message: Pause convergence using Space key
diff: #include <visionaray/detail/tbb_sched.h>
  #endif
  +#include <common/input/keyboard.h>
  #include <common/manip/arcball_manipulator.h>
  #include <common/manip/pan_manipulator.h>
  #include <common/manip/zoom_manipulator.h>
  @@ -508,6 +509,9 @@ struct renderer : viewer_type
  gl::bvh_outline_renderer outlines;
  gl::debug_callback gl_debug_callback;
  + // Control if new path tracer convergence frames are accumulated
  + bool paused = false;
  +
  bool render_async = false;
  std::future<void> render_future;
  std::mutex display_mutex;
  @@ -2140,6 +2144,11 @@ void renderer::render_hud()
  void renderer::render_impl()
  {
  + if (paused)
  + {
  + return;
  + }
  +
  if (use_headlight)
  {
  point_light<float> headlight;
  @@ -2691,6 +2700,10 @@ void renderer::on_key_press(key_event const& event)
  }
  break;
  + case keyboard::Space:
  + paused = !paused;
  + break;
  +
  default:
  break;
  }
  