Add holonomic follower examples (#2052)

wpilibcExamples/src/main/cpp/examples/MecanumControllerCommand/include/subsystems/DriveSubsystem.h

@@ -0,0 +1,166 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019 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 <frc/ADXRS450_Gyro.h>
+#include <frc/Encoder.h>
+#include <frc/PWMVictorSPX.h>
+#include <frc/drive/MecanumDrive.h>
+#include <frc/geometry/Pose2d.h>
+#include <frc/geometry/Rotation2d.h>
+#include <frc/interfaces/Gyro.h>
+#include <frc/kinematics/MecanumDriveOdometry.h>
+#include <frc/kinematics/MecanumDriveWheelSpeeds.h>
+#include <frc2/command/SubsystemBase.h>
+
+#include "Constants.h"
+
+class DriveSubsystem : public frc2::SubsystemBase {
+ public:
+  DriveSubsystem();
+
+  /**
+   * Will be called periodically whenever the CommandScheduler runs.
+   */
+  void Periodic() override;
+
+  // Subsystem methods go here.
+
+  /**
+   * Drives the robot at given x, y and theta speeds. Speeds range from [-1, 1]
+   * and the linear speeds have no effect on the angular speed.
+   *
+   * @param xSpeed        Speed of the robot in the x direction
+   *                      (forward/backwards).
+   * @param ySpeed        Speed of the robot in the y direction (sideways).
+   * @param rot           Angular rate of the robot.
+   * @param fieldRelative Whether the provided x and y speeds are relative to
+   *                      the field.
+   */
+  void Drive(double xSpeed, double ySpeed, double rot, bool feildRelative);
+
+  /**
+   * Resets the drive encoders to currently read a position of 0.
+   */
+  void ResetEncoders();
+
+  /**
+   * Gets the front left drive encoder.
+   *
+   * @return the front left drive encoder
+   */
+  frc::Encoder& GetFrontLeftEncoder();
+
+  /**
+   * Gets the rear left drive encoder.
+   *
+   * @return the rear left drive encoder
+   */
+  frc::Encoder& GetRearLeftEncoder();
+
+  /**
+   * Gets the front right drive encoder.
+   *
+   * @return the front right drive encoder
+   */
+  frc::Encoder& GetFrontRightEncoder();
+
+  /**
+   * Gets the rear right drive encoder.
+   *
+   * @return the rear right drive encoder
+   */
+  frc::Encoder& GetRearRightEncoder();
+
+  /**
+   * Gets the wheel speeds.
+   *
+   * @return the current wheel speeds.
+   */
+  frc::MecanumDriveWheelSpeeds getCurrentWheelSpeeds();
+
+  /**
+   * Sets the drive SpeedControllers to a desired voltage.
+   */
+  void SetSpeedControllersVolts(units::volt_t frontLeftPower,
+                                units::volt_t rearLeftPower,
+                                units::volt_t frontRightPower,
+                                units::volt_t rearRightPower);
+
+  /**
+   * Sets the max output of the drive. Useful for scaling the drive to drive
+   * more slowly.
+   *
+   * @param maxOutput the maximum output to which the drive will be constrained
+   */
+  void SetMaxOutput(double maxOutput);
+
+  /**
+   * Returns the heading of the robot.
+   *
+   * @return the robot's heading in degrees, from 180 to 180
+   */
+  double GetHeading();
+
+  /**
+   * Zeroes the heading of the robot.
+   */
+  void ZeroHeading();
+
+  /**
+   * Returns the turn rate of the robot.
+   *
+   * @return The turn rate of the robot, in degrees per second
+   */
+  double GetTurnRate();
+
+  /**
+   * Returns the currently-estimated pose of the robot.
+   *
+   * @return The pose.
+   */
+  frc::Pose2d GetPose();
+
+  /**
+   * Resets the odometry to the specified pose.
+   *
+   * @param pose The pose to which to set the odometry.
+   */
+  void ResetOdometry(frc::Pose2d pose);
+
+ private:
+  // Components (e.g. motor controllers and sensors) should generally be
+  // declared private and exposed only through public methods.
+
+  // The motor controllers
+  frc::PWMVictorSPX m_frontLeft;
+  frc::PWMVictorSPX m_rearLeft;
+  frc::PWMVictorSPX m_frontRight;
+  frc::PWMVictorSPX m_rearRight;
+
+  // The robot's drive
+  frc::MecanumDrive m_drive{m_frontLeft, m_rearLeft, m_frontRight, m_rearRight};
+
+  // The front-left-side drive encoder
+  frc::Encoder m_frontLeftEncoder;
+
+  // The rear-left-side drive encoder
+  frc::Encoder m_rearLeftEncoder;
+
+  // The front-right--side drive encoder
+  frc::Encoder m_frontRightEncoder;
+
+  // The rear-right-side drive encoder
+  frc::Encoder m_rearRightEncoder;
+
+  // The gyro sensor
+  frc::ADXRS450_Gyro m_gyro;
+
+  // Odometry class for tracking robot pose
+  frc::MecanumDriveOdometry m_odometry;
+};