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X-Windows mouse pointer flickering
Running GNU/Linux on the ARM (I'm using the Raspberry pi 4b) the mouse pointer is constantly flickering. Has anyone noticed this on other platforms?
This is a defect that's very odd because it was literally 30 years ago that, as I remember it, this problem was solved. Specifically when drawing needs to be done by X Windows, the server doesn't erase the mouse pointer first, then draw, then redraw the mouse pointer. That kind of nonsense was done in MSDOS by amateur programmers. No, in X-Windows they used clipping rectangles and a mask to draw around it. If the pointer was not overlapping a window, it was not undrawn and redrawn. If it was directly on top of something being redrawn, a mask was used. Windows, the Mac, the Amiga, all solved this problem of undrawing and redrawing the mouse pointer in an ugly flickery way. That was standard windowing system design back in the early 1990's.
But the defect I'm seeing is so bad that if I move the mouse pointer onto the desktop, even down in a corner away from any window, it still flickers when ANY window's contents is updated. This feels like someone made a change to the code who didn't understand or care to understand the code.
The mouse pointer flickers when:
- the clock panel increases the time each second
- the weather panel does any update or animation
- a video is playing somewhere on-screen (it seems to flicker with every frame)
- a web page updates itself e.g. if you type some text into a <textarea>
Again, the mouse pointer can be anywhere on-screen when it flickers, even in a corner away from windows. This behavior is not representative of how X-Windows was written 30 years ago. This was a solved problem and now it's broken.
Last edited by resolver; 07-08-2020 at 09:23 AM.
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