Split RobotDrive class into a class for each drive type (#552)

DiffDrive.CurvatureDrive (aka CheesyDrive) and KilloughDrive were also added.
This reorganization paves the way for SwerveDrive.

wpilibc/src/main/native/include/Drive/KilloughDrive.h

@@ -0,0 +1,70 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2017 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#pragma once
+
+#include <memory>
+
+#include <llvm/raw_ostream.h>
+
+#include "Drive/RobotDriveBase.h"
+#include "Drive/Vector2d.h"
+
+namespace frc {
+
+class SpeedController;
+
+/**
+ * A class for driving Killough drive platforms.
+ *
+ * Killough drives are triangular with one omni wheel on each corner.
+ *
+ * Drive base diagram:
+ * <pre>
+ *  /_____\
+ * / \   / \
+ *    \ /
+ *    ---
+ * </pre>
+ *
+ * Each Drive() function provides different inverse kinematic relations for a
+ * Killough drive. The default wheel vectors are parallel to their respective
+ * opposite sides, but can be overridden. See the constructor for more
+ * information.
+ */
+class KilloughDrive : public RobotDriveBase {
+ public:
+  KilloughDrive(SpeedController& leftMotor, SpeedController& rightMotor,
+                SpeedController& backMotor);
+  KilloughDrive(SpeedController& leftMotor, SpeedController& rightMotor,
+                SpeedController& backMotor, double leftMotorAngle,
+                double rightMotorAngle, double backMotorAngle);
+  virtual ~KilloughDrive() = default;
+
+  KilloughDrive(const KilloughDrive&) = delete;
+  KilloughDrive& operator=(const KilloughDrive&) = delete;
+
+  void DriveCartesian(double x, double y, double rotation,
+                      double gyroAngle = 0.0);
+  void DrivePolar(double magnitude, double angle, double rotation);
+
+  void StopMotor() override;
+  void GetDescription(llvm::raw_ostream& desc) const override;
+
+ private:
+  SpeedController& m_leftMotor;
+  SpeedController& m_rightMotor;
+  SpeedController& m_backMotor;
+
+  Vector2d m_leftVec;
+  Vector2d m_rightVec;
+  Vector2d m_backVec;
+
+  bool reported = false;
+};
+
+}  // namespace frc