title: Updating a texture in OpenGL with glTexImage2D
body: <p>Are <b>glTexImage2D</b> and <b>glTexSubImage2D</b> the only ways to pass a buffer of pixels to a texture?</p>
  
  <p>At the moment I use in a setup function <b>glTexImage2D</b> passing null as the buffer, and then on the render loop I call <b>glTexSubImage2D</b> with the new buffer data on each iteration.</p>
  
  <p>But knowing that the texture will not change any property such as the dimensions, is there any more efficient way to pass the actual pixel data to the rendering texture?</p>