SKAction problems when reloading the game - swift

I'm having some problems with a SKAction when clicking retry after the player dies. It's the shooting SKAction that I'm having difficulty with. It's shooting well when I run the game but when I click "Retry" to play again only one bullet fires. After that, the SKAction stops. All the other SKActions work when i play again, but not that one.
I know what the problem is. I have all the relevant functions in a func called initialize() that I add in the didMove. But I'm having difficulty calling some of the functions there since the functions have a parameter.
These are the shooting functions I have:
func fireMissile() {
let missile = SKSpriteNode(color: .yellow, size: CGSize(width: 20,
height: 5))
missile.name = "Missile"
missile.position = CGPoint(x: player.position.x + 28, y:
player.position.y + 10)
missile.zPosition = 2
missile.physicsBody = SKPhysicsBody(rectangleOf: missile.size)
missile.physicsBody?.isDynamic = false
missile.physicsBody?.categoryBitMask = ColliderType.Bullet
missile.physicsBody?.collisionBitMask = ColliderType.Enemy |
ColliderType.Boat
missile.physicsBody?.contactTestBitMask = ColliderType.Enemy |
ColliderType.Boat
let missileFlightTime = travelTime(to: missileDestination, from:
player.position, atSpeed: missileSpeed)
missile.zRotation = direction(to: missileDestination, from:
missile.position)
self.addChild(missile)
let missileMove = SKAction.move(to: missileDestination,
duration:
TimeInterval(missileFlightTime))
let missileRemove = SKAction.removeFromParent()
missile.run(SKAction.sequence([missileMove, missileRemove]))
}
func travelTime(to target : CGPoint, from : CGPoint, atSpeed speed :
CGFloat) -> TimeInterval {
let distance = sqrt(pow(abs(target.x - from.x),2) +
pow(abs(target.y - from.y),2))
return TimeInterval(distance/speed)
}
func direction(to target : CGPoint, from: CGPoint) -> CGFloat {
let x = target.x - from.x
let y = target.y - from.y
var angle = atan(y / x)
if x < 0 {
angle = angle + CGFloat.pi
}
return angle
}
And then we have the didMove function:
func initialize() {
score = 0
physicsWorld.contactDelegate = self
createPlayer()
createBG()
createWall()
spawnEnemiesLeft()
spawnEnemiesRight()
spawnBoat()
fireMissile()
createlabel()
}
When i try adding the "func travelTime()" and func "direction()", it requires for me to also add the CGPoint for the "to target" and "from", and I don't know what to type in there, I don't know if thats even the way to go, but it should be.

Related

SpriteKit constant speed from left to right and left to right

i have a SKSpriteNode, that will move from left to right and right to left.
This is Speed
var currentPosition: CGFloat = 20
var rightSpeed = TimeInterval()
var leftSpeed = TimeInterval()
DidMove when SKNode start moving
override func didMove(to view: SKView) {
rightSpeed = moveToRightSpeed()
leftSpeed = moveToLeftSpeed()
personageMoving(position: currentPosition)
}
Method to start sequence of moving
func personageMoving(position: CGFloat) {
rightSpeed = moveToRightSpeed()
leftSpeed = moveToLeftSpeed()
let moveToRight = SKAction.move(to: CGPoint(x: UIScreen.main.bounds.maxX - 20,
y: -UIScreen.main.bounds.maxY + currentPosition),duration: rightSpeed)
let moveToLeft = SKAction.move(to: CGPoint(x: -UIScreen.main.bounds.maxX + 20,
y: -UIScreen.main.bounds.maxY + currentPosition), duration: leftSpeed)
let sequence = SKAction.sequence([moveToRight, moveToLeft])
let forever = SKAction.repeatForever(sequence)
personage.run(forever, withKey: "move")
}
This functions helps me to check speed
func moveToRightSpeed() -> TimeInterval {
let deltaX = UIScreen.main.bounds.maxX - personage.position.x
let deltaY = CGFloat(1)
let distance = (deltaX * deltaX + deltaY * deltaY).squareRoot()
let pixelsPerSecond = CGFloat(400)
let timeToTravel = distance/pixelsPerSecond
return TimeInterval(timeToTravel)
}
func moveToLeftSpeed() -> TimeInterval {
let deltaX = -UIScreen.main.bounds.maxX - personage.position.x
let deltaY = CGFloat(1)
let distance = (deltaX * deltaX + deltaY * deltaY).squareRoot()
let pixelsPerSecond = CGFloat(400)
let timeToTravel = distance/pixelsPerSecond
return TimeInterval(timeToTravel)
}
And in this method i ask person to go up, after it starts left to right and right to left again.
