mockingbirdnest
diff --git a/ksp_plugin/interface_flight_plan.cpp b/ksp_plugin/interface_flight_plan.cpp
@@ -152,9 +152,6 @@ Burn GetBurn(Plugin const& plugin,
 NavigationManoeuvre ToInterfaceNavigationManoeuvre(
     Plugin const& plugin,
     NavigationManœuvre const& manœuvre) {
-  OrthogonalMap<Barycentric, World> const barycentric_to_world =
-      OrthogonalMap<WorldSun, World>::Identity() *
-      plugin.BarycentricToWorldSun();
   NavigationManoeuvre result;
   result.burn = GetBurn(plugin, manœuvre);
   result.initial_mass_in_tonnes = manœuvre.initial_mass() / Tonne;
@@ -167,7 +164,8 @@ NavigationManoeuvre ToInterfaceNavigationManoeuvre(
   Vector<double, Barycentric> const barycentric_inertial_direction =
       manœuvre.InertialDirection();
   Vector<double, World> const world_inertial_direction =
-      barycentric_to_world(barycentric_inertial_direction);
+      plugin.renderer().BarycentricToWorld(plugin.PlanetariumRotation())(
+          barycentric_inertial_direction);
   result.inertial_direction = ToXYZ(world_inertial_direction);
   return result;
 }
@@ -272,22 +270,14 @@ principia__FlightPlanGetManoeuvreFrenetTrihedron(Plugin const* const plugin,
   journal::Method<journal::FlightPlanGetManoeuvreFrenetTrihedron> m(
       {plugin, vessel_guid, index});
   CHECK_NOTNULL(plugin);
-  NavigationManoeuvreFrenetTrihedron result;
 
   NavigationManœuvre const& manœuvre =
       GetFlightPlan(*plugin, vessel_guid).GetManœuvre(index);
-  OrthogonalMap<Barycentric, World> const barycentric_to_world =
-      plugin->BarycentricToWorld();
-  OrthogonalMap<Frenet<Navigation>, Barycentric> frenet_to_barycentric =
-      manœuvre.FrenetFrame();
-  Instant const current_time = plugin->CurrentTime();
-  Instant const initial_time = manœuvre.initial_time();
-  auto const plotting_frame = plugin->GetPlottingFrame();
-  OrthogonalMap<Frenet<Navigation>, World> frenet_to_plotted_world =
-      barycentric_to_world *
-      plotting_frame->FromThisFrameAtTime(current_time).orthogonal_map() *
-      plotting_frame->ToThisFrameAtTime(initial_time).orthogonal_map() *
-      frenet_to_barycentric;
+  OrthogonalMap<Frenet<Navigation>, World> const frenet_to_plotted_world =
+      plugin->renderer().FrenetToWorld(plugin->CurrentTime(),
+                                       manœuvre,
+                                       plugin->PlanetariumRotation());
+  NavigationManoeuvreFrenetTrihedron result;
   result.tangent = ToXYZ(
       frenet_to_plotted_world(Vector<double, Frenet<Navigation>>({1, 0, 0})));
   result.normal = ToXYZ(
@@ -414,10 +404,13 @@ Iterator* principia__FlightPlanRenderedSegment(
   DiscreteTrajectory<Barycentric>::Iterator begin;
   DiscreteTrajectory<Barycentric>::Iterator end;
   GetFlightPlan(*plugin, vessel_guid).GetSegment(index, begin, end);
-  auto rendered_trajectory = CHECK_NOTNULL(plugin)->
-      RenderBarycentricTrajectoryInWorld(
-          begin, end,
-          FromXYZ<Position<World>>(sun_world_position));
+  auto rendered_trajectory =
+      plugin->renderer().RenderBarycentricTrajectoryInWorld(
+          plugin->CurrentTime(),
+          begin,
+          end,
+          FromXYZ<Position<World>>(sun_world_position),
+          plugin->PlanetariumRotation());
   if (index % 2 == 1 && !rendered_trajectory->Empty() &&
       rendered_trajectory->Begin().time() != begin.time()) {
     // TODO(egg): this is ugly; we should centralize rendering.

