message: Key stroke '4' to activate BVH costs kernel
diff: @@ -2642,6 +2642,20 @@ void renderer::on_key_press(key_event const& event)
  clear_frame();
  break;
  + case '4':
  + std::cout << "Switching algorithm: BVH cost debugging\n";
  + if (!rt.get_double_buffering())
  + {
  + rt.set_double_buffering(true);
  +
  + // Make sure that 2nd buffer is allocated!
  + rt.resize(width(), height());
  + }
  + algo = Costs;
  + counter.reset();
  + clear_frame();
  + break;
  +
  case 'b':
  show_bvh = !show_bvh;
  