title: How to change single texel in OpenGL texture
body: <p>I want to change the some texels in a OpenGL texture for a given location. Can anyone help me with this pls ?</p>
  
  <p>This is the functionnality that I want, </p>
  
  <pre><code>void ChangeTexelColor(int x, int y, GLuint id, int texW, int texH, GLenum format)
  {
     //What is here ?     
  }
  </code></pre>
  
  <p>This will use to maintain the minimap of my game (if anyone have a better idea of maintaining a dynamic map-texture-). Btw, this must done fast. Thanks.</p>