ios Swift SpriteKit: how to use a sprite in other functions - ios

I have created some particles animations with specific sprites which works fine if I use them in the function:
override init(size: CGSize)
I use the following lines:
let sheet_particles = Particles()
let particles_node = SKSpriteNode(texture: sheet_particles.particle000())
particles_node.name = kparticles
particles_node.position = CGPoint(x: 500, y: 500)
particles_node.zPosition = 5
background.addChild(particles_node)
particles_node.runAction(particlesAction)
To make them appear in my scene.
The problem I have is if I try to use them in other functions in my scene, I can not see them.
func panForTranslation(translation : CGPoint) {
let position = selectedNode.position
if selectedNode.name! == kpuzzleNodeName {
selectedNode.position = CGPoint(x: position.x + translation.x * 2, y: position.y + translation.y * 2)
switch selectedNode.name2 {
case "0":
if selectedNode.frame.intersects(NPuzzle13.frame) {
particles_node.position = selectedNode.position
particles_node.runAction(particlesAction)
NPuzzle13.hidden = false
selectedNode.removeFromParent()
}
I see no particles sprite when the condition "0" happens but I see correctly the NPuzzle13. When I check the position of the particles_node node, its position is equal with the node selectedNode. All that is OK, except for the visibility of the particles... What am I missing? Thanks.

About zPosition seems all correct. I dont see any anchorPoint in your code.
I think your switch-case is jumped (not fired, not executed) because you check switch selectedNode.name2 instead of switch selectedNode.name

Related

Swift - SpriteKit : Make sprites reacting to eachothers if added with different "addchild" parents

I've added several sprite (SKSpriteNode) in my Scene like this:
let NPuzzle_Texture = SKTexture(imageNamed: "SKTexture.png")
NPuzzle0 = SKSpriteNode(texture: NPuzzle_Texture)
NPuzzle1 = SKSpriteNode(texture: NPuzzle_Texture)
NPuzzle2 = SKSpriteNode(texture: NPuzzle_Texture)
NPuzzle0.position = CGPoint (x: 100, y:125)
NPuzzle0.position = CGPoint (x: 300, y:125)
NPuzzle0.position = CGPoint (x: 500, y:125)
background.addChild(NPuzzle0)
background.addChild(NPuzzle1)
background.addChild(NPuzzle2)
I've also added several sprites in a different texture:
let Grey_Back = SKTexture(imageNamed: "Grey_Back.png")
grey_back = SKSpriteNode(texture: Grey_back)
grey_back.position = CGPoint (x: 1024, y:125)
grey_back.alpha = 0.5
background.addChild(grey_back)
Now I add new sprites (SKSpriteNode) to precedent grey_back like this:
grey_back.addChild(new_sprite1)
grey_back.addChild(new_sprite2)
grey_back.addChild(new_sprite3)
When I try to see if positions of new_sprite intersects with NPuzzle sprites, nothing is happening. But if the new_sprite are added to the scene with:
background.addChild(new_sprite0)
background.addChild(new_sprite1)
background.addChild(new_sprite2)
it works. In fact it doesn't work if the sprites have been added with differents parents (background and grey_back). What I don't understand is grey_back is the child of background, so, it should work. Why it doesn't ?
Here is an example of the code to check if sprites intersects eachothers:
switch selectedNode.name {
case "new_sprite0":
if selectedNode.frame.intersects(NPuzzle0.frame) && (selectedNode.angle == 0) {
Thanks !
switch selectedNode.name {
let framePoint = CGPointMake(selectedNode.frame.origin.x, selectedNode.frame.origin.y)
let translatedPoint = selectedNode.parent!.convertPoint(framePoint, toNode:NPuzzle0.parent!)
let translatedFrame = CGRectMake(translatedPoint.x, translatedPoint.y, selectedNode.frame.size.width, selectedNode.frame.size.height)
if translatedFrame.intersects(NPuzzle0.frame) && (selectedNode.zRotation == 0)
{
print("ok")
}
Obviously, because frames are relative to parents, the node MUST be added to the scene. You can see I also used a forced unwrap for parent...

