Keep looking when a preview plugin returns an empty image.

[basicer]

The documentation for EditorResourcePreviewGenerator::_generate says that "Returning an empty texture is an OK way to fail and let another generator take care."

This patch enables that behavior.

[kleonc]

The behavior matches the documentation now indeed. 👍

godot/doc/classes/EditorResourcePreviewGenerator.xml

Line 26 in fd7239c

Returning an empty texture is an OK way to fail and let another generator take care.

Not fully sure whether we indeed want to prevent zero-size previews though. cc @KoBeWi

[KoBeWi]

Well, zero-size textures are a convenient way to make empty previews, though not sure if there is use-case for that.
The is_valid() check is enough and we can adjust the description to mention null instead of empty image, but it's fine either way probably.

[basicer]

Well, zero-size textures are a convenient way to make empty previews, though not sure if there is use-case for that. The is_valid() check is enough and we can adjust the description to mention null instead of empty image, but it's fine either way probably.

I could see it going either way. Im not too picky as along as I can write a previewer for PackedScene when the builtin one returns null.

[akien-mga]

I believe "empty texture" in the docs was referring to Ref<Texture2D>(), which would indeed be better described as "null".

IMO it's clearer if the way to bail out is to return null instead of also skipping a zero-sized valid texture. If users generate such a texture with no dimensions, I would expect it to be intentional (e.g. to disable the preview as a hack, as mentioned).

[basicer]

Seems like consensus is to allow zero size previews, so I reverted it to the original null-check only version.

[kleonc]

Seems like consensus is to allow zero size previews

Indeed.

so I reverted it to the original null-check only version.

Which makes my first comment hold. The docs could be clarified by changing "Returning an empty texture (...)" to "Returning [code]null[/code] (...)".

godot/doc/classes/EditorResourcePreviewGenerator.xml

Line 26 in 61598c5

Returning an empty texture is an OK way to fail and let another generator take care.

godot/doc/classes/EditorResourcePreviewGenerator.xml

Line 38 in 61598c5

Returning an empty texture is an OK way to fail and let another generator take care.

[kleonc]

Almost good, please squash your commits (should be a single commit). See the PR workflow docs.

[basicer]

Almost good, please squash your commits (should be a single commit). See the PR workflow docs.

Can do. For some reason I thought he rebase on merge option in github was turned on here.

[akien-mga]

Thanks!