title: Get normalized click position on a RectTransform
body: <p>Ive made a ui touch/click controller by using an UI image with collider. The ui is rendered with a stacked camera.</p>
  <p>Im using IPointerDownHandler.OnPointerDown to get the click event.
  The controller is supposed to give a value from 0-1 depending on how far up you click it.</p>
  <p>Im using Canvas Scaler on the UI to make the controllers resize depending on device. But that messes up my calculations since the click position wont be the same. How is this supposed to be handled? Now the calculation is only correct when i disable Canvas Scaler or run it on a display with the default dimensions.</p>
  <pre><code>public void OnPointerDown(PointerEventData pointerEventData)
  {
  
      SetAccelerationValue(pointerEventData.position.y);
  }
      private void SetAccelerationValue(float posY)
  {   
      float percentagePosition;
      var positionOnAccelerator = posY - minY;
      var acceleratorHeight = maxY - minY;
      percentagePosition = positionOnAccelerator / acceleratorHeight;
      
  
      Debug.Log(percentagePosition);
  
  }
  </code></pre>