title: How do I correctly implement texture pixel to texel correction in direct3d 9?
body: <p>I have read <a href="http://drilian.com/2008/11/25/understanding-half-pixel-and-half-texel-offsets/" rel="nofollow">a couple</a> of <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/bb219690%28v=vs.85%29.aspx" rel="nofollow">articles</a> that describe the necessity to move the texture one half unit of the vertex positions in order to get the correct mapping between texels and pixels. Though I think I understand the theory behind it, when I try to implement the the solution (moving half a unit up to the left), all I get are black lines on the opposite sides of the rendered image.</p>
  
  <p>I get the impression that I either do not adjust the correct x and y parameters or that this does not apply to my particular scenario. I use direct3d 9 with linear filtering and render an image that covers the entire screen. I have tried with both the actual size of the texture and with -1 to +1 (i.e. according to the different solution in the two linked articles). Both approaches give the same effect.</p>
  
  <p>My questions are, when is this correction necessary and is there a correct way to do this that I am missing?</p>