Added C++ Encoder samples to Eclipse Plugin.

Reads values from quadrature encoder and displays them on the
SmartDashbord.

Also added Encoder with Motor Control example, which is identical to the
Motor Control sample but displays an encoder value on the
SmartDashboard.

eclipse-plugins/edu.wpi.first.wpilib.plugins.cpp/resources/templates/examples/Encoder/src/Robot.cpp

@@ -0,0 +1,82 @@
+#include "WPILib.h"
+
+/**
+ * Sample program displaying the value of a quadrature encoder on the SmartDashboard.
+ * Quadrature Encoders are digital sensors which can detect the amount the encoder
+ *   has rotated since starting as well as the direction in which the encoder
+ *   shaft is rotating. However, encoders can not tell you the absolute
+ *   position of the encoder shaft (ie, it considers where it starts to be the
+ *   zero position, no matter where it starts), and so can only tell you how
+ *   much the encoder has rotated since starting.
+ * Depending on the precision of an encoder, it will have fewer or greater
+ *   ticks per revolution; the number of ticks per revolution will affect the
+ *   conversion between ticks and distance, as specified by DistancePerPulse.
+ * One of the most common uses of encoders is in the drivetrain, so that the
+ *   distance that the robot drives can be precisely controlled during the
+ *   autonomous mode.
+ */
+class Robot: public SampleRobot
+{
+	Encoder m_encoder;
+
+	/**
+	 * Time to wait between updating SmartDashboard values.
+	 * It is generally a good idea to stick a short wait in these loops
+	 *   to avoid hogging CPU power, especially as there will be no
+	 *   perceivable difference in the SmartDashboard display.
+	 */
+	const double kUpdatePeriod = 0.005; // 5milliseconds / 0.005 seconds.
+
+public:
+	/**
+	 * The Encoder object is constructed with 4 parameters, the last two being optional.
+	 * The first two parameters (1, 2 in this case) refer to the ports on the
+	 *   roboRIO which the encoder uses. Because a quadrature encoder has
+	 *   two signal wires, the signal from two DIO ports on the roboRIO are used.
+	 * The third (optional) parameter is a boolean which defaults to false.
+	 *   If you set this parameter to true, the direction of the encoder will
+	 *   be reversed, in case it makes more sense mechanically.
+	 * The final (optional) parameter specifies encoding rate (k1X, k2X, or k4X)
+	 *   and defaults to k4X. Faster (k4X) encoding gives greater positional
+	 *   precision but more noise in the rate.
+	 */
+	Robot() : m_encoder(1, 2, false, Encoder::k4X)
+	{
+		// Defines the number of samples to average when determining the rate.
+		// On a quadrature encoder, values range from 1-255; larger values
+		//   result in smoother but potentially less accurate rates than lower values.
+		m_encoder.SetSamplesToAverage(5);
+
+		// Defines how far the mechanism attached to the encoder moves per pulse.
+		// In this case, we assume that a 360 count encoder is directly attached
+		//   to a 3 inch diameter (1.5inch radius) wheel, and that we want to
+		//   measure distance in inches.
+		m_encoder.SetDistancePerPulse(1.0 / 360.0 * 2.0 * 3.1415 * 1.5);
+
+		// Defines the lowest rate at which the encoder will not be considered
+		//   stopped, for the purposes of the GetStopped() method.
+		// Units are in distance / second, where distance refers to the units
+		//   of distance that you are using, in this case inches.
+		m_encoder.SetMinRate(1.0);
+	}
+
+	/**
+	 * Retrieve various information from the encoder and display it
+	 *   on the SmartDashboard.
+	 */
+	void OperatorControl()
+	{
+		while (IsOperatorControl())
+		{
+			// Retrieve the net displacement of the Encoder since the lsat Reset.
+			SmartDashboard::PutNumber("Encoder Distance", m_encoder.GetDistance());
+
+			// Retrieve the current rate of the encoder.
+			SmartDashboard::PutNumber("Encoder Rate", m_encoder.GetRate());
+
+			Wait(kUpdatePeriod); // Wait a short bit before updating again.
+		}
+	}
+};
+
+START_ROBOT_CLASS(Robot);