Independent rotation for entities within a bundle?

[Misophistful]

I have a bundle entity where I'd like both sub-entities to move in unison, but for only one of them to rotate when I change :angle. Is that doable?

To give an example: imagine a game with tanks that can only move backwards and forwards, but with rotating gun turrets. Would that be achievable with a bundle, or would it need to be handled in another way?

[oakes]

You would have to change the :angle of the entity inside the bundle. I imagine it would look something like this:

(assoc-in my-bundle [:entities 0 :angle] 45)

[Misophistful]

I haven't been able to get your assoc-in approach to work. I think it's because :entities contain a list, rather than a vector. Should I be converting it to a vector each time? Or is this something that perhaps play-clj should be handling?

[oakes]

Yeah you're right, I should be coercing it into a vector. I just pushed 0.3.8-SNAPSHOT that should do this. Thanks for pointing this out.

[Misophistful]

You're welcome, and thanks for fixing it!

[Misophistful]

assoc-in works perfectly to add :angle to an inner entity with 0.3.8-SNAPSHOT, but the inner entity still seems to be inheriting its angle from the parent, and ignoring its own :angle.

Here's one of my entities:

#play_clj.entities.BundleEntity
{:entities [#play_clj.entities.BundleEntity
{:entities [#play_clj.entities.TextureEntity
{:object #<TextureRegion com.badlogic.gdx.graphics.g2d.TextureRegion@1d78a69c>, :angle 0}
#play_clj.entities.TextureEntity
{:object #<TextureRegion com.badlogic.gdx.graphics.g2d.TextureRegion@5c025ae1>}]}
#play_clj.entities.TextureEntity
{:object #<TextureRegion com.badlogic.gdx.graphics.g2d.TextureRegion@1e9c98f8>}],
:y 713, :coords [-1 3], :angle 180, :id :2-water, :piece? true, :player 2, :element-type :water, :x 224, :hit-box #<Polygon com.badlogic.gdx.math.Polygon@3afed17b>, :selected? false, :moves-remaining 3}

You can see :angle 0 in the first TextureEntity, but that texture is still being rendered with an angle of 180. (I also tried moving :angle 0 to the inner bundle instead of the texture, but that didn't work either.)

What might I be doing wrong?

[oakes]

At the moment, any key in the bundle will override a key in an a bundle's entity. I could change this behavior, but I'm not sure which matches expectations more.

[oakes]

I just pushed a new 0.3.8-SNAPSHOT that reverses the precedence, so an internal entity's keys will override its bundle's keys. I think you are right that this is more logical, and seems to be more consistent with things like CSS precedence rules.

[Misophistful]

After updating to the latest 0.3.8-SNAPSHOT all of my piece entities (the nested bundle entity I posted earlier) have disappeared from the screen. Could the reversed precedence have caused this? Do I need to have :x and :y in all of the sub-elements now?

[oakes]

Yeah I must've not tested correctly before, because I get the same thing. It turns out that my merging was eliminating the entity type, so it didn't know how to draw them. I just pushed a new snapshot that adjusts this, so please let me know how that goes.

[Misophistful]

The new update fixed it, and the independent rotation is working perfectly. Thank you so much!