Refactor screenToWorld for better argument handling

Author: perminder-17

src/core/environment.js

@@ -1314,16 +1314,18 @@ function environment(p5, fn, lifecycles){
    *
    */
   fn.screenToWorld = function(screenPosition) {
-    let origDimension = screenPosition._origDimension;
 
-    const screenToWorldArgs = arguments.length;
+    let origDimension = (typeof screenPosition === 'number')
+    ? arguments.length
+    : screenPosition._origDimension; 
+
     if (typeof screenPosition === 'number') {
       // We got passed numbers, convert to vector
       screenPosition = this.createVector(...arguments);
     }
 
     const matrix = this._renderer.getWorldToScreenMatrix();
-    if (origDimension === 2 || screenToWorldArgs === 2) {
+    if (origDimension === 2) {
       // Calculate a sensible Z value for the current camera projection that
       // will result in 0 once converted to world coordinates
       let z = matrix.mat4[14] / matrix.mat4[15];