Dynamically change position based on scrollView

I have a "U" shaped UIBezierPath which I use as the path for my myImage.layer to animate on. I also have a scrollView. My goal is to have a custom "Pull to Refresh" animation.
The problem I am having is that I want my myImage.layer to update based on how much the scrollView scrolled.
As the scrollView is pulled down, the myImage.layer animates along a "U" shape path. This is the path in my code which I created as a UIBezierPath.
This is how I calculate how far the scrollView is pulled down:
func scrollViewDidScroll(scrollView: UIScrollView) {
let offsetY = CGFloat(max(-(scrollView.contentOffset.y + scrollView.contentInset.top), 0.0))
self.progress = min(max(offsetY / frame.size.height, 0.0), 1.0)
if !isRefreshing {
redrawFromProgress(self.progress)
}
}
This is the function to dynamically update the position (it is not working):
func redrawFromProgress(progress: CGFloat) {
// PROBLEM: This is not correct. Only the `x` position is dynamic based on scrollView position.
// The `y` position is static.
// I want this to be dynamic based on how much the scrollView scrolled.
myImage.layer.position = CGPoint(x: progress, y: 50)
}
Basically, this is what I want:
If the scrollView scrolled is 0.0, then the myImage.layer position should be CGPoint(x: 0, y: 0) or the starting point of the path.
If the scrollView scrolled is 0.5 (50%), then the myImage.layer position should be at 50% of the path, I don't know what the CGPoint value would be here.
and so on...
I tried getting the CGPoint values along the UIBezierPath and based on the % of the scrollView scrolled, assign that CGPoint value to it but don't know how to do this. I also looked at this post but I can't get it to work for me.
EDIT QUESTION 1:
By using this extension, I was able to get an array of CGPoints which contain 10 values based on my UIBezierPath:
extension CGPath {
func forEachPoint(#noescape body: #convention(block) (CGPathElement) -> Void) {
typealias Body = #convention(block) (CGPathElement) -> Void
func callback(info: UnsafeMutablePointer<Void>, element: UnsafePointer<CGPathElement>) {
let body = unsafeBitCast(info, Body.self)
body(element.memory)
}
// print(sizeofValue(body))
let unsafeBody = unsafeBitCast(body, UnsafeMutablePointer<Void>.self)
CGPathApply(self, unsafeBody, callback)
}
func getPathElementsPoints() -> [CGPoint] {
var arrayPoints : [CGPoint]! = [CGPoint]()
self.forEachPoint { element in
switch (element.type) {
case CGPathElementType.MoveToPoint:
arrayPoints.append(element.points[0])
case .AddLineToPoint:
arrayPoints.append(element.points[0])
case .AddQuadCurveToPoint:
arrayPoints.append(element.points[0])
arrayPoints.append(element.points[1])
case .AddCurveToPoint:
arrayPoints.append(element.points[0])
arrayPoints.append(element.points[1])
arrayPoints.append(element.points[2])
default: break
}
}
return arrayPoints
}
I also rewrote the function above called redrawFromProgress(progress: CGFloat) to this:
func redrawFromProgress(progress: CGFloat) {
let enterPath = paths[0]
let pathPointsArray = enterPath.CGPath
let junctionPoints = pathPointsArray.getPathElementsPoints()
// print(junctionPoints.count) // There are 10 junctionPoints
// progress means how much the scrollView has been pulled down,
// it goes from 0.0 to 1.0.
if progress <= 0.1 {
myImage.layer.position = junctionPoints[0]
} else if progress > 0.1 && progress <= 0.2 {
myImage.layer.position = junctionPoints[1]
} else if progress > 0.2 && progress <= 0.3 {
myImage.layer.position = junctionPoints[2]
} else if progress > 0.3 && progress <= 0.4 {
myImage.layer.position = junctionPoints[3]
} else if progress > 0.4 && progress <= 0.5 {
myImage.layer.position = junctionPoints[4]
} else if progress > 0.5 && progress <= 0.6 {
myImage.layer.position = junctionPoints[5]
} else if progress > 0.6 && progress <= 0.7 {
myImage.layer.position = junctionPoints[6]
} else if progress > 0.7 && progress <= 0.8 {
myImage.layer.position = junctionPoints[7]
} else if progress > 0.8 && progress <= 0.9 {
myImage.layer.position = junctionPoints[8]
} else if progress > 0.9 && progress <= 1.0 {
myImage.layer.position = junctionPoints[9]
}
}
If I pull down the scrollView very slow, the myImage.layer actually follows the path. The only problem is that if I pull down on the scrollView very fast, then the myImage.layer jumps to the last point. Could it be because of the way I wrote the if statement above?
Any ideas?
Thanks to #Sam Falconer for making me aware of this:
Your code is relying on the scrollViewDidScroll delegate callback to be called frequently enough to hit all of your keyframe points. When you pull quickly on the scroll view, it does not call that method frequently enough, causing the jump.
Once I confirmed this, he also helped by mentioning:
Additionally, you will find the CAKeyframeAnimation class to be useful.
With CAKeyfraneAnimation I am able to manually control it's value with this code:
func scrollViewDidScroll(scrollView: UIScrollView) {
let offsetY = CGFloat(max(-(scrollView.contentOffset.y + scrollView.contentInset.top), 0.0))
self.progress = min(max(offsetY / frame.size.height, 0.0), 1.0)
if !isRefreshing {
redrawFromProgress(self.progress)
}
}
func redrawFromProgress(progress: CGFloat) {
// Animate image along enter path
let pathAnimation = CAKeyframeAnimation(keyPath: "position")
pathAnimation.path = myPath.CGPath
pathAnimation.calculationMode = kCAAnimationPaced
pathAnimation.timingFunctions = [CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)]
pathAnimation.beginTime = 1e-100
pathAnimation.duration = 1.0
pathAnimation.timeOffset = CFTimeInterval() + Double(progress)
pathAnimation.removedOnCompletion = false
pathAnimation.fillMode = kCAFillModeForwards
imageLayer.addAnimation(pathAnimation, forKey: nil)
imageLayer.position = enterPath.currentPoint
}
Thanks again for the help guys!
Your code is relying on the scrollViewDidScroll delegate callback to be called frequently enough to hit all of your keyframe points. When you pull quickly on the scroll view, it does not call that method frequently enough, causing the jump.
You may want to try calculating a custom path based on a segment of an arc representing the path between your current position, and your desired position. Basing an animation on this, instead of deconstructing your custom path (which looks very close to just being an arc), may be easier.
CGPathAddArc() with x, y, and r being constant, should get you 90% to what your path is now. You could also get fancier with the path to add that line segment like you have at the beginning of your path. It would just take a bit more work to get the partial path to come out right for all the "I'm at this position, get me a path to this other position" logic.
Additionally, you will find the CAKeyframeAnimation class to be useful. You can feed it a CGPath (perhaps one based on the arc segment to travel), and the timing for the animation, and it can make your layer follow the path.
Source: https://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CGPath/index.html#//apple_ref/c/func/CGPathAddArc
Source: https://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CAKeyframeAnimation_class/index.html
Edit:
Here is some example code for how to draw a partial arc on a CGPath from the current progress to the new progress. I made it work in reverse too. You can play with the numbers and constants, but this is the idea of how to draw an arc segment from a certain percentage to a certain percentage.
Please keep in mind when looking at the CoreGraphics math that it may seem backwards (clockwise vs counterclockwise, etc). This is because UIKit flips everything upside down to put the origin in the upper-left, where CG has its origin in the lower-left.
// start out with start percent at zero, but then use the last endPercent instead
let startPercent = CGFloat(0.0)
// end percent is the "progress" in your code
let endPercent = CGFloat(1.0)
// reverse the direction of the path if going backwards
let clockwise = startPercent > endPercent ? false : true
let minArc = CGFloat(M_PI) * 4/5
let maxArc = CGFloat(M_PI) * 1/5
let arcLength = minArc - maxArc
let beginArc = minArc - (arcLength * startPercent)
let endArc = maxArc + (arcLength * (1.0 - endPercent))
let myPath = CGPathCreateMutable()
CGPathAddArc(myPath, nil, view.bounds.width/2, 0, 160, beginArc, endArc, clockwise)
Here is the full arc segment as defined by the constants minArc and maxArc.

