Add AtlasTexture support to Light2D

[crayonape]

Describe the project you are working on

A top-down 2D farming game.

Describe the problem or limitation you are having in your project

Creating a separate texture for each light2d node would clutter my file system.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Like Sprite2D, merging related textures into one big sprite keeps the file system clean.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

Just like Sprite2D is enough.

If this enhancement will not be used often, can it be worked around with a few lines of script?

I think this is very useful in larger projects if I want to create a fantastic night.

Is there a reason why this should be core and not an add-on in the asset library?

Because it is a superset of the current version.

[Calinou]

Moving to discussion, as there is no concrete technical implementation provided.

[arkology]

The most straightforward implementations that could exist (and this is suggested as workaround in source code) - create internal ImageTexture and use it.
But it may be only suitable for lights with not-changing texture, as get_image() is slow.

[reimgrab]

It's not only about having less files. AtlasTexture support would be a first step to bring dynamic Light2D textures back like they used to work in Godot 3 (shameless plug #9855).