From 05bedf0c22ee0ce0f3c512acb3a2815cd6bfcf93 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20N=C3=A9grier?= <d.negrier@thecodingmachine.com>
Date: Fri, 24 Dec 2021 13:20:49 +0100
Subject: [PATCH] Adding an "out-of-bounds" notion for a group.

This allows hiding a group when some players are out of the radius but the group still exists because of the "follow" feature.
---
 back/src/Model/GameRoom.ts | 21 ++++++++++++++++-----
 back/src/Model/Group.ts    | 18 ++++++++++++++++++
 2 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/back/src/Model/GameRoom.ts b/back/src/Model/GameRoom.ts
index 4e7cf441..ff8b7cf0 100644
--- a/back/src/Model/GameRoom.ts
+++ b/back/src/Model/GameRoom.ts
@@ -219,8 +219,8 @@ export class GameRoom {
         if (user.silent) {
             return;
         }
-
-        if (user.group === undefined) {
+        const group = user.group;
+        if (group === undefined) {
             // If the user is not part of a group:
             //  should he join a group?
 
@@ -251,18 +251,29 @@ export class GameRoom {
         } else {
             // If the user is part of a group:
             //  should he leave the group?
-            const users = user.group.getUsers().filter((u) => !u.hasFollowers() && !u.following);
-            users.forEach((foreignUser: User) => {
+            let noOneOutOfBounds = true;
+            group.getUsers().forEach((foreignUser: User) => {
                 if (foreignUser.group === undefined) {
                     return;
                 }
                 const usrPos = foreignUser.getPosition();
                 const grpPos = foreignUser.group.getPosition();
                 const distance = GameRoom.computeDistanceBetweenPositions(usrPos, grpPos);
+
                 if (distance > this.groupRadius) {
-                    this.leaveGroup(foreignUser);
+                    if (foreignUser.hasFollowers() || foreignUser.following) {
+                        // If one user is out of the group bounds BUT following, the group still exists... but should be hidden.
+                        // We put it in 'outOfBounds' mode
+                        group.setOutOfBounds(true);
+                        noOneOutOfBounds = false;
+                    } else {
+                        this.leaveGroup(foreignUser);
+                    }
                 }
             });
+            if (noOneOutOfBounds && !user.group?.isEmpty()) {
+                group.setOutOfBounds(false);
+            }
         }
     }
 
diff --git a/back/src/Model/Group.ts b/back/src/Model/Group.ts
index c59334ec..c35ac7a8 100644
--- a/back/src/Model/Group.ts
+++ b/back/src/Model/Group.ts
@@ -16,6 +16,10 @@ export class Group implements Movable {
     private wasDestroyed: boolean = false;
     private roomId: string;
     private currentZone: Zone | null = null;
+    /**
+     * When outOfBounds = true, a user if out of the bounds of the group BUT still considered inside it (because we are in following mode)
+     */
+    private outOfBounds = false;
 
     constructor(
         roomId: string,
@@ -78,6 +82,10 @@ export class Group implements Movable {
         this.x = x;
         this.y = y;
 
+        if (this.outOfBounds) {
+            return;
+        }
+
         if (oldX === undefined) {
             this.currentZone = this.positionNotifier.enter(this);
         } else {
@@ -154,4 +162,14 @@ export class Group implements Movable {
         }
         return undefined;
     }
+
+    setOutOfBounds(outOfBounds: boolean): void {
+        if (this.outOfBounds === true && outOfBounds === false) {
+            this.positionNotifier.enter(this);
+            this.outOfBounds = false;
+        } else if (this.outOfBounds === false && outOfBounds === true) {
+            this.positionNotifier.leave(this);
+            this.outOfBounds = true;
+        }
+    }
 }