在 UIView 坐标系中快速转换坐标

Posted 2023-03-05

【中文标题】在 UIView 坐标系中快速转换坐标

【英文标题】：Swift translating coordinates in UIView Coordinate System

【发布时间】：2016-11-11 01:37:26

【问题描述】：

我目前正在构建一个应用程序来控制带有操纵杆界面的机器人；但是，我想绘制激光雷达数据；最初，我使用 SpriteKit 执行此操作，但我意识到性能太慢了：

How to draw 720 data points using Swift

现在，我正在使用 UIKit

我的激光雷达传感器返回 360 个数据点，即距离；这些距离是它检测到物体的距离值

我试图在 UIView 上绘制圆圈，但坐标系让我很困惑；

这是我目前正在做的事情：我正在将距离转换为笛卡尔坐标，但这并不能很好地映射到 UIView 的坐标系，因为原点 (0,0) 位于左上角

如何转换我的坐标系，使原点位于“(bounds.width/2, bounds.height/2)”？

正如你在图片中看到的那样，点被移位了

[![import Foundation
import UIKit

@IBDesignable
public class Contours: UIView 

    public var gridColor: UIColor = UIColor.black //  didSet  setNeedsDisplay() 
    public var gridSize: CGSize = CGSize(width: 100, height: 100) //  didSet  setNeedsDisplay() 
    public var gridView = UIView(frame: CGRect(origin: .zero, size: .zero))

    public var dataSize: CGSize = CGSize(width: 10, height: 10) //  didSet  setNeedsDisplay() 
    public var dataColor: UIColor = UIColor.blue //  didSet  setNeedsDisplay() 
    public var dataView = UIView(frame: CGRect(origin: .zero, size: .zero))

    public var fade: CGFloat = 0.5  didSet  setNeedsDisplay() 

    public var distances: \[Int\] = \[2601, 2600, 33, 2608, 2601, 2594, 2625, 2633, 2637, 2651, 2656, 2666, 2683, 2690, 2705, 2712, 2712, 2739, 2752, 53, 1103, 1060, 1019, 980, 944, 911, 33, 851, 826, 801, 777, 757, 737, 718, 701, 683, 667, 654, 53, 486, 470, 457, 448, 440, 432, 424, 416, 409, 403, 396, 389, 383, 378, 372, 367, 362, 357, 353, 348, 344, 340, 336, 333, 329, 326, 323, 319, 317, 314, 311, 309, 307, 305, 303, 301, 299, 298, 297, 295, 294, 293, 292, 291, 290, 290, 290, 290, 291, 293, 295, 303, 386, 383, 53, 350, 53, 53, 53, 53, 53, 3, 364, 362, 360, 356, 358, 355, 353, 351, 350, 349, 347, 345, 53, 53, 53, 308, 3, 309, 309, 312, 313, 315, 316, 319, 321, 53, 329, 332, 335, 332, 53, 53, 53, 53, 53, 53, 53, 3, 53, 53, 53, 53, 53, 53, 670, 33, 706, 728, 750, 772, 799, 825, 856, 887, 925, 755, 749, 744, 739, 734, 730, 727, 722, 719, 716, 714, 634, 709, 706, 704, 703, 701, 699, 700, 695, 697, 697, 338, 696, 697, 696, 698, 698, 700, 702, 703, 705, 707, 710, 712, 714, 718, 53, 53, 53, 53, 53, 53, 53, 53, 3, 53, 53, 53, 53, 53, 53, 53, 53, 3, 53, 53, 53, 53, 53, 53, 53, 3412, 3397, 3384, 53, 3538, 3603, 53, 2426, 2412, 2363, 2330, 2288, 2262, 2214, 2190, 2162, 2130, 53, 53, 53, 2807, 2631, 2408, 2638, 2607, 2601, 2562, 2534, 2515, 2496, 2478, 2462, 2445, 53, 53, 53, 1751, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 3, 53, 53, 53, 53, 53, 2643, 2643, 53, 2660, 53, 2528, 2523, 2221, 1955, 1684, 1677, 1684, 1694, 1705, 1202, 1204, 1211, 1217, 1225, 1233, 1239, 1249, 1259, 1270, 1280, 1289, 1280, 1011, 991, 977, 968, 966, 964, 968, 975, 984, 1003, 2, 53, 1297, 53, 53, 33, 1321, 1299, 1274, 1254, 1233, 1232, 1264, 1293, 3802, 53, 53, 53, 53, 53, 53, 53, 3, 53, 2878, 2870, 2848, 2821, 2803, 2788, 2769, 2753, 2740, 2708, 2711, 2701, 2682, 2656, 2664, 2644, 2644, 2631, 2626, 2616, 2610, 2604, 2605, 2605, 2600, 2598, 2603\]

