Tools (design)

	zoom in
	zoom out
	push the current set of segments on to a stack
	pop the set of segments off the stack ( the set of segments replaces the last on-screen segment but retains its orientation)
	remove last segment
	clear
	grid attractor
	angle attractor
	length attractor (from current point)
	affine transformation attractor
	affine transformation attractor
	vectors radiate from origin
	patterns are created clockwise