jku-ba-react/src/helpers/randomMarkers.js

export function createRandomMarkers(switchLatLng=false){
  let latStart = 4833125
  let lngStart = 1430784
  let markersFromTo = []
  let markers = []
  for (let i=0; i<this.state.noOfMarkers; i++) {
    let latRandom = Math.floor((Math.random() * 1063))
    let latFrom = (latStart + latRandom) / 100000
    latRandom = Math.floor((Math.random() * 1063))
    let latTo = (latStart + latRandom) / 100000
    let lngRandom = Math.floor((Math.random() * 2533))
    let lngFrom = (lngStart + lngRandom) / 100000
    lngRandom = Math.floor((Math.random() * 2533))
    let lngTo = (lngStart + lngRandom) / 100000
    if(switchLatLng){
      markersFromTo.push({from: [lngFrom, latFrom], to: [lngTo, latTo]})
      markers.push([lngFrom, latFrom])
    }else{
      markersFromTo.push({from: [latFrom, lngFrom], to: [latTo, lngTo]})
      markers.push([latFrom, lngFrom])
    }
  }
  this.setState({markersFromTo: markersFromTo})
  this.setState({markers: markers})
}


export function calcMarkerPosition(){
  let noOfSteps = this.state.noOfSteps
  let currStep = this.state.currStep
  if (parseInt(currStep/noOfSteps)%2 === 0){
    currStep = currStep % noOfSteps
  } else{
    currStep = noOfSteps - (currStep % noOfSteps)
  }
  let markers = []
  for (let marker of this.state.markersFromTo){
    let latStart = marker.from[0]
    let lngStart = marker.from[1]
    let latEnd = marker.to[0]
    let lngEnd = marker.to[1]
//      markers.push([latStart, lngStart])
//      markers.push([latEnd, lngEnd])
    let latDiff = latEnd - latStart
    let lngDiff = lngEnd - lngStart
    let lat = latDiff / noOfSteps * currStep + latStart
    let lng = lngDiff / noOfSteps * currStep + lngStart
    markers.push([lat, lng])
  }
  this.setState({markers: markers})
}


export function changeSwitch(event){
  if(this.state.moveMarkers){
    clearInterval(this.timer);
  }else{
    this.timer = setInterval(() => {
      this.setState({currStep: this.state.currStep + 1});
      this.calcMarkerPosition()
    }, this.state.interval);
  }
  this.setState({moveMarkers: !this.state.moveMarkers})
}


export function setNoOfMarkers(event, switchLatLng=false){
  this.setState(
    {noOfMarkers: event.target.value, currStep: 0},
    () => {
      this.measurementsDiv.current.innerHTML = ""
      this.createRandomMarkers(switchLatLng)
    }
  )
}