void vkvgDraw()
{
using (vkvg.Context ctx = new vkvg.Context(vkvgSurf)) {
ctx.SetSource(1.0, 1.0, 1.0);
ctx.Paint();
ctx.Translate(100, 100);
ctx.Scale(3, 3);
ctx.SetSource(0.1, 0.1, 0.1);
ctx.Arc(100, 100, 10.0, 0, Math.PI * 2.0);
ctx.LineWidth = 1.0;
ctx.Stroke();
}
}