import arsd.simpledisplay; void main() { auto window = new SimpleWindow(512, 512); float h = 3; float s = 0.5; float l = 0.5; window.eventLoop(50, () { auto painter = window.draw(); auto dim = 512; while(dim > 5) { h += 3; s += 0.03; l += 0.07; if(h >= 360) h -= 360; if(s >= 1.0) s -= 1.0; if(l >= 1.0) l -= 1.0; painter.fillColor = Color.fromHsl(h, s, l); painter.drawCircle(Point(dim, dim), dim); dim -= 5; } }); }