func personageGoUp() {
personage.removeAction(forKey: "move")
let moveLocation = SKAction.move(to: CGPoint(x: personage.position.x, y: personage.position.y + 100), duration: 0.2)
personage.run(moveLocation) { [weak self] in
guard let self = self else { return }
self.currentPosition += 100
self.personageMoving(position: self.currentPosition)
}
}
Problem is speed that is always changing, i can not understand how can i fix it

SKAction & SKSpriteNode trouble

I'm in the process of creating a card game in Swift using SKSprite Nodes to show the card faces.
In my 'deal' function, it deals 3 cards to each player, one at a time in a 'round-robin' fashion. This is working fine but I'm trying to add a bit of animation - I'm trying to make it show each card being dealt to the local player by animating it moving from the deck to the players hand position.
I can get the Sprite Nodes to show without the animation but when I try with SKAction, it gives me the following error after the action is completed:
reason: 'Attemped to add a SKNode which already has a parent: name:'local player node' texture:[ 'CARD39' (203 x 350)] position:{281.25, 100.05000305175781}
class GameScene: SKScene {
let tempCard = SKSpriteNode(texture: SKTexture(imageNamed: "back"))
func deal() {
players = createPlayers(with: numberOfPlayers)
tempCard.setScale((screenSize.width/100) * 0.2)
tempCard.zPosition = 10
tempCard.name = "tempcard"
addChild(tempCard)
let localPlayer = 0
var i = 0
repeat {
print("Card number: \(i)")
var x = 0
let xPos = screenSize.width * (0.25 * CGFloat(i+1))
players.forEach { player in
let newCard = self.deck.dealOneCard()
player.hand.addCard(card: newCard)
localPlayerNode = players[localPlayer].hand[i].cardImage()
localPlayerNode.position = CGPoint(x: xPos, y: screenSize.height * 0.15)
localPlayerNode.setScale((screenSize.width/100) * 0.2)
localPlayerNode.name = "local player node"
if player.id == localPlayer {
let moveCard = SKAction.move(to: CGPoint(x: xPos, y: screenSize.height * 0.15),duration: 1.5)
//addChild(localPlayerNode) --using this instead of SKAction works
tempCard.run(moveCard, completion: {() -> Void in
self.tempCard.removeFromParent()
self.addChild(self.localPlayerNode)
})
}
x+=1
}
i+=1
} while i<3
I believe the problem is with adding the player nodes within your loop, and then not removing them afterwards. I'm sure you don't want to remove the players every time you call the " deal() " function so you should add the player nodes in the didMove() method.
I've put together a playground that demonstrates this (github Link).
I've tried to use a delay to make the cards deal 1 by one, but this is a different problem you will need to look elsewhere to solve. (Something with the .run( action) makes it so that it doesn't actually animate until the loop is complete.
example gif with bad pixel art
class GameScene: SKScene {
let scale : CGFloat = 50
var deck : [String] = []
let composition = deckComp()
let numberOfPlayers = 3
var players : [Player] = []
override func didMove(to view: SKView) {
// creates deck
for c in deckComp().colors {
for s in deckComp().suits {
deck.append( s + " of " + c )
}
}
players = createPlayers(numberOfPlayers: numberOfPlayers, center : CGPoint(x : 25, y : 25))
// setup the scales, and players
for plyr in players {
plyr.setScale(scale: (frame.width/10000) * scale)
addChild( plyr.node)
}
}
func createPlayers(numberOfPlayers : Int, center : CGPoint) -> [Player] {
let radius = Float(5*scale)
let two_pi = 2 * 3.14159
let angular_positions = two_pi / Double(numberOfPlayers)
var players_out : [Player] = []
for i in 0...numberOfPlayers - 1 {
let sprite = SKSpriteNode(texture: SKTexture(imageNamed: "card_player.png"))
sprite.zPosition = 1
sprite.position = CGPoint( x : center.x + CGFloat(radius * sin( Float(angular_positions) * Float(i) )), y : center.y + CGFloat(radius * cos( Float(angular_positions) * Float(i) )) )
sprite.texture?.filteringMode = .nearest // .linear for blurry, .nearest for pixely
let player_instance = Player(node : sprite, name : "Player " + String(i + 1), id : Int8(i + 1) )
players_out.append(player_instance)
}
return players_out
}
func deal() {
// I moved the setscale stuff for player sprites to didMove()
// first check if there is enough in deck
if deck.count > players.count {
var i = 0
repeat {
// add the temp card
