public void UpdateTranslation(VirtualObject virtualObject, CGPoint midpoint)
{
if (!TranslationThresholdPassed)
{
var initialLocationToCurrentLocation = midpoint.Subtract(InitialMidpoint);
var distanceFromStartLocation = initialLocationToCurrentLocation.Length();
// Check if the translate gesture has crossed the threshold.
// If the user is already rotating and or scaling we use a bigger threshold.
var threshold = TranslationThreshold;
if (RotationThresholdPassed || TranslationThresholdPassed)
{
threshold = TranslationThresholdHarder;
}
if (distanceFromStartLocation >= threshold)
{
TranslationThresholdPassed = true;
var currentObjectLocation = CGPointExtensions.FromVector(SceneView.ProjectPoint(virtualObject.Position));
DragOffset = midpoint.Subtract(currentObjectLocation);
}
}
if (TranslationThresholdPassed)
{
var offsetPos = midpoint.Subtract(DragOffset);
manager.Translate(virtualObject, SceneView, offsetPos, false, true);
LastUsedObject = virtualObject;
}
}
public void PanBy(CGPoint translation)
{
drawAnchor = baseAnchor.Subtract(translation);
ConstrainDrawAnchor();
UpdateGrid();
}
override protected void UpdateGesture(object state)
{
var virtualObject = firstTouchedObject;
if (virtualObject == null)
{
return;
}
// We know there's a first since the gesture begins with at least one
InvokeOnMainThread(() =>
{
if (this.currentTouches.Count() == 0)
{
return;
}
latestTouchPosition = ((UITouch)this.currentTouches.First()).LocationInView(this.SceneView);
if (!translationThresholdPassed)
{
var initialLocationToCurrentPosition = latestTouchPosition.Subtract(initialTouchPosition);
var distanceFromStartLocation = initialLocationToCurrentPosition.Length();
if (distanceFromStartLocation >= translationThreshold)
{
translationThresholdPassed = true;
var currentObjectLocation = SceneView.ProjectPoint(virtualObject.Position).ToCGPoint();
dragOffset = latestTouchPosition.Subtract(currentObjectLocation);
}
}
// A single finger drag will occur if the drag started on the object and the threshold has been passed.
if (translationThresholdPassed)
{
var offsetPos = latestTouchPosition.Subtract(dragOffset);
this.manager.Translate(virtualObject, SceneView, offsetPos, false, true);
hasMovedObject = true;
LastUsedObject = virtualObject;
}
});
}
protected virtual void InitMovement(IViewPort viewPort, CGPoint positionToMove)
{
link = CADisplayLink.Create(OnDisplayLinkLoop);
var positionToMoveOffset = positionToMove.Subtract(new CGPoint(viewPort.ViewPortSize.Width / 2, viewPort.ViewSize.Height / 2));
var moveDelta = positionToMoveOffset.Subtract(viewPort.ViewPortContentOffset);
decelerationVelocityX = 2D * moveDelta.X / MovementTime;
decelerationVelocityY = 2D * moveDelta.Y / MovementTime;
decelerationX = 2D * moveDelta.X / Math.Pow(MovementTime, 2);
decelerationY = 2D * moveDelta.Y / Math.Pow(MovementTime, 2);
lastDecelerationFramePositionX = 0;
lastDecelerationFramePositionY = 0;
decelerationStartTime = CAAnimation.CurrentMediaTime();
link.AddToRunLoop(NSRunLoop.Current, NSRunLoop.NSDefaultRunLoopMode);
}
public static float DistanceTo(this CGPoint self, CGPoint point)
{
return(self.Subtract(point).Length());
}