import * as Cesium from 'cesium'
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import { MapTooltip } from '@ztzf/utils'
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import { ToolBase } from '../ToolBase'
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const POINT_ENTITY_NAME = 'draw-polygon-point'
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const DEFAULT_STYLE = {
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fill: Cesium.Color.fromBytes(45, 140, 240, 99),
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outline: Cesium.Color.fromBytes(45, 140, 240, 255),
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}
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const resolveStyle = style => ({
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fill: style?.fill || DEFAULT_STYLE.fill,
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outline: style?.outline || DEFAULT_STYLE.outline,
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})
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const resolveColorWithAlpha = (baseColor, alphaSource) => {
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if (!baseColor) return alphaSource
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const alpha = typeof alphaSource?.alpha === 'number' ? alphaSource.alpha : 1
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return baseColor.withAlpha(alpha)
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}
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const normalizeRing = points => {
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if (!Array.isArray(points)) return []
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const ring = points.filter(Boolean)
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if (ring.length < 2) return ring
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const first = ring[0]
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const last = ring[ring.length - 1]
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if (Cesium.Cartesian3.equals(first, last)) {
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return ring.slice(0, -1)
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}
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return ring
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}
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const isSelfIntersecting = positions => {
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const ring = normalizeRing(positions)
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if (ring.length < 4) return false
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const epsilon = 1e-12
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const toPoint = cartesian => {
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const carto = Cesium.Cartographic.fromCartesian(cartesian)
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return { x: carto.longitude, y: carto.latitude }
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}
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const pts = ring.map(toPoint)
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const orientation = (a, b, c) => {
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const value = (b.y - a.y) * (c.x - b.x) - (b.x - a.x) * (c.y - b.y)
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if (Math.abs(value) < epsilon) return 0
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return value > 0 ? 1 : 2
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}
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const onSegment = (a, b, c) =>
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b.x <= Math.max(a.x, c.x) + epsilon &&
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b.x + epsilon >= Math.min(a.x, c.x) &&
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b.y <= Math.max(a.y, c.y) + epsilon &&
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b.y + epsilon >= Math.min(a.y, c.y)
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const segmentsIntersect = (p1, q1, p2, q2) => {
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const o1 = orientation(p1, q1, p2)
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const o2 = orientation(p1, q1, q2)
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const o3 = orientation(p2, q2, p1)
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const o4 = orientation(p2, q2, q1)
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if (o1 !== o2 && o3 !== o4) return true
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if (o1 === 0 && onSegment(p1, p2, q1)) return true
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if (o2 === 0 && onSegment(p1, q2, q1)) return true
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if (o3 === 0 && onSegment(p2, p1, q2)) return true
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if (o4 === 0 && onSegment(p2, q1, q2)) return true
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return false
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}
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const count = pts.length
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for (let i = 0; i < count; i += 1) {
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const p1 = pts[i]
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const q1 = pts[(i + 1) % count]
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for (let j = i + 1; j < count; j += 1) {
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const isAdjacent = j === i || j === i + 1 || (i === 0 && j === count - 1)
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if (isAdjacent) continue
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const p2 = pts[j]
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const q2 = pts[(j + 1) % count]
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if (segmentsIntersect(p1, q1, p2, q2)) return true
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}
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}
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return false
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}
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export class DrawPolygonTool extends ToolBase {
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constructor(viewer, options = {}) {
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super(viewer)
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this.tooltip = new MapTooltip(viewer)
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this.dataSource = null
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this.polygonEntity = null
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this.polylineEntity = null
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this.positions = []
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this.floatPosition = null
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this.isDrawing = false
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this.lastMousePosition = null
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this.isIntersecting = false
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this.style = resolveStyle(options?.style)
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}
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start() {
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if (!this.tooltip) {
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this.tooltip = new MapTooltip(this.viewer)
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}
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this.dataSource = new Cesium.CustomDataSource('draw-polygon')
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this.viewer.dataSources.add(this.dataSource)
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this.handler = new Cesium.ScreenSpaceEventHandler(this.viewer.scene.canvas)
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this.handler.setInputAction(click => this.handleLeftClick(click), Cesium.ScreenSpaceEventType.LEFT_CLICK)
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this.handler.setInputAction(click => this.handleRightClick(click), Cesium.ScreenSpaceEventType.RIGHT_CLICK)
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this.handler.setInputAction(movement => this.handleMouseMove(movement), Cesium.ScreenSpaceEventType.MOUSE_MOVE)
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this.isDrawing = true
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this.tooltip.hide()
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}
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handleLeftClick(click) {
