FinalScreenDrawer is an interface for a custom screen rendering. If a
game implements FinalScreenDrawer and is passed to RunGame, its
DrawFinalScreen is called after Draw.
Also this adds `-crt` option to examples/flappy.
Closes#2046
This enables passing the user's Game to internal/ui without wrapping.
This is necessary to check whether the user's Game implements an
optional function or not.
Updates #2046
This change adds NewImageWithOptions, that creates a new image with
the given options.
NewImageWithOptions takes image.Rectangle instead of a width and a
height, then a user can create an image with an arbitrary bounds.
A left-upper position can be a negative number.
NewImageWithOptions can create an unmanged image, that is no longer
on an automatic internal texture atlas. A user can have finer controls
over the image.
This change also adds tests for this function.
Updates #2013
Updates #2017
Updates #2124
