Re: [AD] Using system mouse cursor

[Chris <kcat@xxxxxxxxxx>]

Evert Glebbeek wrote:
> disable_hardware_cursor() isn't for hiding the hardware cursor - it's for 
> disallowing it in case you want to use mickeys. Although I suppose that 
> show_mouse(NULL) could hide the system pointer as well.

IMO, show_mouse(NULL) should hide the cursor regardless of which type it 
is or mode it's in.

> Bear in mind the following distinction in the nomenclature:
>  * Software cursor (the custom cursor drawn by Allegro)
>  * Hardware cursor (the custom cursor drawn by the OS rather than Allegro)
>  * System cursor (the system default cursor)
>
> The system cursor is a different entity from the hardware cursor, although 
> for platforms that have a system cursor it behaves in a similar way in 
> that Allegro doesn't need to handle drawing it. It can be a software 
> cursor if the platform doesn't have a native cursor and Allegro's defaults 
> are used.

This is where you need to be careful. Again IMO, the system cursor 
should just be special extension to hardware cursors. If you do 
something to the hardware cursor, it should have the same exact effect 
on a system cursor. Don't forget, the system cursor is just a nice hack 
on top of hardware cursors, so trying to seperate them will only lead to 
problems.

> Ultimately, the API should hide the differences as much as possible, and 
> the end user would only see a `custom cursor' or a `system default' 
> cursor.

Not even that, IMO. Unless you classify the Allegro defaults as system 
defaults. Because think about it.. if you call
set_mouse_sprite(MOUSE_CURSOR_ARROW, NULL);
there is now no way for the user to tell if they're using a system 
cursor, or if a system cursor isn't available and he got Allegro's 
default. This is why there should be very little, if not no, difference 
in the behavior of system and custom hardware cursors.

> What I think is confusing is that the MOUSE_CURSOR_ARROW and such are 
> really system cursors, which can be turned into custom cursors by 
> specifying a bitmap for them which is not NULL.

You're kinda thinking backwards. It's not that custom cursors become a 
special case of system cursors with a specified bitmap. It's that system 
cursors are a special case of custom cursors when the specified bitmap 
is NULL /and/ the driver supports it.

- Kitty Cat