Change logic to be based on state events

The previous logic was based on changing state and didn't apply if we queued events.

Also, this commit avoids processing the queued events for the simulated Touchscreen.

Author: jfreire-unity

Packages/com.unity.inputsystem/InputSystem/Plugins/EnhancedTouch/TouchSimulation.cs

@@ -122,6 +122,12 @@ protected void RemovePointer(Pointer pointer)
 
         private unsafe void OnEvent(InputEventPtr eventPtr, InputDevice device)
         {
+            if (device == simulatedTouchscreen)
+            {
+                // Avoid processing events queued by this simulation device
+                return;
+            }
+
             var pointerIndex = m_Pointers.IndexOfReference(device, m_NumPointers);
             if (pointerIndex < 0)
                 return;
@@ -290,63 +296,33 @@ private unsafe void UpdateTouch(int touchIndex, int pointerIndex, TouchPhase pha
             Debug.Assert(m_CurrentDisplayIndices[pointerIndex] <= byte.MaxValue, "Display index was larger than expected");
             byte displayIndex = (byte)m_CurrentDisplayIndices[pointerIndex];
 
+            // We need to partially set TouchState in a similar way that the Native side would do, but deriving that
+            // data from the Pointer events.
+            // The handling of the remaining fields is done by the Touchscreen.OnStateEvent() callback.
             var touch = new TouchState
             {
                 phase = phase,
                 position = position,
-                displayIndex = displayIndex
+                displayIndex = displayIndex,
             };
-            var time = eventPtr.valid ? eventPtr.time : InputState.currentTime;
-
-            var oldTouchState = (TouchState*)((byte*)simulatedTouchscreen.currentStatePtr +
-                simulatedTouchscreen.touches[touchIndex].stateBlock.byteOffset);
 
             if (phase == TouchPhase.Began)
             {
-                touch.isPrimaryTouch = m_PrimaryTouchIndex < 0;
-                touch.startTime = time;
+                touch.startTime = eventPtr.valid ? eventPtr.time : InputState.currentTime;
                 touch.startPosition = position;
                 touch.touchId = ++m_LastTouchId;
-                touch.tapCount = oldTouchState->tapCount; // Get reset automatically by Touchscreen.
-
-                if (touch.isPrimaryTouch)
-                    m_PrimaryTouchIndex = touchIndex;
             }
             else
             {
-                touch.touchId = oldTouchState->touchId;
-                touch.isPrimaryTouch = m_PrimaryTouchIndex == touchIndex;
-                touch.delta = position - oldTouchState->position;
-                touch.startPosition = oldTouchState->startPosition;
-                touch.startTime = oldTouchState->startTime;
-                touch.tapCount = oldTouchState->tapCount;
-
-                if (phase == TouchPhase.Ended)
-                {
-                    touch.isTap = time - oldTouchState->startTime <= Touchscreen.s_TapTime &&
-                        (position - oldTouchState->startPosition).sqrMagnitude <= Touchscreen.s_TapRadiusSquared;
-                    if (touch.isTap)
-                        ++touch.tapCount;
-                }
+                touch.touchId = m_LastTouchId;
             }
 
             //NOTE: Processing these events still happen in the current frame.
-            using (StateEvent.From(simulatedTouchscreen, out var touchscreenEventPtr))
-            {
-                if (touch.isPrimaryTouch)
-                {
-                    simulatedTouchscreen.primaryTouch.WriteValueIntoEvent(touch, touchscreenEventPtr);
-                    InputSystem.QueueEvent(touchscreenEventPtr);
-                }
-                simulatedTouchscreen.touches[touchIndex].WriteValueIntoEvent(touch, touchscreenEventPtr);
-                InputSystem.QueueEvent(touchscreenEventPtr);
-            }
+            InputSystem.QueueStateEvent(simulatedTouchscreen, touch);
 
             if (phase.IsEndedOrCanceled())
             {
                 m_Touches[touchIndex] = null;
-                if (m_PrimaryTouchIndex == touchIndex)
-                    m_PrimaryTouchIndex = -1;
             }
         }