title: Allegro 5 - creating a custom bitmap with alpha channel
body: <p><strong>Afternoon everyone,</strong></p>
  
  <p>I was wondering if there's any way I could create a custom bitmap with alpha channel  </p>
  
  <pre><code>bitmap = al_create_bitmap(30, 30);
  al_set_target_bitmap(bitmap);
  al_clear_to_color(al_map_rgb(255,255,255));
  ....
  al_draw_tinted_bitmap(bitmap, al_map_rgba(0, 0, 0, 0.5),  X,  Y, 0);
  </code></pre>
  
  <p>I'm sure that I'm either not creating or drawing the bitmap correctly, so I could really use some advice.</p>
  
  <p>Thanks in advance,
  Alex</p>