I'm using the raw input API for all input events in my own engine, and everything works just fine.
Well, as long as i only run the executable itself.
I also started working on an editor tool suite in Winforms/C#.
The editor starts the engine in a separate process and passes it's window handle along. The engine then creates a child window and renders everything inside the editor, similar to how the BitSquid tools work (http://bitsquid.blogspot.de/2010/04/our-tool-architecture.html).
And that's where my problems arise:
Whenever i hold down a button on my keyboard while the engine is running within the editor window, the mouse input gets very jittery.
Here are two small 60fps videos (~500KB in size) showing the issue:
Running just the engine: https://dl.dropboxusercontent.com/u/6556492/Engine_60fps.mp4
Running the engine inside the editor: https://dl.dropboxusercontent.com/u/6556492/Editor_60fps.mp4
The jitter starts to appear whenever the windows key repeat kicks in.
I don't have a lot of experience in Win32/WinForms, so i'm currently at a loss about how to fix this.
Other games seem to exhibit similar (the same?) issues:
Battlefield 3:
Counter-Strike Source:
The BF3 fix was to limit "RenderFramesAhead" to 1, forcing that in the driver (Nvidia 320.49, GTX580) doesn't fix it in my case.
the CS:S solution was to use raw input, which i already do.
Does anyobody have any ideas on what might be causing this?