Takes the x and y coordinates and transforms them into the same space as defined by the position, rotation and scale values.

Author: photonstorm

v3/src/math/TransformXY.js

@@ -0,0 +1,54 @@
+var Vector2 = require('./Vector2');
+
+/**
+ * Takes the `x` and `y` coordinates and transforms them into the same space as
+ * defined by the position, rotation and scale values.
+ *
+ * @function Phaser.Math.TransformXY
+ * @since 3.0.0
+ *
+ * @param {number} x - The x coordinate to be transformed.
+ * @param {number} y - The y coordinate to be transformed.
+ * @param {number} positionX - Horizontal position of the transform point.
+ * @param {number} positionY - Vertical position of the transform point.
+ * @param {number} rotation - Rotation of the transform point, in radians.
+ * @param {number} scaleX - Horizontal scale of the transform point.
+ * @param {number} scaleY - Vertical scale of the transform point.
+ * @param {Vector2|Point|object} [output] - [description]
+ *
+ * @return {Vector2|Point|object} The translated point.
+ */
+var TransformXY = function (x, y, positionX, positionY, rotation, scaleX, scaleY, output)
+{
+    if (output === undefined) { output = new Vector2(); }
+
+    //  ITRS
+
+    var sr = Math.sin(-rotation);
+    var cr = Math.cos(-rotation);
+
+    var a = cr * scaleX;
+    var b = -sr * scaleX;
+    var c = sr * scaleY;
+    var d = cr * scaleY;
+
+    //  Invert
+
+    var n = a * d - b * c;
+
+    var m0 = d / n;
+    var m1 = -b / n;
+    var m2 = -c / n;
+    var m3 = a / n;
+    var m4 = (c * positionY - d * positionX) / n;
+    var m5 = -(a * positionY - b * positionX) / n;
+
+    //  Transform
+
+    output.x = x * m0 + y * m2 + m4;
+    output.y = x * m1 + y * m3 + m5;
+
+    return output;
+};
+
+module.exports = TransformXY;