let tempCard = SKSpriteNode(texture: SKTexture(imageNamed: "back"))
tempCard.size = CGSize( width: tempCard.size.width * (frame.width/10000) * scale, height : tempCard.size.height * (frame.width/10000) * scale )
tempCard.zPosition = 10
tempCard.texture?.filteringMode = .nearest
self.addChild(tempCard)
// done adding temporary card
let xPos = frame.width * (0.25 * CGFloat(i+1))
tempCard.position = CGPoint(x : xPos, y : 0.75 * frame.height)
let newCard = self.deck.popLast() // replaced dealOneCard() since I haven't defined it
players[i].addCard(card: newCard!) // removed hand.addCard(), since I don't have the array extensions
// player.name = "local player node"
let moveCard = SKAction.move(to: players[i].node.position ,duration: 1.5)
//addChild(localPlayerNode) --using this instead of SKAction works
tempCard.run(moveCard, completion: { () -> Void in tempCard.removeFromParent(); })
i += 1
} while i < players.count
} else { print("not enough cards to deal to everyone")} // when deck is empty
}
override func mouseUp(with event: NSEvent) {
deal()
}

collision not detected between SKSpitekit nodes

I am building a maze and I have added some SKSpritekit nodes for the walls and a dot for the player. however when the dot and the walls collide, there is no detection of collision. my code is as follows:
import UIKit
import SpriteKit
import GameplayKit
import Foundation
import GameplayKit
class level1: SKScene, SKPhysicsContactDelegate {
var entities = [GKEntity]()
var graphs = [String : GKGraph]()
var dot = SKSpriteNode()
override func sceneDidLoad () {
buildMaze()
addDot()
func addDot() {
let startNum = x * (y - 1)
startCoord = coordArray[startNum]
dot = SKSpriteNode(imageNamed: "redDot")
dot.physicsBody?.isDynamic = true
dot.size = CGSize(width: 20, height: 20)
dot.position = startCoord
dot.physicsBody = SKPhysicsBody(circleOfRadius: 10)
dot.physicsBody?.mass = 0
dot.physicsBody?.usesPreciseCollisionDetection = true
self.addChild(dot)
}
func buildMaze() {
let difference = coordArray[1].x - coordArray[0].x
let wallDistance = difference/2
let thickness = CGFloat(3)
let length = difference - CGFloat(thickness)/2
var count = 0
for point in coordArray {
let northWall = SKSpriteNode(color: SKColor.black, size : CGSize (width: length, height: thickness))
northWall.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: length, height: thickness))
northWall.physicsBody?.mass = 200000
let southWall = SKSpriteNode(color: SKColor.black, size : CGSize (width: length, height: thickness))
southWall.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: length, height: thickness))
southWall.physicsBody?.mass = 200000
let eastWall = SKSpriteNode(color: SKColor.black, size : CGSize (width: thickness, height: length ))
eastWall.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: thickness, height: length))
eastWall.physicsBody?.mass = 200000
let westWall = SKSpriteNode(color: SKColor.black, size : CGSize (width: thickness, height: length ))
westWall.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: thickness, height: length))
westWall.physicsBody?.mass = 200000
if !instructions[count].contains("N") {
//print("added north wall")
northWall.position = CGPoint (x: point.x , y: point.y + wallDistance)
if nodes(at: northWall.position) == [] {
addChild(northWall)}
else {print("north wall already there")}
}
if !instructions[count].contains("S") {
//print("added south wall")
southWall.position = CGPoint (x: point.x , y: point.y - wallDistance)
if nodes(at: southWall.position) == [] {
addChild(southWall)}
else {//print("southwall already there")
}
}
if !instructions[count].contains("E") {
//print("added east wall")
eastWall.position = CGPoint (x: point.x + wallDistance , y: point.y)
if nodes(at: eastWall.position) == [] {
addChild(eastWall)}
else {//print("east already there")
}
}
if !instructions[count].contains("W") {
//print("added west wall")
westWall.position = CGPoint (x: point.x - wallDistance , y: point.y)
if nodes(at: westWall.position) == [] {
addChild(westWall)}
else {//print("west wall already there")
}
}
count = count + 1
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for t in touches {
let location = t.location(in: self)
dot.position.x = location.x
dot.position.y = location.y
}
}
func didBegin(_ contact: SKPhysicsContact) {
print("contact!")