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if (!this.isDrawing) return
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const pickedEntity = this.viewer.scene.pick(click.position)?.id
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if (this.isFinishTrigger(pickedEntity)) {
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this.finishDrawing()
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return
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}
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if (pickedEntity?.name === POINT_ENTITY_NAME) return
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const position = this.getPositionFromScreen(click.position)
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if (!position) return
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const preview = [...this.positions, position]
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if (isSelfIntersecting(preview)) {
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this.isIntersecting = true
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this.tooltip.show(this.getTipText(), click.position)
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return
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}
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this.addPoint(position)
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this.tooltip.show(this.getTipText(), click.position)
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}
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handleRightClick(click) {
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if (!this.isDrawing) return
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const pickedEntity = this.viewer.scene.pick(click.position)?.id
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if (!pickedEntity || pickedEntity.name !== POINT_ENTITY_NAME) return
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const index = pickedEntity.customData?.index
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if (typeof index !== 'number') return
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this.removePoint(index)
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this.tooltip.show(this.getTipText(), click.position)
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}
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handleMouseMove(movement) {
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if (!this.isDrawing) return
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const tipText = this.getTipText()
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if (!this.tooltip?.isVisible) {
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this.tooltip?.show(tipText, movement.endPosition)
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} else {
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this.tooltip?.show(tipText)
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this.tooltip?.move(movement.endPosition)
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}
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if (this.positions.length === 0) return
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const position = this.getPositionFromScreen(movement.endPosition)
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if (!position) return
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this.lastMousePosition = position
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this.floatPosition = position
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}
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getTipText() {
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const preview = this.getPreviewPositions()
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this.isIntersecting = isSelfIntersecting(preview)
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if (this.isIntersecting) {
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return '区域存在交叉，请调整位置'
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}
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const count = this.positions.length
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if (count === 0) {
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return '单击增加点'
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}
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if (count < 3) {
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return '单击增加点，右击删除点'
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}
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return '单击增加点，右击删除点，双击结束绘制'
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}
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isFinishTrigger(pickedEntity) {
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if (!pickedEntity || pickedEntity.name !== POINT_ENTITY_NAME) return false
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if (this.positions.length < 3) return false
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const index = pickedEntity.customData?.index
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return index === this.positions.length - 1
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}
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addPoint(position) {
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this.positions.push(position)
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if (!this.polygonEntity) {
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this.createEntities()
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}
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this.rebuildPointEntities()
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}
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removePoint(index) {
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if (index < 0 || index >= this.positions.length) return
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this.positions.splice(index, 1)
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this.rebuildPointEntities()
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if (this.positions.length === 0) {
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this.floatPosition = null
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this.lastMousePosition = null
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return
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}
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if (this.lastMousePosition) {
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this.floatPosition = this.lastMousePosition
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} else {
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this.floatPosition = this.positions[this.positions.length - 1]
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}
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}
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getPreviewPositions() {
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if (this.positions.length === 0) return []
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if (!this.isDrawing || !this.floatPosition) return this.positions
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return [...this.positions, this.floatPosition]
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}
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createEntities() {
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const getIntersecting = () => {
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const preview = this.getPreviewPositions()
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this.isIntersecting = isSelfIntersecting(preview)
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return this.isIntersecting
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}
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this.polygonEntity = this.dataSource.entities.add({
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polygon: {
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hierarchy: new Cesium.CallbackProperty(
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() => new Cesium.PolygonHierarchy(this.getPreviewPositions()),
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false
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),
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material: new Cesium.ColorMaterialProperty(
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new Cesium.CallbackProperty(() => {
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if (getIntersecting()) return resolveColorWithAlpha(Cesium.Color.RED, this.style.fill)
