Added Drivetrain Writer.

Moved drivetrain writer out of year specific, started with changing
2019.

Change-Id: Id4738f4fe04ec390fb5d0a983a5597f1064b04db
diff --git a/y2019/wpilib_interface.cc b/y2019/wpilib_interface.cc
index 7a6a360..b216b4d 100644
--- a/y2019/wpilib_interface.cc
+++ b/y2019/wpilib_interface.cc
@@ -32,6 +32,7 @@
 #include "frc971/control_loops/drivetrain/drivetrain.q.h"
 #include "frc971/wpilib/ADIS16448.h"
 #include "frc971/wpilib/dma.h"
+#include "frc971/wpilib/drivetrain_writer.h"
 #include "frc971/wpilib/encoder_and_potentiometer.h"
 #include "frc971/wpilib/joystick_sender.h"
 #include "frc971/wpilib/logging.q.h"
@@ -128,40 +129,6 @@
   }
 };
 
-class DrivetrainWriter : public ::frc971::wpilib::LoopOutputHandler {
- public:
-  void set_drivetrain_left_victor(::std::unique_ptr<::frc::VictorSP> t) {
-    drivetrain_left_victor_ = ::std::move(t);
-  }
-
-  void set_drivetrain_right_victor(::std::unique_ptr<::frc::VictorSP> t) {
-    drivetrain_right_victor_ = ::std::move(t);
-  }
-
- private:
-  virtual void Read() override {
-    ::frc971::control_loops::drivetrain_queue.output.FetchAnother();
-  }
-
-  virtual void Write() override {
-    auto &queue = ::frc971::control_loops::drivetrain_queue.output;
-    LOG_STRUCT(DEBUG, "will output", *queue);
-    drivetrain_left_victor_->SetSpeed(
-        ::aos::Clip(queue->left_voltage, -12.0, 12.0) / 12.0);
-    drivetrain_right_victor_->SetSpeed(
-        ::aos::Clip(-queue->right_voltage, -12.0, 12.0) / 12.0);
-  }
-
-  virtual void Stop() override {
-    LOG(WARNING, "drivetrain output too old\n");
-    drivetrain_left_victor_->SetDisabled();
-    drivetrain_right_victor_->SetDisabled();
-  }
-
-  ::std::unique_ptr<::frc::VictorSP> drivetrain_left_victor_,
-      drivetrain_right_victor_;
-};
-
 class WPILibRobot : public ::frc971::wpilib::WPILibRobotBase {
  public:
   ::std::unique_ptr<frc::Encoder> make_encoder(int index) {
@@ -201,11 +168,11 @@
     // they are identical, as far as DrivetrainWriter is concerned, to the SP
     // variety so all the Victors are written as SPs.
 
-    DrivetrainWriter drivetrain_writer;
-    drivetrain_writer.set_drivetrain_left_victor(
-        ::std::unique_ptr<::frc::VictorSP>(new ::frc::VictorSP(2)));
-    drivetrain_writer.set_drivetrain_right_victor(
-        ::std::unique_ptr<::frc::VictorSP>(new ::frc::VictorSP(3)));
+    ::frc971::wpilib::DrivetrainWriter drivetrain_writer;
+    drivetrain_writer.set_left_controller0(
+        ::std::unique_ptr<::frc::VictorSP>(new ::frc::VictorSP(2)), false);
+    drivetrain_writer.set_right_controller0(
+        ::std::unique_ptr<::frc::VictorSP>(new ::frc::VictorSP(3)), false);
     ::std::thread drivetrain_writer_thread(::std::ref(drivetrain_writer));
 
     // Wait forever. Not much else to do...