How to draw a line in Sprite-kit

Question

How can one draw a line in Sprite-kit? For example if I want to draw a line in cocos2d, I could easily using ccDrawLine();

Is there an equivalent in sprite-kit?

Bedspread

Answer 1

Using SKShapeNode you can draw line or any shape.

SKShapeNode *yourline = [SKShapeNode node];
CGMutablePathRef pathToDraw = CGPathCreateMutable();
CGPathMoveToPoint(pathToDraw, NULL, 100.0, 100.0);
CGPathAddLineToPoint(pathToDraw, NULL, 50.0, 50.0);
yourline.path = pathToDraw;
[yourline setStrokeColor:[SKColor redColor]];
[self addChild:yourline];

Equivalent for Swift 4:

var yourline = SKShapeNode()
var pathToDraw = CGMutablePath()
pathToDraw.move(to: CGPoint(x: 100.0, y: 100.0))
pathToDraw.addLine(to: CGPoint(x: 50.0, y: 50.0))
yourline.path = pathToDraw
yourline.strokeColor = SKColor.red
addChild(yourline)

Autogiro

no correction at all, Waruna should give it a tick as its correct. – Dasyure

@Smick - Waruna will accept answer buddy whenever he want...dont worry.. its correct answer.. :) – Autogiro

can you try solve this - its a good question #19214540 – Dasyure

may be this will help cocoanetics.com/2010/01/uilabels-with-neon-effect – Autogiro

You should use SKColor, on iOS that compiles to UIColor, on OSX to NSColor. So it works on both platforms. – Yep

Is it possible to change the line's thickness ? – Catching

Swift 2.2 - SKShapeNode still sucks. – Ki

Don't forget to end with CGPathRelease(pathToDraw); or you will have a memory leak. – Loo

Answer 2

Using SKShapeNode I was able to do this.

// enter code here
SKShapeNode *line = [SKShapeNode node];

CGMutablePathRef path = CGPathCreateMutable();
CGPathMoveToPoint(path, NULL, 50.0, 40.0);
CGPathAddLineToPoint(path, NULL, 120.0, 400.0);

line.path = path;
[line setStrokeColor:[UIColor whiteColor]];

[self addChild:line];

Bedspread

Answer 3

Swift 3 for drawing line via SKShapeNode:

            // Define start & end point for line
            let startPoint = CGPoint.zero
            let endPoint = CGPoint.zero

            // Create line with SKShapeNode
            let line = SKShapeNode()
            let path = UIBezierPath()
            path.move(to: startPoint)
            path.addLine(to: endPoint)
            line.path = path.cgPath
            line.strokeColor = UIColor.white
            line.lineWidth = 2

Snafu

Answer 4

If you only want a line, sort of how people use UIViews for lines (only), then you can just use a SKSpriteNode

SKSpriteNode* line = [SKSpriteNode spriteNodeWithColor:[SKColor blackColor] size:CGSizeMake(160.0, 2.0)];
[line setPosition:CGPointMake(136.0, 50.0))];
[self addChild:line];

Palimpsest

Answer 5

Here is the equivalent code in SWIFT:

    let pathToDraw:CGMutablePathRef = CGPathCreateMutable()
    let myLine:SKShapeNode = SKShapeNode(path:pathToDraw)

    CGPathMoveToPoint(pathToDraw, nil, 100.0, 100)
    CGPathAddLineToPoint(pathToDraw, nil, 50, 50)

    myLine.path = pathToDraw
    myLine.strokeColor = SKColor.redColor()

    self.addChild(myLine)

Converted from to @Rajneesh071's objective c code sample.

Tummy

Answer 6

I found this post while trying to draw a line on each mouseDown, of the example xCode / OS X / Game (aka SpriteKit)/ Application.

You can copy/paste this code into GameScene.swift. It should draw a line on each mouse-down event by user. Looks 'etch-a-sketch'-style.

import SpriteKit

var lastPoint: CGPoint = CGPoint(x: 0.0, y: 0.0)
var newPoint: CGPoint = CGPoint(x: 100.0, y: 100.0)


class GameScene: SKScene {
    override func didMoveToView(view: SKView) {
        /* Setup your scene here */
        self.backgroundColor = SKColor.blackColor()
        let myLabel = SKLabelNode(fontNamed:"default")
        myLabel.text = "SKSpriteNode Draw Lines";
        myLabel.fontSize = 15;
        myLabel.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame));

        self.addChild(myLabel)
    }

    override func mouseDown(theEvent: NSEvent) {
        /* Called when a mouse click occurs */

        let location = theEvent.locationInNode(self)
        newPoint = location

        let pathToDraw:CGMutablePathRef = CGPathCreateMutable()
        let myLine:SKShapeNode = SKShapeNode(path:pathToDraw)


        CGPathMoveToPoint(pathToDraw, nil, lastPoint.x, lastPoint.y)
        CGPathAddLineToPoint(pathToDraw, nil, newPoint.x, newPoint.y)
        lastPoint = newPoint

        myLine.path = pathToDraw
        myLine.strokeColor = SKColor.whiteColor()

        self.addChild(myLine)
    }
}

For the newbies, this is what my xCode project looks like:

For the small handful iOS of folks. Same code as above ported to touchBegan of the example iOS / Game (aka SpriteKit) / Application default project.

Put this code in your GameScene.swift file

import SpriteKit

var lastPoint: CGPoint = CGPoint(x: 0.0, y: 0.0)
var newPoint: CGPoint = CGPoint(x: 100.0, y: 100.0)


class GameScene: SKScene {
    override func didMoveToView(view: SKView) {
        /* Setup your scene here */
        self.backgroundColor = SKColor.blackColor()
        let myLabel = SKLabelNode(fontNamed:"default")
        myLabel.text = "SKSpriteNode Draw Lines";
        myLabel.fontSize = 15;
        myLabel.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame));

        self.addChild(myLabel)
    }


override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
    /* Called when a touch begins */

    for touch in (touches as! Set<UITouch>) {
        let location = touch.locationInNode(self)

        newPoint = location

        let pathToDraw:CGMutablePathRef = CGPathCreateMutable()
        let myLine:SKShapeNode = SKShapeNode(path:pathToDraw)


        CGPathMoveToPoint(pathToDraw, nil, lastPoint.x, lastPoint.y)
        CGPathAddLineToPoint(pathToDraw, nil, newPoint.x, newPoint.y)
        lastPoint = newPoint

        myLine.path = pathToDraw
        myLine.strokeColor = SKColor.whiteColor()
        self.addChild(myLine)
   }}}

Enjoy.

Ossie

Answer 7

Here is my Swift 4 function to add a Line between two points:

func drawLine(from: CGPoint, to: CGPoint) {
    let line = SKShapeNode()
    let path = CGMutablePath()
    path.addLines(between: [from, to])
    line.path = path
    line.strokeColor = .black
    line.lineWidth = 2
    addChild(line)
}

Hope it helps!!

Kape