[IOS]CoreGraphics스케치

그래픽 라이브러리를 활용한 스케치 어플을 만들어 보았다.

스토리보드 구성

코드

import UIKit

class ViewController: UIViewController {

    @IBOutlet var imgView: UIImageView!
    
    var lastPoint: CGPoint! //터치하거나, 이동한 위치
    var lineSize:CGFloat = 2.0 //선 두깨
    var lineColor = UIColor.red.cgColor //선 색상
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }

    //버튼을 눌렀을 때 이미지 뷰 초기화
    @IBAction func btnClearImageView(_ sender: UIButton) {
        imgView.image = nil
    }

    //터치가 시작되었을 때
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        let touch = touches.first! as UITouch
        
        lastPoint = touch.location(in: imgView)
    }
    
    //터치된 위치가 움직였을 때
    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        UIGraphicsBeginImageContext(imgView.frame.size)
        UIGraphicsGetCurrentContext()?.setStrokeColor(lineColor)
        UIGraphicsGetCurrentContext()?.setLineCap(CGLineCap.round) //라인 끝 모양을 라운드로 설정
        UIGraphicsGetCurrentContext()?.setLineWidth(lineSize)
        
        let touch = touches.first! as UITouch //발생한 터치 이벤트 가져옴
        let currPoint = touch.location(in: imgView) //터치된 위치 설정
        
        imgView.image?.draw(in: CGRect(x: 0, y: 0, width: imgView.frame.size.width, height: imgView.frame.size.height)) //이미지 뷰 크기로 그림
        
        UIGraphicsGetCurrentContext()?.move(to: CGPoint(x: currPoint.x, y: currPoint.y)) //시작위치 이동
        UIGraphicsGetCurrentContext()?.addLine(to: CGPoint(x: currPoint.x, y: currPoint.y)) //현재위치까지 선 추가
        UIGraphicsGetCurrentContext()?.strokePath()
        
        imgView.image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        lastPoint = currPoint //변수 할당
    }
    
    //터치가 끝났을 때
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        UIGraphicsBeginImageContext(imgView.frame.size)
        UIGraphicsGetCurrentContext()?.setStrokeColor(lineColor)
        UIGraphicsGetCurrentContext()?.setLineCap(CGLineCap.round)
        UIGraphicsGetCurrentContext()?.setLineWidth(lineSize)
        
        imgView.image?.draw(in: CGRect(x: 0, y: 0, width: imgView.frame.size.width, height: imgView.frame.size.height))
        
        UIGraphicsGetCurrentContext()?.move(to: CGPoint(x: lastPoint.x, y: lastPoint.y))
        UIGraphicsGetCurrentContext()?.addLine(to: CGPoint(x: lastPoint.x, y: lastPoint.y))
        UIGraphicsGetCurrentContext()?.strokePath()
        
        imgView.image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
    }
    
    override func motionEnded(_ motion: UIEvent.EventSubtype, with event: UIEvent?) {
        if motion == .motionShake { //폰을 흔들었을 때
            imgView.image = nil //이미지 뷰 초기화
        }
    }
}

실행 결과