[wpimath] Remove unit suffixes from variable names (#7529)

* Move units into API docs instead because suffixes make user code verbose and hard to read
* Rename trackWidth to trackwidth
* Make ultrasonic classes use meters instead of a mix of m, cm, mm, ft,
  and inches

wpilibc/src/main/native/cpp/SharpIR.cpp

@@ -7,6 +7,7 @@
 #include <algorithm>
 
 #include <hal/UsageReporting.h>
+#include <units/length.h>
 #include <wpi/sendable/SendableBuilder.h>
 #include <wpi/sendable/SendableRegistry.h>
 
@@ -15,29 +16,30 @@
 using namespace frc;
 
 SharpIR SharpIR::GP2Y0A02YK0F(int channel) {
-  return SharpIR(channel, 62.28, -1.092, 20, 150.0);
+  return SharpIR(channel, 62.28, -1.092, 20_cm, 150_cm);
 }
 
 SharpIR SharpIR::GP2Y0A21YK0F(int channel) {
-  return SharpIR(channel, 26.449, -1.226, 10.0, 80.0);
+  return SharpIR(channel, 26.449, -1.226, 10_cm, 80_cm);
 }
 
 SharpIR SharpIR::GP2Y0A41SK0F(int channel) {
-  return SharpIR(channel, 12.354, -1.07, 4.0, 30.0);
+  return SharpIR(channel, 12.354, -1.07, 4_cm, 30_cm);
 }
 
 SharpIR SharpIR::GP2Y0A51SK0F(int channel) {
-  return SharpIR(channel, 5.2819, -1.161, 2.0, 15.0);
+  return SharpIR(channel, 5.2819, -1.161, 2_cm, 15_cm);
 }
 
-SharpIR::SharpIR(int channel, double a, double b, double minCM, double maxCM)
-    : m_sensor(channel), m_A(a), m_B(b), m_minCM(minCM), m_maxCM(maxCM) {
+SharpIR::SharpIR(int channel, double a, double b, units::meter_t min,
+                 units::meter_t max)
+    : m_sensor(channel), m_A(a), m_B(b), m_min(min), m_max(max) {
   HAL_ReportUsage("IO", channel, "SharpIR");
   wpi::SendableRegistry::Add(this, "SharpIR", channel);
 
   m_simDevice = hal::SimDevice("SharpIR", m_sensor.GetChannel());
   if (m_simDevice) {
-    m_simRange = m_simDevice.CreateDouble("Range (cm)", false, 0.0);
+    m_simRange = m_simDevice.CreateDouble("Range (m)", false, 0.0);
     m_sensor.SetSimDevice(m_simDevice);
   }
 }
@@ -46,19 +48,16 @@ int SharpIR::GetChannel() const {
   return m_sensor.GetChannel();
 }
 
-units::centimeter_t SharpIR::GetRange() const {
-  double distance;
-
+units::meter_t SharpIR::GetRange() const {
   if (m_simRange) {
-    distance = m_simRange.Get();
+    return std::clamp(units::meter_t{m_simRange.Get()}, m_min, m_max);
   } else {
     // Don't allow zero/negative values
     auto v = std::max(m_sensor.GetVoltage(), 0.00001);
-    distance = m_A * std::pow(v, m_B);
-  }
 
-  // Always constrain output
-  return units::centimeter_t{std::max(std::min(distance, m_maxCM), m_minCM)};
+    return std::clamp(units::meter_t{m_A * std::pow(v, m_B) * 1e-2}, m_min,
+                      m_max);
+  }
 }
 
 void SharpIR::InitSendable(wpi::SendableBuilder& builder) {

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

@@ -18,11 +18,11 @@ using namespace frc;
 using namespace frc::sim;
 
 DifferentialDrivetrainSim::DifferentialDrivetrainSim(
-    LinearSystem<2, 2, 2> plant, units::meter_t trackWidth, DCMotor driveMotor,
+    LinearSystem<2, 2, 2> plant, units::meter_t trackwidth, DCMotor driveMotor,
     double gearRatio, units::meter_t wheelRadius,
     const std::array<double, 7>& measurementStdDevs)
     : m_plant(std::move(plant)),
-      m_rb(trackWidth / 2.0),
+      m_rb(trackwidth / 2.0),
       m_wheelRadius(wheelRadius),
       m_motor(driveMotor),
       m_originalGearing(gearRatio),
@@ -36,11 +36,11 @@ DifferentialDrivetrainSim::DifferentialDrivetrainSim(
 DifferentialDrivetrainSim::DifferentialDrivetrainSim(
     frc::DCMotor driveMotor, double gearing, units::kilogram_square_meter_t J,
     units::kilogram_t mass, units::meter_t wheelRadius,
-    units::meter_t trackWidth, const std::array<double, 7>& measurementStdDevs)
+    units::meter_t trackwidth, const std::array<double, 7>& measurementStdDevs)
     : DifferentialDrivetrainSim(
           frc::LinearSystemId::DrivetrainVelocitySystem(
-              driveMotor, mass, wheelRadius, trackWidth / 2.0, J, gearing),
-          trackWidth, driveMotor, gearing, wheelRadius, measurementStdDevs) {}
+              driveMotor, mass, wheelRadius, trackwidth / 2.0, J, gearing),
+          trackwidth, driveMotor, gearing, wheelRadius, measurementStdDevs) {}
 
 Eigen::Vector2d DifferentialDrivetrainSim::ClampInput(
     const Eigen::Vector2d& u) {

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

@@ -16,9 +16,9 @@ SharpIRSim::SharpIRSim(const SharpIR& sharpIR)
 
 SharpIRSim::SharpIRSim(int channel) {
   frc::sim::SimDeviceSim deviceSim{"SharpIR", channel};
-  m_simRange = deviceSim.GetDouble("Range (cm)");
+  m_simRange = deviceSim.GetDouble("Range (m)");
 }
 
-void SharpIRSim::SetRange(units::centimeter_t rng) {
-  m_simRange.Set(rng.value());
+void SharpIRSim::SetRange(units::meter_t range) {
+  m_simRange.Set(range.value());
 }