feat(Locomotion): add option to only touchpad walk on button press

A new option has been added to the Touchpad Walking script that
allows a button to be specified for enabling movement. Only when
that button is being pressed will the touchpad walking actually
move the user.

The Controller Events script has also been updated to allow for this
with a new public method that checks to see if a given button alias
is being pressed.

Author: thestonefox

Assets/VRTK/Scripts/VRTK_ControllerEvents.cs

@@ -619,6 +619,35 @@ public bool AnyButtonPressed()
             return (triggerPressed || gripPressed || touchpadPressed || applicationMenuPressed);
         }
 
+        /// <summary>
+        /// The IsButtonPressed method takes a given button alias and returns a boolean whether that given button is currently being pressed or not.
+        /// </summary>
+        /// <param name="button">The button to check if it's being pressed.</param>
+        /// <returns>Is true if the button is being pressed.</returns>
+        public bool IsButtonPressed(ButtonAlias button)
+        {
+            switch (button)
+            {
+                case ButtonAlias.Trigger_Hairline:
+                    return triggerHairlinePressed;
+                case ButtonAlias.Trigger_Touch:
+                    return triggerTouched;
+                case ButtonAlias.Trigger_Press:
+                    return triggerPressed;
+                case ButtonAlias.Trigger_Click:
+                    return triggerClicked;
+                case ButtonAlias.Grip:
+                    return grabPressed;
+                case ButtonAlias.Touchpad_Touch:
+                    return touchpadTouched;
+                case ButtonAlias.Touchpad_Press:
+                    return touchpadPressed;
+                case ButtonAlias.Application_Menu:
+                    return applicationMenuPressed;
+            }
+            return false;
+        }
+
         private ControllerInteractionEventArgs SetButtonEvent(ref bool buttonBool, bool value, float buttonPressure)
         {
             buttonBool = value;

Assets/VRTK/Scripts/VRTK_TouchpadWalking.cs

@@ -45,6 +45,8 @@ public bool RightController
         public float maxWalkSpeed = 3f;
         [Tooltip("The speed in which the play area slows down to a complete stop when the user is no longer touching the touchpad. This deceleration effect can ease any motion sickness that may be suffered.")]
         public float deceleration = 0.1f;
+        [Tooltip("If a button is defined then movement will only occur when the specified button is being held down and the touchpad axis changes.")]
+        public VRTK_ControllerEvents.ButtonAlias moveOnButtonPress = VRTK_ControllerEvents.ButtonAlias.Undefined;
 
         private GameObject controllerLeftHand;
         private GameObject controllerRightHand;
@@ -76,6 +78,12 @@ private void Start()
 
         private void DoTouchpadAxisChanged(object sender, ControllerInteractionEventArgs e)
         {
+            var controllerEvents = (VRTK_ControllerEvents)sender;
+            if (moveOnButtonPress != VRTK_ControllerEvents.ButtonAlias.Undefined && !controllerEvents.IsButtonPressed(moveOnButtonPress))
+            {
+                touchAxis = Vector2.zero;
+                return;
+            }
             touchAxis = e.touchpadAxis;
         }
 

DOCUMENTATION.md

@@ -629,6 +629,17 @@ The GetHairTriggerDelta method returns a float representing the difference in ho
 
 The AnyButtonPressed method returns true if any of the controller buttons are being pressed and this can be useful to determine if an action can be taken whilst the user is using the controller.
 
+#### IsButtonPressed/1
+
+  > `public bool IsButtonPressed(ButtonAlias button)`
+
+  * Parameters
+   * `ButtonAlias button` - The button to check if it's being pressed.
+  * Returns
+   * `bool` - Is true if the button is being pressed.
+
+The IsButtonPressed method takes a given button alias and returns a boolean whether that given button is currently being pressed or not.
+
 ### Example
 
 `VRTK/Examples/002_Controller_Events` shows how the events are utilised and listened to. The accompanying example script can be viewed in `VRTK/Examples/Resources/Scripts/VRTK_ControllerEvents_ListenerExample.cs`.
@@ -1431,6 +1442,7 @@ If the Headset Collision Fade script has been applied to the Camera prefab, then
 
  * **Max Walk Speed:** The maximum speed the play area will be moved when the touchpad is being touched at the extremes of the axis. If a lower part of the touchpad axis is touched (nearer the centre) then the walk speed is slower.
  * **Deceleration:** The speed in which the play area slows down to a complete stop when the user is no longer touching the touchpad. This deceleration effect can ease any motion sickness that may be suffered.
+ * **Move On Button Press:** If a button is defined then movement will only occur when the specified button is being held down and the touchpad axis changes.
 
 ### Example