Drive code works on Tantrum.

Need to write the spring code.  Drive now supports doubles...  What a
pain.

Change-Id: Id589acdc443dcd81242a21e3b0c26f81d6974dc8
diff --git a/frc971/control_loops/drivetrain/polydrivetrain.cc b/frc971/control_loops/drivetrain/polydrivetrain.cc
index db9f1c5..266acd5 100644
--- a/frc971/control_loops/drivetrain/polydrivetrain.cc
+++ b/frc971/control_loops/drivetrain/polydrivetrain.cc
@@ -2,340 +2,17 @@
 
 #include "aos/common/commonmath.h"
 #include "aos/common/controls/polytope.h"
-#include "aos/common/logging/logging.h"
-#include "aos/common/logging/matrix_logging.h"
-#include "aos/common/logging/queue_logging.h"
-
-#include "aos/common/messages/robot_state.q.h"
 #include "frc971/control_loops/coerce_goal.h"
+#ifdef __linux__
 #include "frc971/control_loops/drivetrain/drivetrain.q.h"
 #include "frc971/control_loops/drivetrain/drivetrain_config.h"
+#endif  // __linux__
 #include "frc971/control_loops/state_feedback_loop.h"
 
 namespace frc971 {
 namespace control_loops {
 namespace drivetrain {
 
-PolyDrivetrain::PolyDrivetrain(const DrivetrainConfig &dt_config,
-                               StateFeedbackLoop<7, 2, 4> *kf)
-    : kf_(kf),
-      U_Poly_((Eigen::Matrix<double, 4, 2>() << /*[[*/ 1, 0 /*]*/,
-               /*[*/ -1, 0 /*]*/,
-               /*[*/ 0, 1 /*]*/,
-               /*[*/ 0, -1 /*]]*/)
-                  .finished(),
-              (Eigen::Matrix<double, 4, 1>() << /*[[*/ 12 /*]*/,
-               /*[*/ 12 /*]*/,
-               /*[*/ 12 /*]*/,
-               /*[*/ 12 /*]]*/)
-                  .finished(),
-              (Eigen::Matrix<double, 2, 4>() << /*[[*/ 12, 12, -12, -12 /*]*/,
-               /*[*/ -12, 12, 12, -12 /*]*/)
-                  .finished()),
-      loop_(new StateFeedbackLoop<2, 2, 2>(dt_config.make_v_drivetrain_loop())),
-      ttrust_(1.1),
-      wheel_(0.0),
-      throttle_(0.0),
-      quickturn_(false),
-      left_gear_(dt_config.default_high_gear ? Gear::HIGH : Gear::LOW),
-      right_gear_(dt_config.default_high_gear ? Gear::HIGH : Gear::LOW),
-      counter_(0),
-      dt_config_(dt_config) {
-  last_position_.Zero();
-  position_.Zero();
-}
-
-double PolyDrivetrain::MotorSpeed(
-    const constants::ShifterHallEffect &hall_effect, double shifter_position,
-    double velocity, Gear gear) {
-  const double high_gear_speed =
-      velocity / dt_config_.high_gear_ratio / dt_config_.wheel_radius;
-  const double low_gear_speed =
-      velocity / dt_config_.low_gear_ratio / dt_config_.wheel_radius;
-
-  if (shifter_position < hall_effect.clear_low) {
-    // We're in low gear, so return speed for that gear.
-    return low_gear_speed;
-  } else if (shifter_position > hall_effect.clear_high) {
-    // We're in high gear, so return speed for that gear.
-    return high_gear_speed;
-  }
-
-  // Not in gear, so speed-match to destination gear.