}
The walls appear just as I wanted them, and the dot is also in the right position.
I added a masso of 20000 for each of them so that when I move the dot, the walls stay in place. however, when I move the dot with my finger, it just goest straight through the walls of the maze instead of being stopped by them.
I added a print statement to the didBegin function to see if at least it was detecting any contact between the sprites, but it does not.
Why is this?
cheers!
First in your didMoveTo or sceneDidLoad, you need to set the physicsContactDelegate:
override func sceneDidLoad () {
physicsWorld.contactDelegate = self
buildMaze()
addDot()
}
To set the contact/collision mask, you have to do it this way, because they're based on bitwise operation:
Let's suppose you want collision between dot and walls
struct PhysicsCategory {
static let wall: UInt32 = 0x1 << 1
static let dot: UInt32 = 0x1 << 2
}
You can put the struct above you class if you want
Then, when you assign physics body, you have to set the bitmask:
For dots:
dot.physicsBody?.categoryBitMask = PhysicsCategory.dot
dot.physicsBody?.contactTestBitMask = PhysicsCategory.wall
dot.physicsBody?.collisionBitMask = PhysicsCategory.wall
//Collision is different from contact, so if you want to avoid collision
//dot.physicsBody?.collisionBitMask = PhysicsCategory.dot
Collision is different from contact, check apple documentation about it
For walls:
northWall.physicsBody?.categoryBitMask = PhysicsCategory.wall
northWall.physicsBody?.contactTestBitMask = PhysicsCategory.dot
northWall.physicsBody?.collisionBitMask = PhysicsCategory.dot
//Do the same for all walls
If you want walls to contact or collide with more than one object:
northWall.physicsBody?.contactTestBitMask = PhysicsCategory.dot | PhysicsCategory.other
northWall.physicsBody?.collisionBitMask = PhysicsCategory.dot | PhysicsCategory.other
For walls are valid all consideration as per dots
Collision and contact detection don't work very well when you set the position of your sprites directly.
In your code, the lines:
dot.position.x = location.x
dot.position.y = location.y
are directly setting the position of dot, overriding anything that the physics engine wants to do with the objects.
Also, you don't appear to have set up any of the necessary categories or collision/contactTest bit masks.
You allow manual movement of the dot but with contact detection with the walls, then you'd probably need to see if the touch onthe screen was inside a wall and then not move the dot if that was the case. (which would mean that you are not using physics at all).
Edit: my step-by-step guide for collisions and contacts:
https://stackoverflow.com/a/51041474/1430420
And a guide to collision and contactTest bit masks:
https://stackoverflow.com/a/40596890/1430420

Bounce rays with enumerateBodies alongRayStart

I want to trace the path where a bullet will move in my SpriteKit GameScene.
I'm using "enumerateBodies(alongRayStart", I can easily calculate the first collision with a physics body.
I don't know how to calculate the angle of reflection, given the contact point and the contact normal.
I want to calculate the path, over 5 reflections/bounces, so first I:
Cast a ray, get all the bodies it intersects with, and get the closest one.
I then use that contact point as the start of my next reflection/bounce....but I'm struggling with what the end point should be set to....
What I think I should be doing is getting the angle between the contact point and the contact normal, and then calculating a new point opposite to that...
var points: [CGPoint] = []
var start: CGPoint = renderComponent.node.position
var end: CGPoint = crossHairComponent.node.position
points.append(start)
var closestNormal: CGVector = .zero
for i in 0...5 {
closestNormal = .zero
var closestLength: CGFloat? = nil
var closestContact: CGPoint!
// Get the closest contact point.
self.physicsWorld.enumerateBodies(alongRayStart: start, end: end) { (physicsBody, contactPoint, contactNormal, stop) in
let len = start.distance(point: contactPoint)
if closestContact == nil {
closestNormal = contactNormal
closestLength = len
closestContact = contactPoint
} else {
if len <= closestLength! {
closestLength = len
closestNormal = contactNormal
closestContact = contactPoint
}
}
}
// This is where the code is just plain wrong and my math fails me.
if closestContact != nil {
// Calculate intersection angle...doesn't seem right?
let v1: CGVector = (end - start).normalized().toCGVector()
let v2: CGVector = closestNormal.normalized()
var angle = acos(v1.dot(v2)) * (180 / .pi)
let v1perp = CGVector(dx: -v1.dy, dy: v1.dx)
if(v2.dot(v1perp) > 0) {
angle = 360.0 - angle
}
angle = angle.degreesToRadians
// Set the new start point
start = closestContact
// Calculate a new end point somewhere in the distance to cast a ray to, so we can repeat the process again
let x = closestContact.x + cos(angle)*100
let y = closestContact.y + sin(-angle)*100
end = CGPoint(x: x, y: y)
// Add points to array to draw them on the screen
points.append(closestContact)
points.append(end)
}
}
I guess you are looking for something like this right?
