Fish per water type in data/fish.json; worldlets design

- data/fish.json: fish, weights, dawn/dusk odds, bite timing and minimum
  depth per water type; ItemDB.define_water() registers them
- world.water_at(x, z) answers lake / sea / dry land; the float uses it,
  so a worldlet with a sea only needs a "sea" entry
- Clear messages for shallow water and water with nothing to catch
- Lake fish: more of them, bigger, nearer the shore, jumping with splash rings
- docs/WORLDLETS_DESIGN.md: proposal for data-defined world types

scripts/core/item_db.gd

@@ -14,11 +14,14 @@ const ICON_SIZE := 96
 var items: Dictionary = {}     # id -> definition Dictionary
 var recipes: Dictionary = {}   # id -> recipe Dictionary (insertion order kept)
 var icons: Dictionary = {}     # id -> Texture2D
+## Fishing by water type (data/fish.json): {"modifiers": {...}, "waters": {type: {...}}}.
+var fishing: Dictionary = {"modifiers": {}, "waters": {}}
 var _item_mat: StandardMaterial3D
 
 func _ready() -> void:
 	_load("res://data/items.json", "items", define_item)
 	_load("res://data/recipes.json", "recipes", define_recipe)
+	_load_fishing("res://data/fish.json")
 	if DisplayServer.get_name() != "headless":
 		_render_icons.call_deferred()
 
@@ -51,6 +54,31 @@ func define_recipe(r: Dictionary) -> void:
 	r.station = String(r.get("station", ""))
 	recipes[r.id] = r
 
+func _load_fishing(path: String) -> void:
+	var data = JSON.parse_string(FileAccess.get_file_as_string(path))
+	if typeof(data) != TYPE_DICTIONARY or not data.has("waters"):
+		push_error("ItemDB: could not parse %s" % path)
+		return
+	fishing.modifiers = data.get("modifiers", {})
+	for water in data.waters:
+		define_water(water, data.waters[water])
+
+## Registers (or replaces) the fish for one water type. Same shape an addon
+## would use to add, say, a "swamp" water with its own catch.
+func define_water(water: String, d: Dictionary) -> void:
+	var fish: Array = []
+	for f in d.get("fish", []):
+		if not items.has(f.get("id", "")):
+			push_error("ItemDB: fish '%s' in water '%s' is not an item" % [f.get("id", "?"), water])
+			continue
+		fish.append({"id": f.id, "weight": float(f.get("weight", 1)), "dawn_dusk": float(f.get("dawn_dusk", f.get("weight", 1)))})
+	var w: Array = d.get("bite_wait", [5.0, 14.0])
+	fishing.waters[water] = {"min_depth": float(d.get("min_depth", 0.5)), "bite_wait": [float(w[0]), float(w[1])], "fish": fish}
+
+## The fishing table for a water type ({} = nothing to catch there).
+func water_fishing(water: String) -> Dictionary:
+	return fishing.waters.get(water, {})
+
 func get_item(id: String) -> Dictionary:
 	return items.get(id, {})
 

scripts/fishing/bobber.gd

@@ -12,9 +12,11 @@ extends Node3D
 ## A line is drawn from the rod tip each frame (hands.gd gives the tip).
 
 const BITE_WINDOW := 1.5
-const MIN_DEPTH := 0.5            ## water this deep under the float, or no fish
 const LINE_LENGTH := 26.0
 
+var water_type := ""              ## "lake", "sea"... (world.water_at)
+var table: Dictionary = {}        ## that water's fishing table (ItemDB.water_fishing)
+
 var world: Node3D
 var player: Node3D
 var state := "flying"
@@ -59,20 +61,34 @@ func _physics_process(delta: float) -> void:
 func _process(_delta: float) -> void:
 	_draw_line()
 
-## How long until the next bite (seconds).
-func _next_wait() -> float:
+func _dawn_dusk() -> bool:
 	var h: float = world.day_night.hours()
-	var k := 1.0
-	if (h > 5.0 and h < 8.5) or (h > 17.0 and h < 20.5):
-		k *= 0.6                      # fish feed at dawn and dusk
-	if world.weather.precip > 0.3:
-		k *= 0.8
-	return rng.randf_range(5.0, 14.0) * k
+	return (h > 5.0 and h < 8.5) or (h > 17.0 and h < 20.5)
 
