[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.

wpimath/src/main/native/cpp/kinematics/struct/ChassisVelocitiesStruct.cpp

@@ -2,7 +2,7 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
-#include "wpi/math/kinematics/struct/ChassisSpeedsStruct.hpp"
+#include "wpi/math/kinematics/struct/ChassisVelocitiesStruct.hpp"
 
 namespace {
 constexpr size_t kVxOff = 0;
@@ -10,10 +10,10 @@ constexpr size_t kVyOff = kVxOff + 8;
 constexpr size_t kOmegaOff = kVyOff + 8;
 }  // namespace
 
-using StructType = wpi::util::Struct<wpi::math::ChassisSpeeds>;
+using StructType = wpi::util::Struct<wpi::math::ChassisVelocities>;
 
-wpi::math::ChassisSpeeds StructType::Unpack(std::span<const uint8_t> data) {
-  return wpi::math::ChassisSpeeds{
+wpi::math::ChassisVelocities StructType::Unpack(std::span<const uint8_t> data) {
+  return wpi::math::ChassisVelocities{
       wpi::units::meters_per_second_t{
           wpi::util::UnpackStruct<double, kVxOff>(data)},
       wpi::units::meters_per_second_t{
@@ -24,7 +24,7 @@ wpi::math::ChassisSpeeds StructType::Unpack(std::span<const uint8_t> data) {
 }
 
 void StructType::Pack(std::span<uint8_t> data,
-                      const wpi::math::ChassisSpeeds& value) {
+                      const wpi::math::ChassisVelocities& value) {
   wpi::util::PackStruct<kVxOff>(data, value.vx.value());
   wpi::util::PackStruct<kVyOff>(data, value.vy.value());
   wpi::util::PackStruct<kOmegaOff>(data, value.omega.value());

wpimath/src/main/native/cpp/kinematics/struct/DifferentialDriveWheelVelocitiesStruct.cpp

@@ -2,18 +2,19 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
-#include "wpi/math/kinematics/struct/DifferentialDriveWheelSpeedsStruct.hpp"
+#include "wpi/math/kinematics/struct/DifferentialDriveWheelVelocitiesStruct.hpp"
 
 namespace {
 constexpr size_t kLeftOff = 0;
 constexpr size_t kRightOff = kLeftOff + 8;
 }  // namespace
 
-using StructType = wpi::util::Struct<wpi::math::DifferentialDriveWheelSpeeds>;
+using StructType =
+    wpi::util::Struct<wpi::math::DifferentialDriveWheelVelocities>;
 
-wpi::math::DifferentialDriveWheelSpeeds StructType::Unpack(
+wpi::math::DifferentialDriveWheelVelocities StructType::Unpack(
     std::span<const uint8_t> data) {
-  return wpi::math::DifferentialDriveWheelSpeeds{
+  return wpi::math::DifferentialDriveWheelVelocities{
       wpi::units::meters_per_second_t{
           wpi::util::UnpackStruct<double, kLeftOff>(data)},
       wpi::units::meters_per_second_t{
@@ -21,8 +22,9 @@ wpi::math::DifferentialDriveWheelSpeeds StructType::Unpack(
   };
 }
 
-void StructType::Pack(std::span<uint8_t> data,
-                      const wpi::math::DifferentialDriveWheelSpeeds& value) {
+void StructType::Pack(
+    std::span<uint8_t> data,
+    const wpi::math::DifferentialDriveWheelVelocities& value) {
   wpi::util::PackStruct<kLeftOff>(data, value.left.value());
   wpi::util::PackStruct<kRightOff>(data, value.right.value());
 }

wpimath/src/main/native/cpp/kinematics/struct/MecanumDriveWheelVelocitiesStruct.cpp

@@ -2,7 +2,7 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
-#include "wpi/math/kinematics/struct/MecanumDriveWheelSpeedsStruct.hpp"
+#include "wpi/math/kinematics/struct/MecanumDriveWheelVelocitiesStruct.hpp"
 
 namespace {
 constexpr size_t kFrontLeftOff = 0;
@@ -11,11 +11,11 @@ constexpr size_t kRearLeftOff = kFrontRightOff + 8;
 constexpr size_t kRearRightOff = kRearLeftOff + 8;
 }  // namespace
 