diff --git a/ksp_plugin/interface_renderer.cpp b/ksp_plugin/interface_renderer.cpp
@@ -4,22 +4,36 @@
 #include "journal/method.hpp"
 #include "journal/profiles.hpp"
 #include "ksp_plugin/plugin.hpp"
+#include "ksp_plugin/renderer.hpp"
 
 namespace principia {
 namespace interface {
 
+using ksp_plugin::Renderer;
+
+namespace {
+
+Renderer& GetRenderer(Plugin* const plugin) {
+  return CHECK_NOTNULL(plugin)->renderer();
+}
+
+Renderer const& GetRenderer(Plugin const* const plugin) {
+  return CHECK_NOTNULL(plugin)->renderer();
+}
+
+}  // namespace
+
 void principia__ClearTargetVessel(Plugin* const plugin) {
   journal::Method<journal::ClearTargetVessel> m({plugin});
-  CHECK_NOTNULL(plugin);
-  plugin->ClearTargetVessel();
+  GetRenderer(plugin).ClearTargetVessel();
   return m.Return();
 }
 
 // Returns the frame last set by |plugin->SetPlottingFrame|.  No transfer of
 // ownership.  The returned pointer is never null.
 NavigationFrame const* principia__GetPlottingFrame(Plugin const* const plugin) {
   journal::Method<journal::GetPlottingFrame> m({plugin});
-  return m.Return(CHECK_NOTNULL(plugin)->GetPlottingFrame());
+  return m.Return(GetRenderer(plugin).GetPlottingFrame());
 }
 
 Iterator* principia__RenderedPrediction(Plugin* const plugin,
@@ -30,10 +44,13 @@ Iterator* principia__RenderedPrediction(Plugin* const plugin,
                                                   sun_world_position});
   CHECK_NOTNULL(plugin);
   auto const& prediction = plugin->GetVessel(vessel_guid)->prediction();
-  auto rendered_trajectory = plugin->RenderBarycentricTrajectoryInWorld(
-                                 prediction.Begin(),
-                                 prediction.End(),
-                                 FromXYZ<Position<World>>(sun_world_position));
+  auto rendered_trajectory =
+      GetRenderer(plugin).RenderBarycentricTrajectoryInWorld(
+          plugin->CurrentTime(),
+          prediction.Begin(),
+          prediction.End(),
+          FromXYZ<Position<World>>(sun_world_position),
+          plugin->PlanetariumRotation());
   return m.Return(new TypedIterator<DiscreteTrajectory<World>>(
       std::move(rendered_trajectory),
       plugin));
@@ -123,10 +140,13 @@ Iterator* principia__RenderedVesselTrajectory(Plugin const* const plugin,
                                                         sun_world_position});
   CHECK_NOTNULL(plugin);
   auto const& psychohistory = plugin->GetVessel(vessel_guid)->psychohistory();
-  auto rendered_trajectory = plugin->RenderBarycentricTrajectoryInWorld(
-                                 psychohistory.Begin(),
-                                 psychohistory.End(),
-                                 FromXYZ<Position<World>>(sun_world_position));
+  auto rendered_trajectory =
+      GetRenderer(plugin).RenderBarycentricTrajectoryInWorld(
+          plugin->CurrentTime(),
+          psychohistory.Begin(),
+          psychohistory.End(),
+          FromXYZ<Position<World>>(sun_world_position),
+          plugin->PlanetariumRotation());
   return m.Return(new TypedIterator<DiscreteTrajectory<World>>(
       std::move(rendered_trajectory),
       plugin));
@@ -139,8 +159,7 @@ void principia__SetPlottingFrame(Plugin* const plugin,
                                  NavigationFrame** const navigation_frame) {
   journal::Method<journal::SetPlottingFrame> m({plugin, navigation_frame},
                                                {navigation_frame});
-  CHECK_NOTNULL(plugin);
-  plugin->SetPlottingFrame(TakeOwnership(navigation_frame));
+  GetRenderer(plugin).SetPlottingFrame(TakeOwnership(navigation_frame));
   return m.Return();
 }
 

diff --git a/ksp_plugin/ksp_plugin.vcxproj.filters b/ksp_plugin/ksp_plugin.vcxproj.filters
@@ -115,6 +115,12 @@
     <ClCompile Include="integrators.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="renderer.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="interface_renderer.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\base\version.generated.cc">
       <Filter>Source Files</Filter>
     </ClCompile>