From 1b855b2997f2d494f2012e6024e514171fb7af2c Mon Sep 17 00:00:00 2001
From: Travis Hunter <travis@travishunter.io>
Date: Mon, 3 Apr 2023 18:18:39 -0600
Subject: [PATCH] WIP

---
 sim/Propagator.cpp | 18 ++++++++++++++++++
 sim/Propagator.h   | 15 ++++++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/sim/Propagator.cpp b/sim/Propagator.cpp
index 43cdaef..2a072b0 100644
--- a/sim/Propagator.cpp
+++ b/sim/Propagator.cpp
@@ -1,10 +1,28 @@
 #include "Propagator.h"
 
+#include "sim/RK4Solver.h"
+
 namespace sim {
 
 Propagator::Propagator()
 {
 
+//   solver = std::make_unique<sim::DESolver>(
+//            new(RK4Solver(/* xvel */ [this](double, double* x) -> double { return })))
+
+   // The state vector has components of the form: (x, y, z, xdot, ydot, zdot)
+
+   integrator = std::make_unique<sim::DESolver>(new RK4Solver(
+      /* dvx/dt */ [this](double, double* ) -> double { return getForceX() / getMass(); },
+      /* dx/dt  */ [this](double, double* s) -> double {return s[3]; },
+      /* dvy/dt */ [this](double, double* ) -> double { return getForceY() / getMass() },
+      /* dy/dt  */ [this](double, double* s) -> double {return s[4]; },
+      /* dvz/dt */ [this](double, double* ) -> double { return getForceZ() / getMass() },
+      /* dz/dt  */ [this](double, double* s) -> double {return s[5]; }));
+
+
+
+
 }
 
 } // namespace sim
diff --git a/sim/Propagator.h b/sim/Propagator.h
index fca37b9..dfcfaf5 100644
--- a/sim/Propagator.h
+++ b/sim/Propagator.h
@@ -13,9 +13,22 @@ class Propagator
 public:
     Propagator();
 
+   double getForceX();
+   double getForceY();
+   double getForceZ();
+
+   double getTorqueP();
+   double getTorqueQ();
+   double getTorqueR();
+
+   double getMass();
+
 private:
 
-   std::unique_ptr<sim::DESolver> solver;
+   std::unique_ptr<sim::DESolver> integrator;
+
+   double currentState[6]{0.0, 0.0, 0.0, 0.0, 0.0, 0.0};
+   double nextState[6]{0.0, 0.0, 0.0, 0.0, 0.0, 0.0};
 };
 
 } // namespace sim