+## How long until the next bite (seconds), from data/fish.json.
+func _next_wait() -> float:
+	var mods: Dictionary = ItemDB.fishing.modifiers
+	var w: Array = table.get("bite_wait", [5.0, 14.0])
+	var k := 1.0
+	if _dawn_dusk():
+		k *= float(mods.get("dawn_dusk_wait", 0.6))   # fish feed at dawn and dusk
+	if world.weather.precip > 0.3:
+		k *= float(mods.get("rain_wait", 0.8))
+	return rng.randf_range(w[0], w[1]) * k
+
+## A weighted pick from this water's fish (dawn/dusk weights when they apply).
 func _pick_fish() -> String:
-	var h: float = world.day_night.hours()
-	var trout := 0.4 if (h > 5.0 and h < 8.5) or (h > 17.0 and h < 20.5) else 0.22
-	return "trout" if rng.randf() < trout else "perch"
+	var fish: Array = table.get("fish", [])
+	var key := "dawn_dusk" if _dawn_dusk() else "weight"
+	var total := 0.0
+	for f in fish:
+		total += float(f[key])
+	var roll := rng.randf() * total
+	for f in fish:
+		roll -= float(f[key])
+		if roll <= 0.0:
+			return f.id
+	return fish[-1].id if not fish.is_empty() else ""
 
 func step(dt: float) -> void:
 	_t += dt
@@ -86,14 +102,24 @@ func step(dt: float) -> void:
 			velocity.y -= 9.8 * dt
 			var p := global_position + velocity * dt
 			var ground: float = terrain.sample_height(p.x, p.z)
-			if p.y <= terrain.water_level and ground < terrain.water_level - MIN_DEPTH:
-				p.y = terrain.water_level
-				state = "floating"
-				wait_left = _next_wait()
+			var water: Dictionary = world.water_at(p.x, p.z)
+			if not water.is_empty() and p.y <= float(water.surface):
+				p.y = water.surface
+				water_type = water.type
+				table = ItemDB.water_fishing(water_type)
+				if table.is_empty() or table.fish.is_empty():
+					state = "landed"
+					Actions.notify.emit("Nothing to catch here")
+				elif float(water.depth) < float(table.min_depth):
+					state = "landed"
+					Actions.notify.emit("Too shallow here: cast further out")
+				else:
+					state = "floating"
+					wait_left = _next_wait()
 			elif p.y <= ground + 0.03:
 				p.y = ground + 0.03
 				state = "landed"
-				Actions.notify.emit("Cast into the water (deeper than this)" if ground < terrain.water_level else "Cast into the water")
+				Actions.notify.emit("Cast into the water")
 			global_position = p
 		"floating":
 			wait_left -= dt
@@ -110,7 +136,7 @@ func step(dt: float) -> void:
 			if bite_left <= 0.0:
 				state = "floating"
 				fish = ""
-				wait_left = _next_wait() * 1.3
+				wait_left = _next_wait() * float(ItemDB.fishing.modifiers.get("missed_wait", 1.3))
 				_mesh.position.y = 0.0
 				Actions.notify.emit("It got away")
 

scripts/world/world.gd

@@ -487,6 +487,17 @@ func _update_grass_cuts() -> void:
 			xfs.append(p.global_transform)
 	props.set_grass_cuts(xfs, 1.02)
 
+## What water is at (x, z): {"type": "lake"|"sea", "surface": y, "depth": m},
+## or {} on dry land. The one place that knows this island's water bodies, so
+## fishing (and later swimming, boats) work on any world that answers it.
+func water_at(x: float, z: float) -> Dictionary:
+	var ground: float = terrain.sample_height(x, z)
+	if terrain.inside_boundary(x, z, -2.0) and ground < terrain.water_level:
+		return {"type": "lake", "surface": terrain.water_level, "depth": terrain.water_level - ground}
+	if terrain.sea_weight(x, z) > 0.5 and ground < terrain.sea_level:
+		return {"type": "sea", "surface": terrain.sea_level, "depth": terrain.sea_level - ground}
+	return {}
+
 ## Leaves `count` of an item lying in the world at `xf` (an arrow stuck in a
 ## tree, a thrown spear, meat that didn't fit). Saved with the world.
 func drop_item(id: String, count: int, xf: Transform3D) -> Node3D: