cairo/canvas.go
func (v *Context) ClipExtents() (x1, y1, x2, y2 float64) {
	var cx1, cy1, cx2, cy2 C.double
	C.cairo_clip_extents(v.native(), &cx1, &cy1, &cx2, &cy2)
	return float64(cx1), float64(cy1), float64(cx2), float64(cy2)
}
func (v *Context) ClipExtents() (x1, y1, x2, y2 float64) {
	var cx1, cy1, cx2, cy2 C.double
	C.cairo_clip_extents(v.native(), &cx1, &cy1, &cx2, &cy2)
	return float64(cx1), float64(cy1), float64(cx2), float64(cy2)
}
// ClipExtents is a wrapper around cairo_clip_extents().