1. Working code
First of all let me post the full working code. Just create a new Xcode project based SpriteKit and
In GameViewController.swift set
scene.scaleMode = .resizeFill
Remove the usual label you find in GameScene.sks
Replace Scene.swift with the following code
>
import SpriteKit
class GameScene: SKScene {
override func didMove(to view: SKView) {
self.physicsBody = SKPhysicsBody(edgeLoopFrom: frame)
}
var angle: CGFloat = 0
override func update(_ currentTime: TimeInterval) {
removeAllChildren()
drawRayCasting(angle: angle)
angle += 0.001
}
private func drawRayCasting(angle: CGFloat) {
let colors: [UIColor] = [.red, .green, .blue, .orange, .white]
var start: CGPoint = .zero
var direction: CGVector = CGVector(angle: angle)
for i in 0...4 {
guard let result = rayCast(start: start, direction: direction) else { return }
let vector = CGVector(from: start, to: result.destination)
// draw
drawVector(point: start, vector: vector, color: colors[i])
// prepare for next iteration
start = result.destination
direction = vector.normalized().bounced(withNormal: result.normal.normalized()).normalized()
}
}
private func rayCast(start: CGPoint, direction: CGVector) -> (destination:CGPoint, normal: CGVector)? {
let endVector = CGVector(
dx: start.x + direction.normalized().dx * 4000,
dy: start.y + direction.normalized().dy * 4000
)
let endPoint = CGPoint(x: endVector.dx, y: endVector.dy)
var closestPoint: CGPoint?
var normal: CGVector?
physicsWorld.enumerateBodies(alongRayStart: start, end: endPoint) {
(physicsBody:SKPhysicsBody,
point:CGPoint,
normalVector:CGVector,
stop:UnsafeMutablePointer<ObjCBool>) in
guard start.distanceTo(point) > 1 else {
return
}
guard let newClosestPoint = closestPoint else {
closestPoint = point
normal = normalVector
return
}
guard start.distanceTo(point) < start.distanceTo(newClosestPoint) else {
return
}
normal = normalVector
}
guard let p = closestPoint, let n = normal else { return nil }
return (p, n)
}
private func drawVector(point: CGPoint, vector: CGVector, color: SKColor) {
let start = point
let destX = (start.x + vector.dx)
let destY = (start.y + vector.dy)
let to = CGPoint(x: destX, y: destY)
let path = CGMutablePath()
path.move(to: start)
path.addLine(to: to)
path.closeSubpath()
let line = SKShapeNode(path: path)
line.strokeColor = color
line.lineWidth = 6
addChild(line)
}
}
extension CGVector {
init(angle: CGFloat) {
self.init(dx: cos(angle), dy: sin(angle))
}
func normalized() -> CGVector {
let len = length()
return len>0 ? self / len : CGVector.zero
}
func length() -> CGFloat {
return sqrt(dx*dx + dy*dy)
}
static func / (vector: CGVector, scalar: CGFloat) -> CGVector {
return CGVector(dx: vector.dx / scalar, dy: vector.dy / scalar)
}
func bounced(withNormal normal: CGVector) -> CGVector {
let dotProduct = self.normalized() * normal.normalized()
let dx = self.dx - 2 * (dotProduct) * normal.dx
let dy = self.dy - 2 * (dotProduct) * normal.dy
return CGVector(dx: dx, dy: dy)
}
init(from:CGPoint, to:CGPoint) {
self = CGVector(dx: to.x - from.x, dy: to.y - from.y)
}
static func * (left: CGVector, right: CGVector) -> CGFloat {
return (left.dx * right.dx) + (left.dy * right.dy)
}
}
extension CGPoint {
func length() -> CGFloat {
return sqrt(x*x + y*y)
}
func distanceTo(_ point: CGPoint) -> CGFloat {
return (self - point).length()
}
static func - (left: CGPoint, right: CGPoint) -> CGPoint {
return CGPoint(x: left.x - right.x, y: left.y - right.y)
}
}
2. How does it work?
Lets have a look at what this code does. We'll start from the bottom.
