title: How do I plot individual pixels using the XNA APIs?
body: <p>If I wanted to fill my game screen with individually coloured pixels, how would I do this?</p>
  <p>For example, if I wanted to write a '<a href="http://en.wikipedia.org/wiki/Conway%27s_Game_of_Life" rel="nofollow noreferrer">game of life</a>'-type game where each pixel was a cell, how would I achieve this using XNA?</p>
  <p>I've tried just calling <code>SetData()</code> on a <code>Texture2D</code> object using a screen-sized array of <code>Color</code> values, but it complains with:</p>
  <blockquote>
  <p>You may not call SetData on a resource while it is actively set on the GraphicsDevice.</p>
  <p>Unset it from the device before calling SetData.</p>
  </blockquote>
  <p>How do I do as it asks? Or better still... is there an alternative, better, efficient way to fill a screen with arbitrary pixels?</p>