[Win32] How to render on a window while it is in idle?

kwikc 131

That window is in idle here means the window received WM_ENTERIDLE message, like after Alt key was pressed then released.

[Edited]
The rendering is to use DirectX to draw on HWND. While holding on the title bar of the window, all animations were paused.

[Edited]
It is under Windows 7.

Thanks a lot.

Kwik C.

David Lowndes 4,711 Reputation points

2021-11-04T22:21:02.47+00:00

I suspect you might be looking for the GetDC API.
kwikc 131 Reputation points

2021-11-05T00:55:48.403+00:00

Thank you for your reply.

It is to use DirectX (not DC) to draw on HWND.

Sorry for not explaining in detail. I have just edited the question.
RLWA32 40,286 Reputation points

2021-11-05T01:57:21.193+00:00

Do you include any DirectX code for rendering in the application's message loop?
kwikc 131 Reputation points

2021-11-05T04:54:07.703+00:00

Hello, thank you for your reply.

Ordinary game program message loop, running DirectX rendering when PeekMessage() returns zero.

By tracing the code, while the window is in an idle state, usually after receiving a WM_ENTERIDLE message (for example an Alt key gets pressed and released), the DirectX rendering path gets executed as usual, but the animation stops, at where it was just before the window entered idle. After the window leaves the idle state (say pressing and releasing Alt key again), the animation continues.

Is it a supposed behavior of normal window that the client area does not get updated while in an idle state?

I forgot to say it is under Windows 7.
Castorix31 81,726 Reputation points

2021-11-05T08:03:33.15+00:00

With Direct2D, there is just a small pause on Title Bar, but animations are not stopped :

2 answers