Make dual shooter.

Abstracted some stuff to get two shooters running in
the same process.

Change-Id: Id7617d6cf0d90c28fe2c07aefd3896eb592575dc
diff --git a/y2016/control_loops/shooter/shooter.cc b/y2016/control_loops/shooter/shooter.cc
index 41e6f81..9a46906 100644
--- a/y2016/control_loops/shooter/shooter.cc
+++ b/y2016/control_loops/shooter/shooter.cc
@@ -6,131 +6,130 @@
 
 #include "y2016/control_loops/shooter/shooter_plant.h"
 
+
 namespace y2016 {
 namespace control_loops {
 
-Shooter::Shooter(control_loops::ShooterQueue *my_shooter)
-    : aos::controls::ControlLoop<control_loops::ShooterQueue>(my_shooter),
-      loop_(new StateFeedbackLoop<2, 1, 1>(
-          ::y2016::control_loops::shooter::MakeShooterLoop())),
-      history_position_(0),
-      position_goal_(0.0),
-      last_position_(0.0),
-      last_velocity_goal_(0) {
+ShooterSide::ShooterSide()
+    : loop_(new StateFeedbackLoop<2, 1, 1>(
+          ::y2016::control_loops::shooter::MakeShooterLoop())) {
   memset(history_, 0, sizeof(history_));
 }
 
-/*static*/ const double Shooter::dt = 0.005;
-/*static*/ const double Shooter::kMaxSpeed =
-    10000.0 * (2.0 * M_PI) / 60.0 * 15.0 / 34.0;
+void ShooterSide::SetGoal(double angular_velocity_goal_uncapped) {
+  angular_velocity_goal_ = std::min(angular_velocity_goal_uncapped,
+                                    kMaxSpeed);
+}
 
-void Shooter::RunIteration(
-    const control_loops::ShooterQueue::Goal *goal,
-    const control_loops::ShooterQueue::Position *position,
-    ::aos::control_loops::Output *output,
-    control_loops::ShooterQueue::Status *status) {
-  double velocity_goal = std::min(goal->velocity, kMaxSpeed);
-  const double current_position =
-      (position == NULL ? loop_->X_hat(0, 0) : position->position);
-  double output_voltage = 0.0;
+void ShooterSide::EstimatePositionTimestep() {
+  // NULL position, so look at the loop.
+  SetPosition(loop_->X_hat(0, 0));
+}
 
-  // TODO(phil): Set a queue to trigger a shot. For now, disable the fetch from
-  // the queue.
-  if (false) {
-  // if (index_loop.status.FetchLatest() || index_loop.status.get()) {
-    // if (index_loop.status->is_shooting) {
-    if (velocity_goal != last_velocity_goal_ && velocity_goal < 130) {
-      velocity_goal = last_velocity_goal_;
-    }
-  } else {
-    LOG(WARNING, "assuming index isn't shooting\n");
-  }
-  last_velocity_goal_ = velocity_goal;
+void ShooterSide::SetPosition(double current_position) {
+  current_position_ = current_position;
 
   // Track the current position if the velocity goal is small.
-  if (velocity_goal <= 1.0) {
-    position_goal_ = current_position;
-  }
+  if (angular_velocity_goal_ <= 1.0) position_goal_ = current_position_;
 
-  // TODO(phil): Does this change make sense?
-  // loop_->Y << current_position;
+  // Update position in the model.
   Eigen::Matrix<double, 1, 1> Y;
-  Y << current_position;
+  Y << current_position_;
   loop_->Correct(Y);
 
-  // Add the position to the history.
-  history_[history_position_] = current_position;
-  history_position_ = (history_position_ + 1) % kHistoryLength;
-
   // Prevents integral windup by limiting the position error such that the
   // error can't produce much more than full power.
-  const double kVelocityWeightScalar = 0.35;
   const double max_reference =
       (loop_->U_max(0, 0) -
-       kVelocityWeightScalar * (velocity_goal - loop_->X_hat(1, 0)) *
-           loop_->K(0, 1)) /
+       kAngularVelocityWeightScalar *
+           (angular_velocity_goal_ - loop_->X_hat(1, 0)) * loop_->K(0, 1)) /
           loop_->K(0, 0) +
       loop_->X_hat(0, 0);
   const double min_reference =
       (loop_->U_min(0, 0) -
-       kVelocityWeightScalar * (velocity_goal - loop_->X_hat(1, 0)) *
-           loop_->K(0, 1)) /
+       kAngularVelocityWeightScalar *
+           (angular_velocity_goal_ - loop_->X_hat(1, 0)) * loop_->K(0, 1)) /
           loop_->K(0, 0) +
       loop_->X_hat(0, 0);
-
   position_goal_ =
       ::std::max(::std::min(position_goal_, max_reference), min_reference);
-  // TODO(phil): Does this change make sense?
-  // loop_->R << position_goal_, velocity_goal;
-  loop_->mutable_R(0, 0) = position_goal_;
-  loop_->mutable_R(1, 0) = velocity_goal;
-  position_goal_ += velocity_goal * dt;
 
