I have seen a number of posts on looping through a dictionary but they are a different and simpler than what I want to achieve here, in my opinion. I have the following arrays:
pt1.array = [0:[pt2.point],
1:[pt8.point, pt12.point, pt4.point],
2:[pt20.point, pt14.point, pt3.point],
3:[pt7.point, pt8.point, pt9.point]]
pt2.array = [0:[pt5.point],
1:[pt8.point, pt11.point, pt1.point],
2:[pt10.point, pt9.point, pt3.point],
3:[pt6.point, pt1.point, pt4.point]]
pt3.array = [0:[pt13.point],
1:[pt1.point, pt15.point, pt7.point],
2:[pt19.point, pt14.point, pt2.point],
3:[pt10.point, pt11.point, pt12.point]]
pt4.array = [0:[pt8.point],
1:[pt9.point, pt11.point, pt13.point],
2:[pt14.point, pt15.point, pt6.point],
3:[pt3.point, pt2.point, pt1.point]]
pt5.array = [0:[pt18.point],
1:[pt8.point, pt6.point, pt1.point],
2:[pt3.point, pt17.point, pt4.point],
3:[pt16.point, pt15.point, pt14.point]]
allPoints = [pt1, pt2, pt3, pt4, pt5]
How can I iterate to remove pt3.point which is a CGPoint from all the Int-[CGPoint] dictionaries in the allPoints array?
I tried the following:
for pt in allPoints {
for ptArrIndex in pt.arrays {
for (key, value) in ptArrIndex {
//remove point from dict here
}
}
}
but I got the error:
Type '(key: Int, value:[CGPoint])' (aka'(key: Int, value: Array<CGPoint>)') does not conform to protocol 'Sequence'
at the line:
for (key, value) in ptArrIndex {
EDIT
The struct that creates each of the points is below:
struct Point {
var point: CGPoint
var arrays: [Int: [CGPoint]]
}
UPDATED QUESTION
Based on Rob Napier’s suggestion I’ve updated the question:
I have a struct below:
struct Location {
var point: CGPoint
var changedLoc: [Int: [CGPoint]]
}
where point represents a CGPoint for Location and changedLoc represents all the possible groups of CGPoints Location can change to. I calculate this randomly.
I have the following Locations
var location1 = Location(point: initialBallPosition, changedLoc: [0: [CGPoint(x: 421.0, y: 43.0), CGPoint(x: 202.0, y: 69.0)], 1: [CGPoint(x: 121.0, y: 198.0)]])
var location2 = Location(point: initialBallPosition, changedLoc: [0: [CGPoint(x: 421.0, y: 43.0), CGPoint(x: 123.0, y: 254.0)], 1: [CGPoint(x: 90.0, y: 104.0)]])
var allLocations = [location1, location2]
From allLocations how can I remove the point CGPoint(x: 421.0, y: 43.0) which is in both location1 and location2 changedLoc?
func locationsRemoving(changedLoc removePoint: CGPoint, from locations: [Location]) -> [Location] {
return locations.map { location in
var changedLoc: [Int: [CGPoint]] = [:]
for (key, values) in location.changedLoc {
changedLoc[key] = values.filter{ $0 != removePoint }
}
return Location(point: location.point, changedLoc: changedLoc)
}
}
let removePoint = CGPoint(x: 421.0, y: 43.0)
print(allLocations)
print(locationsRemoving(changedLoc: removePoint, from: allLocations))
The confusing thing you have is that the property named array in the ptN instances is actually a Dictionary<Int, [CGPoint]>
So, for the structure you currently have, you'll need to amend your code to match:
for pt in allPoints {
for (key, ptArray) in pt.array {
for elem in ptArray {
//remove point from dict here
}
}
}
Related
I’m playing around with learning about pointers in Swift.
