Value: 640
Standard quantized DPI for extra-extra-extra-high-density screens. Applications should not generally worry about this density; relying on XHIGH graphics being scaled up to it should be sufficient for almost all cases. A typical use of this density would be 4K television screens -- 3840x2160, which is 2x a traditional HD 1920x1080 screen which runs at DENSITY_XHIGH.