Drawing an Arrow with Swift

UIBezier+Arrow.swift

extension UIBezierPath {
  
  class func getAxisAlignedArrowPoints(inout points: Array<CGPoint>, forLength: CGFloat, tailWidth: CGFloat, headWidth: CGFloat, headLength: CGFloat ) {

    let tailLength = forLength - headLength
    points.append(CGPointMake(0, tailWidth/2))
    points.append(CGPointMake(tailLength, tailWidth/2))
    points.append(CGPointMake(tailLength, headWidth/2))
    points.append(CGPointMake(forLength, 0))
    points.append(CGPointMake(tailLength, -headWidth/2))
    points.append(CGPointMake(tailLength, -tailWidth/2))
    points.append(CGPointMake(0, -tailWidth/2))

  }
  
  
  class func transformForStartPoint(startPoint: CGPoint, endPoint: CGPoint, length: CGFloat) -> CGAffineTransform{
    let cosine: CGFloat = (endPoint.x - startPoint.x)/length
    let sine: CGFloat = (endPoint.y - startPoint.y)/length
    
    return CGAffineTransformMake(cosine, sine, -sine, cosine, startPoint.x, startPoint.y)
  }
  
  
  class func bezierPathWithArrowFromPoint(startPoint:CGPoint, endPoint: CGPoint, tailWidth: CGFloat, headWidth: CGFloat, headLength: CGFloat) -> UIBezierPath {
    
    let xdiff: Float = Float(endPoint.x) - Float(startPoint.x)
    let ydiff: Float = Float(endPoint.y) - Float(startPoint.y)
    let length = hypotf(xdiff, ydiff)
    
    var points = [CGPoint]()
    self.getAxisAlignedArrowPoints(&points, forLength: CGFloat(length), tailWidth: tailWidth, headWidth: headWidth, headLength: headLength)
    
    var transform: CGAffineTransform = self.transformForStartPoint(startPoint, endPoint: endPoint, length:  CGFloat(length))
    
    var cgPath: CGMutablePathRef = CGPathCreateMutable()
    CGPathAddLines(cgPath, &transform, points, 7)
    CGPathCloseSubpath(cgPath)
    
    var uiPath: UIBezierPath = UIBezierPath(CGPath: cgPath)
    return uiPath
  }
}

Use it like this

let arrowPath = UIBezier. bezierPathWithArrowFromPoint(CGPointMake(0,0), CGPointMake(0,20), 4, 8, 6)

Good job!

Perfect job 💯

Excellent "mwermuth" Awesome work ... Helps me lot ... Please let me know this to draw in the real time drawing from one point to another point ... thanks in advance.

How to use it between views?

how to draw curved arrow ???

let arrowPath = UIBezier. bezierPathWithArrowFromPoint(CGPointMake(0,0), CGPointMake(0,20), 4, 8, 6)

How overlay this arrowPath on UIImageView() ?

Updated for Swift 5:

`extension UIBezierPath {
class func getAxisAlignedArrowPoints(points: inout [CGPoint], forLength: CGFloat, tailWidth: CGFloat, headWidth: CGFloat, headLength: CGFloat) {
let tailLength = forLength - headLength
points.append(CGPointMake(0, tailWidth / 2))
points.append(CGPointMake(tailLength, tailWidth / 2))
points.append(CGPointMake(tailLength, headWidth / 2))
points.append(CGPointMake(forLength, 0))
points.append(CGPointMake(tailLength, -headWidth / 2))
points.append(CGPointMake(tailLength, -tailWidth / 2))
points.append(CGPointMake(0, -tailWidth / 2))
}

class func transformForStartPoint(startPoint: CGPoint, endPoint: CGPoint, length: CGFloat) -> CGAffineTransform {
    let cosine: CGFloat = (endPoint.x - startPoint.x) / length
    let sine: CGFloat = (endPoint.y - startPoint.y) / length

    return CGAffineTransformMake(cosine, sine, -sine, cosine, startPoint.x, startPoint.y)
}

class func bezierPathWithArrowFromPoint(startPoint: CGPoint,
                                        endPoint: CGPoint,
                                        tailWidth: CGFloat,
                                        headWidth: CGFloat,
                                        headLength: CGFloat) -> UIBezierPath
{
    let xdiff = Float(endPoint.x) - Float(startPoint.x)
    let ydiff = Float(endPoint.y) - Float(startPoint.y)
    let length = hypotf(xdiff, ydiff)

    var points = [CGPoint]()
    getAxisAlignedArrowPoints(points: &points, forLength: CGFloat(length), tailWidth: tailWidth, headWidth: headWidth, headLength: headLength)

    let transform: CGAffineTransform = transformForStartPoint(startPoint: startPoint, endPoint: endPoint, length: CGFloat(length))

    let cgPath = CGMutablePath()
    cgPath.addLines(between: points, transform: transform)
    cgPath.closeSubpath()

    let uiPath = UIBezierPath(cgPath: cgPath)
    return uiPath
}

}`