Gui handler and basic inventory screen

client/gui/gui_systems.ts

@@ -0,0 +1,25 @@
+import { System } from "$/common/ecs/mod.ts";
+import { ClientWorld } from "../client_world.ts";
+import { PlayerComponent } from "../player.ts";
+
+export class GuiRenderSystem extends System {
+	update(world: ClientWorld, _delta: number): void {
+		const [player] = world.get_tag("player")!;
+		const player_component = player.get(PlayerComponent)!;
+
+		for (const screen of player_component.screens) {
+			screen.on_render();
+		}
+	}
+}
+
+export class GuiTickSystem extends System {
+	update(world: ClientWorld, delta: number): void {
+		const [player] = world.get_tag("player")!;
+		const player_component = player.get(PlayerComponent)!;
+
+		for (const screen of player_component.screens) {
+			screen.on_tick(delta);
+		}
+	}
+}