Day night cycle

client/client.ts

@@ -53,6 +53,7 @@ export class Client {
 		this.#on_disconnect = on_disconnect;
 
 		this.level = new ClientLevel(connection.seed);
+		this.level.time = connection.time;
 		for (const [x, y, z, id, state] of connection.initial_changes) {
 			this.level.record_change(x, y, z, id, state);
 		}

client/gui/debug_overlay.ts

@@ -1,10 +1,13 @@
 import type { Client } from "$/client/client.ts";
 import { DebugUI } from "$/client/debug_ui.ts";
+import { format_clock } from "$/common/time.ts";
 
 // f3: every entity's fields, editable
 export class DebugOverlay {
 	render(client: Client) {
 		DebugUI.begin("Entities", 10, 10, 300);
+		DebugUI.text(`${format_clock(client.level.time)} (tick ${client.level.time})`);
+		DebugUI.separator();
 
 		for (const entity of client.level.entities.values()) {
 			if (DebugUI.collapsing_header(`${entity.constructor.name} - ${entity.id}`)) {

client/level/client_level.ts

@@ -87,6 +87,8 @@ export class ClientLevel {
 	second_timer = 0;
 	tick_timer = 0;
 	seed: string;
+	// world time in ticks, counted here between the server's updates. see common/time.ts
+	time = 0;
 
 	// blocks players changed from the generated terrain, per chunk, so they survive reloading chunks
 	changes = new Map<string, Map<string, BlockChange>>();
@@ -129,6 +131,7 @@ export class ClientLevel {
 	}
 
 	tick() {
+		this.time += 1;
 		for (const entity of this.entities.values()) {
 			entity.save_previous_position();
 			entity.tick();

client/mods.ts

@@ -100,6 +100,9 @@ function client_context(listing: ModListing): ClientContext {
 				if (nid === AIR) return AIR_ID;
 				return EverythingRegistry.get_by_id<BlockRegistry>("blocks", nid)?.id;
 			},
+			get time() {
+				return need_client().level.time;
+			},
 		},
 		log: (...args) => console.log(`[${mod}]`, ...args),
 	};

client/network.ts

@@ -11,6 +11,7 @@ export class Connection {
 	initial_changes: BlockChange[];
 	spawn: { x: number; y: number; z: number; yaw: number; pitch: number };
 	selected_slot: number;
+	time: number;
 	// who was already there when we joined, they become entities in the level
 	initial_players: PlayerInfo[];
 	initial_entities: EntityInfo[];
@@ -24,6 +25,7 @@ export class Connection {
 		this.initial_changes = join.changes;
 		this.spawn = join.spawn;
 		this.selected_slot = join.selected_slot;
+		this.time = join.time;
 		this.initial_players = join.players;
 		this.initial_entities = join.entities;
 	}

client/packet_listener.ts

@@ -31,6 +31,9 @@ export class ClientPacketListener {
 			case "player_join":
 				level.add_entity(new RemotePlayer(level, message.player));
 				break;
+			case "time":
+				level.time = message.time;
+				break;
 			case "player_leave":
 				level.remove_entity(message.id);
 				break;

client/rendering/game_renderer.ts

@@ -1,19 +1,41 @@
 import type { Client } from "$/client/client.ts";
-import { begin_mode_3d, end_mode_3d } from "$/client/renderer/mod.ts";
+import { begin_mode_3d, clear_background, end_mode_3d, update_lightmap } from "$/client/renderer/mod.ts";
+import { daylight } from "$/common/time.ts";
 import { Hud } from "$/client/gui/hud.ts";
 import { DebugOverlay } from "$/client/gui/debug_overlay.ts";
 import { LevelRenderer } from "./level_renderer.ts";
 
+// the sky at noon and in the middle of the night
+const DAY_SKY = [0.69, 0.8, 1];
+const NIGHT_SKY = [0.02, 0.03, 0.08];
+// minecraft's darkest sky: moonlight still lights things a little
+const NIGHT_SKY_LIGHT = 0.2;
+
 // draws a frame, like minecraft's GameRenderer: the level from the camera, then the hud and screens on top
 export class GameRenderer {
 	level_renderer = new LevelRenderer();
 	hud = new Hud();
 	debug_overlay = new DebugOverlay();
+	// what the lightmap was last made for, so it's only rebuilt when the light changes
+	#lightmap_daylight = -1;
+
+	// sky color and sky light for the time of day
+	#setup_sky(client: Client, partial_tick: number) {
+		const light = daylight(client.level.time + partial_tick);
+		const [r, g, b] = DAY_SKY.map((day, i) => NIGHT_SKY[i] + (day - NIGHT_SKY[i]) * light);
+		clear_background(r, g, b, 1);
+
+		if (Math.abs(light - this.#lightmap_daylight) > 0.001) {
+			this.#lightmap_daylight = light;
+			update_lightmap(NIGHT_SKY_LIGHT + (1 - NIGHT_SKY_LIGHT) * light);
+		}
+	}
 
 	// partial_tick is how far this frame is between the last tick and the next, entities are drawn in between
 	render(client: Client, partial_tick: number) {
 		const camera = client.camera;
 		camera.setup(client.player, partial_tick);
+		this.#setup_sky(client, partial_tick);
 
 		begin_mode_3d(camera);
 		this.level_renderer.render_opaque(client.level, camera);