Fill game: Allow varying projectile (appearance) by label

[wjt]

Currently the fill game (or rather the throwing enemy) has a few different ways to vary the projectiles that are thrown:

• Each enemy can throw a different projectile scene (and apply various properties to it)
• Projectiles can be recolored (via modulate) to match the colour of a barrel. Barrels have an optional label and optional colour. It is assumed that all barrels in the scene that have the same label also have the same colour.

Projectiles can only fill barrels with a matching label. When spawning a projectile, the enemy assigns it a label (and corresponding colour, if any) out of the labels for the remaining barrels in the scene.

In two quests, the creators have wanted to do something that is not supported by this:

1. In Stella, the idea was that four kinds of sea creature fly out of the water: 3 different regular fish, or a starfish. Only the starfish should be accepted by the boat (barrel). This was not possible without custom logic. One thing we tried was having offscreen barrels with 3 different labels but what's missing is the ability to use different spriteframes (or scenes) for different labels.
2. In Champ, there is a sign on the shore that tells you which colour of fish needs to go into each of 3 targets. There is custom logic to swap the SpriteFrames of the projectile based on the target label.

[wjt]

@manuq In #1308 we had the idea that it would be enough to make the behaviour pick from a list of PackedScenes. That would work for Stella because we would give it a list of scenes with the 4 different creatures, each with a different label, and put a label on the ship that only matches one of them. But where would the list come from? One nice thing about the current logic is that the labels are determined automatically, and when all barrels of one colour/label are removed, that colour/label is removed from the pool of possible projectiles.

I wonder whether we could do this with:

# throwing_enemy.gd

## Scene to spawn for each label
@export var projectile_scene_for_label: Dictionary[String, PackedScene]

## Scene to spawn if the target label is not in [member projectile_scene_for_label].
## Can be null if [member projectile_scene_for_label] has all the necessary keys for the scene
@export var projectile_scene: PackedScene  # the current property

We would keep the code to assign label and color to the spawned projectile, for the simple case which just uses a single scene. And this would keep the ability to have different enemies throw specific different projectile (the first case above - this is used in shjourney, at least).

[manuq]

@wjt interesting. In principle yes, I agree with a projectile_scene_for_label that pairs with the existing color_per_label.

Alternatively, I wonder if the projectile scene / labels / modulate color mapping corresponds to the logic node (FillGameLogic node for now, but can be multiple ones). If each ThrowingEnemy could have a reference to the scene game logic, they can say "game logic, give me a projectile instance" when they shoot (fallback to the projectile_scene). Then an ink-color-matching game logic will return a colored/labelled instance, and a Stella game logic would provide a star with a "good" label or 3 other different sprites with a "bad" label, etc.

Maybe this double reference is too much. So going with a projectile_scene_for_label seems aligned with the existing code and doesn't require further refactoring.

[wjt]

Actually I was wondering the same thing overnight.

But there is a case where different enemies throw different projectiles. In https://play.threadbare.game/branches/endlessm/main/#quests/story_quests/shjourney/7_shjourney_combate/Combate the monsters are different colours and fire different-coloured projectiles. Functionally they are equivalent.

So in this case you'd actually have to have a way to override the scene factory function for each enemy...

[wjt]

It does make for a lot of duplication to have 3 scenes in champ which are identical except for the colour of the fish. Actually I think the modulate logic would be fine for that scene - make the fish greyscale, modulate for the different targets - but if a learner wanted to make the fish more different, then it would be the stella case again. (@felixwalberg I guess that's why you added this custom logic rather than modulating a single white fish.)

[felixwalberg]

but if a learner wanted to make the fish more different, then it would be the stella case again. (@felixwalberg I guess that's why you added this custom logic rather than modulating a single white fish.)

Yes, this is a good point, but I was hoping the learners would be able to add entirely different designs for the fish (and possibly even other items that could serve as bait) as well as the color. I just didn't spend the time to design them on my own and swapped the colors.