[wpimath] Replace Speeds with Velocities (#8479)

I left "free speed" alone since that's the technical term for it. In
general, velocity is a vector quantity, and speed is a magnitude (i.e.,
a strictly positive value).

This PR also replaces the speed verbiage in MotorController with duty
cycle.

Fixes #8423.

wpilibcExamples/src/main/cpp/examples/RapidReactCommandBot/cpp/RapidReactCommandBot.cpp

@@ -45,6 +45,6 @@ void RapidReactCommandBot::ConfigureBindings() {
 wpi::cmd::CommandPtr RapidReactCommandBot::GetAutonomousCommand() {
   return m_drive
       .DriveDistanceCommand(AutoConstants::kDriveDistance,
-                            AutoConstants::kDriveSpeed)
+                            AutoConstants::kDriveVelocity)
       .WithTimeout(AutoConstants::kTimeout);
 }

wpilibcExamples/src/main/cpp/examples/RapidReactCommandBot/cpp/subsystems/Drive.cpp

@@ -43,14 +43,14 @@ wpi::cmd::CommandPtr Drive::ArcadeDriveCommand(std::function<double()> fwd,
 }
 
 wpi::cmd::CommandPtr Drive::DriveDistanceCommand(wpi::units::meter_t distance,
-                                                 double speed) {
+                                                 double velocity) {
   return RunOnce([this] {
            // Reset encoders at the start of the command
            m_leftEncoder.Reset();
            m_rightEncoder.Reset();
          })
-      // Drive forward at specified speed
-      .AndThen(Run([this, speed] { m_drive.ArcadeDrive(speed, 0.0); }))
+      // Drive forward at specified velocity
+      .AndThen(Run([this, velocity] { m_drive.ArcadeDrive(velocity, 0.0); }))
       .Until([this, distance] {
         return wpi::units::math::max(
                    wpi::units::meter_t(m_leftEncoder.GetDistance()),

wpilibcExamples/src/main/cpp/examples/RapidReactCommandBot/cpp/subsystems/Intake.cpp

@@ -6,7 +6,7 @@
 
 wpi::cmd::CommandPtr Intake::IntakeCommand() {
   return RunOnce([this] { m_piston.Set(wpi::DoubleSolenoid::kForward); })
-      .AndThen(Run([this] { m_motor.Set(1.0); }))
+      .AndThen(Run([this] { m_motor.SetDutyCycle(1.0); }))
       .WithName("Intake");
 }
 

wpilibcExamples/src/main/cpp/examples/RapidReactCommandBot/cpp/subsystems/Shooter.cpp

@@ -34,6 +34,6 @@ wpi::cmd::CommandPtr Shooter::ShootCommand(
              // run the feeder
              wpi::cmd::cmd::WaitUntil([this] {
                return m_shooterFeedback.AtSetpoint();
-             }).AndThen([this] { m_feederMotor.Set(1.0); }))
+             }).AndThen([this] { m_feederMotor.SetDutyCycle(1.0); }))
       .WithName("Shoot");
 }

wpilibcExamples/src/main/cpp/examples/RapidReactCommandBot/cpp/subsystems/Storage.cpp

@@ -10,5 +10,5 @@ Storage::Storage() {
 }
 
 wpi::cmd::CommandPtr Storage::RunCommand() {
-  return Run([this] { m_motor.Set(1.0); }).WithName("Run");
+  return Run([this] { m_motor.SetDutyCycle(1.0); }).WithName("Run");
 }

wpilibcExamples/src/main/cpp/examples/RapidReactCommandBot/include/Constants.hpp

@@ -80,7 +80,7 @@ inline constexpr wpi::units::volt_t kS = 0.05_V;
 // Should have value 12V at free speed
 inline constexpr auto kV = 12_V / kShooterFree;
 
-inline constexpr double kFeederSpeed = 0.5;
+inline constexpr double kFeederVelocity = 0.5;
 }  // namespace ShooterConstants
 
 namespace OIConstants {
@@ -90,5 +90,5 @@ inline constexpr int kDriverControllerPort = 0;
 namespace AutoConstants {
 constexpr wpi::units::second_t kTimeout = 3_s;
 constexpr wpi::units::meter_t kDriveDistance = 2_m;
-constexpr double kDriveSpeed = 0.5;
+constexpr double kDriveVelocity = 0.5;
 }  // namespace AutoConstants

wpilibcExamples/src/main/cpp/examples/RapidReactCommandBot/include/subsystems/Drive.hpp

@@ -32,13 +32,13 @@ class Drive : public wpi::cmd::SubsystemBase {
 
   /**
    * Returns a command that drives the robot forward a specified distance at a
-   * specified speed.
+   * specified velocity.
    *
    * @param distance The distance to drive forward in meters
-   * @param speed The fraction of max speed at which to drive
+   * @param velocity The fraction of max velocity at which to drive
    */
   wpi::cmd::CommandPtr DriveDistanceCommand(wpi::units::meter_t distance,
-                                            double speed);
+                                            double velocity);
 
   /**
    * Returns a command that turns to robot to the specified angle using a motion
@@ -55,8 +55,8 @@ class Drive : public wpi::cmd::SubsystemBase {
   wpi::PWMSparkMax m_rightFollower{DriveConstants::kRightMotor2Port};
 
   wpi::DifferentialDrive m_drive{
-      [&](double output) { m_leftLeader.Set(output); },
-      [&](double output) { m_rightLeader.Set(output); }};
+      [&](double output) { m_leftLeader.SetDutyCycle(output); },
+      [&](double output) { m_rightLeader.SetDutyCycle(output); }};
 
   wpi::Encoder m_leftEncoder{DriveConstants::kLeftEncoderPorts[0],
                              DriveConstants::kLeftEncoderPorts[1],