-  switch (gear) {
-    case Gear::HIGH:
-    case Gear::SHIFTING_UP:
-      return high_gear_speed;
-    case Gear::LOW:
-    case Gear::SHIFTING_DOWN:
-    default:
-      return low_gear_speed;
-      break;
-  }
-}
-
-Gear PolyDrivetrain::UpdateSingleGear(Gear requested_gear, Gear current_gear) {
-  const Gear shift_up =
-      (dt_config_.shifter_type == ShifterType::HALL_EFFECT_SHIFTER)
-          ? Gear::SHIFTING_UP
-          : Gear::HIGH;
-  const Gear shift_down =
-      (dt_config_.shifter_type == ShifterType::HALL_EFFECT_SHIFTER)
-          ? Gear::SHIFTING_DOWN
-          : Gear::LOW;
-  if (current_gear != requested_gear) {
-    if (IsInGear(current_gear)) {
-      if (requested_gear == Gear::HIGH) {
-        if (current_gear != Gear::HIGH) {
-          current_gear = shift_up;
-        }
-      } else {
-        if (current_gear != Gear::LOW) {
-          current_gear = shift_down;
-        }
-      }
-    } else {
-      if (requested_gear == Gear::HIGH && current_gear == Gear::SHIFTING_DOWN) {
-        current_gear = Gear::SHIFTING_UP;
-      } else if (requested_gear == Gear::LOW &&
-                 current_gear == Gear::SHIFTING_UP) {
-        current_gear = Gear::SHIFTING_DOWN;
-      }
-    }
-  }
-  return current_gear;
-}
-
-void PolyDrivetrain::SetGoal(
-    const ::frc971::control_loops::DrivetrainQueue::Goal &goal) {
-  const double wheel = goal.wheel;
-  const double throttle = goal.throttle;
-  const bool quickturn = goal.quickturn;
-  const bool highgear = goal.highgear;
-
-  // Apply a sin function that's scaled to make it feel better.
-  const double angular_range = M_PI_2 * dt_config_.wheel_non_linearity;
-
-  wheel_ = sin(angular_range * wheel) / sin(angular_range);
-  wheel_ = sin(angular_range * wheel_) / sin(angular_range);
-  wheel_ = 2.0 * wheel - wheel_;
-  quickturn_ = quickturn;
-
-  if (quickturn_) {
-    wheel_ *= dt_config_.quickturn_wheel_multiplier;
-  } else {
-    wheel_ *= dt_config_.wheel_multiplier;
-  }
-
-  static const double kThrottleDeadband = 0.05;
-  if (::std::abs(throttle) < kThrottleDeadband) {
-    throttle_ = 0;
-  } else {
-    throttle_ = copysign(
-        (::std::abs(throttle) - kThrottleDeadband) / (1.0 - kThrottleDeadband),
-        throttle);
-  }
-
-  Gear requested_gear = highgear ? Gear::HIGH : Gear::LOW;
-
-  left_gear_ = PolyDrivetrain::UpdateSingleGear(requested_gear, left_gear_);
-  right_gear_ = PolyDrivetrain::UpdateSingleGear(requested_gear, right_gear_);
-}
-
-void PolyDrivetrain::SetPosition(
-    const ::frc971::control_loops::DrivetrainQueue::Position *position,
-    Gear left_gear, Gear right_gear) {
-  left_gear_ = left_gear;
-  right_gear_ = right_gear;
-  last_position_ = position_;
-  position_ = *position;
-}
-
-double PolyDrivetrain::FilterVelocity(double throttle) const {
-  const Eigen::Matrix<double, 2, 2> FF =
-      loop_->plant().B().inverse() *
-      (Eigen::Matrix<double, 2, 2>::Identity() - loop_->plant().A());
-
-  constexpr int kHighGearController = 3;
-  const Eigen::Matrix<double, 2, 2> FF_high =
-      loop_->plant().coefficients(kHighGearController).B.inverse() *
-      (Eigen::Matrix<double, 2, 2>::Identity() -
-       loop_->plant().coefficients(kHighGearController).A);
-
-  ::Eigen::Matrix<double, 1, 2> FF_sum = FF.colwise().sum();
-  int min_FF_sum_index;
-  const double min_FF_sum = FF_sum.minCoeff(&min_FF_sum_index);
-  const double min_K_sum = loop_->controller().K().col(min_FF_sum_index).sum();
-  const double high_min_FF_sum = FF_high.col(0).sum();
