swift 円のグラデーション

swift
1import UIKit
2
3class ViewController: UIViewController {
4
5    override func viewDidLoad() {
6        super.viewDidLoad()
7        // Do any additional setup after loading the view.
8        
9        var colorArr:[UIColor] = []
10
11        var red:CGFloat = 1
12        var green:CGFloat = 0
13        var blue:CGFloat = 0
14        
15        for _ in 0 ..< 100 {
16            if green <= 1 && red == 1 && blue == 0{//赤1緑1青0
17                colorArr.append(UIColor(red: red, green: green, blue: blue, alpha: 1))
18                green += 0.06
19            }else if red >= 0 && blue == 0 {//赤0緑1青0
20                colorArr.append(UIColor(red:  red, green: green, blue: blue, alpha: 1))
21                red -= 0.06
22
23            }else if blue < 1 && green > 1 {//赤0緑1青1
24                colorArr.append(UIColor(red:  red, green: green, blue: blue, alpha: 1))
25                blue += 0.06
26                print(red,green,blue)
27            }else if green >= 0 && blue > 1{//赤0緑0青1
28                colorArr.append(UIColor(red:  red, green: green, blue: blue, alpha: 1))
29                green -= 0.06
30            }else if red < 1{//赤1緑0青1
31                colorArr.append(UIColor(red:  red, green: green, blue: blue, alpha: 1))
32                red += 0.06
33            }else if blue > 0 {//赤1緑0青0
34                colorArr.append(UIColor(red:  red, green: green, blue: blue, alpha: 1))
35                blue -= 0.06
36
37            }
38        }
39        let radius = self.view.bounds.width / 4
40        let center = self.view.center
41        
42        let theta = 2 * CGFloat.pi / CGFloat(colorArr.count)
43        
44        for i in 0 ..< colorArr.count{
45            let colorView = UIView(frame: CGRect(x: 0, y: 0, width: 30, height: 30))
46            colorView.backgroundColor = colorArr[i]
47            colorView.center.x = center.x + radius * cos(CGFloat(i) * theta)
48            colorView.center.y = center.y + radius * sin(CGFloat(i) * theta)
49            view.addSubview(colorView)
50        }
51    }
52}
53

swift
1for _ in 0 ..< 100 {
2            if green <= 1 && red == 1 && blue == 0{//赤1緑1青0
3                colorArr.append(UIColor(red: red, green: green, blue: blue, alpha: 1))
4                green += 0.06
5            }else if red >= 0 && blue == 0 {//赤0緑1青0
6                colorArr.append(UIColor(red:  red, green: green, blue: blue, alpha: 1))
7                red -= 0.06
8
9            }else if blue < 1 && green > 1 {//赤0緑1青1
10                colorArr.append(UIColor(red:  red, green: green, blue: blue, alpha: 1))
11                blue += 0.06
12                print(red,green,blue)
13            }else if green >= 0 && blue > 1{//赤0緑0青1
14                colorArr.append(UIColor(red:  red, green: green, blue: blue, alpha: 1))
15                green -= 0.06
16            }else if red < 1{//赤1緑0青1
17                colorArr.append(UIColor(red:  red, green: green, blue: blue, alpha: 1))
18                red += 0.06
19            }else if blue > 0 {//赤1緑0青0
20                colorArr.append(UIColor(red:  red, green: green, blue: blue, alpha: 1))
21                blue -= 0.06
22
23            }