title: How do I apply a circular mask to a texture in XNA?
body: <p>I've made a start on a game for Windows Phone 7.1, using a pure XNA 4.0 solution. The game will essentially involve moving around a maze, and I'd like in the top right corner to feature a circle that shows a zoomed-out view of where the player is in the maze.</p>
  
  <p>I've written the code that generates a random maze, and so I can render all of the walls, save this render to a texture in memory and scale that to whatever size it needs to be. But this will be a rectangle.. and I need it to be shown inside a circle.</p>
  
  <p>Any ideas on the best approach?</p>