Normalising a CGFloat Array to UIView frame height - swift

Question

I am plotting an array of CGFloat values within a UIBezierPath. Now I want to Normalise the values so the max value of the array will occupy the whole height.
So far
let scaleFactor = (waveView.frame.height) * readFile.maxValue
for point in readFile.points {
let nextPoint = CGPoint(x: soundPath.currentPoint.x + sampleSpace, y: middleY - (point * scaleFactor) - 1.0)
soundPath.addLine(to: nextPoint)
soundPath.move(to: nextPoint)
}
But it does not seem to work...
EDIT
ReadFile:
class ReadFile {
public enum ReadFileError:Error{
case errorReading(String)
}
/* Player Interval Measured in Miliseconds (By now..) */
var beginPosition:Int32 = 0
var endPosition:Int32 = 0
/* Sample Rate -> Default 48KHz */
var sampleRate:Double = 48000
var samplesSeconds:CGFloat = 5
var maxValue:CGFloat = 0
var points:[CGFloat] = []
}
And
sampleSpace = 0.2

Answer 1

Thank you Andy for your answer but I have finally figured it out.
I am drawing a sound wave so it has positives and negatives values.
heightMax = waveView.frame.height/2
Applying a rule of three (Spanish translation) I end up with this:
func drawSoundWave(windowLength:Int32){
// Drawing code
print("\(logClassName): Drawing!!!")
print("\(logClassName): points COUNT = \(readFile.points.count)")
let soundPath = UIBezierPath()
soundPath.lineWidth = lineWidth
soundPath.move(to: CGPoint(x:0.0 , y: middleY))
print("\(logClassName) max ")
for point in readFile.points{
let normalizedHeight:CGFloat = (waveView.frame.height * point) / (2 * readFile.maxValue)
let nextPoint = CGPoint(x: soundPath.currentPoint.x + sampleSpace, y: middleY - (normalizedHeight))
soundPath.addLine(to: nextPoint)
soundPath.move(to: nextPoint)
}
let trackLayer = CAShapeLayer()
trackLayer.path = soundPath.cgPath
waveView.layer.addSublayer(trackLayer)
trackLayer.strokeColor = UIColor.red.cgColor
trackLayer.lineWidth = lineWidth
trackLayer.fillColor = UIColor.green.cgColor
trackLayer.lineCap = kCALineCapRound
}
where
let normalizedHeight:CGFloat = (waveView.frame.height * point) / (2 * readFile.maxValue)
is the normalize value given a readFile.maxValue and waveView.frame.height