Change some image error messages to output the file path

[ChrisBase]

• Fixes: Error messages for failed image imports do not print the affected file path #94946

Test environment

Godot Engine v4.3.rc1.official
Windows 11 Pro, Version 23H2, Build 22631.3880

Issue

TextureStorage::texture_2d_get() and TextureStorage::texture_2d_layer_get() do not print the path of the affected texture image when they fail. This is how an example output currently looks like:

● Expected Image data size of 1010x277x1 (DXT5 RGBA8 with 9 mipmaps) = 378896 bytes, got 379184 bytes instead.
● drivers\gles3\storage\texture_storage.cpp:1043 - Condition "image->is_empty()" is true. Returning: Ref<Image>()

This makes it hard to find and fix the affected image file.

Fix

The fix replaces some ERR_FAIL_COND_V() with ERR_FAIL_COND_V_MSG() to also output the file path. The output then looks like this:

● Expected Image data size of 1010x277x1 (DXT5 RGBA8 with 9 mipmaps) = 378896 bytes, got 379184 bytes instead.
● Texture with path 'res://assets/images/placeholder.png' has no data.

[Calinou]

I suggest applying the same change in RenderingDevice, so this also impacts the Forward+ and Mobile rendering methods. Otherwise, the improved error messages will only be visible when using the Compatibility rendering method.

[RandomShaper]

Also, bear in mind that (I think) not all textures will have a path (programatically created).

Also, the wording of the message feels a bit werid to me.

I'd suggest something like this:

if (image->is_empty()) {
    const String& path_str = texture->path.is_empty() ? "with no path" : vformat("with path '%s'", texture->path));
    ERR_FAIL_V_MSG(Ref<Image>(), vformat("Texture (%s) has no data.
}

[ChrisBase]

@Calinou @RandomShaper

Thank you both for your feedback. I updated the PR accordingly.

[RandomShaper]

I think this is good enough for now, but if may be good to refactor these blocks into something more compact, such as a (maybe templated) utility function in RendererTextureStorage. For the time being, I'll give my approval, but other contributors may think it's better to do the refactor now.

[Mickeon]

This could use a rebase and perhaps someone else from the rendering team could take a look at it, too.

[Calinou]

Should be good to merge after squashing commits together (see PR workflow for details).

[Repiteo]

Thanks!