//    public var circleViews: \[UIView\] = \[\]
    public var distx: \[Double\] = \[\]
    public var disty: \[Double\] = \[\]
    public var scalex: \[Double\] = \[\]
    public var scaley: \[Double\] = \[\]

    override public init(frame: CGRect) 
        super.init(frame: frame)
    

    public required init?(coder aDecoder: NSCoder) 
        super.init(coder: aDecoder)
    

    public override func draw(_ rect: CGRect) 

        alpha = 1
        layer.backgroundColor = gridColor.cgColor

        for index in 0...356 
            let radians = Double(index) * M_PI / 180.0
            let x = Double(distances\[index\]) * cos(Double(radians))
            let y = Double(distances\[index\]) * sin(Double(radians))
            distx.append(x)
            disty.append(y)
        

        let xmin: Double = Double(distx.min()!)
        let xmax: Double = Double(distx.max()!)
        let ymin: Double = Double(disty.min()!)
        let ymax: Double = Double(disty.max()!)

        let scale = max(xmax - xmin, ymax - ymin)

        var circles = \[UIView\]()
        circles.reserveCapacity(360)
        for _ in 0...356 
            circles.append(UIView(frame: CGRect(origin: .zero, size: .zero)))
        

//        CGSize(width: 30, height: 30)
//        circles\[index\].alpha = 1
//        circles\[index\].frame = CGRect(origin: CGPoint(x: bounds.width/2, y: bounds.height/2), size: dataSize)
//        circles\[index\].center = CGPoint(x: x, y: y)
//        circles\[index\].layer.backgroundColor = dataColor.cgColor
//        circles\[index\].layer.cornerRadius = circles\[index\].bounds.width / 2

        print("width: \(bounds.width), height: \(bounds.height)")

        for index in 0...356 
            let radians = Double(index) * M_PI / 180.0
            let x = ((Double(distances\[index\]) * cos(Double(radians)) / scale) * Double(bounds.width))
            let y = (Double(distances\[index\]) * sin(Double(radians)) / scale) * Double(bounds.height)

            circles\[index\].alpha = 1
            circles\[index\].frame = CGRect(origin: .zero, size: dataSize)

//            circles\[index\].frame = CGRect(origin: CGPoint(x: bounds.width/2, y: bounds.height/2), size: dataSize)
            circles\[index\].center = CGPoint(x: x, y: y)
            circles\[index\].layer.backgroundColor = dataColor.cgColor
            circles\[index\].layer.cornerRadius = circles\[index\].bounds.width / 2

            print("x: \(x), y: \(y)")
//            print("zero: \(layer.anchorPoint)")

            if let superview = circles\[index\].superview 
                superview.bringSubview(toFront: circles\[index\])
             else 
                addSubview(circles\[index\])
            

//            scalex.append(x)
//            scaley.append(y)
        

    

    private func reset() 
        UIView.animate(withDuration: 0.25)  () -> Void in
            self.gridView.center = CGPoint(x: self.bounds.width / 2, y: self.bounds.height / 2)
        
    

][1]][1]

【参考方案1】：

您的代码当前在Contours 类中使用addSubview。因此，圆圈将相对于轮廓视图的边界。我假设轮廓视图的原点位于屏幕的左上角，而您需要将其框架设置为这样，因为您正在绘制红色矩形。