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return this.style.fill
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}, false)
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),
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outline: false,
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heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
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show: new Cesium.CallbackProperty(() => this.getPreviewPositions().length >= 3, false),
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},
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})
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this.polylineEntity = this.dataSource.entities.add({
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polyline: {
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positions: new Cesium.CallbackProperty(() => {
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const positions = this.getPreviewPositions()
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if (positions.length < 2) return positions
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if (positions.length >= 3) {
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return [...positions, positions[0]]
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}
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return positions
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}, false),
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clampToGround: true,
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width: 2,
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material: new Cesium.ColorMaterialProperty(
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new Cesium.CallbackProperty(() => {
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if (getIntersecting()) return resolveColorWithAlpha(Cesium.Color.RED, this.style.outline)
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return this.style.outline
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}, false)
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),
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show: new Cesium.CallbackProperty(() => this.getPreviewPositions().length >= 2, false),
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},
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})
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}
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rebuildPointEntities() {
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this.dataSource.entities.values
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.slice()
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.filter(entity => entity?.name === POINT_ENTITY_NAME)
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.forEach(entity => this.dataSource.entities.remove(entity))
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this.positions.forEach((position, index) => {
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this.dataSource.entities.add({
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name: POINT_ENTITY_NAME,
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position: position.clone ? position.clone() : position,
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point: {
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pixelSize: 12,
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color: Cesium.Color.WHITE,
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outlineColor: this.style.outline,
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outlineWidth: 2,
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heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
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disableDepthTestDistance: Number.POSITIVE_INFINITY,
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},
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customData: {
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index,
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},
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})
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})
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}
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finishDrawing() {
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if (this.positions.length < 3) return
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this.isDrawing = false
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this.floatPosition = null
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this.isIntersecting = false
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this.notify('getPolygonPositions', this.positions)
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this.tooltip?.hide()
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this.clearPreviewEntities()
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}
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setStyle(style) {
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this.style = resolveStyle(style)
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if (this.dataSource) {
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this.dataSource.entities.values
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.filter(entity => entity?.name === POINT_ENTITY_NAME)
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.forEach(entity => {
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if (entity?.point) {
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entity.point.outlineColor = this.style.outline
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}
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})
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}
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}
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clearPreviewEntities() {
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if (!this.dataSource) return
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this.dataSource.entities.removeAll()
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this.polygonEntity = null
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this.polylineEntity = null
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this.isIntersecting = false
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}
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getPositionFromScreen(screenPosition) {
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const scene = this.viewer.scene
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const cartesian = scene.pickPosition(screenPosition)
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if (cartesian) return cartesian
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return scene.camera.pickEllipsoid(screenPosition, scene.globe.ellipsoid)
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}
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destroy() {
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if (this.dataSource) {
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this.dataSource.entities.removeAll()
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this.viewer.dataSources.remove(this.dataSource)
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this.dataSource = null
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}
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if (this.handler) {
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this.handler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_CLICK)
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this.handler.removeInputAction(Cesium.ScreenSpaceEventType.RIGHT_CLICK)
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this.handler.removeInputAction(Cesium.ScreenSpaceEventType.MOUSE_MOVE)
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this.handler.destroy()
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this.handler = null
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}
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this.tooltip?.destroy()
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this.tooltip = null
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this.positions = []
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this.floatPosition = null
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this.isDrawing = false
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this.lastMousePosition = null
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this.isIntersecting = false
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}
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}
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