Implement 2D instance shader parameters

[huwpascoe]

From KoBeWi to EIREXE to here. Issue #62943.

instvartest.zip

Now feature complete with the exception of compatibility renderer.

[KoBeWi]

Parameter list doesn't work properly. It's not updated right when modifying shaders and some operations may replace it with nulls:

godot.windows.editor.dev.x86_64_PfbFzWf1sD.mp4

Other than that they look functional, which is nice.

[Calinou]

Tested locally (rebased on top of master 99a7a9c), it works as expected in Forward+ and Mobile.

When running in Compatibility, you get a shader compilation error like in 3D (as expected):

SHADER ERROR: Uniform instances are not supported in gl_compatibility shaders.

Testing project: test_pr_97058.zip

PS: What is this checkbox for? It's present for both 3D and 3D per-instance uniforms. I can't uncheck it (nothing happens when I click it), regardless of whether the value is modified from its default or not.

[huwpascoe]

What is this checkbox for?

Don't know, I think it was like that in 4.2 as well.

[KoBeWi]

To update property list, you need to use notify_property_list_changed. Here's how it's done in 3D:

godot/scene/3d/visual_instance_3d.cpp

Lines 244 to 246 in 02b16d2

	if (material_override.is_valid()) {
	material_override->connect(CoreStringName(property_list_changed), callable_mp((Object *)this, &Object::notify_property_list_changed));
	}

However modifying shader does not add the CanvasItem to _instance_update_list, I think it also has to be done manually.
The parameters no longer become null, so the list not updating is only an inconvenience now.

Also if you want the instance parameters to have revert button, you need to implement _property_can_revert() (return true if instance uniform exists) and _property_get_revert() (return default value of uniform).

[huwpascoe]

Redid everything from the ground up, refactored all the common code into a class. Everything should work identically to the 3D instances now.

[Chaosus]

Please squash the commits as it's required by our pipeline (see https://docs.godotengine.org/en/latest/contributing/workflow/pr_workflow.html).

[huwpascoe]

Please squash the commits

Do I need to do anything special to keep the other contributor's names or do I just squash?

[clayjohn]

Please squash the commits

Do I need to do anything special to keep the other contributor's names or do I just squash?

You will need to have the "Co-Authored by:" lines for both of them (one is already there).

I suggest waiting to squash until you are finished with the PR and it is ready to merge.

[bunnybreaker]

Any idea on if/when this will get added to the main branch?

[huwpascoe]

Any idea on if/when this will get added to the main branch?

Depends on #97340. Soon as it's merged, I'll submit the final revision and then it's in the hands of the maintainers.

[huwpascoe]

It's finished. But they want compat renderer support added.

Someone else can do that, I'm tired.

[Delsin-Yu]

It's finished. But they want compat renderer support added.

Someone else can do that, I'm tired.

Is there any chance can we merge this and leave the compact renderer support for future contributors?

[KoBeWi]

It will at least need a warning that Compatibility is not supported.