protected static HDRExposure getExposure( HDRExposure oldExposure, int w, int h, boolean clear ) {
		if( oldExposure != null && oldExposure.width == w && oldExposure.height == h ) {
			// Can re-use the object!
			if( clear ) oldExposure.clear();
			return oldExposure;
		} else if( clear ) {
			// Then just make a new one.
			return new HDRExposure(w, h);
		} else {
			// Then scale up the old one.
			return ExposureScaler.scaleTo(oldExposure, w, h);
		}
	}