I have a direct3d application running in a windows forms custom control that is hosted in a windows forms form.
The form has a toolbar on top, then the 3d control.
I am using SlimDX framefork for the direct3d stuff. The rendering thread has a message pump that runs the rendering stuff, and the windows form obviously has it own message pump to process the input.
The frame rate is manually controlled by the rendering message pump via sleep time which never goes below 10ms , that is at the end of each render loop there is a Sleep(10) at least.
Despite this whenever there is a drop in frame rate below the 50 FPS level when I hover (or try to click) over the buttons in the toolbar (that is direct child of the form) there is a freeze in input processing that is the rendering continues as usual but the mouse input is not processed and also the buttons of the toolbar that are supposed to highlight when hovered are not highlighted. The freeze continues for a few seconds (2-3) then returns to normal until I try to interact with the form again.