Swift / SpriteKit help: Increase CGFloat continuously to allow continuous rotation around a fixed point

Im making a simple game with apple's SpriteKit and Swift and have encountered a problem. Im trying to get a paddle node (paddle) to rotate continuously around a fixed node (anchorNode) inside a circle; however, I cannot figure out how to make the paddle node (paddle) keep rotating around the fixed point node (anchorNode) because of the constrains in the SKAction.rotateByAngle statement making it end after a certain amount of time / rotation.
Any help is greatly appreciated!
Here is my code for reference:
//Setting up anchor Node
anchorNode.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
anchorNode.size.height = (self.frame.size.height / 1000)
anchorNode.size.width = anchorNode.size.height
self.addChild(anchorNode)
//Setting up achor Node's physucs
anchorNode.physicsBody = SKPhysicsBody(circleOfRadius: (circle.frame.size.height / 1000))
anchorNode.physicsBody?.dynamic = false
anchorNode.physicsBody?.affectedByGravity = false
anchorNode.physicsBody?.friction = 0
//Making the anchor Node rotate
let rotate = SKAction.rotateByAngle(CGFloat(3.14), duration: NSTimeInterval(1.5))
anchorNode.runAction(rotate)
//Setting up the paddle node
paddle.position = CGPointMake((circle.frame.width / 2), 0)
paddle.size.height = (self.frame.size.height / 50)
paddle.size.width = (self.frame.size.width / 7)
anchorNode.addChild(paddle)
Try adding this code.
override func update(currentTime: NSTimeInterval) {
//How to make it spin
let speed = CGFloat(5)
let degreeRotation = CDouble(speed) * M_PI / 180
paddle.zRotation -= CGFloat(degreeRotation)
}
Using this fixed my problem:
anchorNode.runAction(SKAction.repeatActionForever(rotate))
Thanks, User:
0x141E

How can I make a sprite object set it's moving direction at the point of a touch?