3. CGPoint and CGVector extensions
These are just simple extensions (mainly taken from Ray Wenderlich's repository on GitHub) to simplify the geometrical operations we are going to perform.
4. drawVector(point:vector:color)
This is a simple method to draw a vector with a given color starting from a given point.
Nothing fancy here.
private func drawVector(point: CGPoint, vector: CGVector, color: SKColor) {
let start = point
let destX = (start.x + vector.dx)
let destY = (start.y + vector.dy)
let to = CGPoint(x: destX, y: destY)
let path = CGMutablePath()
path.move(to: start)
path.addLine(to: to)
path.closeSubpath()
let line = SKShapeNode(path: path)
line.strokeColor = color
line.lineWidth = 6
addChild(line)
}
5. rayCast(start:direction) -> (destination:CGPoint, normal: CGVector)?
This method perform a raycasting and returns the ALMOST closest point where the ray enter in collision with a physics body.
private func rayCast(start: CGPoint, direction: CGVector) -> (destination:CGPoint, normal: CGVector)? {
let endVector = CGVector(
dx: start.x + direction.normalized().dx * 4000,
dy: start.y + direction.normalized().dy * 4000
)
let endPoint = CGPoint(x: endVector.dx, y: endVector.dy)
var closestPoint: CGPoint?
var normal: CGVector?
physicsWorld.enumerateBodies(alongRayStart: start, end: endPoint) {
(physicsBody:SKPhysicsBody,
point:CGPoint,
normalVector:CGVector,
stop:UnsafeMutablePointer<ObjCBool>) in
guard start.distanceTo(point) > 1 else {
return
}
guard let newClosestPoint = closestPoint else {
closestPoint = point
normal = normalVector
return
}
guard start.distanceTo(point) < start.distanceTo(newClosestPoint) else {
return
}
normal = normalVector
}
guard let p = closestPoint, let n = normal else { return nil }
return (p, n)
}
What does it mean ALMOST the closets?
It means the the destination point must be at least 1 point distant from the start point
guard start.distanceTo(point) > 1 else {
return
}
Ok but why?
Because without this rule the ray gets stuck into a physics body and it is never able to get outside of it.
6. drawRayCasting(angle)
This method basically keeps the local variables up to date to properly generate 5 segments.
private func drawRayCasting(angle: CGFloat) {
let colors: [UIColor] = [.red, .green, .blue, .orange, .white]
var start: CGPoint = .zero
var direction: CGVector = CGVector(angle: angle)
for i in 0...4 {
guard let result = rayCast(start: start, direction: direction) else { return }
let vector = CGVector(from: start, to: result.destination)
// draw
drawVector(point: start, vector: vector, color: colors[i])
// prepare next direction
start = result.destination
direction = vector.normalized().bounced(withNormal: result.normal.normalized()).normalized()
}
}
The first segment has starting point equals to zero and a direction diving my the angle parameter.
Segments 2 to 5 use the final point and the "mirrored direction" of the previous segment.
update(_ currentTime: TimeInterval)
Here I am just calling drawRayCasting every frame passing the current angle value and the increasing angle by 0.001.
var angle: CGFloat = 0
override func update(_ currentTime: TimeInterval) {
removeAllChildren()
drawRayCasting(angle: angle)
angle += 0.001
}
6. didMove(to view: SKView)
Finally here I create a physics body around the scene in order to make the ray bounce over the borders.
override func didMove(to view: SKView) {
self.physicsBody = SKPhysicsBody(edgeLoopFrom: frame)
}
7. Wrap up
I hope the explanation is clear.
Should you have any doubt let me know.
Update
There was a bug in the bounced function. It was preventing a proper calculation of the reflected ray.
It is now fixed.

