Refactor PacketSceneTransToPointRsp and add a null check when getting ScenePointEntries

src/main/java/emu/grasscutter/command/commands/ChangeSceneCommand.java

@@ -23,11 +23,17 @@ public final class ChangeSceneCommand implements CommandHandler {
 
         try {
             int sceneId = Integer.parseInt(args.get(0));
-            boolean result = sender.getWorld().transferPlayerToScene(sender, sceneId, sender.getPos());
             
+            if (sceneId == sender.getSceneId()) {
+            	CommandHandler.sendMessage(sender, "You are already in that scene");
+            	return;
+            }
+            
+            boolean result = sender.getWorld().transferPlayerToScene(sender, sceneId, sender.getPos());
             CommandHandler.sendMessage(sender, "Changed to scene " + sceneId);
+            
             if (!result) {
-                CommandHandler.sendMessage(sender, "Scene does not exist or you are already in it");
+                CommandHandler.sendMessage(sender, "Scene does not exist");
             }
         } catch (Exception e) {
             CommandHandler.sendMessage(sender, "Usage: changescene <scene id>");

src/main/java/emu/grasscutter/game/World.java

@@ -207,27 +207,8 @@ public class World implements Iterable<GenshinPlayer> {
 		this.getScenes().remove(scene.getId());
 	}
 	
-	public boolean forceTransferPlayerToScene(GenshinPlayer player, int sceneId, Position pos) {
-		// Forces the client to reload the scene map to prevent the player from falling off the map.
-		if (GenshinData.getSceneDataMap().get(sceneId) == null) {
-			return false;
-		}
-
-		if (player.getScene() != null) {
-			player.getScene().removePlayer(player);
-		}
-		
-		GenshinScene scene = this.getSceneById(sceneId);
-		scene.addPlayer(player);
-		player.getPos().set(pos);
-		
-		// Teleport packet
-		player.sendPacket(new PacketPlayerEnterSceneNotify(player, EnterType.EnterSelf, EnterReason.TransPoint, sceneId, pos));
-		return true;
-	}
-	
 	public boolean transferPlayerToScene(GenshinPlayer player, int sceneId, Position pos) {
-		if (player.getScene().getId() == sceneId || GenshinData.getSceneDataMap().get(sceneId) == null) {
+		if (GenshinData.getSceneDataMap().get(sceneId) == null) {
 			return false;
 		}
 		

src/main/java/emu/grasscutter/server/packet/recv/HandlerSceneTransToPointReq.java

 package emu.grasscutter.server.packet.recv;
 
+import emu.grasscutter.data.GenshinData;
+import emu.grasscutter.data.custom.ScenePointEntry;
 import emu.grasscutter.net.packet.Opcodes;
 import emu.grasscutter.net.packet.PacketOpcodes;
 import emu.grasscutter.net.proto.SceneTransToPointReqOuterClass.SceneTransToPointReq;
+import emu.grasscutter.net.proto.SceneTransToPointRspOuterClass.SceneTransToPointRsp;
 import emu.grasscutter.net.packet.PacketHandler;
 import emu.grasscutter.server.game.GameSession;
 import emu.grasscutter.server.packet.send.PacketSceneTransToPointRsp;
+import emu.grasscutter.utils.Position;
 
 @Opcodes(PacketOpcodes.SceneTransToPointReq)
 public class HandlerSceneTransToPointReq extends PacketHandler {
@@ -13,7 +17,20 @@ public class HandlerSceneTransToPointReq extends PacketHandler {
 	@Override
 	public void handle(GameSession session, byte[] header, byte[] payload) throws Exception {
 		SceneTransToPointReq req = SceneTransToPointReq.parseFrom(payload);
+		
+		String code = req.getSceneId() + "_" + req.getPointId();
+		ScenePointEntry scenePointEntry = GenshinData.getScenePointEntries().get(code);
+		
+		if (scenePointEntry != null) {
+			float x = scenePointEntry.getPointData().getTranPos().getX();
+			float y = scenePointEntry.getPointData().getTranPos().getY();
+			float z = scenePointEntry.getPointData().getTranPos().getZ();
+
+			session.getPlayer().getWorld().transferPlayerToScene(session.getPlayer(), req.getSceneId(), new Position(x, y, z));
 			session.send(new PacketSceneTransToPointRsp(session.getPlayer(), req.getPointId(), req.getSceneId()));
+		} else {
+			session.send(new PacketSceneTransToPointRsp());
+		}
 	}
 
 }

src/main/java/emu/grasscutter/server/packet/send/PacketSceneTransToPointRsp.java

@@ -13,17 +13,6 @@ public class PacketSceneTransToPointRsp extends GenshinPacket {
 	public PacketSceneTransToPointRsp(GenshinPlayer player, int pointId, int sceneId) {
 		super(PacketOpcodes.SceneTransToPointRsp);
 
-		String code = sceneId + "_" + pointId;
-		ScenePointEntry scenePointEntry = GenshinData.getScenePointEntries().get(code);
-
-		float x = scenePointEntry.getPointData().getTranPos().getX();
-		float y = scenePointEntry.getPointData().getTranPos().getY();
-		float z = scenePointEntry.getPointData().getTranPos().getZ();
-
-		player.getPos().set(new Position(x, y, z));
-
-		player.getWorld().forceTransferPlayerToScene(player, sceneId, player.getPos());
-
 		SceneTransToPointRsp proto = SceneTransToPointRsp.newBuilder()
 				.setRetcode(0)
 	            .setPointId(pointId)
@@ -32,4 +21,14 @@ public class PacketSceneTransToPointRsp extends GenshinPacket {
 
 		this.setData(proto);
 	}
+
+	public PacketSceneTransToPointRsp() {
+		super(PacketOpcodes.SceneTransToPointRsp);
+		
+		SceneTransToPointRsp proto = SceneTransToPointRsp.newBuilder()
+				.setRetcode(1) // Internal server error
+	            .build();
+
+		this.setData(proto);
+	}
 }