[wpilib] Add DutyCycleEncoderSim (#2798)

wpilibc/src/main/native/cpp/simulation/DutyCycleEncoderSim.cpp

@@ -0,0 +1,33 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2020 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "frc/simulation/DutyCycleEncoderSim.h"
+
+#include <wpi/SmallString.h>
+#include <wpi/raw_ostream.h>
+
+#include "frc/DutyCycleEncoder.h"
+#include "frc/simulation/SimDeviceSim.h"
+
+using namespace frc::sim;
+
+DutyCycleEncoderSim::DutyCycleEncoderSim(const frc::DutyCycleEncoder& encoder) {
+  wpi::SmallString<128> fullname;
+  wpi::raw_svector_ostream os(fullname);
+  os << "DutyCycleEncoder" << '[' << encoder.GetSourceChannel() << ']';
+  frc::sim::SimDeviceSim deviceSim{fullname.c_str()};
+  m_simPosition = deviceSim.GetDouble("Position");
+  m_simDistancePerRotation = deviceSim.GetDouble("DistancePerRotation");
+}
+
+void DutyCycleEncoderSim::Set(units::turn_t turns) {
+  m_simPosition.Set(turns.to<double>());
+}
+
+void DutyCycleEncoderSim::SetDistance(double distance) {
+  m_simPosition.Set(distance / m_simDistancePerRotation.Get());
+}