For any given event name, events execute in order of decreasing priority.
Priority is a real number, and may be assigned via the `priority` attribute for
the WML [event] tag, or through the Lua APIs:
- wesnoth.game_events.add({priority = number})
- wesnoth.game_events.add_repeating(name, action, [priority])
Note that delayed variable substitution is not currently supported in the WML attribute.
* Add new [screen_fade] WML action
It takes (for now) the arguments:
* red, green, blue = values between 0 and 255
* alpha = value between 0 and 255
* duration = time in ms over which to fade
The game display is faded to the given colour over the duration.
It will be left with an overlay of that colour and alpha until
a screen_fade to 0 alpha is performed.
This returns a label handle which allows you to remove, reposition, or replace the label later.
In addition to all the features of wesnoth.print, you can now specify where the label appears onscreen, as well as a fadeout time separate from the duration.
You can also anchor the text to an edge or corner instead of centering in on the screen,
specify the maximum width it can occupy as an absolute width or a percentage,
and specify a background colour and transparency.
It includes a demo scenario that demonstrates many of the capabilities of the API.
To play the demo scenario, run with -toverlay_text_demo or select it from the in-game test list.
