A simple animation in Zajal 0.3.3, a circle that grows and shrinks over time.

zajalAnimation.rb

# Simple animation example
# in Zajal

sizeBase 	= 0
speed 		= 0.05

setup do
	title 		"Simple Circle"
	framerate	60
	smoothing	true
end

update do
	sizeBase += speed
end

draw do
	radius = sin( sizeBase )*25
	circle width/2,height/2,radius

	text "FPS %0.2f"%framerate, 20, height - 20
	text "Radius %0.2f"%radius, 20, height - 35
end