How to Reset or Clear UI View - ios

Question

I am programming something like PONG in IOS Playgrounds.
It is all working but it is crashing after a few seconds.
I don't really know why. Can someone please help me?
The Position of the Ball is changing and The Touch Event is working but it crashes in the draw Function of the UIView
I tried to turn clear Context and all but it didn't work
import UIKit;
import PlaygroundSupport;
import CoreGraphics;
import Dispatch;
func delay (delay:Double)
{
let t = CACurrentMediaTime()
var b = true
while b {
if(CACurrentMediaTime()>t+delay){
b=false;
return
}
}
}
let page = PlaygroundPage.current
var sheight:Double = 700 //Double(UIScreen.main.bounds.height);
var swidth:Double = 900 //Double(UIScreen.main.bounds.width);
let v = UIView(frame: CGRect(x: -100, y: -100, width: swidth, height: sheight))
swidth = Double(v.bounds.width)
sheight = Double(v.bounds.height)
let moveStab = sheight / 300;
var dirX = 1.0
var dirY = 1.0
let bsp:Double = 3.0
var Point1 = 0;
var Point2 = 0;
let psp:Double = 2.0
var up = [false,false]
var down = [false,false]
var ballx = swidth / 2;
var bally = sheight / 2;
let ballRad = 30.0
var p1x = 20.0
var p1y = sheight / 2
var p2x = swidth - 40.0
var p2y = sheight / 2
let pw = 20.0
let ph = 75.0
class Draw: UIView {
func PointInRad (point: CGPoint, point2 : CGPoint, rad : CGFloat) -> Bool{
let x1 = point.x;
let y1 = point.y
let x2 = point2.x
let y2 = point2.y
var dx = x1-x2
var dy = y1 - y2
if (dx < 0){dx=dx * -1}
if (dy < 0){dy=dy * -1}
let e = sqrt(dx*dx + dy*dy)
if(e <= rad){
return true
}
return false
}
func PointInRad (point: CGPoint, x2 : CGFloat, y2: CGFloat, rad: CGFloat) -> Bool {
let x1 = point.x;
let y1 = point.y
var dx = x1-x2
var dy = y1 - y2
if (dx < 0){dx=dx * -1}
if (dy < 0){dy=dy * -1}
let e = sqrt(dx*dx + dy*dy)
if(e <= rad){
return true
}
return false
}
func PointInRad ( x1 : CGFloat, y1 : CGFloat, x2 : CGFloat, y2 : CGFloat, rad: CGFloat) -> Bool{
var dx = x1-x2
var dy = y1 - y2
if (dx < 0){dx=dx * -1}
if (dy < 0){dy=dy * -1}
let e = sqrt(dx*dx + dy*dy)
if(e <= rad){
return true
}
return false
}
func update(){
self.isMultipleTouchEnabled = true;
self.clearsContextBeforeDrawing = true;
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
if(PointInRad(point: touch.location(in: view), x2: 700, y2:400 , rad: 50)){
up[1] = true
}
if(PointInRad(point: touch.location(in: view), x2: 100, y2:400 , rad: 50)){
up[0] = true
}
if(PointInRad(point: touch.location(in: view), x2: 700, y2:500 , rad: 50)){
down[1] = true
}
if(PointInRad(point: touch.location(in: view), x2: 100, y2:500 , rad: 50)){
down[0] = true
}
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
if(!PointInRad(point: touch.location(in: view), x2: 700, y2:400 , rad: 50)){
up[1] = false
}
if(!PointInRad(point: touch.location(in: view), x2: 100, y2:400 , rad: 50)){
up[0] = false
}
if(!PointInRad(point: touch.location(in: view), x2: 700, y2:500 , rad: 50)){
down[1] = false
}
if(!PointInRad(point: touch.location(in: view), x2: 100, y2:500 , rad: 50)){
down[0] = false
}}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
if(PointInRad(point: touch.location(in: view), x2: 700, y2:400 , rad: 50)){
up[1] = false
}
if(PointInRad(point: touch.location(in: view), x2: 100, y2:400 , rad: 50)){
up[0] = false
}
if(PointInRad(point: touch.location(in: view), x2: 700, y2:500 , rad: 50)){
down[1] = false
}
if(PointInRad(point: touch.location(in: view), x2: 100, y2:500 , rad: 50)){
down[0] = false
}}
}
override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
touchesEnded(touches, with: event)
self.setNeedsDisplay()
}
var n = false;
func drawCircle (color : UIColor, x:CGFloat, y:CGFloat, rad: CGFloat){
// Circle Drawing
let newx = x - rad / 2
let newy = y - rad / 2
