I am currently building an app that controls a robot with joytstick interface; however, I want to plot lidar data; initially, I did this using SpriteKit but I realized the performance was too slow:
How to draw 720 data points using Swift
Now, I am using UIKit
My lidar sensor returns 360 data points i.e. distances; these distances are values of how far it detected an object
I am trying to plot circles on a UIView but the coordinate system is very confusing to me;
here is what I am doing currently: I am translating the distances to cartesian coordinates but this doesn't map nice to UIView's coordinate system since the origin (0,0) is on the top left
How can I translate my coordinate system so that the origin is at "(bounds.width/2, bounds.height/2)"?
As you can see in the picture the dots are displaced
[![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]
