Add Discord GameSDK.

Assets/Cryville/Crtr/DiscordController.cs

@@ -0,0 +1,54 @@
+using Discord;
+using System;
+using UnityEngine;
+
+namespace Cryville.Crtr {
+	internal class DiscordController : MonoBehaviour {
+		public static DiscordController Instance;
+
+		const long CLIENT_ID = 1059021675578007622L;
+
+		Discord.Discord dc;
+		ActivityManager am;
+		long launchTime;
+
+		void Start() {
+			Instance = this;
+			launchTime = (long)(DateTime.UtcNow - DateTime.UnixEpoch).TotalSeconds;
+			dc = new Discord.Discord(CLIENT_ID, (UInt64)CreateFlags.Default);
+			am = dc.GetActivityManager();
+			SetIdle();
+		}
+
+		void Update() {
+			dc.RunCallbacks();
+		}
+
+		void OnApplicationQuit() {
+			dc.Dispose();
+		}
+
+		void Callback(Result result) { }
+
+		public void SetIdle() {
+			am.UpdateActivity(new Activity {
+				State = "Idle",
+				Instance = false,
+				Timestamps = { Start = launchTime },
+			}, Callback);
+		}
+
+		public void SetPlaying(string detail, double? duration) {
+			long now = (long)(DateTime.UtcNow - DateTime.UnixEpoch).TotalSeconds;
+			am.UpdateActivity(new Activity {
+				State = "Playing a chart",
+				Details = detail,
+				Instance = true,
+				Timestamps = {
+					Start = now,
+					End = duration == null ? 0 : now + (long)duration,
+				},
+			}, Callback);
+		}
+	}
+}