title: Simple HLSL glow/blur effect in DirectX9
body: <p>I have been struggling for days to find any resources to help me write a simple glow/blur shader using High Level Shader Language and DirectX 9 Managed Libraries.</p>
  
  <p>All I need to do is have an array of <code>CustomVertex.TransformedColored</code> vertices drawn as simple lines and then blurred/glowed by the HLSL effect.</p>
  
  <p>I have searched the internet for about three days now with some results, but I just cannot find a really good tutorial or example.  I have a basic understanding of HLSL but I do not understand it enough to figure out how to write this shader (I have read the HLSL chapter in 3 DirectX books as well).</p>
  
  <p>Here is some (abridged) code:</p>
  
  <pre><code>CustomVertex.TransformedColored[] glowVertices = new CustomVertex.TransformedColored[4];
  glowVertices[0] = new CustomVertex.TransformedColored(random.Next(this.render.Width), random.Next(this.render.Height), 1, 1, Color.Cyan.ToArgb());
  glowVertices[1] = new CustomVertex.TransformedColored(random.Next(this.render.Width), random.Next(this.render.Height), 1, 1, Color.Blue.ToArgb());
  glowVertices[2] = new CustomVertex.TransformedColored(random.Next(this.render.Width), random.Next(this.render.Height), 1, 1, Color.Cyan.ToArgb());
  glowVertices[3] = new CustomVertex.TransformedColored(random.Next(this.render.Width), random.Next(this.render.Height), 1, 1, Color.Blue.ToArgb());
  
  this.device.BeginScene();
  int passes = this.glowEffect.Begin(0);
  for (int i = 0; i &lt; passes; i++)
   {
       this.glowEffect.BeginPass(i);
       this.device.DrawUserPrimitives(PrimitiveType.LineStrip, glowVertices.Length - 1, glowVertices);
       this.glowEffect.EndPass();
   }
   this.glowEffect.End();
   this.device.EndScene();
  </code></pre>
  
  <p>I guess I'm not so much looking for help on a specific part of HLSL, given the number of questions and amount of code I would have to post I'm really just looking for some help finding resources!</p>