Fixed an issue where drag gesture wouldn't trigger directly when threshold is zero

Author: ekcoh

Assets/Samples/RebindingUI/OnScreen/CustomOnScreenControl.cs

@@ -168,7 +168,7 @@ protected override void OnEnable()
             if (control is ButtonControl)
                 m_Detector = new Detector<ActiveDetector>(1, new ActiveDetector());
             else if (control is StickControl)
-                m_Detector = new Detector<DragDetector>(1, new DragDetector(threshold));
+                m_Detector = new Detector<DragDetector>(1, new DragDetector(0.0f));
             else
                 throw new Exception($"Unsupported control type: {control.GetType()}");
 

Assets/Samples/RebindingUI/OnScreen/DragDetector.cs

@@ -23,6 +23,13 @@ public void OnTouchBegin(Detector context, in TouchState[] touches, int count, i
             {
                 m_InitialPosition = touches[index].position;
                 m_InitialTime = Time.realtimeSinceStartupAsDouble;
+
+                // Require that we move outside "dead zone" before we consider the drag to start.
+                if (IsWithinMargin(touches[index].position))
+                    return;
+
+                m_Valid = true;
+                Fire(context, touches, count, index, GestureEvent.Flags.PhaseStart);
             }
             else if (m_Valid)
             {
@@ -78,7 +85,7 @@ private void Fire(Detector context, in TouchState[] touches, int count, int inde
         private bool IsWithinMargin(Vector2 point)
         {
             var sqrMagnitude = (point - m_InitialPosition).sqrMagnitude;
-            return sqrMagnitude <= m_ThresholdSqr;
+            return sqrMagnitude < m_ThresholdSqr;
         }
     }
 }

Assets/Samples/RebindingUI/OnScreen/GestureEvent.cs

@@ -39,9 +39,24 @@ public enum Flags
             /// </summary>
             Active = 1 << 3,
 
+            /// <summary>
+            /// Indicates that the interaction of the associated continuous gesture started.
+            /// </summary>
             PhaseStart = 1 << 28,
+
+            /// <summary>
+            /// Indicates that the interaction of the associated continuous gesture was updated and changed.
+            /// </summary>
             PhaseChange = 1 << 29,
+
+            /// <summary>
+            /// Indicates that the interaction of the associated continuous gesture ended.
+            /// </summary>
             PhaseEnd = 1 << 30,
+
+            /// <summary>
+            /// Indicates that the interaction of the associated continuous gesture was cancelled.
+            /// </summary>
             PhaseCancel = 1 << 31,
         }
 
@@ -50,6 +65,13 @@ public enum Flags
         public readonly Vector2 delta;
         public readonly double duration;
 
+        /// <summary>
+        /// Constructs a new gesture event.
+        /// </summary>
+        /// <param name="delta">The delta of the gesture event.</param>
+        /// <param name="duration">The duration of the gesture event.</param>
+        /// <param name="flags">Flags indicating what type of event it is.</param>
+        /// <param name="start">The initial absolute position of the gesture event.</param>
         public GestureEvent(Vector2 delta, double duration, Flags flags, Vector2 start)
         {
             this.delta = delta;
@@ -58,6 +80,9 @@ public GestureEvent(Vector2 delta, double duration, Flags flags, Vector2 start)
             this.start = start;
         }
 
+        /// <summary>
+        /// Converts the event to string representation.
+        /// </summary>
         public override string ToString()
         {
             var sb = new StringBuilder();

Assets/Samples/RebindingUI/OnScreen/OnScreenControlUI.cs

@@ -6,7 +6,9 @@
 // Should warn about not having a canvas or parent canvas assigned.
 // Should warn about ray-casted UI consuming events.
 
-
+/// <summary>
+/// A passive UI visualization of an on-screen control in Unity UI (UGUI).
+/// </summary>
 [ExecuteInEditMode]
 public class OnScreenControlUI : MonoBehaviour
 {
@@ -17,41 +19,6 @@ public class OnScreenControlUI : MonoBehaviour
     public RectTransform bounds;
     public RectTransform knob;
 
-    private void OnDrawGizmosSelected()
-    {
-        // This will not produce meaningful results unless we have a rect transform (ISXB-915, ISXB-916).
-        var parentRectTransform = transform.parent as RectTransform;
-        if (parentRectTransform == null)
-            return;
-
-        Gizmos.matrix = parentRectTransform.localToWorldMatrix;
-
-        var startPos = parentRectTransform.anchoredPosition;
-
-        /*var startPos = parentRectTransform.anchoredPosition;
-        if (Application.isPlaying)
-            startPos = m_StartPos;
-*/
-        Gizmos.color = new Color32(84, 173, 219, 255);
-
-        var center = startPos;
-        /*if (Application.isPlaying && m_Behaviour == Behaviour.ExactPositionWithDynamicOrigin)
-            center = m_PointerDownPos;*/
-
-        var radius = UnitConverter.MillimetersToPixels(control.stickRadiusMillimeters);
-        ScreenGizmos.DrawGizmoCircle(center, radius);
-
-        //if (m_Behaviour != Behaviour.ExactPositionWithDynamicOrigin) return;
-
-        //Gizmos.color = new Color32(158, 84, 219, 255);
-        //DrawGizmoCircle(startPos, m_DynamicOriginRange);
-    }
-
-    // Start is called once before the first execution of Update after the MonoBehaviour is created
-    void Start()
-    {
-    }
-
     void OnEnable()
     {
         if (canvas == null)
@@ -118,8 +85,11 @@ void Update()
         var stickRadiusPixels = UnitConverter.MillimetersToPixels(control.stickRadiusMillimeters);
         var stickCenter = control.stickCenter;
         var stickViewport = camera.ScreenToViewportPoint(new Vector2(stickRadiusPixels, stickRadiusPixels));
-        var stickRect = new Rect(stickCenter.x - stickViewport.x,
-            stickCenter.y - stickViewport.y, stickViewport.x * 2, stickViewport.y * 2);
+        var stickRect = new Rect(
+            x: stickCenter.x - stickViewport.x,
+            y: stickCenter.y - stickViewport.y,
+            width: stickViewport.x * 2,
+            height: stickViewport.y * 2);
 
         // Optionally transform a UI object to represent the interactable area in viewport space.
         if (area != null)