I've been racking my brain and searching here and all over to try to find out how to generate a random position on screen to spawn a circle. I'm hoping someone here can help me because I'm completely stumped. Basically, I'm trying to create a shape that always spawns in a random spot on screen when the user touches.
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
let screenSize: CGRect = UIScreen.mainScreen().bounds
let screenHeight = screenSize.height
let screenWidth = screenSize.width
let currentBall = SKShapeNode(circleOfRadius: 100)
currentBall.position = CGPointMake(CGFloat(arc4random_uniform(UInt32(Float(screenWidth)))), CGFloat(arc4random_uniform(UInt32(Float(screenHeight)))))
self.removeAllChildren()
self.addChild(currentBall)
}
If you all need more of my code, there really isn't any more. But thank you for whatever help you can give! (Just to reiterate, this code kind of works... But a majority of the spawned balls seem to spawn offscreen)
The problem there is that you scene is bigger than your screen bounds
let viewMidX = view!.bounds.midX
let viewMidY = view!.bounds.midY
print(viewMidX)
print(viewMidY)
let sceneHeight = view!.scene!.frame.height
let sceneWidth = view!.scene!.frame.width
print(sceneWidth)
print(sceneHeight)
let currentBall = SKShapeNode(circleOfRadius: 100)
currentBall.fillColor = .green
let x = view!.scene!.frame.midX - viewMidX + CGFloat(arc4random_uniform(UInt32(viewMidX*2)))
let y = view!.scene!.frame.midY - viewMidY + CGFloat(arc4random_uniform(UInt32(viewMidY*2)))
print(x)
print(y)
currentBall.position = CGPoint(x: x, y: y)
view?.scene?.addChild(currentBall)
self.removeAllChildren()
self.addChild(currentBall)
First: Determine the area that will be valid. It might not be the frame of the superview because perhaps the ball (let's call it ballView) might be cut off. The area will likely be (in pseudocode):
CGSize( Width of the superview - width of ballView , Height of the superview - height of ballView)
Once you have a view of that size, just place it on screen with the origin 0, 0.
Secondly: Now you have a range of valid coordinates. Just use a random function (like the one you are using) to select one of them.
Create a swift file with the following:
extension Int
{
static func random(range: Range<Int>) -> Int
{
var offset = 0
if range.startIndex < 0 // allow negative ranges
{
offset = abs(range.startIndex)
}
let mini = UInt32(range.startIndex + offset)
let maxi = UInt32(range.endIndex + offset)
return Int(mini + arc4random_uniform(maxi - mini)) - offset
}
}
And now you can specify a random number as follows:
Int.random(1...1000) //generate a random number integer somewhere from 1 to 1000.
You can generate the values for the x and y coordinates now using this function.
Given the following random generators:
public extension CGFloat {
public static var random: CGFloat { return CGFloat(arc4random()) / CGFloat(UInt32.max) }
public static func random(between x: CGFloat, and y: CGFloat) -> CGFloat {
let (start, end) = x < y ? (x, y) : (y, x)
return start + CGFloat.random * (end - start)
}
}
public extension CGRect {
public var randomPoint: CGPoint {
var point = CGPoint()
point.x = CGFloat.random(between: origin.x, and: origin.x + width)
point.y = CGFloat.random(between: origin.y, and: origin.y + height)
return point
}
}
You can paste the following into a playground:
import XCPlayground
import SpriteKit
let view = SKView(frame: CGRect(x: 0, y: 0, width: 500, height: 500))
XCPShowView("game", view)
let scene = SKScene(size: view.frame.size)
view.presentScene(scene)
let wait = SKAction.waitForDuration(0.5)
let popIn = SKAction.scaleTo(1, duration: 0.25)
let popOut = SKAction.scaleTo(0, duration: 0.25)
let remove = SKAction.removeFromParent()
let popInAndOut = SKAction.sequence([popIn, wait, popOut, remove])
let addBall = SKAction.runBlock { [unowned scene] in
let ballRadius: CGFloat = 25
let ball = SKShapeNode(circleOfRadius: ballRadius)
var popInArea = scene.frame
popInArea.inset(dx: ballRadius, dy: ballRadius)
ball.position = popInArea.randomPoint
ball.xScale = 0
ball.yScale = 0
ball.runAction(popInAndOut)
scene.addChild(ball)
}
scene.runAction(SKAction.repeatActionForever(SKAction.sequence([addBall, wait])))
(Just make sure to also paste in the random generators, too, or to copy them to the playground's Sources, as well as to open the assistant editor so you can see the animation.)