Tower defense: turret tracking enemy and shooting issues

Here is my code:
func bombTowerTurnShoot() {
var prevDistance:CGFloat = 1000000
var closesetZombie = zombieArray[0]
self.enumerateChildNodes(withName: "bomb tower") {
node, stop in
if self.zombieArray.count > 0 {
for zombie in self.zombieArray {
if let bombTower = node as? SKSpriteNode {
let angle = atan2(closesetZombie.position.x - bombTower.position.x , closesetZombie.position.y - bombTower.position.y)
let actionTurn = SKAction.rotate(toAngle: -(angle - CGFloat(Double.pi/2)), duration: 0.2)
bombTower.run(actionTurn)
let turretBullet = SKSpriteNode(imageNamed: "Level 1 Turret Bullet")
turretBullet.position = bombTower.position
turretBullet.zPosition = 20
turretBullet.size = CGSize(width: 20, height: 20)
//turretBullet.setScale (frame.size.height / 5000)
turretBullet.physicsBody = SKPhysicsBody(circleOfRadius: max(turretBullet.size.width / 2, turretBullet.size.height / 2))
turretBullet.physicsBody?.affectedByGravity = false
turretBullet.physicsBody!.categoryBitMask = PhysicsCategories.Bullet //new contact
turretBullet.physicsBody!.collisionBitMask = PhysicsCategories.None
turretBullet.physicsBody!.contactTestBitMask = PhysicsCategories.Zombie
self.addChild(turretBullet)
var dx = CGFloat(closesetZombie.position.x - bombTower.position.x)
var dy = CGFloat(closesetZombie.position.y - bombTower.position.y)
let magnitude = sqrt(dx * dx + dy * dy)
dx /= magnitude
dy /= magnitude
let vector = CGVector(dx: 4.0 * dx, dy: 4.0 * dy)
func fire () {
turretBullet.physicsBody?.applyImpulse(vector)
}
func deleteBullet() {
turretBullet.removeFromParent()
}
turretBullet.run(SKAction.sequence([SKAction.wait(forDuration: 0), SKAction.run(fire), SKAction.wait(forDuration: 2.0), SKAction.run(deleteBullet) ]))
let distance = hypot(zombie.position.x - bombTower.position.x, zombie.position.y - bombTower.position.y)
if distance < prevDistance {
prevDistance = distance
closesetZombie = zombie
}
}
}
}
}
}
What this code does is turns a turret towards the closest zombie and shoot at it. As far as I can tell the turret is turn towards the closest zombie (if you can tell whether this code actually accomplishes that or not I would like to know). The bigger problem I am having is that the turrets sometimes shoot more than one bullet. I think it is because it is trying to fire at all zombies in the array not the specified one (the closest to the tower). How can I make it so that the turret only shoots the zombie that is closest?
class GameScene: SKScene, SKPhysicsContactDelegate {//new contact
var zombieArray:[SKSpriteNode] = []
...
...
}
And I append all the zombie to the array once they are added and remove them from the array once they die.
Basically, I don't know what you were doing wrong exactly. You had a ton of stuff going on, and trying to figure out the bug would probably have taken longer than rewriting it (for me at least). So that is what I did.
Here is a link to the project on github:
https://github.com/fluidityt/ShootClosestZombie/tree/master
For me, this was all about separating actions into somewhat distinct methods, and separating actions in general from logic.
You had so much going on, it was hard to test / see which parts were working correctly or not. This is where having somewhat smaller methods come in, as well as separating action from logic.. Your action may work fine, but perhaps it's not getting called due to a logic error.
So, how I implemented this was to just make your bomb turret it's own class.. that way we can have the bomb turret be in charge of most of its actions, and then let gameScene handle most of the implementation / and or logic.
The demo I've uploaded shows two turrets that auto-orient themselves to the closest zombie every frame, then shoot at them every second. Click the screen to add more zombies.
The turrets independently track the closest zombie to them so if you spawn a zombie on the left and the right, then the left turret will shoot at left zombie, and right turret will shoot at right zombie (and only once!).
class BombTower: SKSpriteNode {
static let bombName = "bomb tower"
var closestZombie: SKSpriteNode!
