Kawase dual filter blur for GameMaker LTS 2022

A Kawase blur is a close approximation of a Gaussian blur, but one that is more performant and requires slightly less texture memory. Kawase blurs were developed for use with bloom in mind but can realistically be used anywhere blurring is needed.

This repo demonstrates an implementation of Kawase dual filter blur, based on Masaki Kawase's work shown in his 2003 GDC talk. More information on this technique can be found in this 2015 paper (.pdf) and in an Intel video that does a reasonable job of explaining the basic principles at work.

For Gaussian or sigmoid blur, please see my other blur repo.