circle-done.red

Red [
	Needs: 'View
]

dangle: pi / 255
pi2:    pi * 2

angle:  0.0
radius: 200
buffer: make image! 500x500

drawer: does [
	append copy [line 250x250] (as-pair
		(cos angle) * radius
		(sin angle) * radius) + 250x250
]

view [
	base 0x0 image buffer rate 60
	on-time [
		if (angle: angle + dangle) < pi2
			[draw buffer drawer]
	]
]