-  // TODO(phil): Does this change make sense?
-  // loop_->Update(position, output == NULL);
-  loop_->Update(output == NULL);
+  loop_->mutable_R() << position_goal_, angular_velocity_goal_;
+  position_goal_ +=
+      angular_velocity_goal_ * ::aos::controls::kLoopFrequency.ToSeconds();
 
-  // Kill power at low velocity goals.
-  if (velocity_goal < 1.0) {
-    loop_->mutable_U(0, 0) = 0.0;
-  } else {
-    output_voltage = loop_->U(0, 0);
-  }
+  // Add the position to the history.
+  history_[history_position_] = current_position_;
+  history_position_ = (history_position_ + 1) % kHistoryLength;
+}
 
-  LOG(DEBUG,
-      "PWM: %f, raw_pos: %f rotations: %f "
-      "junk velocity: %f, xhat[0]: %f xhat[1]: %f, R[0]: %f R[1]: %f\n",
-      output_voltage, current_position, current_position / (2 * M_PI),
-      (current_position - last_position_) / dt,
-      // TODO(phil): Does this change make sense?
-      // loop_->X_hat[0], loop_->X_hat[1], loop_->R[0], loop_->R[1]);
-      loop_->X_hat(0, 0), loop_->X_hat(1, 0), loop_->R(0, 0), loop_->R(1, 0));
-
-  // Calculates the velocity over the last kHistoryLength * .01 seconds
-  // by taking the difference between the current and next history positions.
+const ShooterStatus ShooterSide::GetStatus() {
+  // Calculate average over dt * kHistoryLength.
   int old_history_position =
       ((history_position_ == 0) ? kHistoryLength : history_position_) - 1;
-  average_velocity_ =
-      (history_[old_history_position] - history_[history_position_]) / dt /
-      (double)(kHistoryLength - 1);
+  double avg_angular_velocity =
+      (history_[old_history_position] - history_[history_position_]) /
+      ::aos::controls::kLoopFrequency.ToSeconds() /
+      static_cast<double>(kHistoryLength - 1);
 
-  status->average_velocity = average_velocity_;
+  // Ready if average angular velocity is close to the goal.
+  bool ready = (std::abs(angular_velocity_goal_ - avg_angular_velocity) <
+                    kTolerance &&
+                angular_velocity_goal_ != 0.0);
 
-  // Determine if the velocity is close enough to the goal to be ready.
-  if (std::abs(velocity_goal - average_velocity_) < 10.0 &&
-      velocity_goal != 0.0) {
-    LOG(DEBUG, "Steady: ");
-    status->ready = true;
-  } else {
-    LOG(DEBUG, "Not ready: ");
-    status->ready = false;
+  return {avg_angular_velocity, ready};
+}
+
+double ShooterSide::GetOutput() {
+  if (angular_velocity_goal_ < 1.0) {
+    // Kill power at low angular velocities.
+    return 0.0;
   }
-  LOG(DEBUG, "avg = %f goal = %f\n", average_velocity_, velocity_goal);
 
-  last_position_ = current_position;
+  return loop_->U(0, 0);
+}
+
+void ShooterSide::UpdateLoop(bool output_is_null) {
+  loop_->Update(output_is_null);
+}
+
+Shooter::Shooter(control_loops::ShooterQueue *my_shooter)
+    : aos::controls::ControlLoop<control_loops::ShooterQueue>(my_shooter) {}
+
+void Shooter::RunIteration(
+    const control_loops::ShooterQueue::Goal *goal,
+    const control_loops::ShooterQueue::Position *position,
+    control_loops::ShooterQueue::Output *output,
+    control_loops::ShooterQueue::Status *status) {
+  if (goal) {
+    // Update position/goal for our two shooter sides.
+    left_.SetGoal(goal->angular_velocity_left);
+    right_.SetGoal(goal->angular_velocity_right);
+
+    if (position == nullptr) {
+      left_.EstimatePositionTimestep();
+      right_.EstimatePositionTimestep();
+    } else {
+      left_.SetPosition(position->theta_left);
+      right_.SetPosition(position->theta_right);
+    }
+  }
+
+  ShooterStatus status_left = left_.GetStatus();
+  ShooterStatus status_right = right_.GetStatus();
+  status->avg_angular_velocity_left = status_left.avg_angular_velocity;
+  status->avg_angular_velocity_right = status_right.avg_angular_velocity;
+
+  status->ready_left = status_left.ready;
+  status->ready_right = status_right.ready;
+  status->ready_both = (status_left.ready && status_right.ready);
+
+  left_.UpdateLoop(output == nullptr);
+  right_.UpdateLoop(output == nullptr);
 
   if (output) {
-    output->voltage = output_voltage;
+    output->voltage_left = left_.GetOutput();
+    output->voltage_right = right_.GetOutput();
   }
 }