based on the fact that the crash never seemed to have happened with default screen resolutions and also inspired by the only other getmem usage in the code I came up with this simple solution which seems to work just fine.
I do not understand why getmem seems to need this, but well - feel free to explain.
unit uCursor;
interface
procedure init;
procedure updatePosition;
implementation
uses SDLh, uVariables;
procedure init;
begin
SDL_WarpMouse(cScreenWidth div 2, cScreenHeight div 2);
end;
procedure updatePosition;
var x, y: LongInt;
begin
SDL_GetMouseState(@x, @y);
if(x <> cScreenWidth div 2) or (y <> cScreenHeight div 2) then
begin
CursorPoint.X:= CursorPoint.X + x - cScreenWidth div 2;
CursorPoint.Y:= CursorPoint.Y - y + cScreenHeight div 2;
if cHasFocus then SDL_WarpMouse(cScreenWidth div 2, cScreenHeight div 2);
end
end;
end.