func updateClosestZombie() {
let gameScene = (self.scene! as! GameScene)
let zombieArray = gameScene.zombieArray
var prevDistance:CGFloat = 1000000
var closestZombie = zombieArray[0]
for zombie in zombieArray {
let distance = hypot(zombie.position.x - self.position.x, zombie.position.y - self.position.y)
if distance < prevDistance {
prevDistance = distance
closestZombie = zombie
}
}
self.closestZombie = closestZombie
}
func turnTowardsClosestZombie() {
let angle = atan2(closestZombie.position.x - self.position.x , closestZombie.position.y - self.position.y)
let actionTurn = SKAction.rotate(toAngle: -(angle - CGFloat(Double.pi/2)), duration: 0.2)
self.run(actionTurn)
}
private func makeTurretBullet() -> SKSpriteNode {
let turretBullet = SKSpriteNode(imageNamed: "Level 1 Turret Bullet")
turretBullet.position = self.position
turretBullet.zPosition = 20
turretBullet.size = CGSize(width: 20, height: 20)
//turretBullet.setScale (frame.size.height / 5000)
turretBullet.physicsBody = SKPhysicsBody(circleOfRadius: max(turretBullet.size.width / 2, turretBullet.size.height / 2))
turretBullet.physicsBody?.affectedByGravity = false
// turretBullet.physicsBody!.categoryBitMask = PhysicsCategories.Bullet //new contact
// turretBullet.physicsBody!.collisionBitMask = PhysicsCategories.None
// turretBullet.physicsBody!.contactTestBitMask = PhysicsCategories.Zombie
return turretBullet
}
private func fire(turretBullet: SKSpriteNode) {
var dx = CGFloat(closestZombie.position.x - self.position.x)
var dy = CGFloat(closestZombie.position.y - self.position.y)
let magnitude = sqrt(dx * dx + dy * dy)
dx /= magnitude
dy /= magnitude
let vector = CGVector(dx: 4.0 * dx, dy: 4.0 * dy)
turretBullet.physicsBody?.applyImpulse(vector)
}
func addBulletThenShootAtClosestZOmbie() {
let bullet = makeTurretBullet()
scene!.addChild(bullet)
fire(turretBullet: bullet)
}
}
// TODO: delete bullets, hit detection, and add SKConstraint for tracking instead of update.
// Also, I think that we are iterating too much looking for nodes. Should be able to reduce that.
// Also also, there are sure to be bugs if zombieArray is empty.
class GameScene: SKScene {
var zombieArray: [SKSpriteNode] = []
private func makeBombArray() -> [BombTower]? {
guard self.zombieArray.count > 0 else { return nil }
var towerArray: [BombTower] = []
self.enumerateChildNodes(withName: BombTower.bombName) { node, _ in towerArray.append(node as! BombTower) }
guard towerArray.count > 0 else { return nil }
return towerArray
}
private func towersShootEverySecond(towerArray: [BombTower]) {
let action = SKAction.run {
for bombTower in towerArray {
guard bombTower.closestZombie != nil else { continue } // I haven't tested this guard statement yet.
bombTower.addBulletThenShootAtClosestZOmbie()
}
}
self.run(.repeatForever(.sequence([.wait(forDuration: 1), action])))
}
override func didMove(to view: SKView) {
// Demo setup:
removeAllChildren()
makeTestZombie: do {
spawnZombie(at: CGPoint.zero)
}
makeTower1: do {
let tower = BombTower(color: .yellow, size: CGSize(width: 55, height: 55))
let turretGun = SKSpriteNode(color: .gray, size: CGSize(width: 25, height: 15))
turretGun.position.x = tower.frame.maxX + turretGun.size.height/2
tower.name = BombTower.bombName
tower.addChild(turretGun)
addChild(tower)
}
makeTower2: do {
let tower = BombTower(color: .yellow, size: CGSize(width: 55, height: 55))
let turretGun = SKSpriteNode(color: .gray, size: CGSize(width: 25, height: 15))
turretGun.position.x = tower.frame.maxX + turretGun.size.height/2
tower.addChild(turretGun)
tower.position.x += 200
tower.name = BombTower.bombName
addChild(tower)
}
guard let towerArray = makeBombArray() else { fatalError("couldn't make array!") }
towersShootEverySecond(towerArray: towerArray)
}
private func spawnZombie(at location: CGPoint) {
let zombie = SKSpriteNode(color: .blue, size: CGSize(width: 35, height: 50))
zombieArray.append(zombie)
zombie.position = location
zombie.run(.move(by: CGVector(dx: 3000, dy: -3000), duration: 50))
addChild(zombie)
}
// Just change this to touchesBegan for it to work on iOS:
override func mouseDown(with event: NSEvent) {
let location = event.location(in: self)
spawnZombie(at: location)
}
// I think this could be a constrain or action, but I couldn't get either to work right now.
private func keepTowersTrackingNearestZombie() {
guard let towerArray = makeBombArray() else { return }
for tower in towerArray {
tower.updateClosestZombie()
tower.turnTowardsClosestZombie()
}
}
override func update(_ currentTime: TimeInterval) {
keepTowersTrackingNearestZombie()
}
}