From 0385d108a87298195e1fe1755ad2e6b6e9e0704f Mon Sep 17 00:00:00 2001
From: Richard Davey <rich@photonstorm.com>
Date: Fri, 31 Jul 2020 10:28:09 +0100
Subject: [PATCH] `Transform.getLocalPoint` is a new method, available on all
 Game Objects, that takes an `x` / `y` pair and translates them into the local
 space of the Game Object, factoring in parent transforms and display origins.

---
 src/gameobjects/components/Transform.js | 52 +++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/src/gameobjects/components/Transform.js b/src/gameobjects/components/Transform.js
index e0028946a..5fcef6b67 100644
--- a/src/gameobjects/components/Transform.js
+++ b/src/gameobjects/components/Transform.js
@@ -6,8 +6,10 @@
 
 var MATH_CONST = require('../../math/const');
 var TransformMatrix = require('./TransformMatrix');
+var TransformXY = require('../../math/TransformXY');
 var WrapAngle = require('../../math/angle/Wrap');
 var WrapAngleDegrees = require('../../math/angle/WrapDegrees');
+var Vector2 = require('../../math/Vector2');
 
 //  global bitmask flag for GameObject.renderMask (used by Scale)
 var _FLAG = 4; // 0100
@@ -502,6 +504,56 @@ var Transform = {
         return tempMatrix;
     },
 
+    /**
+     * Takes the given `x` and `y` coordinates and converts them into local space for this
+     * Game Object, taking into account parent and local transforms, and the Display Origin.
+     *
+     * The returned Vector2 contains the translated point in its properties.
+     *
+     * A Camera needs to be provided in order to handle modified scroll factors. If no
+     * camera is specified, it will use the `main` camera from the Scene to which this
+     * Game Object belongs.
+     *
+     * @method Phaser.GameObjects.Components.Transform#getLocalPoint
+     * @since 3.50.0
+     *
+     * @param {number} x - The x position to translate.
+     * @param {number} y - The y position to translate.
+     * @param {Phaser.Math.Vector2} [point] - A Vector2, or point-like object, to store the results in.
+     * @param {Phaser.Cameras.Scene2D.Camera} [camera] - The Camera which is being tested against. If not given will use the Scene default camera.
+     *
+     * @return {Phaser.Math.Vector2} The translated point.
+     */
+    getLocalPoint: function (x, y, point, camera)
+    {
+        if (!point) { point = new Vector2(); }
+        if (!camera) { camera = this.scene.sys.cameras.main; }
+
+        var csx = camera.scrollX;
+        var csy = camera.scrollY;
+
+        var px = x + (csx * this.scrollFactorX) - csx;
+        var py = y + (csy * this.scrollFactorY) - csy;
+
+        if (this.parentContainer)
+        {
+            this.getWorldTransformMatrix().applyInverse(px, py, point);
+        }
+        else
+        {
+            TransformXY(px, py, this.x, this.y, this.rotation, this.scaleX, this.scaleY, point);
+        }
+
+        //  Normalize origin
+        if (this._originComponent)
+        {
+            point.x += this._displayOriginX;
+            point.y += this._displayOriginY;
+        }
+
+        return point;
+    },
+
     /**
      * Gets the sum total rotation of all of this Game Objects parent Containers.
      *