OK, it's getting embarassing now. The very first, core piece of code that eventually spawned the Minecraft Structure Planner was a simple pixel-art editor. I've added three dimensional views, models that are parametrically generated, freeform designers, import and export of multiple file formats, and yet the pixel-art editor code still sits there lonely and unincorporated.
Enough is enough. The next piece of functionality that I'm going to add to the application is going to be the Pixel Art tab. Depending on how much free time I have to work on it, expect it on or shortly after the weekend.