Allowed sharing of common C++ code between RoboRIO and Simulation.

Change-Id: I8bf2bda9df389c13ae0567a62dbf0ca931ceb6f8

wpilibc/wpilibC++Devices/include/Encoder.h

@@ -0,0 +1,81 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2008. 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 $(WIND_BASE)/WPILib.  */
+/*----------------------------------------------------------------------------*/
+#pragma once
+
+#include "HAL/HAL.hpp"
+#include "CounterBase.h"
+#include "SensorBase.h"
+#include "Counter.h"
+#include "PIDSource.h"
+#include "LiveWindow/LiveWindowSendable.h"
+
+class DigitalSource;
+
+/**
+ * Class to read quad encoders.
+ * Quadrature encoders are devices that count shaft rotation and can sense direction. The output of
+ * the QuadEncoder class is an integer that can count either up or down, and can go negative for
+ * reverse direction counting. When creating QuadEncoders, a direction is supplied that changes the
+ * sense of the output to make code more readable if the encoder is mounted such that forward movement
+ * generates negative values. Quadrature encoders have two digital outputs, an A Channel and a B Channel
+ * that are out of phase with each other to allow the FPGA to do direction sensing.
+ *
+ * All encoders will immediately start counting - Reset() them if you need them
+ * to be zeroed before use.
+ */
+class Encoder : public SensorBase, public CounterBase, public PIDSource, public LiveWindowSendable
+{
+public:
+
+	Encoder(uint32_t aChannel, uint32_t bChannel, bool reverseDirection = false,
+			EncodingType encodingType = k4X);
+	Encoder(DigitalSource *aSource, DigitalSource *bSource, bool reverseDirection = false,
+			EncodingType encodingType = k4X);
+	Encoder(DigitalSource &aSource, DigitalSource &bSource, bool reverseDirection = false,
+			EncodingType encodingType = k4X);
+	virtual ~Encoder();
+
+	// CounterBase interface
+	int32_t Get();
+	int32_t GetRaw();
+	void Reset();
+	double GetPeriod();
+	void SetMaxPeriod(double maxPeriod);
+	bool GetStopped();
+	bool GetDirection();
+	double GetDistance();
+	double GetRate();
+	void SetMinRate(double minRate);
+	void SetDistancePerPulse(double distancePerPulse);
+	void SetReverseDirection(bool reverseDirection);
+	void SetSamplesToAverage(int samplesToAverage);
+	int GetSamplesToAverage();
+	void SetPIDSourceParameter(PIDSourceParameter pidSource);
+	double PIDGet();
+
+	void UpdateTable();
+	void StartLiveWindowMode();
+	void StopLiveWindowMode();
+	std::string GetSmartDashboardType();
+	void InitTable(ITable *subTable);
+	ITable * GetTable();
+
+private:
+	void InitEncoder(bool _reverseDirection, EncodingType encodingType);
+	double DecodingScaleFactor();
+
+	DigitalSource *m_aSource;		// the A phase of the quad encoder
+	DigitalSource *m_bSource;		// the B phase of the quad encoder
+	bool m_allocatedASource;		// was the A source allocated locally?
+	bool m_allocatedBSource;		// was the B source allocated locally?
+	void* m_encoder;
+	double m_distancePerPulse;		// distance of travel for each encoder tick
+	Counter *m_counter;				// Counter object for 1x and 2x encoding
+	EncodingType m_encodingType;	// Encoding type
+	PIDSourceParameter m_pidSource;	// Encoder parameter that sources a PID controller
+
+	ITable *m_table;
+};