Added support for getting & setting location of Renderer.

allg5ui/renderer.go

@@ -288,7 +288,8 @@ func (r *Renderer) Line(p, q geom.PointF32, color color.Color, thickness float32
 }
 
 func (r *Renderer) Location() geom.Point {
-	return geom.Pt(r.disp.Position()...)
+	x, y := r.disp.Position()
+	return geom.Pt(x, y)
 }
 
 func (r *Renderer) Move(to geom.Point) {