Touch: Added a firstInput so that if we ever get more than

max amount of inputs in our Deque, we will still have our
first point stored (for pinching around a start-centroid mainly)

include/openspace/util/touch.h

@@ -80,6 +80,7 @@ public:
 private:
     //A deque of recorded inputs. Adding newer points to the front of the queue
     std::deque<TouchInput> _inputs;
+    TouchInput _firstInput;
 
     size_t _touchDeviceId;
     size_t _fingerId;

src/util/touch.cpp

@@ -73,6 +73,7 @@ float TouchInput::angleToPos(float otherX, float otherY) const {
 
 TouchInputHolder::TouchInputHolder(TouchInput input)
     : _inputs{ input }
+    , _firstInput(input)
     , _touchDeviceId(input.touchDeviceId)
     , _fingerId(input.fingerId)
 {}
@@ -182,7 +183,7 @@ size_t TouchInputHolder::numInputs() const {
 }
 
 const TouchInput& TouchInputHolder::firstInput() const {
-    return _inputs.back();
+    return _firstInput;
 }
 
 const TouchInput& TouchInputHolder::latestInput() const {