Add planet scanner and octopus biome

world/WorldGen.gd

@@ -9,7 +9,7 @@ const PLANET_DEFINITIONS = preload("res://planets/PlanetDefinitions.gd")
 # revisiting the same chunk always yields the same biome, and biomes form
 # smooth multi-chunk regions instead of a per-chunk random checkerboard.
 
-enum Biome { SPACE, ASTEROID_FIELD }
+enum Biome { SPACE, ASTEROID_FIELD, OCTOPUS }
 
 const CHUNK_SIZE: float = 1200.0
 const NOISE_SEED: int = 1337
@@ -37,10 +37,18 @@ const BLACK_HOLE_CHANCE: float = 0.05
 # from 0.08 after playtesting found that rate too scarce for how central
 # research points had become to progression.
 const RESEARCH_LAB_CHANCE: float = 0.16
-# A boss world is rarer than every ordinary discovery. Its roll uses a
-# separately seeded generator below, so adding it cannot rename or re-roll
-# any planet in an existing world.
-const BOSS_PLANET_CHANCE: float = 0.025
+# The hostile region is authored into procedural space as one finite,
+# deterministic island. A probability per chunk can only say "rare"; over an
+# infinite world it inevitably creates infinitely many boss worlds. One
+# anchor and one shape make the actual rule representable: one multi-chunk
+# octopus biome, with its boss at the centre.
+const OCTOPUS_BIOME_CENTER: Vector2i = Vector2i(12, -9)
+const OCTOPUS_BIOME_OFFSETS: Array[Vector2i] = [
+	Vector2i(0, 0), Vector2i(-1, 0), Vector2i(1, 0),
+	Vector2i(0, -1), Vector2i(0, 1),
+	Vector2i(-1, -1), Vector2i(1, -1),
+	Vector2i(-1, 1), Vector2i(1, 1),
+]
 
 # DEV MODE ONLY: one of every planet type, parked in the chunks immediately
 # around the spawn so all five can be reached in seconds.
@@ -113,6 +121,8 @@ static func chunk_origin(chunk: Vector2i) -> Vector2:
 
 
 static func biome_at_chunk(chunk: Vector2i) -> int:
+	if is_octopus_chunk(chunk):
+		return Biome.OCTOPUS
 	var n: float = _get_noise().get_noise_2d(float(chunk.x), float(chunk.y))
 	if n > ASTEROID_FIELD_THRESHOLD:
 		return Biome.ASTEROID_FIELD
@@ -122,6 +132,10 @@ static func biome_at_chunk(chunk: Vector2i) -> int:
 static func has_planet_at_chunk(chunk: Vector2i) -> bool:
 	if _dev_planets_active() and DEV_PLANET_CHUNKS.has(chunk):
 		return true
+	if chunk == OCTOPUS_BIOME_CENTER:
+		return true
+	if is_octopus_chunk(chunk):
+		return false
 	var n: float = _get_planet_noise().get_noise_2d(float(chunk.x), float(chunk.y))
 	return (biome_at_chunk(chunk) == Biome.ASTEROID_FIELD and n > PLANET_THRESHOLD) or (biome_at_chunk(chunk) == Biome.SPACE and n > GAS_GIANT_THRESHOLD)
 
@@ -148,17 +162,12 @@ static func planet_data_at_chunk(chunk: Vector2i) -> Dictionary:
 	var black_hole_roll: float = rng.randf()
 	# Same principle, its own independent roll (#63).
 	var research_lab_roll: float = rng.randf()
-	# Independent from the established generation stream: existing chunks keep
-	# their old names and shapes when this new rare outcome is introduced.
-	var boss_rng := RandomNumberGenerator.new()
-	boss_rng.seed = hash("boss:%d:%d" % [chunk.x, chunk.y])
-	var boss_roll: float = boss_rng.randf()
 	# A stable per-chunk roll makes gas giants persistent landmarks rather
 	# than a different resource whenever the scene reloads.
 	var gas_giant: bool = biome_at_chunk(chunk) == Biome.SPACE
 	var definition_id: String = PLANET_DEFINITIONS.GAS_GIANT_ID if gas_giant else PLANET_DEFINITIONS.ROCKY_ID
 	# Rare authored outcomes, seeded deterministically like everything else.
-	if boss_roll < BOSS_PLANET_CHANCE:
+	if chunk == OCTOPUS_BIOME_CENTER:
 		definition_id = PLANET_DEFINITIONS.BOSS_ID
 	elif black_hole_roll < BLACK_HOLE_CHANCE:
 		definition_id = PLANET_DEFINITIONS.BLACK_HOLE_ID
@@ -186,5 +195,26 @@ static func biome_color(biome: int) -> Color:
 	match biome:
 		Biome.ASTEROID_FIELD:
 			return Color(0.55, 0.36, 0.18, 1.0)
+		Biome.OCTOPUS:
+			return Color(0.34, 0.07, 0.24, 1.0)
 		_:
 			return Color(0.10, 0.13, 0.28, 1.0)
+
+
+static func biome_background_color(biome: int) -> Color:
+	match biome:
+		Biome.OCTOPUS:
+			return Color(0.075, 0.012, 0.065, 1.0)
+		_:
+			return Color(0.02, 0.02, 0.08, 1.0)
+
+
+static func is_octopus_chunk(chunk: Vector2i) -> bool:
+	return chunk - OCTOPUS_BIOME_CENTER in OCTOPUS_BIOME_OFFSETS
+
+
+static func octopus_biome_chunks() -> Array[Vector2i]:
+	var chunks: Array[Vector2i] = []
+	for offset in OCTOPUS_BIOME_OFFSETS:
+		chunks.append(OCTOPUS_BIOME_CENTER + offset)
+	return chunks