Create a straight line with SpriteKit

Question

How can I create a straight line using SpriteKit and UITouch?

I wanted a method that allowed me to add the start point and the end point instead of a path. Just like a rubber band.

Answer 1

1. Create a SKShapeNode that is a line when user begins the touch movement e.g. in touchesBegan:.

   SKShapeNode *line = [SKShapeNode node];
   CGPoint startPoint = CGPointMake(..., ...)
   CGPoint endPoint = CGPointMake(..., ...)
   
   CGMutablePathRef pathToDraw = CGPathCreateMutable();
   CGPathMoveToPoint(pathToDraw, NULL, startPoint.x, startPoint.y);
   CGPathAddLineToPoint(pathToDraw, NULL, endPoint.x, endPoint.y);
   
   line.path = pathToDraw;
   line.strokeColor = [UIColor redColor]];
   [self addChild:line];
   

2. Modify its path to change its length in touchesMoved: