This patch includes a new shadow algorithm. I think it looks much better. It also includes shadow for text
thank you for the modifications to the shadow that was introduced by Tracker # 2635032 from Wolfgang. I only had to change your patch slightly as there was an inconsistency with the EllipseContainer (int currentStep = lineThickness/2; whereas the others had plain and simple "int currentStep = 1;".) I don't know if this was "as designed" or a copy/paste error. But I didn't notice any major change so I used the "int currentStep = 1;" for consistency.
I also changed the check as I turned the shadow off when the lineThickes is only 1, as I didn't like it than, with your enhancement it looks quite good when it is 1.