Method _startRenderLoop

packages/runtime-core/src/GameRuntime.ts:570–576

* 启动渲染循环

()

     * 启动渲染循环
     */
    private _startRenderLoop(): void {
        if (this._animationFrameId !== null) {
            return;
        }
        this._lastTime = performance.now();
        this._renderLoop();
    }

    /**
     * 渲染循环