title: Smooth Paint Brush
body: <p>I am developing  an iPad Application which allows the users to select the Air Brush , this is being achieved by drawing the image texture in the current context.</p>
  
  <p>But when i draw the image i am getting this king of effect - <img src="https://i.stack.imgur.com/g3pTR.png" alt="enter image description here"> </p>
  
  <p>where as to avoid this i tried using blendmodeLighten ,  which give me the right way as below
  <img src="https://i.stack.imgur.com/zCxnS.png" alt="enter image description here"></p>
  
  <p>but using this i came across the another problem, where when i draw another color on the top of one color , due to blending i am not the getting the actual color. </p>
  
  <p>Can any one help me on this  ?</p>