quality but avoid dpr over 2 which is too large for mobile to render if (isMobile) { const dprLimit = Math.min(window.devicePixelRatio, 2); outputResolution.width = nearEvenize(renderPosition.width * dprLimit); outputResolution.height = nearEvenize(renderPosition.height * dprLimit); } アスペクト比を維持した状態の表示サイズ * min(dpr, 2) dprが2超えた場合を2にする