[wpilib] Clean up DifferentialDrivetrainSim API (#2747)

Co-authored-by: Tyler Veness <calcmogul@gmail.com>

wpilibc/src/main/native/cpp/simulation/DifferentialDrivetrainSim.cpp

@@ -66,7 +66,7 @@ Rotation2d DifferentialDrivetrainSim::GetHeading() const {
   return Rotation2d(units::radian_t(m_x(State::kHeading)));
 }
 
-Pose2d DifferentialDrivetrainSim::GetEstimatedPosition() const {
+Pose2d DifferentialDrivetrainSim::GetPose() const {
   return Pose2d(units::meter_t(m_x(State::kX)), units::meter_t(m_x(State::kY)),
                 Rotation2d(units::radian_t(m_x(State::kHeading))));
 }

wpilibc/src/main/native/include/frc/simulation/DifferentialDrivetrainSim.h

@@ -62,7 +62,7 @@ class DifferentialDrivetrainSim {
                             units::meter_t trackWidth);
 
   /**
-   * Set the applied voltage to the drivetrain. Note that positive voltage must
+   * Sets the applied voltage to the drivetrain. Note that positive voltage must
    * make that side of the drivetrain travel forward (+X).
    *
    * @param leftVoltage  The left voltage.
@@ -71,7 +71,7 @@ class DifferentialDrivetrainSim {
   void SetInputs(units::volt_t leftVoltage, units::volt_t rightVoltage);
 
   /**
-   * Set the gearing reduction on the drivetrain. This is commonly used for
+   * Sets the gearing reduction on the drivetrain. This is commonly used for
    * shifting drivetrains.
    *
    * @param newGearing The new gear ratio, as output over input.
@@ -94,7 +94,8 @@ class DifferentialDrivetrainSim {
   double GetState(int state) const;
 
   /**
-   * Get the current gearing reduction of the drivetrain, as output over input.
+   * Returns the current gearing reduction of the drivetrain, as output over
+   * input.
    */
   double GetGearing() const;
 
@@ -104,15 +105,17 @@ class DifferentialDrivetrainSim {
   Eigen::Matrix<double, 7, 1> GetState() const;
 
   /**
-   * Get the estimated direction the robot is pointing. Note that this angle is
-   * counterclockwise-positive, while most gyros are clockwise positive.
+   * Returns the direction the robot is pointing.
+   *
+   * Note that this angle is counterclockwise-positive, while most gyros are
+   * clockwise positive.
    */
   Rotation2d GetHeading() const;
 
   /**
-   * Returns the current estimated position.
+   * Returns the current pose.
    */
-  Pose2d GetEstimatedPosition() const;
+  Pose2d GetPose() const;
 
   /**
    * Returns the currently drawn current.
@@ -173,7 +176,7 @@ class DifferentialDrivetrainSim {
    * @param gearing   The gearing reduction used.
    * @param wheelSize The wheel size.
    */
-  static DifferentialDrivetrainSim createKitbotSim(frc::DCMotor motor,
+  static DifferentialDrivetrainSim CreateKitbotSim(frc::DCMotor motor,
                                                    double gearing,
                                                    units::meter_t wheelSize) {
     // MOI estimation -- note that I = m r^2 for point masses
@@ -195,7 +198,7 @@ class DifferentialDrivetrainSim {
    * @param J         The moment of inertia of the drivebase. This can be
    * calculated using frc-characterization.
    */
-  static DifferentialDrivetrainSim createKitbotSim(
+  static DifferentialDrivetrainSim CreateKitbotSim(
       frc::DCMotor motor, double gearing, units::meter_t wheelSize,
       units::kilogram_square_meter_t J) {
     return DifferentialDrivetrainSim{motor, gearing,         J,

wpilibc/src/test/native/cpp/simulation/DifferentialDriveSimTest.cpp

@@ -46,7 +46,7 @@ TEST(DifferentialDriveSim, Convergence) {
 
   for (double t = 0; t < trajectory.TotalTime().to<double>(); t += 0.02) {
     auto state = trajectory.Sample(20_ms);
-    auto ramseteOut = ramsete.Calculate(sim.GetEstimatedPosition(), state);
+    auto ramseteOut = ramsete.Calculate(sim.GetPose(), state);
 
     auto [l, r] = kinematics.ToWheelSpeeds(ramseteOut);
     auto voltages = feedforward.Calculate(
@@ -111,6 +111,5 @@ TEST(DifferentialDriveSim, ModelStability) {
     sim.Update(20_ms);
   }
 
-  EXPECT_LT(units::math::abs(sim.GetEstimatedPosition().Translation().Norm()),
-            100_m);
+  EXPECT_LT(units::math::abs(sim.GetPose().Translation().Norm()), 100_m);
 }

wpilibj/src/main/java/edu/wpi/first/wpilibj/simulation/DifferentialDrivetrainSim.java

@@ -101,7 +101,7 @@ public class DifferentialDrivetrainSim {
   }
 
   /**
-   * Set the applied voltage to the drivetrain. Note that positive voltage must make that
+   * Sets the applied voltage to the drivetrain. Note that positive voltage must make that
    * side of the drivetrain travel forward (+X).
    *
    * @param leftVoltageVolts  The left voltage.
@@ -123,24 +123,26 @@ public class DifferentialDrivetrainSim {
   }
 
   /**
-   * Get the full simulated state of the drivetrain.
+   * Returns the full simulated state of the drivetrain.
    */
   public Matrix<N7, N1> getState() {
     return m_x;
   }
 
   /**
-   * Get the estimated direction the robot is pointing. Note that this angle is
-   * counterclockwise-positive, while most gyros are clockwise positive.
+   * Returns the direction the robot is pointing.
+   *
+   * <p>Note that this angle is counterclockwise-positive, while most gyros are
+   * clockwise positive.
    */
   public Rotation2d getHeading() {
     return new Rotation2d(getState(State.kHeading));
   }
 
   /**
-   * Get the estimated position of the drivetrain.
+   * Returns the current pose.
    */
-  public Pose2d getEstimatedPosition() {
+  public Pose2d getPose() {
     return new Pose2d(m_x.get(0, 0),
       m_x.get(1, 0),
       new Rotation2d(m_x.get(2, 0)));
@@ -163,7 +165,7 @@ public class DifferentialDrivetrainSim {
   }
 
   /**
-   * Set the gearing reduction on the drivetrain. This is commonly used for
+   * Sets the gearing reduction on the drivetrain. This is commonly used for
    * shifting drivetrains.
    *
    * @param newGearRatio The new gear ratio, as output over input.

wpilibj/src/test/java/edu/wpi/first/wpilibj/simulation/DifferentialDrivetrainSimTest.java

@@ -65,7 +65,7 @@ class DifferentialDrivetrainSimTest {
 
     for (double t = 0; t < traj.getTotalTimeSeconds(); t += 0.020) {
       var state = traj.sample(0.020);
-      var ramseteOut = ramsete.calculate(sim.getEstimatedPosition(), state);
+      var ramseteOut = ramsete.calculate(sim.getPose(), state);
 
       var wheelSpeeds = kinematics.toWheelSpeeds(ramseteOut);
 
@@ -141,6 +141,6 @@ class DifferentialDrivetrainSimTest {
       sim.update(0.020);
     }
 
-    assertTrue(Math.abs(sim.getEstimatedPosition().getTranslation().getNorm()) < 100);
+    assertTrue(Math.abs(sim.getPose().getTranslation().getNorm()) < 100);
   }
 }