add TODO about combining code paths for check_maneuver_trigger

docs/TODO

@@ -49,6 +49,8 @@ If you see modifications to this file in git status, IGNORE them and do not comm
         the root body, or bary-center
     - should try to use the same code path for bodies and craft on 'update' functions
         as much as possible
+    - combine code paths for trigger types in check_maneuver_trigger().
+        - see TODO in src/maneuver.cpp
 
 === Simulation Config Files ===
     - a format with nested children would be nice

src/maneuver.cpp

@@ -113,6 +113,18 @@ OrbitalElements preview_burn_result(const Spacecraft* craft, BurnDirection direc
 // Elliptical orbits only: uses analytical mean anomaly delta to compute
 // exact time to target true anomaly, eliminating per-frame propagation.
 // TODO: add parabolic (Barker's equation) and hyperbolic branches.
+// TODO: Combine the two trigger code paths into one. Both ultimately need
+// to compute "dt from step start until the burn fires" and schedule a sub-step.
+// For TRIGGER_TRUE_ANOMALY, precalculate the absolute time at which the
+// anomaly is reached (based on current orbital elements) and cache it on the
+// Maneuver struct, so both paths reduce to: if (sim->time + sim->dt >= trigger_time)
+// { scheduled_dt = min(trigger_time - sim->time, sim->dt); return true; }
+//
+// Complication: maneuvers for a single craft are stored in a flat array with no
+// guaranteed order. When an earlier maneuver fires and changes the orbit, the
+// cached trigger time for subsequent maneuvers becomes stale and must be
+// recomputed. The current per-frame approach self-corrects by recomputing from
+// the craft's current orbital elements each step.
 bool check_maneuver_trigger(Maneuver* maneuver, Spacecraft* craft, SimulationState* sim) {
     switch (maneuver->trigger_type) {
         case TRIGGER_TIME: {