Gerry JJ

The state bitmask in SDL_MouseMotionEvent is stored in an Uint8. Unfortunately this doesn't actually have room for 8 buttons because SDL skips 4 button indices after the third mouse button (at least here on Linux x86-64, probably related to wheel handling?), so it's really just enough to track 4 buttons. For example, on a Logitech MX310 mouse I've got, even though the mouse has 6 buttons total, the left and right side buttons and extra middle button have indexes 8, 9 and 10, and the last two won't fit in the 8 bit button state.

The source of the button state (in SDL_Mouse) is already 32-bit, and the state field in SDL_MouseMotionEvent is 32-bit aligned and followed by three 8-bit padding fields. So simply changing the SDL_MouseMotionEvent state to an Uint32 and removing the padding fields fixes this, and I think it should be binary compatible, at least for little endian.