For instance, this code starts with a CGPoint array, creates an UnsafePointer and then extracts all the x values into a CGFloat array:
import Foundation
let points = [CGPoint(x:1.2, y:3.33), CGPoint(x:1.5, y:1.21), CGPoint(x:1.48, y:3.97)]
print(points)
let ptr = UnsafePointer(points)
print(ptr)
func xValues(buffer: UnsafePointer<CGPoint>, count: Int) -> [CGFloat]? {
return UnsafeBufferPointer(start: buffer, count: count).map { $0.x }
}
let x = xValues(buffer: ptr, count: points.count)
print(x)
And the expected output is:
[Foundation.CGPoint(x: 1.2, y: 3.33), Foundation.CGPoint(x: 1.5, y: 1.21), Foundation.CGPoint(x: 1.48, y: 3.97)]
0x0000556d6b818aa0
Optional([1.2, 1.5, 1.48])
Now I’d like to have the xValues function return directly UnsafePointer<CGFloat>, instead of going through [CGFloat].
How do I do that, is that possible?
It is unsafe to output pointers like that. As mentioned in comments you should use withUnsafeBufferPointer method to access the underlying buffer:
let points = [
CGPoint(x:1.2, y:3.33),
CGPoint(x:1.5, y:1.21),
CGPoint(x:1.48, y:3.97)
]
let xValues = points.withUnsafeBufferPointer { buffer in
return buffer.map { $0.x }
}
If you need a pointer to the array of CGFloat just use the same method as above:
xValues.withUnsafeBufferPointer { buffer in
// Do things with UnsafeBufferPointer<CGFloat>
}
A good Swift Pointer tutorial here.
Edit
Here is a working example:
let points = [
CGPoint(x:1.2, y:3.33),
CGPoint(x:1.5, y:1.21),
CGPoint(x:1.48, y:3.97)
]
// Create, init and defer dealoc
let ptr = UnsafeMutablePointer<CGFloat>.allocate(capacity: points.count)
ptr.initialize(repeating: 0.0, count: points.count)
defer {
ptr.deallocate()
}
// Populate pointer
points.withUnsafeBufferPointer { buffer in
for i in 0..<buffer.count {
ptr.advanced(by: i).pointee = buffer[i].x
}
}
// Do things with UnsafeMutablePointer<CGFloat>, for instance:
let buffer = UnsafeBufferPointer(start: ptr, count: points.count)
for (index, value) in buffer.enumerated() {
print("index: \(index), value: \(value)")
}
I have this code:
var triangles: [[[CAShapeLayer]]] = Array(repeating: Array(repeating: Array(repeating: 0, count: 2), count: 15), count: 15);
But it generates an "Cannot convert value of type..." compilation error.
How can I solve that? I want to access my CAShapeLayers like this:
triangles[1][2][1].fillColor = UIColor(red: 40/255, green: 73/255, blue: 80/255, alpha: 1).cgColor;
Use optionals.
var triangles: [[[CAShapeLayer?]]] = Array(repeating: Array(repeating: Array(repeating: nil, count: 2), count: 15), count: 15)
Now there's a nil instead of a 0, which is what I think you were hinting at. But every triangles[x][y][z] is now an optional type you'll have to safely unwrap.
So now you have to do something like triangles[x][y][z] = CAShapeLayer() before you do anything to that object.
Edit for correction. Thanks #OOPer
I thought about it some more, and realized I didn't really answer your question.
So you may use for loops to initialize everything (which would be a pain), or you could do something like this every time you access an index:
if triangles[x][y][z] == nil
{
triangles[x][y][z] = CAShapeLayer()
}
let bloop = triangles[x][y][z]!
bloop.fillColor = UIColor(...
Then you could pull it out into an outside method so it becomes a 1 liner. Like:
func tri(at x: Int, _ y: Int, _ z: Int) -> CAShapeLayer
{
if triangles[x][y][z] == nil
{
triangles[x][y][z] = CAShapeLayer()
}
return triangles[x][y][z]!
}
Then when using it:
tri(at: 1, 2, 1).fillColor = ...
Of course, you should pull triangles out and make it a property of the class you're in, or you can include it in the parameter list of that 1 liner method.
