     public init(width: Int, height: Int) {
         self.width = width
         self.height = height
-        self._image = GPContext.clear
+        self._image = CIImage.empty()
     }
     
     private init(width: Int, height: Int, image: CIImage) {

        
        if opacity < 1 {
            let mask = CIImage(color: CIColor(red: 1, green: 1, blue: 1, alpha: CGFloat(opacity)))
            image = image.applyingFilter("CIBlendWithAlphaMask", parameters: [kCIInputBackgroundImageKey: GPContext.clear, kCIInputMaskImageKey: mask])
        }
        
        self.blend_layer(image)

    }
    
    public var image: CIImage {
        return _image.clamped(to: extent).cropped(to: extent)
    }
}

