From 69d2fa69446eb4913029975c2c5e0f559263f731 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20N=C3=A9grier?= <d.negrier@thecodingmachine.com>
Date: Wed, 3 Jun 2020 11:14:04 +0200
Subject: [PATCH] Allowing several start positions in a given start layer

If more than one tile was set in the "start" layer, the last tile would be selected.
Now, the tile is selected at random among available tiles.

Also, a message is issued if no tiles have been put on the "start" layer.
---
 front/src/Phaser/Game/GameScene.ts | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/front/src/Phaser/Game/GameScene.ts b/front/src/Phaser/Game/GameScene.ts
index 60acf98d..8bdbbee5 100644
--- a/front/src/Phaser/Game/GameScene.ts
+++ b/front/src/Phaser/Game/GameScene.ts
@@ -136,7 +136,9 @@ export class GameScene extends Phaser.Scene {
                 this.loadNextGame(layer, this.map.width, this.map.tilewidth, this.map.tileheight);
             }
             if (layer.type === 'tilelayer' && layer.name === "start") {
-                this.startUser(layer);
+                let startPosition = this.startUser(layer);
+                this.startX = startPosition.x;
+                this.startY = startPosition.y;
             }
             if (layer.type === 'objectgroup' && layer.name === 'floorLayer') {
                 depth = 10000;
@@ -252,14 +254,18 @@ export class GameScene extends Phaser.Scene {
     /**
      * @param layer
      */
-    private startUser(layer: ITiledMapLayer): void {
+    private startUser(layer: ITiledMapLayer): PositionInterface {
         if (this.initPosition !== undefined) {
             this.startX = this.initPosition.x;
             this.startY = this.initPosition.y;
-            return;
+            return {
+                x: this.initPosition.x,
+                y: this.initPosition.y
+            };
         }
 
         let tiles : any = layer.data;
+        let possibleStartPositions : PositionInterface[]  = [];
         tiles.forEach((objectKey : number, key: number) => {
             if(objectKey === 0){
                 return;
@@ -267,9 +273,18 @@ export class GameScene extends Phaser.Scene {
             let y = Math.floor(key / layer.width);
             let x = key % layer.width;
 
-            this.startX = (x * 32);
-            this.startY = (y * 32);
+            possibleStartPositions.push({x: x*32, y: y*32});
         });
+        // Get a value at random amongst allowed values
+        if (possibleStartPositions.length === 0) {
+            console.warn('The start layer "'+layer.name+'" for this map is empty.');
+            return {
+                x: 0,
+                y: 0
+            };
+        }
+        // Choose one of the available start positions at random amongst the list of available start positions.
+        return possibleStartPositions[Math.floor(Math.random() * possibleStartPositions.length)];
     }
 
     //todo: in a dedicated class/function?