Detect overlaping if enumerating nodes - swift

Question

I would like to know how should I detect overlapping nodes while enumerating them? Or how should I make that every random generated position in Y axis is at least some points higher or lower.
This is what I do:
1 - Generate random number between -400 and 400
2 - Add those into array
3 - Enumerate and add nodes to scene with generated positions like this:
var leftPositions = [CGPoint]()
for _ in 0..<randRange(lower: 1, upper: 5){
leftPositions.append(CGPoint(x: -295, y: Helper().randomBetweenTwoNumbers(firstNumber: leftSparkMinimumY, secondNumber: leftSparkMaximumY)))
}
leftPositions.enumerated().forEach { (index, point) in
let leftSparkNode = SKNode()
leftSparkNode.position = point
leftSparkNode.name = "LeftSparks"
let leftSparkTexture = SKTexture(imageNamed: "LeftSpark")
LeftSpark = SKSpriteNode(texture: leftSparkTexture)
LeftSpark.name = "LeftSparks"
LeftSpark.physicsBody = SKPhysicsBody(texture: leftSparkTexture, size: LeftSpark.size)
LeftSpark.physicsBody?.categoryBitMask = PhysicsCatagory.LeftSpark
LeftSpark.physicsBody?.collisionBitMask = PhysicsCatagory.Bird
LeftSpark.physicsBody?.contactTestBitMask = PhysicsCatagory.Bird
LeftSpark.physicsBody?.isDynamic = false
LeftSpark.physicsBody?.affectedByGravity = false
leftSparkNode.addChild(LeftSpark)
addChild(leftSparkNode)
}
But like this sometimes they overlap each other because the generated CGPoint is too close to the previous one.
I am trying to add some amount of triangles to the wall and those triangles are rotated by 90°
To describe in image what I want to achieve:
And I want to avoid thing like this:

Answer 1

Your approach to this is not the best, i would suggest only storing the Y values in your position array and check against those values to make sure your nodes will not overlap. The following will insure no two sparks are within 100 points of each other. You may want to change that value depending on your node's actual height or use case.
Now, obviously if you end up adding too many sparks within an 800 point range, this just will not work and cause an endless loop.
var leftPositions = [Int]()
var yWouldOverlap = false
for _ in 0..<randRange(lower: 1, upper: 5){
//Moved the random number generator to a function
var newY = Int(randY())
//Start a loop based on the yWouldOverlap Bool
repeat{
yWouldOverlap = false
//Nested loop to range from +- 100 from the randomly generated Y
for p in newY - 100...newY + 100{
//If array already contains one of those values
if leftPosition.contains(p){
//Set the loop Bool to true, get a new random value, and break the nested for.
yWouldOverlap = true
newY = Int(randY())
break
}
}
}while(yWouldOverlap)
//If we're here, the array does not contain the new value +- 100, so add it and move on.
leftPositions.append(newY)
}
func randY() -> CGFloat{
return Helper().randomBetweenTwoNumbers(firstNumber: leftSparkMinimumY, secondNumber: leftSparkMaximumY)
}
And here is a different version of your following code.
for (index,y) in leftPositions.enumerated() {
let leftSparkNode = SKNode()
leftSparkNode.position = CGPoint(x:-295,y:CGFloat(y))
leftSparkNode.name = "LeftSparks\(index)" //All node names should be unique
let leftSparkTexture = SKTexture(imageNamed: "LeftSpark")
LeftSpark = SKSpriteNode(texture: leftSparkTexture)
LeftSpark.name = "LeftSparks"
LeftSpark.physicsBody = SKPhysicsBody(texture: leftSparkTexture, size: LeftSpark.size)
LeftSpark.physicsBody?.categoryBitMask = PhysicsCatagory.LeftSpark
LeftSpark.physicsBody?.collisionBitMask = PhysicsCatagory.Bird
LeftSpark.physicsBody?.contactTestBitMask = PhysicsCatagory.Bird
LeftSpark.physicsBody?.isDynamic = false
LeftSpark.physicsBody?.affectedByGravity = false
leftSparkNode.addChild(LeftSpark)
addChild(leftSparkNode)
}