-
-  const double adjusted_ff_voltage =
-      ::aos::Clip(throttle * 12.0 * min_FF_sum / high_min_FF_sum, -12.0, 12.0);
-  return (adjusted_ff_voltage +
-          ttrust_ * min_K_sum * (loop_->X_hat(0, 0) + loop_->X_hat(1, 0)) /
-              2.0) /
-         (ttrust_ * min_K_sum + min_FF_sum);
-}
-
-double PolyDrivetrain::MaxVelocity() {
-  const Eigen::Matrix<double, 2, 2> FF =
-      loop_->plant().B().inverse() *
-      (Eigen::Matrix<double, 2, 2>::Identity() - loop_->plant().A());
-
-  constexpr int kHighGearController = 3;
-  const Eigen::Matrix<double, 2, 2> FF_high =
-      loop_->plant().coefficients(kHighGearController).B.inverse() *
-      (Eigen::Matrix<double, 2, 2>::Identity() -
-       loop_->plant().coefficients(kHighGearController).A);
-
-  ::Eigen::Matrix<double, 1, 2> FF_sum = FF.colwise().sum();
-  int min_FF_sum_index;
-  const double min_FF_sum = FF_sum.minCoeff(&min_FF_sum_index);
-  // const double min_K_sum = loop_->K().col(min_FF_sum_index).sum();
-  const double high_min_FF_sum = FF_high.col(0).sum();
-
-  const double adjusted_ff_voltage =
-      ::aos::Clip(12.0 * min_FF_sum / high_min_FF_sum, -12.0, 12.0);
-  return adjusted_ff_voltage / min_FF_sum;
-}
-
-void PolyDrivetrain::Update() {
-  if (dt_config_.loop_type == LoopType::CLOSED_LOOP) {
-    loop_->mutable_X_hat()(0, 0) = kf_->X_hat()(1, 0);
-    loop_->mutable_X_hat()(1, 0) = kf_->X_hat()(3, 0);
-  }
-
-  // TODO(austin): Observer for the current velocity instead of difference
-  // calculations.
-  ++counter_;
-
-  if (IsInGear(left_gear_) && IsInGear(right_gear_)) {
-    // FF * X = U (steady state)
-    const Eigen::Matrix<double, 2, 2> FF =
-        loop_->plant().B().inverse() *
-        (Eigen::Matrix<double, 2, 2>::Identity() - loop_->plant().A());
-
-    // Invert the plant to figure out how the velocity filter would have to
-    // work
-    // out in order to filter out the forwards negative inertia.
-    // This math assumes that the left and right power and velocity are
-    // equals,
-    // and that the plant is the same on the left and right.
-    const double fvel = FilterVelocity(throttle_);
-
-    const double sign_svel = wheel_ * ((fvel > 0.0) ? 1.0 : -1.0);
-    double steering_velocity;
-    if (quickturn_) {
-      steering_velocity = wheel_ * MaxVelocity();
-    } else {
-      steering_velocity = ::std::abs(fvel) * wheel_;
-    }
-    const double left_velocity = fvel - steering_velocity;
-    const double right_velocity = fvel + steering_velocity;
-    goal_left_velocity_ = left_velocity;
-    goal_right_velocity_ = right_velocity;
-
-    // Integrate velocity to get the position.
-    // This position is used to get integral control.
-    loop_->mutable_R() << left_velocity, right_velocity;
-
-    if (!quickturn_) {
-      // K * R = w
-      Eigen::Matrix<double, 1, 2> equality_k;
-      equality_k << 1 + sign_svel, -(1 - sign_svel);
-      const double equality_w = 0.0;
-
-      // Construct a constraint on R by manipulating the constraint on U
-      ::aos::controls::HVPolytope<2, 4, 4> R_poly_hv(
-          U_Poly_.static_H() * (loop_->controller().K() + FF),
-          U_Poly_.static_k() +
-              U_Poly_.static_H() * loop_->controller().K() * loop_->X_hat(),
-          (loop_->controller().K() + FF).inverse() *
-              ::aos::controls::ShiftPoints<2, 4>(
-                  U_Poly_.StaticVertices(),
-                  loop_->controller().K() * loop_->X_hat()));
-
-      // Limit R back inside the box.
