True, many factors at play. The last time this code ran was in 2012, and computers and JS engines were slower then. Also, my Comfy language interpreter is eas

True, many factors at play. The last time this code ran was in 2012, and computers and JS engines were slower then. Also, my Comfy language interpreter is easy to bog down with sprite signal processing. The only cure for that is improving interpreter performance. I need it to run good on tablets and phones, lots of tuning to do in general. I like your algorithm idea! Stensils are indeed a fast way to work. I think I'll still do better on a worker thread with bit swizzling in the CPU rather than reading back stencil video memory. I'll have to spike it.