andy - 2 months ago 8
Swift Question

# Swift: How to calculate the distance CGPoint travelled from one place to another?

What the method do I have to use for calculating the distance that CGPoint travelled from its old position to its new position?

``````  var point: CGPoint = CGPointMake(x:50.0, y:50.0)
``````

and there is a method for dragging a point with LMB:

``````  func mouseDragged(event: NSEvent) {

var pointDragged = self.convertPoint(event.locationInWindow, fromView: nil)
}
``````

Use Pythagorean theorem and `mouseLocation = event.mouseLocation()` where `event` in your case is of type `NSEvent`.

``````let point1: CGPoint = CGPointMake(30.0, 20.0)
let point2: CGPoint = CGPointMake(50.0, 50.0)

let xDist = (point1.x - point2.x)
let yDist = (point1.y - point2.y)
let distance = sqrt((xDist * xDist) + (yDist * yDist))

print(distance)
``````

`point1` would be your starting position and you can obtain the position where the user clicked - `point2`, from the `NSEvent` in your `mouseDragged` function:

``````mouseLocation = event.mouseLocation()
point2 = CGPointMake(mouseLocation.x, mouseLocation.y)
``````