All that nesting makes your code hard to understand, and Array(repeating:count:) can't do what you want anyway.
func newGrid() -> [[[CAShapeLayer]]] {
func newStack() -> [CAShapeLayer] {
return (0 ..< 2).map({ _ in CAShapeLayer() })
}
func newRow() -> [[CAShapeLayer]] {
return (0 ..< 15).map({ _ in newStack() })
}
return (0 ..< 15).map({ _ in newRow() })
}
var triangles = newGrid()
You cannot use "0" as the repeating value, it will be inferred to be type [[[Int]]]. Just replace "0" with "CAShapeLayer()"
I would like to extract a value from an array loaded from plist
var buttonPointReload = data!["\(strFromPass)"] as? Dictionary<String, String>
if var dict = buttonPointReload {
for (one, two) in dict {
println(dict) // I have [Button 1: [-200, -90]]
println(one) // I have Button 1
println(two) // I have [-200, -90]
println("\(one[0])")
}}
I save my Array in this mode
var arrPosition : [String] = []
var x: Int = ("\(line)").toInt()!
var y: Int = ("\(column)").toInt()!
arrPosition = ["\(x)"]
arrPosition.append("\(y)")
dict["Button \(index)"] = "\(arrPosition)"
data?.setValue(dict, forKey: "\(strFromPass)")
data?.writeToFile(path, atomically: true)
I am trying in this way but I get
Int doesn't have member named 'substring'
how can I get the value -200 ?
You can use CGPointFromString to convert a String
"[-200, -90]"
into a CGPoint struct.
Once you have a CGPoint you can easily access the x and y values.
You can paste this code inside your FOR loop.
let point : CGPoint = CGPointFromString(two)
println("x: \(point.x) and y: \(point.y)") // "x: -200.0 and y: -90.0"
Just note the CGPoint stores the x and y into Float(s), not Int(s).
I'm working with Swift, Xcode 6 and SpriteKit,
I want make a game where some sprites fall down from the top of the screen, but each sprite have a defined speed, position and activation time. I have this working code, but I really don't think that it's the most optimised way to do it:
class obstacles: SKSpriteNode
{
var isOnScreen = false
var type: Int = 0
var initTime: Int = 0
}
var obstacle = [obstacles]() // obstacle is an array of SKSpriteNode
// type : initTime : speed : position : xScale : yScale
var level1: [String] = ["0:120:3:0:1:1", "0:130:4:80:2:2","1:140:8:120:6:1","0:150:6:240:2:2"]
override func didMoveToView(view: SKView)
{
initObstacles()
}
func initObstacles()
{
for var x = 0; x < level1.count; x++ // for each obstacle
{
var index = 0
var type = String("")
var initTime = String("")
var speed = String("")
var position = String("")
var xScale = String("")
var yScale = String("")
var lastIndex = obstacle.count
for Character in level1[x] // we read each character one by one
{
if Character == ":" { index++ } // if it's a ":" we change the variable
else
{
switch index
{
case 0:
type += String(Character)
case 1:
initTime += String(Character)
case 2:
speed += String(Character)
case 3:
position += String(Character)
case 4:
xScale += String(Character)
case 5:
yScale += String(Character)
default:
break;
}
}
}
obstacle.append(obstacles(imageNamed: "Rectangle")) // we add an element to the array
obstacle[lastIndex].type = type.toInt()! // we init all the values
obstacle[lastIndex].initTime = initTime.toInt()!
obstacle[lastIndex].speed = CGFloat(speed.toInt()!)
obstacle[lastIndex].size.width = DEFAULT_OBSTACLE_SIZE * CGFloat(xScale.toInt()!)
obstacle[lastIndex].size.height = DEFAULT_OBSTACLE_SIZE * CGFloat(yScale.toInt()!)
obstacle[lastIndex].position = CGPointMake(CGFloat(position.toInt()!) - obstacle[lastIndex].size.width/2, CGRectGetMaxY(frame) + obstacle[lastIndex].size.height/2)
}
}
Do you know how could I manage to do the same thing, but more "clean" ?