let circlePath = UIBezierPath(ovalIn: CGRect(x: newx, y: newy, width: rad, height: rad))
color.setFill()
circlePath.fill()
}
func drawRect ( color : UIColor, x:CGFloat, y:CGFloat, width: CGFloat, height: CGFloat ) {
let circlePath = UIBezierPath(rect: CGRect(x: x, y: y, width: width, height: height))
color.setFill()
circlePath.fill()
}
override func draw(_: CGRect) {
var Path = UIBezierPath(ovalIn: CGRect(x: -100, y: -100, width: 900, height: 700))
let con = UIGraphicsGetCurrentContext();
con?.clear(CGRect(x: -100, y: -100, width: 1000, height: 1000))
// Color Declarations
var color = UIColor.white;
let ButtonN = UIColor(white: 0.5, alpha: 0.5)
let ButtonT = UIColor(white: 0.8, alpha: 0.8)
var p1 = NSString(string: String(Point1))
p1.draw(in: CGRect(x: 325, y: 100, width: 75, height: 100), withAttributes: [NSAttributedString.Key.foregroundColor: UIColor.white,NSAttributedString.Key.font: UIFont(name: "Arial", size: 80) ])
p1 = NSString(string: String(Point2))
p1.draw(in: CGRect(x: 430, y: 100, width: 75, height: 100), withAttributes: [NSAttributedString.Key.foregroundColor: UIColor.white,NSAttributedString.Key.font: UIFont(name: "Arial", size: 80) ])
p1 = NSString(string: String("Pong by Jakob"))
p1.draw(in: CGRect(x: 700, y: 25, width: 100, height: 100), withAttributes: [NSAttributedString.Key.foregroundColor: UIColor.white,NSAttributedString.Key.font: UIFont(name: "Arial", size: 20) ])
var rad = CGFloat(50);
var newx:CGFloat = 100.0
var newy:CGFloat = 400.0
var circlePath = UIBezierPath(ovalIn: CGRect(x: newx, y: newy, width: rad, height: rad))
if up[0] {
ButtonT.setFill();
} else {
ButtonN.setFill();
}
circlePath.fill()
circlePath = UIBezierPath(ovalIn: CGRect(x: 700, y: newy, width: rad, height: rad))
if up[1] {
ButtonT.setFill();
} else {
ButtonN.setFill();
}
circlePath.fill()
circlePath = UIBezierPath(ovalIn: CGRect(x: newx, y: 500, width: rad, height: rad))
if down[0] {
ButtonT.setFill();
} else {
ButtonN.setFill();
}
circlePath.fill()
circlePath = UIBezierPath(ovalIn: CGRect(x: 700, y: 500, width: rad, height: rad))
if down[1] {
ButtonT.setFill();
} else {
ButtonN.setFill();
}
circlePath.fill()
for i in 0 ... 30 {
color = UIColor.white
circlePath = UIBezierPath(rect: CGRect(x: CGFloat(393), y:CGFloat(Double(i)*50), width: CGFloat(14), height: CGFloat(30)))
color.setFill()
circlePath.fill()
}
circlePath = UIBezierPath(rect: CGRect(x: p1x, y: p1y, width: pw, height: ph))
color.setFill()
circlePath.fill()
circlePath = UIBezierPath(rect: CGRect(x: p2x, y: p2y, width: pw, height: ph))
color.setFill()
circlePath.fill()
rad = CGFloat(ballRad);
color = UIColor.white;
newx = (CGFloat(ballx) - rad / 2)
newy = CGFloat(bally) - rad / 2
circlePath = UIBezierPath(ovalIn: CGRect(x: newx, y: newy, width: rad, height: rad))
color.setFill()
circlePath.fill()
}
}
let view = Draw(frame: CGRect(x: 0, y: 0, width: swidth, height: sheight))
view.setNeedsDisplay()
view.update()
let T = Thread(block: {
while true {
if(Int(ballx)<Int(p1x + pw) && bally+ballRad <= p1y + ph && bally - ballRad >= p1y){
dirX *= -1
}
if(ballx<p2x && bally+ballRad <= p2y + ph && bally - ballRad >= p2y){
dirX *= -1
}
if(bally < 0 + ballRad || bally > 600 - ballRad){
dirY *= -1;
}
if (ballx - ballRad < 0){
ballx = 800/2
dirX = 1;
Point2+=1
}
if (ballx + ballRad > 800){
ballx = swidth/2
dirX = -1;
Point1+=1
}
if up[0] {
p1y -= psp
}
if up[1]{
p2y -= psp
}
if down[0] {
p1y += psp
}
if down[1]{
p2y += psp
}
ballx += bsp * dirX
bally += bsp * dirY
view.setNeedsDisplay()
view.updateFocusIfNeeded()
for i in 1 ... 10000 {
print(i)
}
}
})
T.start()
let t = Thread(block: {
while true {
DispatchQueue.main.sync {
view .setNeedsDisplay()
}}
})
t.start()
page.liveView = view;
page.needsIndefiniteExecution = true
page.wantsFullScreenLiveView = true
Because i am on my IPad i dont have any Error message