Better world generation

server/game/game_server.ts

@@ -466,6 +466,8 @@ export class GameServer {
 		const saved = this.#saved_players[player.name];
 		if (saved) {
 			player.load(saved);
+		} else {
+			Object.assign(player, this.world.spawn_point());
 		}
 
 		this.#send(player, {

server/game/world.ts

@@ -6,9 +6,11 @@ import { AIR_ID, BlockChange } from "$/common/protocol.ts";
 import { block_value, chunk_key, default_block_value } from "$/common/utils.ts";
 import { LruMap } from "./lru.ts";
 
-// generation only, rebuilt when needed. 128 KB each
-const RAW_CACHE_SIZE = 256;
-const CHUNK_CACHE_SIZE = 512;
+// generation only, rebuilt when needed. 256 KB each
+const RAW_CACHE_SIZE = 128;
+const CHUNK_CACHE_SIZE = 256;
+// how far from the middle of the world to look for dry land to spawn on, in chunks
+const SPAWN_SEARCH_CHUNKS = 32;
 
 // a block with state the server keeps, like a chest's items. never sent to clients as is
 export interface Tile {
@@ -56,6 +58,36 @@ export class ServerWorld {
 		});
 	}
 
+	#spawn: { x: number; y: number; z: number } | undefined;
+
+	// where new players start: the dry land closest to the middle of the world, like minecraft's world spawn
+	spawn_point() {
+		if (!this.#spawn) {
+			this.#spawn = this.#find_spawn();
+		}
+		return this.#spawn;
+	}
+
+	#find_spawn() {
+		const water = this.block_ids["bworld:water"];
+		// chunks in rings around the middle, one column each
+		for (let radius = 0; radius <= SPAWN_SEARCH_CHUNKS; radius++) {
+			for (let cz = -radius; cz <= radius; cz++) {
+				for (let cx = -radius; cx <= radius; cx++) {
+					if (Math.max(Math.abs(cx), Math.abs(cz)) !== radius) continue;
+					const x = cx * CHUNK_SIZE + CHUNK_SIZE / 2;
+					const z = cz * CHUNK_SIZE + CHUNK_SIZE / 2;
+					let y = CHUNK_HEIGHT - 1;
+					while (y > 0 && this.get_block_nid(x, y, z) === AIR) y--;
+					if (y > 0 && this.get_block_nid(x, y, z) !== water) {
+						return { x: x + 0.5, y: y + 1, z: z + 0.5 };
+					}
+				}
+			}
+		}
+		return { x: 0.5, y: CHUNK_HEIGHT - 1, z: 0.5 };
+	}
+
 	get_block_id(x: number, y: number, z: number): string {
 		const nid = this.get_block_nid(x, y, z);
 		return nid === AIR ? AIR_ID : EverythingRegistry.get_by_id<BlockRegistry>("blocks", nid)?.id ?? AIR_ID;