title: Can I use a grayscale image with the OpenGL glTexImage2D function?
body: <p>I have a texture which has only 1 channel as it's a grayscale image. When I pass the pixels in to glTexImage2D, it comes out red (obviously because channel 1 is red; RGB).</p>
  
  <pre><code>glTexImage2D(
      GL_TEXTURE_2D, 0, GL_RGBA,
      dicomImage-&gt;GetColumns(), dicomImage-&gt;GetRows(),
      0, GL_RGBA, GL_UNSIGNED_BYTE, pixelArrayPtr);
  </code></pre>
  
  <p>Do I change GL_RGBA? If so, what to?</p>