paint by π — a digital painting & Conway's Game of Life simulator

Guide to controls, shortcuts, settings & URL configuration

<--- get back to painting

paint by π is a painting tool and a Game of Life cellular automaton. Every brush stroke seeds cells into the simulation — which evolve over time based on rules.


On-Screen Menu (bottom-right corner)

Tap / click the UI buttons in the lower-right corner to open the control wheel. Buttons navigate levels and adjust parameters:

UI appears only if ui=1 or the user hasn't hidden it, and can be toggled at any time with keyboard \.


Keyboard Controls

Painting & Evolution
SPACE — Pause / Play simulation
R — Reset / restart simulation
Visual / Display
F — Fade trail toggle
D — Full clear toggle
L — Light / Dark mode
C — Cycle color modes
Q — Cursor stroke toggle
\ — Show / Hide UI menu
Speed
, — Faster evolution
. — Slower evolution
Feedback (experimental)
↑ ↓ ← → — Offset simulation border
Shift — Turn feedback scrolling on/off
/ — Enable/disable 'hot-edges'
Debugging
S — Log full settings to console

URL “Modes” — Presets that apply multiple settings at once

The mode parameter can include multiple space-separated modes and they are applied in order:

?mode=penandpaper colordrop
Available modes:

Color / Theme Modes

Cell Size / Brush Size

Speed / Frame Buffer

Random Cell Excitment

Initialization Algorithm

UI / Controls

Border / Fade / Cursor

Brush Tips

Playback

Timing / Cycle


URL “Direct Control” — Modify engine values manually

Append parameters to the URL:

?alg=4&color=2&fade=1&scale=6&ran=8&ranwait=600
algStarting algorithm (0–5)
color0 ink · 1 sakura · 2 rainbow
fade1 fade trail · 0 static
clearRemove background each update
scaleCell size
ranRandom seed drops per cycle
ranwaitRandom seed frequency (frames)
buffFrame buffer (simulation speed)
ui1 show menu · 0 hide menu
light1 light mode · 0 dark mode
clCursor line trail on/off
bsBrush size

Example:

/paint?mode=sakura&buff=1&cl=1&bs=14

Feedback & Help ✨

if you have any questions or suggestions for what i could add to this app, please feel free to reach out [ @gqz7777 on instagram ]