Related
I am running a for loop in my game that would generate SKSpriteNodes.
I want my first block to start at (20, 40) and add 20 to the x position and 40 to the y position for every new block.
First block (20, 40)
Second block (40, 80)
Third Block (60, 120)
And so on.
The y position is behaving the way I want to, however the x position would randomly start anywhere on my screen then add 20 for every new block generated.
Below is my code.
func generateBlocks() {
for _ in 1..<5 {
xP += 20
yP += 40
let xx = CGFloat (xP)
let yy = CGFloat (yP)
print("x position: \(xx)")
print("y position: \(yy)")
let resourcePath = NSBundle.mainBundle().pathForResource("Blocks", ofType: "sks")
let blocks = MSReferenceNode(URL: NSURL (fileURLWithPath: resourcePath!))
blocks.goals.position = CGPoint (x: xx,y: yy)
addChild(blocks)
}
}
I also added the print statement of how it would look like when I run the code.
Below is the print statement of the x and y positions of the blocks.
I tried switching the order of the xP and yP initializing. That didn't work.
Any suggestions?
I would prefer to use while loops for this kind of operations where you must impose a condition from start, for example limits:
class GameScene: SKScene {
let deltaX:CGFloat = 20.0
let deltaY:CGFloat = 40.0
override func didMoveToView(view: SKView) {
let widthLimit = self.frame.width-40
let heightLimit = self.frame.height-140
let startX:CGFloat = 80.0
drawStair(startX,limits:CGSizeMake(widthLimit,heightLimit))
}
func drawStair(startFromX:CGFloat,limits:CGSize) {
var currentX:CGFloat = startFromX
var currentY:CGFloat = startFromX+deltaY
while currentX<limits.width && currentY<limits.height {
drawBlock(CGPointMake(currentX,currentY))
currentX += deltaX
currentY += deltaY
}
}
func drawBlock(position: CGPoint,size:CGSize = CGSizeMake(40,40)) {
let block = SKSpriteNode(color: UIColor.redColor(), size: size)
block.position = position
block.name = "block"
addChild(block)
}
}
Output:
I have an array of buttons and when I append them to a view I want the to be positioned around a image view which is in the center. Based on how many objects there are in the array, I want them to be evenly spaced around the whole circle. Below is my attempt to do so. What am I doing wrong and how should I fix it? There is more than one button behind the moose.
var userbutton = [UIButton]()
var upimage = [UIImage]()
var locationpic = [AnyObject]()
func locationsSet(){
for (index, users) in upimage.enumerate() {
let userbutton = UIButton()
userbutton.addTarget(self, action: "buttonAction:", forControlEvents: .TouchUpInside)
userbutton.frame = CGRectMake(100, 100, 50, 50)
userbutton.layer.cornerRadius = userbutton.frame.size.width/2
userbutton.clipsToBounds = true
userbutton.setImage(users, forState: .Normal)
let radians = CGFloat(M_PI) * 2.0 / CGFloat(upimage.count) * CGFloat(index)
let centerx = self.view.bounds.width / 2.0
let radius = currentuserpic.frame.size.width / 2.0
let centery = self.view.bounds.height / 2.0
let pointx = centerx + cos(radians) * (radius + 40)
let pointy = (centery) + (sin(radians)) * (radius + 40)
userbutton.center.x = pointx
userbutton.center.y = pointy
self.userbutton.append(userbutton)
self.view.addSubview(userbutton)
print("x\(pointx)")
print("y\(pointy)")
}
}
How I would do this:
Create an extension to UIView to get the diagonal and radius. These are handy because we want our "satellites" to have predictable placing even when the "planet" isn't square.
extension UIView {
var diagonal : CGFloat {
return sqrt(pow(self.frame.width, 2) + pow(self.frame.height, 2))
}
var radius : CGFloat {
return diagonal / 2
}
}
This will return a point based on an angle and a distance from an origin.
