From 4e0d78535685a1f3fd34f55d64aa1c7554aba0b9 Mon Sep 17 00:00:00 2001
From: Gold856 <117957790+Gold856@users.noreply.github.com>
Date: Wed, 30 Aug 2023 16:22:42 -0400
Subject: [PATCH] [wpimath] ChassisSpeeds: document that values aren't relative
 to the robot (NFC) (#5551)

---
 .../edu/wpi/first/math/kinematics/ChassisSpeeds.java  | 11 +++++------
 .../native/include/frc/kinematics/ChassisSpeeds.h     |  7 +++----
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/wpimath/src/main/java/edu/wpi/first/math/kinematics/ChassisSpeeds.java b/wpimath/src/main/java/edu/wpi/first/math/kinematics/ChassisSpeeds.java
index 5018d1d7d82..c0370cea0b5 100644
--- a/wpimath/src/main/java/edu/wpi/first/math/kinematics/ChassisSpeeds.java
+++ b/wpimath/src/main/java/edu/wpi/first/math/kinematics/ChassisSpeeds.java
@@ -8,20 +8,19 @@
 import edu.wpi.first.math.geometry.Rotation2d;
 
 /**
- * Represents the speed of a robot chassis. Although this struct contains similar members compared
- * to a Twist2d, they do NOT represent the same thing. Whereas a Twist2d represents a change in pose
- * w.r.t to the robot frame of reference, this ChassisSpeeds struct represents a velocity w.r.t to
- * the robot frame of reference.
+ * Represents the speed of a robot chassis. Although this class contains similar members compared to
+ * a Twist2d, they do NOT represent the same thing. Whereas a Twist2d represents a change in pose
+ * w.r.t to the robot frame of reference, a ChassisSpeeds object represents a robot's velocity.
  *
  * <p>A strictly non-holonomic drivetrain, such as a differential drive, should never have a dy
  * component because it can never move sideways. Holonomic drivetrains such as swerve and mecanum
  * will often have all three components.
  */
 public class ChassisSpeeds {
-  /** Represents forward velocity w.r.t the robot frame of reference. (Fwd is +) */
+  /** Velocity along the x-axis. (Fwd is +) */
   public double vxMetersPerSecond;
 
-  /** Represents sideways velocity w.r.t the robot frame of reference. (Left is +) */
+  /** Velocity along the y-axis. (Left is +) */
   public double vyMetersPerSecond;
 
   /** Represents the angular velocity of the robot frame. (CCW is +) */
diff --git a/wpimath/src/main/native/include/frc/kinematics/ChassisSpeeds.h b/wpimath/src/main/native/include/frc/kinematics/ChassisSpeeds.h
index ab6dd1d042b..b388d5cec85 100644
--- a/wpimath/src/main/native/include/frc/kinematics/ChassisSpeeds.h
+++ b/wpimath/src/main/native/include/frc/kinematics/ChassisSpeeds.h
@@ -16,8 +16,7 @@ namespace frc {
  * Represents the speed of a robot chassis. Although this struct contains
  * similar members compared to a Twist2d, they do NOT represent the same thing.
  * Whereas a Twist2d represents a change in pose w.r.t to the robot frame of
- * reference, this ChassisSpeeds struct represents a velocity w.r.t to the robot
- * frame of reference.
+ * reference, a ChassisSpeeds struct represents a robot's velocity.
  *
  * A strictly non-holonomic drivetrain, such as a differential drive, should
  * never have a dy component because it can never move sideways. Holonomic
@@ -25,12 +24,12 @@ namespace frc {
  */
 struct WPILIB_DLLEXPORT ChassisSpeeds {
   /**
-   * Represents forward velocity w.r.t the robot frame of reference. (Fwd is +)
+   * Velocity along the x-axis. (Fwd is +)
    */
   units::meters_per_second_t vx = 0_mps;
 
   /**
-   * Represents strafe velocity w.r.t the robot frame of reference. (Left is +)
+   * Velocity along the y-axis. (Left is +)
    */
   units::meters_per_second_t vy = 0_mps;