dc-sdk/modules/plot/graphics/DoubleArrowGraphics.js

/**
 * @Author: Caven
 * @Date: 2020-08-30 16:27:29
 */

import { Cesium } from '@dc-modules/namespace'
import Parse from '@dc-modules/parse/Parse'
import { Transform } from '@dc-modules/transform'
import { PlotUtil } from '@dc-modules/utils'

const HALF_PI = Math.PI / 2

class DoubleArrowGraphics {
  constructor(options) {
    this._positions = options?.positions || []
    this.headHeightFactor = 0.25
    this.headWidthFactor = 0.3
    this.neckHeightFactor = 0.85
    this.neckWidthFactor = 0.15
  }

  set positions(positions) {
    this._positions = positions
  }

  get positions() {
    return this._positions
  }

  get hierarchy() {
    return this._createHierarchy()
  }

  _getArrowPoints(pnt1, pnt2, pnt3, clockWise) {
    let midPnt = PlotUtil.mid(pnt1, pnt2)
    let len = PlotUtil.distance(midPnt, pnt3)
    let midPnt1 = PlotUtil.getThirdPoint(pnt3, midPnt, 0, len * 0.3, true)
    let midPnt2 = PlotUtil.getThirdPoint(pnt3, midPnt, 0, len * 0.5, true)
    midPnt1 = PlotUtil.getThirdPoint(
      midPnt,
      midPnt1,
      HALF_PI,
      len / 5,
      clockWise
    )
    midPnt2 = PlotUtil.getThirdPoint(
      midPnt,
      midPnt2,
      HALF_PI,
      len / 4,
      clockWise
    )
    let points = [midPnt, midPnt1, midPnt2, pnt3]
    // 计算箭头部分
    let arrowPnts = this._getArrowHeadPoints(points)
    let neckLeftPoint = arrowPnts[0]
    let neckRightPoint = arrowPnts[4]
    // 计算箭身部分
    let tailWidthFactor =
      PlotUtil.distance(pnt1, pnt2) / PlotUtil.getBaseLength(points) / 2
    let bodyPnts = this._getArrowBodyPoints(
      points,
      neckLeftPoint,
      neckRightPoint,
      tailWidthFactor
    )
    let n = bodyPnts.length
    let lPoints = bodyPnts.slice(0, n / 2)
    let rPoints = bodyPnts.slice(n / 2, n)
    lPoints.push(neckLeftPoint)
    rPoints.push(neckRightPoint)
    lPoints = lPoints.reverse()
    lPoints.push(pnt2)
    rPoints = rPoints.reverse()
    rPoints.push(pnt1)
    return lPoints.reverse().concat(arrowPnts, rPoints)
  }

  _getArrowHeadPoints(points) {
    let len = PlotUtil.getBaseLength(points)
    let headHeight = len * this.headHeightFactor
    let headPnt = points[points.length - 1]
    let headWidth = headHeight * this.headWidthFactor
    let neckWidth = headHeight * this.neckWidthFactor
    let neckHeight = headHeight * this.neckHeightFactor
    let headEndPnt = PlotUtil.getThirdPoint(
      points[points.length - 2],
      headPnt,
      0,
      headHeight,
      true
    )
    let neckEndPnt = PlotUtil.getThirdPoint(
      points[points.length - 2],
      headPnt,
      0,
      neckHeight,
      true
    )
    let headLeft = PlotUtil.getThirdPoint(
      headPnt,
      headEndPnt,
      HALF_PI,
      headWidth,
      false
    )
    let headRight = PlotUtil.getThirdPoint(
      headPnt,
      headEndPnt,
      HALF_PI,
      headWidth,
      true
    )
    let neckLeft = PlotUtil.getThirdPoint(
      headPnt,
      neckEndPnt,
      HALF_PI,
      neckWidth,
      false
    )
    let neckRight = PlotUtil.getThirdPoint(
      headPnt,
      neckEndPnt,
      HALF_PI,
      neckWidth,
      true
    )
    return [neckLeft, headLeft, headPnt, headRight, neckRight]
  }

  _getArrowBodyPoints(points, neckLeft, neckRight, tailWidthFactor) {
    let allLen = PlotUtil.wholeDistance(points)
    let len = PlotUtil.getBaseLength(points)
    let tailWidth = len * tailWidthFactor
    let neckWidth = PlotUtil.distance(neckLeft, neckRight)
    let widthDif = (tailWidth - neckWidth) / 2
    let tempLen = 0
    let leftBodyPnts = []
    let rightBodyPnts = []
    for (let i = 1; i < points.length - 1; i++) {
      let angle =
        PlotUtil.getAngleOfThreePoints(
          points[i - 1],
          points[i],
          points[i + 1]
        ) / 2
      tempLen += PlotUtil.distance(points[i - 1], points[i])
      let w = (tailWidth / 2 - (tempLen / allLen) * widthDif) / Math.sin(angle)
      let left = PlotUtil.getThirdPoint(
        points[i - 1],
        points[i],
        Math.PI - angle,
        w,
        true
      )
      let right = PlotUtil.getThirdPoint(
        points[i - 1],
        points[i],
        angle,
        w,
        false
      )
      leftBodyPnts.push(left)
      rightBodyPnts.push(right)
    }
    return leftBodyPnts.concat(rightBodyPnts)
  }