So I'm playing around and slowly making my first iOS game. I'm trying to get my sprite object to set out a straight path angled towards the location of the player (which is where the user last touched).
The code I have makes the bee move towards the player and stop when it gets to it, instead of going from one side of the screen, through the player and off the other side of the screen.
var beeSpeed = 2.0
var moveAccross = SKAction.moveTo(CGPointMake(player.position.x,player.position.y), duration:beeSpeed)
badBee.runAction(moveAccross)
I will be having many objects constantly spawning that should all set their path once to the player location at the time they spawn.
Any help would be great,
I think I figured it out, if anyone could check my code and make sure it's doing the right thing that would be great :)
let actionMove = SKAction.moveTo(CGPoint(x: player.position.x-player.position.x-bee.size.width, y: player.position.y), duration: NSTimeInterval(actualDuration))
let actionMoveDone = SKAction.removeFromParent()
bee.runAction(SKAction.sequence([actionMove, actionMoveDone]))
You have to calculate the slope from the spawning point to the player and then interpolate to somewhere outside the screen.
func add(location:CGPoint)
{
let bee = SKSpriteNode(color: UIColor.redColor(), size: CGSizeMake(10, 10))
bee.name = "Bee"
bee.position = location
self.addChild(bee)
let slopeToPlayer = (bee.position.y - player.position.y) / (bee.position.x - player.position.x)
let constant = bee.position.y - slopeToPlayer * bee.position.x
let finalX : CGFloat = bee.position.x < player.position.x ? 500.0 : -500.0 // Set it to somewhere outside screen size
let finalY = constant + slopeToPlayer * finalX
let distance = (bee.position.y - finalY) * (bee.position.y - finalY) + (bee.position.x - finalX) * (bee.position.x - finalX)
let beeSpeed : CGFloat = 100.0
let timeToCoverDistance = sqrt(distance) / beeSpeed
let moveAction = SKAction.moveTo(CGPointMake(finalX, finalY), duration: NSTimeInterval(timeToCoverDistance))
let removeAction = SKAction.runBlock { () -> Void in
bee.removeFromParent()
println("removed")
}
bee.runAction(SKAction.sequence([moveAction,removeAction]))
}

checking to see if location in scene is occupied by sprite

I am building my first iPhone game using Xcode, SpriteKit and Swift. I am new to these technologies but I am familiar with general programming concepts.
Here is what I am trying to do in English. I want circles to randomly appear on the screen and then begin to expand in size. However, I do not want a circle to appear in a location where a circle currently exists. I am having trouble determining each circle's position.
Inside GameScene.swift I have the following code inside the didMoveToView:
runAction(SKAction.repeatActionForever(
SKAction.sequence([
SKAction.runBlock(addCircle), SKAction.waitForDuration(3, withRange: 2)]
)))
The piece of code above calls my "addCircle" method:
func addCircle() {
// Create sprite.
let circle = SKSpriteNode(imageNamed: "grad640x640_circle")
circle.name = "circle"
circle.xScale = 0.1
circle.yScale = 0.1
// Determine where to position the circle.
let posX = random(min: 50, max: 270)
let posY = random(min: 50, max: 518)
// ***Check to see if position is currently occupied by another circle here.
circle.position = CGPoint(x: posX, y: posY)
// Add circle to the scene.
addChild(circle)
// Expand the circle.
let expand = SKAction.scaleBy(2, duration: 0.5)
circle.runAction(expand)
}
The random function above just chooses a random number within the given range. How can I check to see if my random functions are generating a location that is currently occupied by another circle?
I was thinking of using a do..while loop to randomly generate a set of x and y coordinates and then check to see if a circle is at that location but I cannot find how to check for that condition. Any help would be greatly appreciated.
There are a few methods which can help you in this regard:
(BOOL) intersectsNode: (SKNode*)node, available with SKNode, and
CGRectContainsPoint() as well as the CGRectContainsRect() methods.
For instance the loop to check for intersection can look as follows:
var point: CGPoint
var exit:Bool = false
while (!exit) {
let posX = random(min: 50, max: 270)
let posY = random(min: 50, max: 518)
point = CGPoint(x: posX, y: posY)
var pointFound: Bool = true
self.enumerateChildNodesWithName("circle", usingBlock: {
node, stop in
let sprite:SKSpriteNode = node as SKSpriteNode
if (CGRectContainsPoint(sprite.frame, point))
{
pointFound = false
stop.memory = true
}
})
if (pointFound)
{
exit = true
}
}
//point contains CGPoint where no other circle exists
//Declare new circle at point

Resources