Pulled polydrivetrain out into a separate file.

Change-Id: I315e25dddce79b1db5316634a3934b5e6738fa12
diff --git a/y2014/control_loops/drivetrain/polydrivetrain.h b/y2014/control_loops/drivetrain/polydrivetrain.h
new file mode 100644
index 0000000..82ebd24
--- /dev/null
+++ b/y2014/control_loops/drivetrain/polydrivetrain.h
@@ -0,0 +1,81 @@
+#ifndef Y2014_CONTROL_LOOPS_DRIVETRAIN_POLYDRIVETRAIN_H_
+#define Y2014_CONTROL_LOOPS_DRIVETRAIN_POLYDRIVETRAIN_H_
+
+#include "aos/common/controls/polytope.h"
+
+#include "y2014/constants.h"
+#include "y2014/control_loops/drivetrain/drivetrain.q.h"
+#include "frc971/control_loops/state_feedback_loop.h"
+#include "y2014/control_loops/drivetrain/drivetrain_dog_motor_plant.h"
+
+namespace frc971 {
+namespace control_loops {
+
+class PolyDrivetrain {
+ public:
+  enum Gear { HIGH, LOW, SHIFTING_UP, SHIFTING_DOWN };
+  // Stall Torque in N m
+  static constexpr double kStallTorque =
+      ::y2014::control_loops::drivetrain::kStallTorque;
+  // Stall Current in Amps
+  static constexpr double kStallCurrent = ::y2014::control_loops::drivetrain::kStallCurrent;
+  // Free Speed in RPM. Used number from last year.
+  static constexpr double kFreeSpeed =
+      ::y2014::control_loops::drivetrain::kFreeSpeedRPM;
+  // Free Current in Amps
+  static constexpr double kFreeCurrent =
+      ::y2014::control_loops::drivetrain::kFreeCurrent;
+  static constexpr double kWheelRadius =
+      ::y2014::control_loops::drivetrain::kWheelRadius;
+  // Resistance of the motor, divided by the number of motors.
+  static constexpr double kR = ::y2014::control_loops::drivetrain::kR;
+  // Motor velocity constant
+  static constexpr double Kv = ::y2014::control_loops::drivetrain::kV;
+
+  // Torque constant
+  static constexpr double Kt = ::y2014::control_loops::drivetrain::kT;
+
+  PolyDrivetrain();
+
+  static bool IsInGear(Gear gear) { return gear == LOW || gear == HIGH; }
+
+  static double MotorSpeed(const constants::ShifterHallEffect &hall_effect,
+                           double shifter_position, double velocity);
+
+  Gear ComputeGear(const constants::ShifterHallEffect &hall_effect,
+                   double velocity, Gear current);
+
+  void SetGoal(double wheel, double throttle, bool quickturn, bool highgear);
+
+  void SetPosition(const DrivetrainQueue::Position *position);
+
+  double FilterVelocity(double throttle);
+
+  double MaxVelocity();
+
+  void Update();
+
+  void SendMotors(DrivetrainQueue::Output *output);
+
+ private:
+  const ::aos::controls::HPolytope<2> U_Poly_;
+
+  ::std::unique_ptr<StateFeedbackLoop<2, 2, 2>> loop_;
+
+  const double ttrust_;
+  double wheel_;
+  double throttle_;
+  bool quickturn_;
+  int stale_count_;
+  double position_time_delta_;
+  Gear left_gear_;
+  Gear right_gear_;
+  DrivetrainQueue::Position last_position_;
+  DrivetrainQueue::Position position_;
+  int counter_;
+};
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif  // Y2014_CONTROL_LOOPS_DRIVETRAIN_POLYDRIVETRAIN_H_