presentRenderbuffer：GL_RENDERBUFFER_OES需要很长时间

Question

我在我的游戏中添加了一个分析器并隔离了此功能。它有时会导致FPS下降。这是我的结果：

Present buffer time: 22 
Present buffer time: 1 
Present buffer time: 9 
Present buffer time: 1 
Present buffer time: 20 
Present buffer time: 6 
Present buffer time: 4 
Present buffer time: 4 
Present buffer time: 22 
Present buffer time: 4 
Present buffer time: 8 
Present buffer time: 4 
Present buffer time: 4 
Present buffer time: 15 
Present buffer time: 1 
Present buffer time: 1 
Present buffer time: 1 
Present buffer time: 11 
Present buffer time: 1 
Present buffer time: 6 
Present buffer time: 1 
Present buffer time: 1 
Present buffer time: 25 
Present buffer time: 6 
Present buffer time: 7 
Present buffer time: 1 
Present buffer time: 10 
Present buffer time: 7 
Present buffer time: 3 
Present buffer time: 1 
Present buffer time: 12 
Present buffer time: 9 
Present buffer time: 6 
Present buffer time: 9 

你知道为什么在每隔几帧这个功能需要更多时间吗？

这是我的代码：

    f64 time = -System::GetTime();  
    [m_context presentRenderbuffer:GL_RENDERBUFFER_OES]; 
    Log("Present buffer time: %d\n", u32((System::GetTime() + time) * 1000.)); 

Answer 1

如果您没有明确地调用glFlush()，则当您显示缓冲区时，驱动程序将被强制执行此操作，因为调用缓冲区上的渲染操作可能尚未完成。

在呈现缓冲区并分别测量缓冲区的时间之前，请尝试调用glFlush。

Answer 2

渲染缓冲器演示实际上转到显示器可以被量化为30赫兹或60赫兹的刷新率。快速渲染可能实际上只是在先前的渲染完成之前丢弃之前的渲染。