[wpilib] Add a default deadband to all gamepads (#8897)

The FTC DS had a deadband. Additionally, the FRC one had an implicit
deadband due to the only 8 bit resolution. We need a deadband by default
now with the high resolution gamepads.

wpilibc/src/main/native/cpp/driverstation/Gamepad.cpp

@@ -4,39 +4,71 @@
 
 #include "wpi/driverstation/Gamepad.hpp"
 
+#include <algorithm>
+#include <cmath>
+
 #include "wpi/event/BooleanEvent.hpp"
 #include "wpi/hal/UsageReporting.hpp"
+#include "wpi/math/util/MathUtil.hpp"
 #include "wpi/util/sendable/SendableBuilder.hpp"
 
 using namespace wpi;
 
+static double ClampDeadband(double deadband) {
+  if (std::isnan(deadband)) {
+    return 0.0;
+  }
+  return std::clamp(deadband, 0.0, std::nextafter(1.0, 0.0));
+}
+
 Gamepad::Gamepad(int port) : GenericHID(port) {
   HAL_ReportUsage("HID", port, "Gamepad");
 }
 
 double Gamepad::GetLeftX() const {
-  return GetAxis(Axis::LEFT_X);
+  return wpi::math::ApplyDeadband(GetAxis(Axis::LEFT_X), m_leftXDeadband);
+}
+
+void Gamepad::SetLeftXDeadband(double deadband) {
+  m_leftXDeadband = ClampDeadband(deadband);
 }
 
 double Gamepad::GetLeftY() const {
-  return GetAxis(Axis::LEFT_Y);
+  return wpi::math::ApplyDeadband(GetAxis(Axis::LEFT_Y), m_leftYDeadband);
+}
+
+void Gamepad::SetLeftYDeadband(double deadband) {
+  m_leftYDeadband = ClampDeadband(deadband);
 }
 
 double Gamepad::GetRightX() const {
-  return GetAxis(Axis::RIGHT_X);
+  return wpi::math::ApplyDeadband(GetAxis(Axis::RIGHT_X), m_rightXDeadband);
+}
+
+void Gamepad::SetRightXDeadband(double deadband) {
+  m_rightXDeadband = ClampDeadband(deadband);
 }
 
 double Gamepad::GetRightY() const {
-  return GetAxis(Axis::RIGHT_Y);
+  return wpi::math::ApplyDeadband(GetAxis(Axis::RIGHT_Y), m_rightYDeadband);
+}
+
+void Gamepad::SetRightYDeadband(double deadband) {
+  m_rightYDeadband = ClampDeadband(deadband);
 }
 
 double Gamepad::GetLeftTriggerAxis() const {
-  return GetAxis(Axis::LEFT_TRIGGER);
+  return wpi::math::ApplyDeadband(GetAxis(Axis::LEFT_TRIGGER),
+                                  m_leftTriggerDeadband);
+}
+
+void Gamepad::SetLeftTriggerDeadband(double deadband) {
+  m_leftTriggerDeadband = ClampDeadband(deadband);
 }
 
 BooleanEvent Gamepad::LeftTrigger(double threshold, EventLoop* loop) const {
   return BooleanEvent(loop, [this, threshold] {
-    return this->GetLeftTriggerAxis() > threshold;
+    return this->GetAxis(Axis::LEFT_TRIGGER) > threshold;
   });
 }
 
@@ -45,12 +77,17 @@ BooleanEvent Gamepad::LeftTrigger(EventLoop* loop) const {
 }
 
 double Gamepad::GetRightTriggerAxis() const {
-  return GetAxis(Axis::RIGHT_TRIGGER);
+  return wpi::math::ApplyDeadband(GetAxis(Axis::RIGHT_TRIGGER),
+                                  m_rightTriggerDeadband);
+}
+
+void Gamepad::SetRightTriggerDeadband(double deadband) {
+  m_rightTriggerDeadband = ClampDeadband(deadband);
 }
 
 BooleanEvent Gamepad::RightTrigger(double threshold, EventLoop* loop) const {
   return BooleanEvent(loop, [this, threshold] {
-    return this->GetRightTriggerAxis() > threshold;
+    return this->GetAxis(Axis::RIGHT_TRIGGER) > threshold;
   });
 }
 

wpilibc/src/main/native/include/wpi/driverstation/Gamepad.hpp

@@ -116,39 +116,99 @@ class Gamepad : public GenericHID,
   /**
    * Get the X axis value of left side of the controller. Right is positive.
    *
+   * A deadband of 0.1 is applied by default. Use SetLeftXDeadband() to change
+   * it.
+   *
    * @return the axis value.
    */
   double GetLeftX() const;
 
