Print warning once when loading an image from res:// path

[Xrayez]

Closes #24222.

I write unit tests for image processing methods and run them via command line. Unfortunately, the output is polluted with the warning messages for each and every image.load(), often "shadowing" any error messages:

* test_image_resize_hqx2_rgb
WARNING: load: Loaded resource as image file, this will not work on export: 'res://rect_rgb.png'. Instead, import the image file as an Image resource and load it normally as a resource.
   At: core/image.cpp:1889.
* test_image_resize_hqx3_rgba
WARNING: load: Loaded resource as image file, this will not work on export: 'res://rect_rgba.png'. Instead, import the image file as an Image resource and load it normally as a resource.
   At: core/image.cpp:1889.
* test_image_rotate
WARNING: load: Loaded resource as image file, this will not work on export: 'res://rect_rgb.png'. Instead, import the image file as an Image resource and load it normally as a resource.
   At: core/image.cpp:1889.
* test_image_rotate_90_cw
WARNING: load: Loaded resource as image file, this will not work on export: 'res://rect_rgba.png'. Instead, import the image file as an Image resource and load it normally as a resource.
   At: core/image.cpp:1889.
* test_image_rotate_90_ccw
WARNING: load: Loaded resource as image file, this will not work on export: 'res://rect_rgba.png'. Instead, import the image file as an Image resource and load it normally as a resource.
   At: core/image.cpp:1889.
* test_image_rotate_180_grayscale
WARNING: load: Loaded resource as image file, this will not work on export: 'res://rect_grayscale.png'. Instead, import the image file as an Image resource and load it normally as a resource.
   At: core/image.cpp:1889.

This PR makes it so that the warning is printed only once during the lifetime of Godot instance.

[akien-mga]

The warning message includes the path, so it's relevant to print it for each affected path, so IMO this change is not a good one.

This warning tells you that your tests are doing something wrong, so either your tests should be changed, or this warning is maybe wrong itself.

[Xrayez]

I've already initially loaded the images from the imported textures as:

var texture = preload("res://rect_rgba.png")
var input = texture.get_data()
# ... and then perhaps `image.duplicate()` to avoid operating on the same image data...

instead of:

var input = Image.new()
input.load("res://rect_rgba.png")

The problem with the former approach is that they must be imported. I run tests with Travis CI command line (scons platform=server). In order to import those images, I must:

1. Run the binary once without running any tests with the --editor --quit option.
2. Actually run the tests with imported images.

In fact, I've already tried this approach. The first step (1) causes various crashes. Likely due to

1. When certain modules are disabled (I disable compiling most of the Godot modules to increase the build times by like 10 minutes), and the crashes seem to be related to HeightMapShape error with disabled Bullet module on project startup #32217 (3.2) (please don't ask me to give up these time saving gains). 🙂
2. There's no video driver available on server builds which might cause crashes in some cases (?).
3. There's just some editor stuff which crashes on server builds.

Another workaround I've tried is to simply version the .import folder so that the engine doesn't need to reimport it. Unfortunately some tests still kept failing. And yeah I personally don't want to choose this poison either. 🙂

So, I wouldn't want to rely on the import process for the "raw" image data to get tested.

P.S. I find the warning too verbose. That's something which belongs to documentation IMO. There seems to be no way to control the verbosity of warnings (or the severity of them). The message is more like informational. I think it's enough for users to read this message once, and it's easy to find all the .load("res://") references if users choose to make this change, which is only relevant when you export the project (also given the fact that you can distribute a project without exporting).

[Xrayez]

Well I've figured a nice workaround to this problem, you just have to explicitly globalize the path:

static func image_load_no_warning(filepath):
    var image = Image.new()
    image.load(ProjectSettings.globalize_path(filepath))
    return image

Feel free to close this. But it would be nice to:

1. Have informational type of messages (INFO_PRINT, just like WARN_PRING, ERR_PRINT), so informational ones can be somehow disabled. WARN_PRINT_ONCE is the closest to INFO_PRINT which this PR aims for.
2. Have an option to re-import assets as a command line option (AFAIK this is already the case when you --export the project, so might just require some tinkering).

[Calinou]

Have an option to re-import assets as a command line option (AFAIK this is already the case when you --export the project, so might just require some tinkering).

Indeed, you can use --export-pack and not bother about the generated PCK. We should probably have an --import CLI argument to make this more explicit, without generating any stray files.

[realkotob]

Slightly offtopic, but I'd love having an --import CLI option, it would allow for better optimized CI/CD scripts when targeting multiple platforms. (See abarichello/godot-ci#11)

[Xrayez]

Continuing the import problem, I stumbled upon a limitation/fix in WAT: watplugin/wat@b2fe586. @CodeDarigan do you have anything to add regarding what I've described in #39396 (comment)?

[AlexDarigan]

@Xrayez For a start I don't even think the files get re-imported doing that. They're just ignored but all of the tests work fine doing it.

This (image below) from https://godotengine.org/article/core-refactoring-progress-report-2 may solve the issue but it's probably impossible to backport.

might solve the problem in future (note it says server is a work around so I might build a docker image and test with that instead).

Edit: Seems the Server doesn't recognize the EditorPlugin.

[Xrayez]

No clear consensus and I've already found a workaround, so closing.

Things to work on:

• need better support for command line importing of assets.
• make server work alright with editor stuff.
• would be nice to have informational type of messages (like INFO_PRINT over WARN_PRINT).

[Xrayez]

Reopening because I've stumbled upon a previously reported issue which may objectively justify this change now: #24222.

[Xrayez]

Alternatively, this warning can be removed, because I've already documented this in #42412, see also #24222 (comment):

• prescriptive fixes, as mentioned in Print warning once when loading an image from res:// path #39396 should not be printed unless they absolutely apply to the problem.

The confusion for beginners can be further mitigated by renaming Image.load to Image.load_from_file, as proposed in #16863 (comment).

Again, the use cases where this is a valid situation are:

• editor image load and pre-processing, saving and reimporting modified images.
• loading external images once exported, because there's no way to import images as textures at run-time.

I don't see a way to make this warning more specific to exclude those situations.

[Xrayez]

Closing in favor to #42653.