cocos creator 帧率60 不生效meta50 能刷新到90

丶党玲儿2024-05-15 20:15

环境：

cocos creator 2.4.3

华为meta 50

背景：

小游戏需要在update 里取帧率发现跟时间对不上

游戏设置60帧

手机上显示 90帧

cc.game.setFrameRate(30) 显示 30帧

cc.game.setFrameRate(60) 显示 90帧

结论：

对于老版本的cocos creator 如果有依赖帧率的逻辑

需要自行注意逻辑正确性

cc.game.getFrameRate() 取出来的帧率有可能并不是当前真实帧率只是逻辑帧率

源码分析：

java 复制代码

	cocos2dxRenderer.java 

	@Override
    public void onDrawFrame(final GL10 gl) {
        if (mNeedToPause)
            return;

        if (mNeedShowFPS) {
            /
            //IDEA: show FPS in Android Text control rather than outputing log.
            ++mFrameCount;
            long nowFpsTime = System.nanoTime();
            long fpsTimeInterval = nowFpsTime - mOldNanoTime;
            if (fpsTimeInterval > 1000000000L) {
                double frameRate = 1000000000.0 * mFrameCount / fpsTimeInterval;
                Cocos2dxHelper.OnGameInfoUpdatedListener listener = Cocos2dxHelper.getOnGameInfoUpdatedListener();
                if (listener != null) {
                    listener.onFPSUpdated((float) frameRate);
                }
                mFrameCount = 0;
                mOldNanoTime = System.nanoTime();
            }
            /
        }
        /*
         * No need to use algorithm in default(60 FPS) situation,
         * since onDrawFrame() was called by system 60 times per second by default.
         */
        if (sAnimationInterval <= INTERVAL_60_FPS) {
            Cocos2dxRenderer.nativeRender();
        } else {
            final long now = System.nanoTime();
            final long interval = now - this.mLastTickInNanoSeconds;

            if (interval < Cocos2dxRenderer.sAnimationInterval) {
                try {
                    Thread.sleep((Cocos2dxRenderer.sAnimationInterval - interval) / Cocos2dxRenderer.NANOSECONDSPERMICROSECOND);
                } catch (final Exception e) {
                }
            }
            /*
             * Render time MUST be counted in, or the FPS will slower than appointed.
            */
            this.mLastTickInNanoSeconds = System.nanoTime();
            Cocos2dxRenderer.nativeRender();
        }
    }

分析上述代码

java 复制代码

if (sAnimationInterval <= INTERVAL_60_FPS) {
            Cocos2dxRenderer.nativeRender();
}

说明 >= 60帧的设置。没有处理刷新帧率走的系统是高刷

所以会导致 dt 并不是 60帧的dt