Day night cycle

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);