  _getTempPoint4(linePnt1, linePnt2, point) {
    let midPnt = PlotUtil.mid(linePnt1, linePnt2)
    let len = PlotUtil.distance(midPnt, point)
    let angle = PlotUtil.getAngleOfThreePoints(linePnt1, midPnt, point)
    let symPnt, distance1, distance2, mid
    if (angle < HALF_PI) {
      distance1 = len * Math.sin(angle)
      distance2 = len * Math.cos(angle)
      mid = PlotUtil.getThirdPoint(linePnt1, midPnt, HALF_PI, distance1, false)
      symPnt = PlotUtil.getThirdPoint(midPnt, mid, HALF_PI, distance2, true)
    } else if (angle >= HALF_PI && angle < Math.PI) {
      distance1 = len * Math.sin(Math.PI - angle)
      distance2 = len * Math.cos(Math.PI - angle)
      mid = PlotUtil.getThirdPoint(linePnt1, midPnt, HALF_PI, distance1, false)
      symPnt = PlotUtil.getThirdPoint(midPnt, mid, HALF_PI, distance2, false)
    } else if (angle >= Math.PI && angle < Math.PI * 1.5) {
      distance1 = len * Math.sin(angle - Math.PI)
      distance2 = len * Math.cos(angle - Math.PI)
      mid = PlotUtil.getThirdPoint(linePnt1, midPnt, HALF_PI, distance1, true)
      symPnt = PlotUtil.getThirdPoint(midPnt, mid, HALF_PI, distance2, true)
    } else {
      distance1 = len * Math.sin(Math.PI * 2 - angle)
      distance2 = len * Math.cos(Math.PI * 2 - angle)
      mid = PlotUtil.getThirdPoint(linePnt1, midPnt, HALF_PI, distance1, true)
      symPnt = PlotUtil.getThirdPoint(midPnt, mid, HALF_PI, distance2, false)
    }
    return symPnt
  }

  _createHierarchy() {
    let count = this._positions.length
    let tempPoint4 = undefined
    let connPoint = undefined
    let pnts = Parse.parsePolygonCoordToArray(
      Transform.transformCartesianArrayToWGS84Array(this._positions)
    )[0]
    let pnt1 = pnts[0]
    let pnt2 = pnts[1]
    let pnt3 = pnts[2]
    if (count === 3) tempPoint4 = this._getTempPoint4(pnt1, pnt2, pnt3)
    else tempPoint4 = pnts[3]
    if (count === 3 || count === 4) connPoint = PlotUtil.mid(pnt1, pnt2)
    else connPoint = pnts[4]
    let leftArrowPnts, rightArrowPnts
    if (PlotUtil.isClockWise(pnt1, pnt2, pnt3)) {
      leftArrowPnts = this._getArrowPoints(pnt1, connPoint, tempPoint4, false)
      rightArrowPnts = this._getArrowPoints(connPoint, pnt2, pnt3, true)
    } else {
      leftArrowPnts = this._getArrowPoints(pnt2, connPoint, pnt3, false)
      rightArrowPnts = this._getArrowPoints(connPoint, pnt1, tempPoint4, true)
    }
    let m = leftArrowPnts.length
    let t = (m - 5) / 2
    let llBodyPnts = leftArrowPnts.slice(0, t)
    let lArrowPnts = leftArrowPnts.slice(t, t + 5)
    let lrBodyPnts = leftArrowPnts.slice(t + 5, m)
    let rlBodyPnts = rightArrowPnts.slice(0, t)
    let rArrowPnts = rightArrowPnts.slice(t, t + 5)
    let rrBodyPnts = rightArrowPnts.slice(t + 5, m)
    rlBodyPnts = PlotUtil.getBezierPoints(rlBodyPnts)
    let bodyPnts = PlotUtil.getBezierPoints(
      rrBodyPnts.concat(llBodyPnts.slice(1))
    )
    lrBodyPnts = PlotUtil.getBezierPoints(lrBodyPnts)
    return new Cesium.PolygonHierarchy(
      Transform.transformWGS84ArrayToCartesianArray(
        Parse.parsePositions(
          rlBodyPnts.concat(rArrowPnts, bodyPnts, lArrowPnts, lrBodyPnts)
        )
      )
    )
  }
}

export default DoubleArrowGraphics