The Shadow filter is used in many common situations, including a component of the DropShadow and InnerShadow effects and also the PhongLighting effect. Right now any device without hardware (GPU) acceleration will use either a native compiled (SSE enabled) function or a Java method that was written by the automated JSL compiler. The code is surprisingly fast for code that was derived from a Shader source language, but it isn't as fast as it could be by rewriting the inner loops by hand.

A quick hand-tuning of the inner loops of the Java and SSE backends for Shadow show approximately a 6x improvement in Shadow and DropShadow. Here is a quick table of the results:

                                      radius 10 radius 63
JSL Java 89 955
JSL SSE 56 650

Hand tuned Java 21 150
Hand tuned SSE 12.5 83

D3D 5 13