It uses dreadful trigonometry.
func getPoint(fromPoint point: CGPoint, atDistance distance: CGFloat, withAngleRadians angle:CGFloat) -> CGPoint {
let x = point.x
let y = point.y
let dx = (distance * cos(angle))
let dy = (distance * sin(angle))
return CGPoint(x: (dx + x), y: (dy + y))
}
Now the real function. Generate a bunch of points in a circle pattern. I used a running sum for the angle instead of multiplying each time by the index. This just returns the centre points for the views.
func encirclePoint(point : CGPoint, distance:CGFloat, inParts parts: Int) -> [CGPoint] {
let angle = 2 * CGFloat(M_PI) / CGFloat(parts) // critical part, you need radians for trigonometry
var runningAngle : CGFloat = -(CGFloat(M_PI) / 2) // start at the top
var points : [CGPoint] = []
for _ in 0..<parts {
let circlePoint = getPoint(fromPoint: point, atDistance: distance, withAngleRadians: runningAngle)
points.append(circlePoint)
runningAngle += angle
}
return points
}
Now you can create a simple function that takes a view, a margin and an array of "satellite" views. It will set their centre and add them to the superview of the view we used to input. It makes sense not to add them to the view itself since they might not be placed inside it.
func encircleView(view : UIView, withSubViews subViews : [UIView], withMargin margin : CGFloat) {
guard !(subViews.isEmpty) else { // if there are no subviews : abort
return
}
let distance = view.radius + margin
let points = encirclePoint(view.center, distance: distance, inParts: subViews.count)
guard subViews.count == points.count, let uberView = view.superview else { // if the count is not the same or there is no superview: abort
return
}
for (point, subView) in zip(points, subViews) { subView.center = point }
}
Notice how I did nothing except for the centre calculations in these functions. Styling them goes in another function. This makes it super easy to maintain and debug.
I might even let the last function just return the subviews with updated frames and add them later.
Or negative margin :)
Gist
A full circle is 2 * pi radians. You need to divide that by the number of items you have and multiply that by the index of the item you are currently processing. Use trig to find the location on the circle:
for (index, users) in upimage.enumerate() {
let radians = CGFloat(M_PI) * 2.0 / CGFloat(upimage.count) * CGFloat(index)
......
let centerx = self.view.bounds.width / 2.0
let radius = currentuserpic.frame.size.width / 2.0
let centery = self.view.bounds.height / 2.0
let pointx = centerx + cos(radians) * radius
let pointy = centery + sin(radians) * radius
......
}
I have an array of buttons and when I append them to a view I want the to be positioned around a image view which is in the center. Based on how many objects there are in the array, I want them to be evenly spaced around the whole circle. Below is my attempt to do so. What am I doing wrong and how should I fix it? There is more than one button behind the moose.
var userbutton = [UIButton]()
var upimage = [UIImage]()
var locationpic = [AnyObject]()
func locationsSet(){
for (index, users) in upimage.enumerate() {
let userbutton = UIButton()
userbutton.addTarget(self, action: "buttonAction:", forControlEvents: .TouchUpInside)
userbutton.frame = CGRectMake(100, 100, 50, 50)
userbutton.layer.cornerRadius = userbutton.frame.size.width/2
userbutton.clipsToBounds = true
userbutton.setImage(users, forState: .Normal)
let radians = CGFloat(M_PI) * 2.0 / CGFloat(upimage.count) * CGFloat(index)
let centerx = self.view.bounds.width / 2.0
let radius = currentuserpic.frame.size.width / 2.0
let centery = self.view.bounds.height / 2.0
let pointx = centerx + cos(radians) * (radius + 40)
let pointy = (centery) + (sin(radians)) * (radius + 40)
userbutton.center.x = pointx
userbutton.center.y = pointy
self.userbutton.append(userbutton)
self.view.addSubview(userbutton)
print("x\(pointx)")
print("y\(pointy)")
}
}
How I would do this:
Create an extension to UIView to get the diagonal and radius. These are handy because we want our "satellites" to have predictable placing even when the "planet" isn't square.
extension UIView {
var diagonal : CGFloat {
return sqrt(pow(self.frame.width, 2) + pow(self.frame.height, 2))
}
var radius : CGFloat {
return diagonal / 2
}
}
This will return a point based on an angle and a distance from an origin.
