For Marina we added API to all of the *Shadow classes to allow a Box filter implementation of the Shadow. We also changed the default setting for that API from Gaussian (which would be 100% identical to 1.1) to ThreePassBox (which should be within 3% of the 1.1 implementation). The new Box filter is a little faster than the Gaussian filter using its default implementation, but the real benefit of this new algorithm is that a software implementation can use an incremental algorithm which is much, much faster than the Gaussian, or the general Box filter implementation.

This issue is created to track the creation of the incremental software algorithms to handle the new Box filter for the Shadow classes.