node-red-contrib-tak-registration
Version:
A Node-RED node to register to TAK and to help wrap files as datapackages to send to TAK
51 lines (49 loc) • 1.67 kB
JavaScript
import Coordinate from '../Coordinate'
import GeometricShapeFactory from '../../util/GeometricShapeFactory'
export default class SineStarFactory extends GeometricShapeFactory {
constructor (geomFact) {
super(geomFact)
this._numArms = 8
this._armLengthRatio = 0.5
}
setNumArms (numArms) {
this._numArms = numArms
}
setArmLengthRatio (armLengthRatio) {
this._armLengthRatio = armLengthRatio
}
createSineStar () {
const env = this._dim.getEnvelope()
const radius = env.getWidth() / 2.0
let armRatio = this._armLengthRatio
if (armRatio < 0.0) armRatio = 0.0
if (armRatio > 1.0) armRatio = 1.0
const armMaxLen = armRatio * radius
const insideRadius = (1 - armRatio) * radius
const centreX = env.getMinX() + radius
const centreY = env.getMinY() + radius
const pts = new Array(this._nPts + 1).fill(null)
let iPt = 0
for (let i = 0; i < this._nPts; i++) {
const ptArcFrac = i / this._nPts * this._numArms
const armAngFrac = ptArcFrac - Math.floor(ptArcFrac)
const armAng = 2 * Math.PI * armAngFrac
const armLenFrac = (Math.cos(armAng) + 1.0) / 2.0
const curveRadius = insideRadius + armMaxLen * armLenFrac
const ang = i * (2 * Math.PI / this._nPts)
const x = curveRadius * Math.cos(ang) + centreX
const y = curveRadius * Math.sin(ang) + centreY
pts[iPt++] = this.coord(x, y)
}
pts[iPt] = new Coordinate(pts[0])
const ring = this._geomFact.createLinearRing(pts)
const poly = this._geomFact.createPolygon(ring, null)
return poly
}
interfaces_ () {
return []
}
getClass () {
return SineStarFactory
}
}