New mouse warp semantics

If the input is grabbed and the cursor is hidden, then SDL will set the
mouse in relative mode, using DGA if it is available, or warping the mouse
if it is not. The warping and DGA will be handled internally, so the
application doesn’t have to worry about it, or filter motion events.

I will be implementing these semantics this weekend. It should greatly
simplify code which uses SDL for relative mouse motion (3D shooters)

See ya!
-Sam Lantinga (slouken at

Lead Programmer, Loki Entertainment Software–
“Any sufficiently advanced bug is indistinguishable from a feature”
– Rich Kulawiec