Server authority

common/protocol.ts

@@ -1,4 +1,6 @@
 // messages sent between the client and the server, as json over a websocket
+import type { Faces } from "./constants.ts";
+import type { ItemData } from "./inventory.ts";
 
 export const AIR_ID = "bworld:air";
 
@@ -15,19 +17,64 @@ export interface PlayerInfo {
 // x, y, z, block id
 export type BlockChange = [number, number, number, string];
 
+// the containers a client can see and click. "screen" is whatever the open server screen shows
+export type ContainerKey = "inventory" | "crafting" | "screen";
+
+export const CRAFTING_RESULT_SLOT = 9;
+
+// a screen the server opens, drawn below the player's inventory and hotbar
+export interface ScreenLayout {
+	// height of the screen's own area, in slots
+	rows: number;
+	// x and y in slots, can be fractional
+	// output slots can only be taken from, like the furnace result
+	slots: { index: number; x: number; y: number; output?: boolean }[];
+	// progress bars filled from properties[value] / properties[max]
+	bars: {
+		x: number;
+		y: number;
+		value: string;
+		max: string;
+		direction: "up" | "right";
+		empty_texture: string;
+		full_texture: string;
+	}[];
+}
+
+// clients send what the player is trying to do, the server decides what happens
 export type ClientMessage =
 	| { type: "hello"; name: string }
 	| { type: "move"; x: number; y: number; z: number; yaw: number; pitch: number }
-	| { type: "set_block"; x: number; y: number; z: number; id: string }
+	| { type: "break_block"; x: number; y: number; z: number }
+	// right click on a block: interact with it, or place the held block against `face`
+	| { type: "use_block"; x: number; y: number; z: number; face: Faces }
+	| { type: "select_slot"; slot: number }
+	| { type: "click"; container: ContainerKey; index: number; button: number }
+	// closes the open screen, including the player's own inventory screen
+	| { type: "close_screen" }
 	| { type: "chat"; text: string };
 
 export type ServerMessage =
-	| { type: "welcome"; id: string; seed: string; players: PlayerInfo[]; changes: BlockChange[] }
+	| {
+		type: "welcome";
+		id: string;
+		seed: string;
+		players: PlayerInfo[];
+		changes: BlockChange[];
+		spawn: { x: number; y: number; z: number; yaw: number; pitch: number };
+		selected_slot: number;
+	}
 	| { type: "player_join"; player: PlayerInfo }
 	| { type: "player_leave"; id: string }
 	| { type: "player_move"; id: string; x: number; y: number; z: number; yaw: number; pitch: number }
+	// also sent to the player who caused it, which corrects anything their client predicted wrong
 	| { type: "set_block"; x: number; y: number; z: number; id: string }
-	| { type: "chat"; from?: string; text: string };
+	| { type: "chat"; from?: string; text: string }
+	| { type: "container"; container: ContainerKey; items: (ItemData | null)[] }
+	| { type: "cursor"; item: ItemData | null }
+	| { type: "open_screen"; layout: ScreenLayout; properties: Record<string, number> }
+	| { type: "screen_properties"; properties: Record<string, number> }
+	| { type: "close_screen" };
 
 export const MAX_NAME_LENGTH = 16;
 export const MAX_CHAT_LENGTH = 256;