Disable SDL relative mouse mode when in_nograb is enabled. Relative
mouse mode hides the cursor and it cannot exit the window regardless
of the window's grab state.
This wasn't always the case. SDL before 2.0.4 on GNU/Linux released
the mouse cursor in relative mode. However, SDL 2.0.3/4 on Windows
does not. (I did not test other Windows versions.) So I think SDL
2.0.4 made GNU/Linux X11 behavior consistent with other platforms.
This fixes mouse input being unusable when debuging client crashes
in gdb.
SDL doesn't provide exact the exact time that input events happen
so use the earliest possible time that an event could happen.
This make sub-frame input actions such as walking take affect
immediately instead of in the next frame.
Based on patch by Alexander "wareya" Nadeau.
Only send mouse events if both values are non-zero.
Hopefully this helps with the event overflow spam that can sometimes
happen on loads or laggy situations.
When starting the game in windowed mode, the window buffer used whatever
was on the screen before running the game. Kind of like you could see
through the window, but it doesn't update what happens behind it.
It makes it look like something is broken or non-responsive.
So clear the window opengl buffer to black.
Credit to theinvsblman for the code.
Appling the diff to renderergl2 mostly worked.
Had to change GLimp_HaveExtension to use GL_EXTENTIONS
directly because Elite Forces GL2 requires an extension that didn't fit in (the smaller than Q3)
glConfig.extensions_string.
Had to set ambientLight for RF_FULLBRIGHT, GL2 doesn't use ambientLightInt.
Made the RF_FORCE_ENT_ALPHA code change pStage->stateBits because the stateBits
are read a lot, whereas in GL1 it's done as an expression and passed to GL_State.
Copied from Spearmint.
There are a few issues; holodeck doors are missing and parts of light grid are black (???).
