[scummvm-devel] ATTN Porters: Change to OSystem::setShakePos

[Thierry Crozat]

Hi all,

When the setShakePos() function was added to OSystem, it was designed and documented as taking only positive offsets. However we found out that some engines need the ability to shake the screen with a negative offset to be accurate. So the function documentation has now been changed to indicate that it can take negative offsets,

Some backends already handle this properly. This should be the case of both the OpenGL and the SurfaceSDL backends. The latter actually did not handle negative offsets properly when using SDL 1.2, but this was fixed yesterday. If you are maintaining another backend that has a custom implementation of setShakePos, please check that your implementation correctly handles negative offsets, and update your code if needed.

I have update the testbed engine to do shaking with negative offsets, so you can use this to test your backend. Otherwise this can also be tested with Day of the Tentacle by turning on the stereo in the room with green tentacle.

Thierry / criezy