-using StructType = wpi::util::Struct<wpi::math::MecanumDriveWheelSpeeds>;
+using StructType = wpi::util::Struct<wpi::math::MecanumDriveWheelVelocities>;
 
-wpi::math::MecanumDriveWheelSpeeds StructType::Unpack(
+wpi::math::MecanumDriveWheelVelocities StructType::Unpack(
     std::span<const uint8_t> data) {
-  return wpi::math::MecanumDriveWheelSpeeds{
+  return wpi::math::MecanumDriveWheelVelocities{
       wpi::units::meters_per_second_t{
           wpi::util::UnpackStruct<double, kFrontLeftOff>(data)},
       wpi::units::meters_per_second_t{
@@ -28,7 +28,7 @@ wpi::math::MecanumDriveWheelSpeeds StructType::Unpack(
 }
 
 void StructType::Pack(std::span<uint8_t> data,
-                      const wpi::math::MecanumDriveWheelSpeeds& value) {
+                      const wpi::math::MecanumDriveWheelVelocities& value) {
   wpi::util::PackStruct<kFrontLeftOff>(data, value.frontLeft.value());
   wpi::util::PackStruct<kFrontRightOff>(data, value.frontRight.value());
   wpi::util::PackStruct<kRearLeftOff>(data, value.rearLeft.value());

wpimath/src/main/native/cpp/kinematics/struct/SwerveModuleStateStruct.cpp

@@ -1,26 +0,0 @@
-// Copyright (c) FIRST and other WPILib contributors.
-// Open Source Software; you can modify and/or share it under the terms of
-// the WPILib BSD license file in the root directory of this project.
-
-#include "wpi/math/kinematics/struct/SwerveModuleStateStruct.hpp"
-
-namespace {
-constexpr size_t kSpeedOff = 0;
-constexpr size_t kAngleOff = kSpeedOff + 8;
-}  // namespace
-
-using StructType = wpi::util::Struct<wpi::math::SwerveModuleState>;
-
-wpi::math::SwerveModuleState StructType::Unpack(std::span<const uint8_t> data) {
-  return wpi::math::SwerveModuleState{
-      wpi::units::meters_per_second_t{
-          wpi::util::UnpackStruct<double, kSpeedOff>(data)},
-      wpi::util::UnpackStruct<wpi::math::Rotation2d, kAngleOff>(data),
-  };
-}
-
-void StructType::Pack(std::span<uint8_t> data,
-                      const wpi::math::SwerveModuleState& value) {
-  wpi::util::PackStruct<kSpeedOff>(data, value.speed.value());
-  wpi::util::PackStruct<kAngleOff>(data, value.angle);
-}

wpimath/src/main/native/cpp/kinematics/struct/SwerveModuleVelocityStruct.cpp

@@ -0,0 +1,27 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include "wpi/math/kinematics/struct/SwerveModuleVelocityStruct.hpp"
+
+namespace {
+constexpr size_t kVelocityOff = 0;
+constexpr size_t kAngleOff = kVelocityOff + 8;
+}  // namespace
+
+using StructType = wpi::util::Struct<wpi::math::SwerveModuleVelocity>;
+
+wpi::math::SwerveModuleVelocity StructType::Unpack(
+    std::span<const uint8_t> data) {
+  return wpi::math::SwerveModuleVelocity{
+      wpi::units::meters_per_second_t{
+          wpi::util::UnpackStruct<double, kVelocityOff>(data)},
+      wpi::util::UnpackStruct<wpi::math::Rotation2d, kAngleOff>(data),
+  };
+}
+
+void StructType::Pack(std::span<uint8_t> data,
+                      const wpi::math::SwerveModuleVelocity& value) {
+  wpi::util::PackStruct<kVelocityOff>(data, value.velocity.value());
+  wpi::util::PackStruct<kAngleOff>(data, value.angle);
+}