title: Texture Brush (Drawing Application ) Using Metal
body: <p>I am trying to implement a metal-backed drawing application where brushstrokes are drawn on an MTKView by textured square repeatedly along a finger position. 
  <a href="https://i.stack.imgur.com/bF0Dx.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bF0Dx.jpg" alt="enter image description here"></a> </p>
  
  <p>I am drawing this with alpha 0.2. When the squares are overlapped the color is added. How can I draw with alpha 0.2.</p>