add FIXMEs

src/renderer.cpp

@@ -313,6 +313,7 @@ float scale_radius(double radius, double scale) {
     return (float)(radius * scale);
 }
 
+// FIXME: no longer used, can maybe re-use when refactoring render_simulation()
 // Render a single celestial body
 void render_body(CelestialBody* body, RenderState* render_state) {
     Vector3 position = sim_to_render(body->global_position, render_state->distance_scale);
@@ -589,6 +590,7 @@ void end_frame() {
     EndDrawing();
 }
 
+// FIXME: refactor for readability
 // Render the entire simulation
 void render_simulation(SimulationState* sim, RenderState* render_state) {
     BeginMode3D(render_state->camera);