode.Invert());
}