I got this bug report from a beta tester:
On newer versions of Mac OS X, when the user waves the mouse around in circles, it causes the cursor to magnify to a larger size, helping users locate the mouse cursor if they’ve lost it somewhere on the screen. (Apparently this feature is new to El Capitan specifically.)
I can get this to happen inside the game, but only while in a menu, not in while in actual gameplay. The mouse cursor is invisible as it should be, replaced by the crosshair, until I “shake” the mouse, and the crosshair disappears to be replaced by the enlarged mouse cursor.
I’m not on El Capitan myself (I’m still on Yosemite) so I haven’t seen this firsthand, but it seems straightforward enough. Here’s a screenshot of my game shell with the cursor comped in (Application.CaptureScreenshot doesn’t render the hardware cursor itself):
See the crosshair hovering over the “windowed” checkbox? That’s my hardware cursor; specifically, it’s a texture set as the “Default Cursor” in Player Settings.
What my beta tester seems to be describing is that, on El Capitan, waving the mouse cursor around can replace my custom cursor with an enlarged OS X standard cursor.
I strongly suspect this is something I can’t do anything about. Whether it’s a “bug” or not is, I guess, up for debate, but my guess is the only way to prevent this behavior would be in Unity’s code.
Am I wrong? Because if there’s something I can do in my game code/configuration to make this nicer (ideally allowing my custom cursor to be scaled in accordance with El Capitan’s behavior, instead of being replaced by El Capitan’s own cursor) then I’d love to do it.