+  /**
+   * Set the deadband for the left X axis.
+   *
+   * The deadband is clamped to [0, 1).
+   *
+   * @param deadband The deadband to apply.
+   */
+  void SetLeftXDeadband(double deadband);
+
   /**
    * Get the Y axis value of left side of the controller. Back is positive.
    *
+   * A deadband of 0.1 is applied by default. Use SetLeftYDeadband() to change
+   * it.
+   *
    * @return the axis value.
    */
   double GetLeftY() const;
 
+  /**
+   * Set the deadband for the left Y axis.
+   *
+   * The deadband is clamped to [0, 1).
+   *
+   * @param deadband The deadband to apply.
+   */
+  void SetLeftYDeadband(double deadband);
+
   /**
    * Get the X axis value of right side of the controller. Right is positive.
    *
+   * A deadband of 0.1 is applied by default. Use SetRightXDeadband() to change
+   * it.
+   *
    * @return the axis value.
    */
   double GetRightX() const;
 
+  /**
+   * Set the deadband for the right X axis.
+   *
+   * The deadband is clamped to [0, 1).
+   *
+   * @param deadband The deadband to apply.
+   */
+  void SetRightXDeadband(double deadband);
+
   /**
    * Get the Y axis value of right side of the controller. Back is positive.
    *
+   * A deadband of 0.1 is applied by default. Use SetRightYDeadband() to change
+   * it.
+   *
    * @return the axis value.
    */
   double GetRightY() const;
 
+  /**
+   * Set the deadband for the right Y axis.
+   *
+   * The deadband is clamped to [0, 1).
+   *
+   * @param deadband The deadband to apply.
+   */
+  void SetRightYDeadband(double deadband);
+
   /**
    * Get the left trigger axis value of the controller. Note that this axis
    * is bound to the range of [0, 1] as opposed to the usual [-1, 1].
    *
+   * A deadband of 0.01 is applied by default. Use SetLeftTriggerDeadband() to
+   * change it.
+   *
    * @return the axis value.
    */
   double GetLeftTriggerAxis() const;
 
+  /**
+   * Set the deadband for the left trigger axis.
+   *
+   * The deadband is clamped to [0, 1).
+   *
+   * @param deadband The deadband to apply.
+   */
+  void SetLeftTriggerDeadband(double deadband);
+
   /**
    * Constructs an event instance around the axis value of the left trigger.
    * The returned trigger will be true when the axis value is greater than
@@ -175,10 +235,22 @@ class Gamepad : public GenericHID,
    * Get the right trigger axis value of the controller. Note that this axis
    * is bound to the range of [0, 1] as opposed to the usual [-1, 1].
    *
+   * A deadband of 0.01 is applied by default. Use SetRightTriggerDeadband() to
+   * change it.
+   *
    * @return the axis value.
    */
   double GetRightTriggerAxis() const;
 
+  /**
+   * Set the deadband for the right trigger axis.
+   *
+   * The deadband is clamped to [0, 1).
+   *
+   * @param deadband The deadband to apply.
+   */
+  void SetRightTriggerDeadband(double deadband);
+
   /**
    * Constructs an event instance around the axis value of the right trigger.
    * The returned trigger will be true when the axis value is greater than
@@ -1090,6 +1162,13 @@ class Gamepad : public GenericHID,
  private:
   double GetAxisForSendable(Axis axis) const;
   bool GetButtonForSendable(Button button) const;
+
+  double m_leftXDeadband = 0.1;
+  double m_leftYDeadband = 0.1;
+  double m_rightXDeadband = 0.1;
+  double m_rightYDeadband = 0.1;
+  double m_leftTriggerDeadband = 0.01;
+  double m_rightTriggerDeadband = 0.01;
 };
 
 }  // namespace wpi

wpilibc/src/main/python/semiwrap/Gamepad.yml

@@ -8,15 +8,21 @@ classes:
     methods:
       Gamepad:
       GetLeftX:
+      SetLeftXDeadband:
       GetLeftY:
+      SetLeftYDeadband:
       GetRightX:
+      SetRightXDeadband:
       GetRightY:
+      SetRightYDeadband:
       GetLeftTriggerAxis:
+      SetLeftTriggerDeadband:
       LeftTrigger:
         overloads:
           double, EventLoop* [const]:
           EventLoop* [const]:
       GetRightTriggerAxis:
+      SetRightTriggerDeadband:
       RightTrigger:
         overloads:
           double, EventLoop* [const]: