I've created a sub class of a UIView in which I draw a graph. I made it a public class so I can pass it new data and have it update when needed.
It all worked perfectly until I upgraded to Xcode 6.3 / Swift 1.2. Now when that view attempts to render my app crashes.
The error I get is:
Assertion failed: (CGFloatIsValid(x) && CGFloatIsValid(y)), function void CGPathMoveToPoint(CGMutablePathRef, const
CGAffineTransform *, CGFloat, CGFloat), file Paths/CGPath.cc, line
254.
Here is my code for the class:
import UIKit
public class GraphView: UIView {
//Data from parent VC
var graphPoints = [0, 0, 0, 0, 0, 0, 0]
var keyColor = BabyMasterStyleKit.bathsBase
override public func drawRect(rect: CGRect) {
let context = UIGraphicsGetCurrentContext()
let colorSpace = CGColorSpaceCreateDeviceRGB()
let width = rect.width
let height = rect.height
//calculate the x point
let margin:CGFloat = 15.0
var columnXPoint = { (column:Int) -> CGFloat in
//Calculate gap between points
let spacer = (width - margin*2 - 4) /
CGFloat((self.graphPoints.count - 1))
var x:CGFloat = CGFloat(column) * spacer
x += margin + 2
return x
}
// calculate the y point
let topBorder:CGFloat = 15
let bottomBorder:CGFloat = 15
let graphHeight = height - topBorder - bottomBorder
let maxValue = maxElement(graphPoints)
var columnYPoint = { (graphPoint:Int) -> CGFloat in
var y:CGFloat = CGFloat(graphPoint) /
CGFloat(maxValue) * graphHeight
y = graphHeight + topBorder - y // Flip the graph
return y
}
//Draw horizontal graph lines on the top of everything
var linePath = UIBezierPath()
//top line
linePath.moveToPoint(CGPoint(x:0, y: topBorder))
linePath.addLineToPoint(CGPoint(x: width,
y:topBorder))
//center line
linePath.moveToPoint(CGPoint(x:0,
y: graphHeight/2 + topBorder))
linePath.addLineToPoint(CGPoint(x:width,
y:graphHeight/2 + topBorder))
let color = UIColor.lightGrayColor()
color.setStroke()
linePath.lineWidth = 0.5
linePath.stroke()
// draw the line graph
keyColor.setFill()
keyColor.setStroke()
// set up the points line
var graphPath = UIBezierPath()
// go to start of line
graphPath.moveToPoint(CGPoint(x:columnXPoint(0), y:columnYPoint(graphPoints[0])))
// add points for each item in the graph points array
// at the correct (x, y) for the point
for i in 1..<graphPoints.count {
let nextPoint = CGPoint(x:columnXPoint(i),
y:columnYPoint(graphPoints[i]))
graphPath.addLineToPoint(nextPoint)
}
graphPath.stroke()
//Draw the circles on top of graph stroke
for i in 0..<graphPoints.count {
var point = CGPoint(x:columnXPoint(i), y:columnYPoint(graphPoints[i]))
point.x -= 5.0/2
point.y -= 5.0/2
let circle = UIBezierPath(ovalInRect:
CGRect(origin: point,
size: CGSize(width: 6.0, height: 6.0)))
circle.fill()
}
// add left and bottom borders
UIColor.lightGrayColor().setStroke()
var borderPath = UIBezierPath()
borderPath.moveToPoint(CGPoint(x:0, y:0))
borderPath.addLineToPoint(CGPoint(x:0, y:height))
borderPath.addLineToPoint(CGPoint(x:width, y:height))
borderPath.stroke()
}
}
The app fails at this line:
graphPath.moveToPoint(CGPoint(x:columnXPoint(0), y:columnYPoint(graphPoints[0])))
The array graphPoints is the data I am passing in. I have it set to all 0s as a default. In my ViewController I have a function that passes in an array of real data (7 different numbers) and then does a setNeedsDislay() to re-render the view as needed.
Thanks for your help.
When the input array is
var graphPoints = [0, 0, 0, 0, 0, 0, 0]
then
let maxValue = maxElement(graphPoints)
makes maxValue 0, so that the line in columnYpoint
var y:CGFloat = CGFloat(graphPoint) / CGFloat(maxValue) * graphHeight
does a divide-by-zero and makes y a NaN. It's a special case of having all zero elements in the initial array.
I think the default graphPoints array was being ignored, so when the view first loaded it didn't have values (though it did show that it was passing a 0 into the columnYPoint function, so who knows). As a work around I just tested for y.isNAN and if it was set it to equal 0. After I did that everything worked.
edit: Just checked to see if in fact the default array for graphPoints was getting ignored, and it wasn't. I think that it just doesn't like that it was being passed in a 0 value. If anyone has an idea as to why this would be, I'd love to hear about it.
Related
I am trying to make a rectangle that is made of little squares in it. I am able to create the rectangle using the code given but I want to add a marking on the squares. This way the user can make a distinction between each and every square. I want it to look like a grid.
func drawBoard(boundingRect: CGSize) -> some View {
let columns = self.numColumns
let rows = self.numRows
let blocksize = min(boundingRect.width/CGFloat(columns), boundingRect.height/CGFloat(rows))
let xoffset = (boundingRect.width - blocksize*CGFloat(columns))/2
let yoffset = (boundingRect.height - blocksize*CGFloat(rows))/2
let gameBoard = self.gameBoard
return ForEach(0...columns-1, id:\.self) { (column:Int) in
ForEach(0...rows-1, id:\.self) { (row:Int) in
Path { path in
let x = xoffset + blocksize * CGFloat(column)
let y = boundingRect.height - yoffset - blocksize*CGFloat(row+1)
let rect = CGRect(x: x, y: y, width: blocksize, height: blocksize)
path.addRect(rect)
}
.fill(gameBoard[column][row].color)
}
}
}
I am willing to change the entire code. I just need to make a grid...
GRID
Something like this or with borders or anything. Please help with this solution.
I have a UIView class in my app which plots a line graph. In there, I assign my graphPoints variables like so :
var graphPoints:[Int] = [1,2,3,5,7,9]
var graphPoints2:[Int] = [1,2,3,5,7,9]
What I want to do is pass an array of Int from another class and assign those variables, but I am not sure how to do it. Initially i put all my code into one func with array [Int] as parameters and called it from another class but it stopped plotting the graph altogether. How do i do this?
Here is my UIVIew GraphPlotter class code :
import UIKit
#IBDesignable class GraphPlotter: UIView {
var graphPoints:[Int] = [1,2,3,5,7,9]
var graphPoints2:[Int] = [1,2,3,5,7,9]
//1 - the properties for the gradient
var startColor: UIColor = UIColor.redColor()
var endColor: UIColor = UIColor.greenColor()
override func drawRect(rect: CGRect) {
let width = rect.width
let height = rect.height
//set up background clipping area
let path = UIBezierPath(roundedRect: rect,
byRoundingCorners: UIRectCorner.AllCorners,
cornerRadii: CGSize(width: 8.0, height: 8.0))
path.addClip()
//2 - get the current context
let context = UIGraphicsGetCurrentContext()
let colors = [startColor.CGColor, endColor.CGColor]
//3 - set up the color space
let colorSpace = CGColorSpaceCreateDeviceRGB()
//4 - set up the color stops
let colorLocations:[CGFloat] = [0.0, 1.0]
//5 - create the gradient
let gradient = CGGradientCreateWithColors(colorSpace,
colors,
colorLocations)
//6 - draw the gradient
var startPoint = CGPoint.zero
var endPoint = CGPoint(x:0, y:self.bounds.height)
CGContextDrawLinearGradient(context,
gradient,
startPoint,
endPoint,
[])
//calculate the x point
let margin:CGFloat = 40.0
let columnXPoint = { (column:Int) -> CGFloat in
//Calculate gap between points
let spacer = (width - margin*2 - 4) /
CGFloat((self.graphPoints.count - 1))
var x:CGFloat = CGFloat(column) * spacer
x += margin + 2
return x
}
// calculate the y point
let topBorder:CGFloat = 60
let bottomBorder:CGFloat = 50
let graphHeight = height - topBorder - bottomBorder
let maxValue = graphPoints2.maxElement()!
let columnYPoint = { (graphPoint2:Int) -> CGFloat in
var y:CGFloat = CGFloat(graphPoint2) /
CGFloat(maxValue) * graphHeight
y = graphHeight + topBorder - y // Flip the graph
return y
}
// draw the line graph
UIColor.flatTealColor().setFill()
UIColor.flatTealColor().setStroke()
//set up the points line
let graphPath = UIBezierPath()
//go to start of line
graphPath.moveToPoint(CGPoint(x:columnXPoint(0),
y:columnYPoint(graphPoints2[0])))
//add points for each item in the graphPoints array
//at the correct (x, y) for the point
for i in 1..<graphPoints.count {
let nextPoint = CGPoint(x:columnXPoint(i),
y:columnYPoint(graphPoints2[i]))
graphPath.addLineToPoint(nextPoint)
}
//Create the clipping path for the graph gradient
//1 - save the state of the context (commented out for now)
CGContextSaveGState(context)
//2 - make a copy of the path
let clippingPath = graphPath.copy() as! UIBezierPath
//3 - add lines to the copied path to complete the clip area
clippingPath.addLineToPoint(CGPoint(
x: columnXPoint(graphPoints.count - 1),
y:height))
clippingPath.addLineToPoint(CGPoint(
x:columnXPoint(0),
y:height))
clippingPath.closePath()
//4 - add the clipping path to the context
clippingPath.addClip()
let highestYPoint = columnYPoint(maxValue)
startPoint = CGPoint(x:margin, y: highestYPoint)
endPoint = CGPoint(x:margin, y:self.bounds.height)
CGContextDrawLinearGradient(context, gradient, startPoint, endPoint, [])
CGContextRestoreGState(context)
//draw the line on top of the clipped gradient
graphPath.lineWidth = 2.0
graphPath.stroke()
//Draw the circles on top of graph stroke
for i in 0..<graphPoints.count {
var point = CGPoint(x:columnXPoint(i), y:columnYPoint(graphPoints2[i]))
point.x -= 5.0/2
point.y -= 5.0/2
let circle = UIBezierPath(ovalInRect:
CGRect(origin: point,
size: CGSize(width: 5.0, height: 5.0)))
circle.fill()
let label = UILabel(frame: CGRectMake(0, 0, 200, 21))
label.center = CGPointMake(160, 284)
label.textAlignment = NSTextAlignment.Center
// label.text = "I'am a test label"
self.addSubview(label)
}
//Draw horizontal graph lines on the top of everything
let linePath = UIBezierPath()
//top line
linePath.moveToPoint(CGPoint(x:margin, y: topBorder))
linePath.addLineToPoint(CGPoint(x: width - margin,
y:topBorder))
//center line
linePath.moveToPoint(CGPoint(x:margin,
y: graphHeight/2 + topBorder))
linePath.addLineToPoint(CGPoint(x:width - margin,
y:graphHeight/2 + topBorder))
//bottom line
linePath.moveToPoint(CGPoint(x:margin,
y:height - bottomBorder))
linePath.addLineToPoint(CGPoint(x:width - margin,
y:height - bottomBorder))
let color = UIColor.flatTealColor()
color.setStroke()
linePath.lineWidth = 1.0
linePath.stroke()
}
}
DBController, func dosmth where I pass the array :
func dosmth(metadata: DBMetadata!) {
let documentsDirectoryPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0]
let localFilePath = (documentsDirectoryPath as NSString).stringByAppendingPathComponent(metadata.filename)
var newarray = [Int]()
do{
let data = try String(contentsOfFile: localFilePath as String,
encoding: NSASCIIStringEncoding)
print(data)
newarray = data.characters.split(){$0 == ","}.map{
Int(String.init($0).stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet()))!}
print(newarray)
}
catch let error { print(error) }
//Probably wrong
GraphPlotter().graphPoints = newarray
GraphPlotter().graphPoints2 = newarray
}
So your drawRect method is based on the two variables graphPoints and graphPoints2. Create a method whose job is to update the arrays of these two variables, and then invoke setNeedsDisplay - which will go on to redraw the view.
func plotGraphPoints(gpArray1 : [Int], andMorePoints gpArray2: [Int] ) {
print("Old Values", self.graphPoints)
self.graphPoints = gpArray1
self.graphPoints2 = gpArray2
print("New values", self.graphPoints)
self.setNeedsDisplay()
}
First, I'd set these up so that any update will redraw the view:
var graphPoints:[Int]? { didSet { setNeedsDisplay() } }
var graphPoints2:[Int]? { didSet { setNeedsDisplay() } }
Note, I made those optionals, because you generally want it to handle the absence of data with nil values rather than dummy values. This does assume, though, that you'll tweak your implementation to detect and handle these nil values, e.g., before you start drawing the lines, do a
guard graphPoints != nil && graphPoints2 != nil else { return }
But, I notice that this whole class is IBDesignable, in which case, you probably want a prepareForInterfaceBuilder that provides sample data:
override func prepareForInterfaceBuilder() {
super.prepareForInterfaceBuilder()
graphPoints = [1,2,3,5,7,9]
graphPoints2 = [1,2,3,5,7,9]
}
Second, your other class needs to have a reference to this custom view.
If this "other" class is the view controller and you added the custom view via IB, you would just add a #IBOutlet for the custom view to this view controller. If you added this custom view programmatically, you'd just keep a reference to it in some property after adding it to the view hierarchy. But, however you added a reference to that view, say graphView, you'd just set these properties:
graphView.graphPoints = ...
graphView.graphPoints2 = ...
If this "other" class is something other than a view controller (and in discussion, it sounds like the class in question is a controller for processing of asynchronous DropBox API), you also need to give that class some mechanism to reference the view controller (and thus the custom view). You can accomplish this by either implementing a "completion handler pattern" or a "delegate-protocol" pattern.
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
......
}
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.)