A GDShader editor/viewer panel or subwindow, for viewing art with realtime post-processing effects

[its-bearnadette]

Pixel art made targeting a flat panel looks wholly different from pixel art made targeting a CRT, and while post-processing shaders aren't a perfect solution to getting a "CRT effect" by any means, it could work well as a preview for how a game's sprites would look in-game with all the post-processing without leaving the editor. It feels to me like it'd be about as useful as realtime compositing in Blender.