I would suggest to create a class or struct that holds all necessary data for an obstacle and additionally change your type from a standard number to an enum, e.g.:
enum ObstacleType {
case Block, Tree, WhatEverObstaclesYouHave...
}
struct Obstacle {
var type: ObstacleType
var initializationTime: NSTimeInterval
var speed: Double
// and similarly for position, your scales and what you may need in future
}
and create them using, e.g.
Obstacle(type: .Block, initializationTime: 0, speed: 12.0, ...)
Advantage (obviously) is that you have no problems anymore parsing your string (there is no string anymore) and can provide all necessary information using the appropriate type directly. And you can easily use an enum for your type, which should be an enum, because your Obstacle is not a 1, but a Block, Tree or whatever.
Your level1 variable could then be defined like this:
var level1 : [Obstacle] = [
Obstacle(type: .Block, initializationTime: 120, speed: 3.0, ...),
Obstacle(type: .Block, initializationTime: 130, speed: 4.0, ...),
Obstacle(type: .Tree, initializationTime: 140, speed: 8.0, ...),
Obstacle(type: .Block, initializationTime: 150, speed: 6.0, ...)
]
To get rid of the labels in the initializer, just define your own initializer. Just add this to your struct:
init(_ type: ObstacleType, _ time: NSTimeInterval, _ speed: Double, ...) {
self.type = type
self.initializationTime = time
self.speed = speed
// other variables...
}
Then you can create every Obstacle like this:
Obstacle(.Block, 120, 3.0, ...)
But now you can not easily tell anymore which number has what meaning from reading the instantiation. I do not recommend this just to type less as autocomplete will present you with most of it.
I got error: '(Int, Int)' is not identical to 'CGPoint'
How to convert a (Int, Int) to CGPoint
let zigzag = [(100,100),
(100,150),(150,150),
(150,200)]
override func drawRect(rect: CGRect)
{
// Get the drawing context.
let context = UIGraphicsGetCurrentContext()
// Create the shape (a vertical line) in the context.
CGContextBeginPath(context)
//Error is here
CGContextAddLines(context, zigzag, zigzag.count)
// Configure the drawing environment.
CGContextSetStrokeColorWithColor(context,UIColor.redColor().CGColor)
// Request the system to draw.
CGContextStrokePath(context)
}
CGContextAddLines() expects an array of CGPoint. If you already have an
array of (Int, Int) tuples then you can convert it with
let points = zigzag.map { CGPoint(x: $0.0, y: $0.1) }
An alternate way to avoid the boilerplate code required to create instances of the same type is to make CGPoint implement the ArrayLiteralConvertible, making it initializable by assigning an array of CGFloat:
extension CGPoint : ArrayLiteralConvertible {
public init(arrayLiteral elements: CGFloat...) {
self.x = elements.count > 0 ? elements[0] : 0.0
self.y = elements.count > 1 ? elements[1] : 0.0
}
}
and then use it as follows:
let zigzag:[CGPoint] = [
[100,100],
[100,150],
[150,150],
[150,200]
]
A few notes:
stylistically, it doesn't look good - it would be good if literals could be used for tuples, but I am not aware of any way to do that
if an empty array is used, the CGPoint is initialized with x = 0 and y = 0
if an array with one element is used, it is initialized with y = 0
if more than 2 values are used, all the ones after the 2nd are ignored
If it tells you to use CGPoint, use it! Just (number,number) is a pair of ints.
let zigzag = [CGPointMake(100,100),
CGPointMake(100,150),CGPointMake(150,150),
CGPointMake(150,200)]
Yet another:
func CGPoints(points:(x:CGFloat, y:CGFloat)...) -> [CGPoint] {
return map(points) { CGPoint($0) }
}
let zigzag = CGPoints(
(100,100),(100,150),(150,150),(150,200)
)