It uses dreadful trigonometry.
func getPoint(fromPoint point: CGPoint, atDistance distance: CGFloat, withAngleRadians angle:CGFloat) -> CGPoint {
let x = point.x
let y = point.y
let dx = (distance * cos(angle))
let dy = (distance * sin(angle))
return CGPoint(x: (dx + x), y: (dy + y))
}
Now the real function. Generate a bunch of points in a circle pattern. I used a running sum for the angle instead of multiplying each time by the index. This just returns the centre points for the views.
func encirclePoint(point : CGPoint, distance:CGFloat, inParts parts: Int) -> [CGPoint] {
let angle = 2 * CGFloat(M_PI) / CGFloat(parts) // critical part, you need radians for trigonometry
var runningAngle : CGFloat = -(CGFloat(M_PI) / 2) // start at the top
var points : [CGPoint] = []
for _ in 0..<parts {
let circlePoint = getPoint(fromPoint: point, atDistance: distance, withAngleRadians: runningAngle)
points.append(circlePoint)
runningAngle += angle
}
return points
}
Now you can create a simple function that takes a view, a margin and an array of "satellite" views. It will set their centre and add them to the superview of the view we used to input. It makes sense not to add them to the view itself since they might not be placed inside it.
func encircleView(view : UIView, withSubViews subViews : [UIView], withMargin margin : CGFloat) {
guard !(subViews.isEmpty) else { // if there are no subviews : abort
return
}
let distance = view.radius + margin
let points = encirclePoint(view.center, distance: distance, inParts: subViews.count)
guard subViews.count == points.count, let uberView = view.superview else { // if the count is not the same or there is no superview: abort
return
}
for (point, subView) in zip(points, subViews) { subView.center = point }
}
Notice how I did nothing except for the centre calculations in these functions. Styling them goes in another function. This makes it super easy to maintain and debug.
I might even let the last function just return the subviews with updated frames and add them later.
Or negative margin :)
Gist
A full circle is 2 * pi radians. You need to divide that by the number of items you have and multiply that by the index of the item you are currently processing. Use trig to find the location on the circle:
for (index, users) in upimage.enumerate() {
let radians = CGFloat(M_PI) * 2.0 / CGFloat(upimage.count) * CGFloat(index)
......
let centerx = self.view.bounds.width / 2.0
let radius = currentuserpic.frame.size.width / 2.0
let centery = self.view.bounds.height / 2.0
let pointx = centerx + cos(radians) * radius
let pointy = centery + sin(radians) * radius
......
}
What would be the best way to draw a grid like this by using the SpriteKit 2D game engine?
Requirements:
Input programatically the number of columns and rows (5x5, 10x3, 3x4 etc.).
Draw it programmatically using something like SKSpriteNode or SKShapeNode, since just using images of a square like this doesn't seem very efficient to me.
The squares should have a fixed size (let's say each is 40x40).
The grid should be vertically and horizontally centred in the view.
I'm planning to use a SKSpriteNode (from an image) as a player moving in different squares in this grid.
So, I'll save in a 2 dimensional array the central point (x,y) of each square and then move from the player's current position to that position. If you have a better suggestion for this too, I'd like to hear it.
I would appreciate a solution in Swift (preferably 2.1), but Objective-C would do too. Planning on using this only on iPhone devices.
My question is close to this one. Any help is appreciated.
I suggest you implement the grid as a texture of an SKSpriteNode because Sprite Kit will renders the grid in a single draw call. Here's a example of how to do that:
class Grid:SKSpriteNode {
var rows:Int!
var cols:Int!
var blockSize:CGFloat!
convenience init?(blockSize:CGFloat,rows:Int,cols:Int) {
guard let texture = Grid.gridTexture(blockSize: blockSize,rows: rows, cols:cols) else {
return nil
}
self.init(texture: texture, color:SKColor.clear, size: texture.size())
self.blockSize = blockSize
self.rows = rows
self.cols = cols
}
class func gridTexture(blockSize:CGFloat,rows:Int,cols:Int) -> SKTexture? {
// Add 1 to the height and width to ensure the borders are within the sprite
let size = CGSize(width: CGFloat(cols)*blockSize+1.0, height: CGFloat(rows)*blockSize+1.0)
UIGraphicsBeginImageContext(size)
guard let context = UIGraphicsGetCurrentContext() else {
return nil
}
let bezierPath = UIBezierPath()
let offset:CGFloat = 0.5
// Draw vertical lines
for i in 0...cols {
let x = CGFloat(i)*blockSize + offset
bezierPath.move(to: CGPoint(x: x, y: 0))
bezierPath.addLine(to: CGPoint(x: x, y: size.height))
}
// Draw horizontal lines
for i in 0...rows {
let y = CGFloat(i)*blockSize + offset
bezierPath.move(to: CGPoint(x: 0, y: y))
bezierPath.addLine(to: CGPoint(x: size.width, y: y))
}
SKColor.white.setStroke()
bezierPath.lineWidth = 1.0
bezierPath.stroke()
context.addPath(bezierPath.cgPath)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return SKTexture(image: image!)