-      loop_->mutable_R() =
-          CoerceGoal(R_poly_hv, equality_k, equality_w, loop_->R());
-    }
-
-    const Eigen::Matrix<double, 2, 1> FF_volts = FF * loop_->R();
-    const Eigen::Matrix<double, 2, 1> U_ideal =
-        loop_->controller().K() * (loop_->R() - loop_->X_hat()) + FF_volts;
-
-    for (int i = 0; i < 2; i++) {
-      loop_->mutable_U()[i] = ::aos::Clip(U_ideal[i], -12, 12);
-    }
-
-    if (dt_config_.loop_type == LoopType::OPEN_LOOP) {
-      loop_->mutable_X_hat() =
-          loop_->plant().A() * loop_->X_hat() + loop_->plant().B() * loop_->U();
-    }
-
-    // Housekeeping: set the shifting logging values to zero, because we're not shifting
-    left_motor_speed_ = 0.0;
-    right_motor_speed_ = 0.0;
-    current_left_velocity_ = 0.0;
-    current_right_velocity_ = 0.0;
-  } else {
-    current_left_velocity_ =
-        (position_.left_encoder - last_position_.left_encoder) / dt_config_.dt;
-    current_right_velocity_ =
-        (position_.right_encoder - last_position_.right_encoder) /
-        dt_config_.dt;
-    left_motor_speed_ =
-        MotorSpeed(dt_config_.left_drive, position_.left_shifter_position,
-                   current_left_velocity_, left_gear_);
-    right_motor_speed_ =
-        MotorSpeed(dt_config_.right_drive, position_.right_shifter_position,
-                   current_right_velocity_, right_gear_);
-
-    goal_left_velocity_ = current_left_velocity_;
-    goal_right_velocity_ = current_right_velocity_;
-
-    // Any motor is not in gear. Speed match.
-    ::Eigen::Matrix<double, 1, 1> R_left;
-    ::Eigen::Matrix<double, 1, 1> R_right;
-    R_left(0, 0) = left_motor_speed_;
-    R_right(0, 0) = right_motor_speed_;
-
-    const double wiggle =
-        (static_cast<double>((counter_ % 30) / 15) - 0.5) * 8.0;
-
-    loop_->mutable_U(0, 0) = ::aos::Clip(
-        (R_left / dt_config_.v)(0, 0) + (IsInGear(left_gear_) ? 0 : wiggle),
-        -12.0, 12.0);
-    loop_->mutable_U(1, 0) = ::aos::Clip(
-        (R_right / dt_config_.v)(0, 0) + (IsInGear(right_gear_) ? 0 : wiggle),
-        -12.0, 12.0);
-    loop_->mutable_U() *= 12.0 / ::aos::robot_state->voltage_battery;
-  }
-}
-
-void PolyDrivetrain::SetOutput(
-    ::frc971::control_loops::DrivetrainQueue::Output *output) {
-  if (output != NULL) {
-    output->left_voltage = loop_->U(0, 0);
-    output->right_voltage = loop_->U(1, 0);
-    output->left_high = MaybeHigh(left_gear_);
-    output->right_high = MaybeHigh(right_gear_);
-  }
-}
-
-void PolyDrivetrain::PopulateStatus(
-    ::frc971::control_loops::DrivetrainQueue::Status *status) {
-  status->left_velocity_goal = goal_left_velocity_;
-  status->right_velocity_goal = goal_right_velocity_;
-
-  status->cim_logging.left_in_gear = IsInGear(left_gear_);
-  status->cim_logging.left_motor_speed = left_motor_speed_;
-  status->cim_logging.left_velocity = current_left_velocity_;
-
-  status->cim_logging.right_in_gear = IsInGear(right_gear_);
-  status->cim_logging.right_motor_speed = right_motor_speed_;
-  status->cim_logging.right_velocity = current_right_velocity_;
-}
-
 }  // namespace drivetrain
 }  // namespace control_loops
 }  // namespace frc971