Add block between two points. SpriteKit

Question

I am trying to add a SKNode between two points like picture below.

What I have:

I count the distance between those two points with this code (works fine):

 func distanceCount(_ point: CGPoint) -> CGFloat {
 return abs(CGFloat(hypotf(Float(point.x - x), Float(point.y - y))))  }

Then I count the middle point(also works fine)

  func middlePointCount(_ point: CGPoint) -> CGPoint {
  return CGPoint(x: CGFloat((point.x + x) / 2), y: CGFloat((point.y + y) / 2))
   }

Finally this function adds my object (SKNode) :

func addBlock(_ size:CGSize, rotation:CGFloat, point: CGPoint) -> SKNode{

        let block = SKSpriteNode(color: UIColor.lightGray , size: size)
        block.physicsBody = SKPhysicsBody(rectangleOf: block.frame.size)
        block.position = point //This is my middle point
        block.physicsBody!.affectedByGravity = false
        block.physicsBody!.isDynamic = false
        block.zRotation = rotation 

        return block

    }

Summary: My addBlock function adds object with right width and centred on the right place , but angle is wrong.

Note: I have tried to create functions which should count the angle but they were all wrong :/ .

My question: How can I get the right angle , or is there some other how can I reach my goal?

If you need more details just let me know.

Thank you :)

score 3 · Answer 1 · answered Nov 18 '16 at 17:31

Midpoint

The midpoint between 2 points A and B is defined as

midpoint = {(A.x + B.x) / 2, (A.y + B.y) / 2}

CGPoint Extension

So let's create and extension of CGPoint to easily build a Midpoint starting from 2 points

extension CGPoint {
    init(midPointBetweenA a: CGPoint, andB b: CGPoint) {
        self.x = (a.x + b.x) / 2
        self.y = (a.y + b.y) / 2
    }
}

Test

Now let's test it

let a = CGPoint(x: 1, y: 4)
let b = CGPoint(x: 2, y: 3)

let c = CGPoint(midPointBetweenA: a, andB: b) // {x 1,5 y 3,5}

Looks good right?

Wrap up

Now given your 2 points you just need to calculate the midpoint and assign it to the position of your SKNode.

let nodeA: SKNode = ...
let nodeB: SKNode = ...
let nodeC: SKNode = ...

nodeC.position = CGPoint(midPointBetweenA: nodeA.position, andB: nodeB.position)

When you begin writing an iBook on Swift Extensions, lemme do the editing, design, illustrations and layout for you! Legend! — Confused, Nov 18 '16 at 18:48
Some say Swift is POP, others say it's Functional, the creators say it's a blend of about a dozen language ideas and the desire to make an all purpose systems language... I suspect the ability to write extensions with incredible performance, and aliases makes it like Logo on steroids. Granted, a big dose of steroids, over a long period of time. Kind of like Arnold is to Trump. — Confused, Nov 18 '16 at 18:55

score 3 · Accepted Answer · answered Nov 18 '16 at 17:48

3

To get the angle between two points you'll need to use the following

atan2(p2.y-p1.y, p2.x-p1.x)

answered Nov 18 '16 at 17:48

Craig Siemens

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