Basic crops system

server/game/blocks.ts

@@ -1,6 +1,7 @@
 import { Container, ItemStack } from "$/common/inventory.ts";
 import { ScreenLayout } from "$/common/protocol.ts";
-import { EverythingRegistry, ItemRegistry } from "$/common/everything_registry.ts";
+import { BlockRegistry, EverythingRegistry, ItemRegistry } from "$/common/everything_registry.ts";
+import { get_state_value, set_state_value } from "$/common/utils.ts";
 import type { RecipeBook } from "$/common/mod_loader.ts";
 import type { GameServer } from "./game_server.ts";
 import type { ServerPlayer } from "./player.ts";
@@ -51,6 +52,36 @@ function hoe_into_hoed_dirt(
 BLOCK_BEHAVIORS["bworld:grass"] = { on_interact: hoe_into_hoed_dirt };
 BLOCK_BEHAVIORS["bworld:dirt"] = { on_interact: hoe_into_hoed_dirt };
 
+// crops
+
+// minecraft's bone meal: a crop grows 2 to 5 stages at once, and the bone meal is used up
+function grow_with_bone_meal(
+	game: GameServer,
+	block: { x: number; y: number; z: number; id: string },
+	player: ServerPlayer,
+): boolean {
+	const held = player.held_item;
+	if (held?.type_id !== "bworld:bone_meal") {
+		return false;
+	}
+	const info = EverythingRegistry.get<BlockRegistry>("blocks", block.id)!;
+	const value = game.world.get_block_value(block.x, block.y, block.z);
+	const age = get_state_value(value, info, "age")!;
+	const max_age = 2 ** info.states!.find((s) => s.name === "age")!.bits - 1;
+	// fully grown, keep the bone meal
+	if (age >= max_age) {
+		return false;
+	}
+
+	const new_age = Math.min(age + 1, max_age);
+	game.set_block_state(block.x, block.y, block.z, set_state_value(value, info, "age", new_age)! >>> 16);
+	const slot = player.inventory.get_slot(player.selected_slot);
+	slot.amount = slot.amount! - 1;
+	return true;
+}
+
+BLOCK_BEHAVIORS["bworld:wheat"] = { on_interact: grow_with_bone_meal };
+
 // chest
 
 const CHEST_LAYOUT: ScreenLayout = {