Draw circle and segments from circle

Question

I would like to draw a circle and draw segments from this circle. Sorry because I've found a lot of topics on stackoverflow however still no one can help me understand fully. Can you give me a sample code on this? I want results like the image below. Thank you very much

Answer 1

Open up a new Swift 3 playground and paste the following code into it. You should see a "w 512 h 512" annotation on the right, tap on it and an eye will appear. You should see some drawing at that point.

    //: Playground - noun: a place where people can play
import UIKit
import CoreGraphics

public func makePieChart()-> UIImage?
{
    let size = CGSize(width: 512, height:512)
    let centerX = size.width/2.0
    let centerY = size.height/2.0
    let center = CGPoint(x: centerX, y: centerY)
    let chartRadius = size.width/2.0

    UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
    defer
    {
        UIGraphicsEndImageContext()
    }


    guard let quartz = UIGraphicsGetCurrentContext() else
    {
        return nil
    }
    let π = CGFloat.pi

    quartz.move(to: center)
    quartz.addArc(center: center, radius: chartRadius, startAngle: 0.0, endAngle: π/3.0, clockwise: false)
    quartz.closePath() // path will complete back at the last move to (center of the circle)

    quartz.setFillColor(UIColor.red.cgColor)
    quartz.fillPath()


    quartz.move(to: center)
    quartz.addArc(center: center, radius: chartRadius, startAngle:  π/3.0, endAngle: π, clockwise: false)

    quartz.closePath() // path will complete back at the last move to (center of the circle)

    quartz.setFillColor(UIColor.yellow.cgColor)
    quartz.fillPath()
    quartz.move(to: center)
    quartz.addArc(center: center, radius: chartRadius, startAngle:  π, endAngle: 0.0, clockwise: false)

    quartz.closePath() // path will complete back at the last move to (center of the circle)

    quartz.setFillColor(UIColor.blue.cgColor)
    quartz.fillPath()
    return UIGraphicsGetImageFromCurrentImageContext()
}

let image = makePieChart()