At program start I'm warping the mouse to center (after which I'm eating all events). However, the next time the mouse is moved the warped distance (from where the mouse was before the warp) is included in the move delta. This results in the mouse cursor jumping.

Also according to the docs SDL_WarpMouseInWindow generates a mouse motion event, which it doesn't on the mac.

CGWarpMouseCursorPosition doesn't generate events.

The patch below generates a motion event manually after a warp.

Having typed all this, I should probably be using SDL_SetRelativeMouseMode ...

--- a/src/video/cocoa/SDL_cocoamouse.m	Sat Jan 28 14:53:23 2012 -0500
+++ b/src/video/cocoa/SDL_cocoamouse.m	Sun Jan 29 21:55:18 2012 -0800
@@ -116,6 +116,12 @@
     point.x = (float)window->x + x;
     point.y = (float)window->y + y;
     CGWarpMouseCursorPosition(point);
+
+    /* CGWarpMouseCursorPosition doesn't create an event, so generate a move event manually */
+    /* If we don't do this, the warp will be included in the next motion event, which causes the mouse to jump */
+    CGEventRef event = CGEventCreateMouseEvent(NULL, kCGEventMouseMoved, point, kCGMouseButtonLeft);
+    CGEventPost(kCGHIDEventTap, event);
+    CFRelease(event);
 }
 
 static int