[AD] Projection transform

[Trent Gamblin <trent@xxxxxxxxxx>]

Just found out that there’s a problem with al_use_projection_transform. When using shaders, after the call the shader’s matrices aren’t updated… if you call al_use_transform after al_use_projection_transform, it works as expected because al_use_transform has this code in it:

   /*
    * When the drawing is held, we apply the transformations in software,
    * so the hardware transformation has to be kept at identity.
    */
   if (!al_is_bitmap_drawing_held()) {
      display = _al_get_bitmap_display(target);
      if (display) {
         display->vt->update_transformation(display, target);
      }
   }

I think al_use_projection_transform should have something like that, but I haven’t looked into it deeply.