winapi – 在窗口模式下在Windows 10上等待VBLANK的正确方法

D3DKMTWaitForVerticalBlankEvent(&waitData);
swapchain->Present(0,0);

然而,这会导致偶尔的口吃.我目前关于口吃的理论如下：
DWM在VBLANK事件之前的某个时间完成合成,然后在VBLANK间隔期间,DWM尝试尽可能快地写入前端缓冲区.因此,如果在VBLANK间隔中调用Present,则可能在DWM写入前缓冲区后发生.这是我头脑中的画面：

因此,更正确的方法是在VBLANK之前调用Present(1,0)以使用DWM对窗口的后缓冲区进行排队.然后调用D3DKMTWaitForVerticalBlankEvent等到下一个VBLANK.那是：

swapchain->Present(1,0);
D3DKMTWaitForVerticalBlankEvent(&waitData);

有相应的图片：

第二种方法看起来很完美,不再有任何口吃.

我的问题是：
什么是在VBLANK间隔中呈现的正确方法
我的理论是正确的还是有更复杂/更简单的事情发生？
还有什么资源可以了解这种互动的更多信息吗？

潜在有用的链接：
MSDN Present
DXGI Best Practices
DXGI Waitable Swap Chain
D3DKMTWaitForVerticalBlankEvent

编辑：
不确定这应该是答案还是编辑.
经过一些谷歌搜索后,我发现this explanation by Nicholas Steel似乎与我的理论一致

There is no sure fire way to detect exactly when VBlank will occur
because Windows doesn’t expose a VBlank interrupt,and displays/GPU
aren’t necessarily required to generate one anyway (in addition,
‘current scanline’ information as given by e.g.
IDirect3DDevice9::GetRasterStatus may not be accurate). As a result,
programs generally poll for VBlank or rely on Direct3D/OpenGL to do it
for them.

Programs present video frames during VBlank to avoid tearing,since
the monitor will happily switch to the new frame mid-draw. With the
compositor in Windows Vista and later versions of Windows,these
programs will still detect VBlank and only present frames during it,
as they think they are presenting video frames directly,when in
reality the video frames are feeding into the compositor first. Frames
sent to the compositor (from any running programs on the PC) will be
queued up by the compositor,and merged together to be swapped/copied
into place during VBlank.

Problems that can occur with this system:

1) A program polling for VBlank may miss composition. This will cause
the frame to be queued up for the next composition,meaning the
previous frame will be shown twice as long.

2) Worse,the next frame may not miss composition,and end up
overwriting the previously queued up frame – so you end up with a
duplicate frame followed by a skipped frame.

3) The program’s VSync implementation may naturally fail to detect
VBlank (which has only a short duration),causing it to wait until the
next VBlank and risk problems 1 and/or 2.

4) These problems may even combine to generate a ‘perfect storm’ of
duplicate and/or missed frames.

As you can see,this polling setup is not ideal,and far worse when a
compositor is present. There are multiple problems that can cause a
new video frame to fail to be displayed,causing a previous frame to
be displayed for longer than intended and potentially skipping the new
frame altogether!

The solution is to work with the compositor instead of against it.
Present a new video frame immediately and afterward,call a command
that will block until the compositor has completed it’s task
(DwmFlush). This will ensure that at most 1 new video frame is
presented to the compositor between each VBlank period. As long as the
compositor is active,you also won’t have to worry about polling for
VBlank yourself anymore.

所以最好的办法是：

if (DWM.isEnabled()) 
{ 
    present(); 
    DwmFlush(); 
} 
else 
{
    waitForVBlank(); 
    present(); 
}

另一个编辑：
对于未来的读者,还有另外两种等待VBLANK的方法我不知道它们是IDXGIOutput :: WaitForVBlank和IDirectDraw7 :: WaitForVerticalBlank后者被弃用了.