CONTROLS
- [esc]: show / hide UI
- [space]: pause / play
- [enter]: next step
- [<--]: reset to random
- [del]: reset to empty
- [LMB]: draw alive cell
- [shift+LMB]: erase cell
- [Mouse Wheel]: zoom
- [RMB]: pan around
- [h]: toggle history shader
- [1]...[9]: change brush size
- [F11]: fullscreen
- [c][s][r]: change brush shape
- [Tab]: save current state image