pp::MouseInputEvent.GetMovement() returns incorrect values after changing text size

[Amruth Raj]

Hi,

I opened a bug https://crbug.com/459551 which is about MouseInputEvent.GetMovement() returning erroneous values. This happens after changing the Text size to Large and calling pp::MouseLock::LockMouse() API on Windows 7. Once this is done, the outputs of GetMovement() sometimes are erroneous and the plugin is almost unusable with a mouse. Can someone please take a look at it.

Thanks.

[Amruth Raj]

For this, I compiled mouse_lock example from ppapi/examples, clicked on the plugin to lock the mouse and circularly rotated the mouse a few times. What I see is that, MouseInputEvent.GetMovement() which is supposed to return values corresponding to my mouse movement sometimes incorrectly returns very large values, as high as 669. The attached log has some error references(marked in bold). Eg:

mouse_lock.html:1 ppapi_example_mouse_lock.dll: [156440] movementX: 359; movementY: 331

mouse_lock.html:1 ppapi_example_mouse_lock.dll: [156481] movementX: 27; movementY: 669

These come quite frequently.

Here is a sample video recording of what happens: https://www.youtube.com/watch?v=hsKuqJwxSt0

Note that this happens after changing the text size to large(by right click->Screen Resolution->Make text and other items larger or smaller->Select Large) which is commonly done by many users on Windows. After doing that, my plugin is unusable.