}
func gridPosition(row:Int, col:Int) -> CGPoint {
let offset = blockSize / 2.0 + 0.5
let x = CGFloat(col) * blockSize - (blockSize * CGFloat(cols)) / 2.0 + offset
let y = CGFloat(rows - row - 1) * blockSize - (blockSize * CGFloat(rows)) / 2.0 + offset
return CGPoint(x:x, y:y)
}
}
And here's how to create a grid and add a game piece to the grid
class GameScene: SKScene {
override func didMove(to: SKView) {
if let grid = Grid(blockSize: 40.0, rows:5, cols:5) {
grid.position = CGPoint (x:frame.midX, y:frame.midY)
addChild(grid)
let gamePiece = SKSpriteNode(imageNamed: "Spaceship")
gamePiece.setScale(0.0625)
gamePiece.position = grid.gridPosition(row: 1, col: 0)
grid.addChild(gamePiece)
}
}
}
Update:
To determine which grid square was touched, add this to init
self.isUserInteractionEnabled = true
and this to the Grid class:
override func touchesBegan(_ touches: Set<UITouch>, withEvent event: UIEvent?) {
for touch in touches {
let position = touch.location(in:self)
let node = atPoint(position)
if node != self {
let action = SKAction.rotate(by:CGFloat.pi*2, duration: 1)
node.run(action)
}
else {
let x = size.width / 2 + position.x
let y = size.height / 2 - position.y
let row = Int(floor(x / blockSize))
let col = Int(floor(y / blockSize))
print("\(row) \(col)")
}
}
}
I am trying to generate circles that nearly border the edge of the screen. I tried creating my own coordinate generator, my issue is that the circles that I am randomly generating are only appearing at the top and bottom of the screen. Here is a screenshot of what it is doing:
http://imgur.com/oP5Wvne
I have no idea why this is happening because when I print the x and y coordinate of the circle's position, it says that both points are less than the frame's width and height. In my GameScene.swift I call this function.
private func generateRandomCoorindates() -> CGPoint {
let randomNumber = arc4random_uniform(2)
var xCoordinate: Double
var yCoordinate: Double
if randomNumber == 0 {
var _xCoordinate: Double {
let _randomNumber = arc4random_uniform(2)
//x-corrdinate either 50 or width-50
if _randomNumber == 0 {
return 50
} else {
return Double(self.frame.width - 50)
}
}
xCoordinate = _xCoordinate
//random y-coordinate from 50 to height-50
yCoordinate = Double.random(lower: 50, upper: Double(self.frame.height) - 50)
}
else {
//random x-coordinate from 50 to width-50
xCoordinate = Double.random(lower: 50, upper: Double(self.frame.width) - 50)
var _yCoordinate: Double {
//y-coordinate either 50 or height - 50
let _randomNumber = arc4random_uniform(2)
if _randomNumber == 0 {
return 50
} else {
return Double(self.frame.height - 50)
}
}
yCoordinate = _yCoordinate
}
return CGPoint(x: CGFloat(xCoordinate), y: CGFloat(yCoordinate))
}
My extensions are:
public func arc4random <T: IntegerLiteralConvertible> (type: T.Type) -> T {
var r: T = 0
arc4random_buf(&r, Int(sizeof(T)))
return r
}
public extension Double {
public static func random(lower lower: Double, upper: Double) -> Double {
let r = Double(arc4random(UInt64)) / Double(UInt64.max)
return (r * (upper - lower)) + lower
}
}
I'm not certain why you've chosen to extend Double when you only need one computed property - it seems to be overcomplicating things. Here's a function that will return a random point somewhere along the edge of the screen, and requires a lot less code.
let screenwidth = UIScreen.mainScreen().bounds.width
let screenheight = UIScreen.mainScreen().bounds.height
func randomCoordinates -> CGPoint {
var coordinates = CGPoint()
let randomX = arc4random(screenwidth) - screenwidth/2 // subtracting half of the screen to center it
let randomY = arc4random(screenheight) - screenheight/2
let randomDirection = arc4random_uniform(4)
switch randomDirection {
case 0: returnCoordinates = CGPoint(x: randomX, y: screenheight/2) // north edge
case 1: returnCoordinates = CGPoint(x: screenwidth/2, y: randomY) // east edge
case 2: returnCoordinates = CGPoint(x: randomX, y: -screenheight/2) // south edge
case 3: returnCoordinates = CGPoint(x: -screenwidth/2, y: randomY) // west edge
}
return coordinates
}