Turtle Drawing

Scripts

Variables

declare vars with: var name = 6 [3 20]

speed 30

Script Reference

Turtle commands, helpers, and quick patterns

Use the editor on the left, then run the script or drag sliders to re-render. Expressions use degrees for trig functions, and # starts a line comment unless it forms a hex color.

Movement

fd n forward bk n back rt deg turn right lt deg turn left home center + heading setpos x y relative to center seth deg absolute heading

Pen + Color

pu pen up pd pen down size n stroke width alpha n 0 to 1 opacity color #hex or named color color hsl h s l HSL color rainbow animated hue norainbow fixed color

Shapes + State

circle r draw circle arc r deg partial circle dot n filled point tree len depth [angle] recursive tree push save turtle state pop restore turtle state cs clear canvas

push and pop are useful for branching structures and radial variations, especially with random angles.

Flow + Variables

var name = 6 [3 20] slider variable let x = expr local value repeat n [ ... ] fixed loop for i from to [ ... ] loop with index

Math Functions

sin cos tan degree-based trig asin acos atan atan2 inverse trig sqrt abs floor ceil round basics pow min max mod exp log log2 utilities random(a, b) float between bounds randint(a, b) integer between bounds clamp(x, lo, hi) constrain value lerp(a, b, t) interpolate 0..1 pi tau e constants

random(n) returns a float from 0 to n. random(a, b) works in either order.

Quick Example

var branches = 42 [8 90]
var step = 14 [4 40]
var spread = 28 [6 75]

color hsl 145 62 58
size 1.5
repeat branches [
  push
  rt random(-spread, spread)
  fd step + random(step * 0.25, step * 1.4)
  pop
  rt 360 / branches
]

Shortcuts: Ctrl/Cmd+Enter run, Ctrl/Cmd+S save, Ctrl/Cmd+Z undo, Shift+Ctrl/Cmd+Z redo, Esc closes this panel.