feat:区域绘制相关处理

shuishen

2026-01-28 b52826e703a5b53082905d887669906a8b710f48

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import * as Cesium from 'cesium'
import { MapTooltip } from '../Tooltip'
import { ToolBase } from '../ToolBase'
import { getBoundsFromCartesians, rectanglePositionsFromBounds } from '../shapeUtils'
 
export class DrawRectangleTool extends ToolBase {
    constructor(viewer) {
        super(viewer)
        this.tooltip = new MapTooltip(viewer)
        this.dataSource = null
        this.rectangleEntity = null
        this.outlineEntity = null
        this.startPosition = null
        this.endPosition = null
        this.isDrawing = false
    }
 
    start() {
        this.dataSource = new Cesium.CustomDataSource('draw-rectangle')
        this.viewer.dataSources.add(this.dataSource)
        this.handler = new Cesium.ScreenSpaceEventHandler(this.viewer.scene.canvas)
 
        this.handler.setInputAction(click => this.handleLeftClick(click), Cesium.ScreenSpaceEventType.LEFT_CLICK)
        this.handler.setInputAction(movement => this.handleMouseMove(movement), Cesium.ScreenSpaceEventType.MOUSE_MOVE)
 
        this.tooltip.show('单击设置起点', { x: 0, y: 0 })
    }
 
    handleLeftClick(click) {
        const position = this.getPositionFromScreen(click.position)
        if (!position) return
 
        if (!this.startPosition) {
            this.startPosition = position
            this.endPosition = position
            this.isDrawing = true
            this.createEntities()
            this.tooltip.show('单击结束绘制', click.position)
            return
        }
 
        if (this.isDrawing) {
            this.endPosition = position
            this.isDrawing = false
            const positions = this.getRectanglePositions()
            this.notify('getPolygonPositions', positions)
            this.tooltip.hide()
        }
    }
 
    handleMouseMove(movement) {
        if (!this.isDrawing) {
            this.tooltip.move(movement.endPosition)
            return
        }
        const position = this.getPositionFromScreen(movement.endPosition)
        if (!position) return
        this.endPosition = position
        this.tooltip.move(movement.endPosition)
    }
 
    createEntities() {
        if (this.rectangleEntity) return
        const hierarchy = new Cesium.CallbackProperty(() => {
            const positions = this.getRectanglePositions()
            return new Cesium.PolygonHierarchy(positions)
        }, false)
 
        this.rectangleEntity = this.dataSource.entities.add({
            polygon: {
                hierarchy,
                material: Cesium.Color.fromBytes(45, 140, 240, 99),
                outline: false,
                heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
            },
        })
 
        this.outlineEntity = this.dataSource.entities.add({
            polyline: {
                positions: new Cesium.CallbackProperty(() => {
                    const positions = this.getRectanglePositions()
                    return positions.length ? [...positions, positions[0]] : []
                }, false),
                clampToGround: true,
                width: 2,
                material: Cesium.Color.fromBytes(45, 140, 240, 255),
            },
        })
    }
 
    getRectanglePositions() {
        if (!this.startPosition || !this.endPosition) return []
        const bounds = getBoundsFromCartesians([this.startPosition, this.endPosition])
        return rectanglePositionsFromBounds(bounds)
    }
 
    getPositionFromScreen(screenPosition) {
        const scene = this.viewer.scene
        const cartesian = scene.pickPosition(screenPosition)
        if (cartesian) return cartesian
        return scene.camera.pickEllipsoid(screenPosition, scene.globe.ellipsoid)
    }
 
    destroy() {
        if (this.dataSource) {
            this.dataSource.entities.removeAll()
            this.viewer.dataSources.remove(this.dataSource)
            this.dataSource = null
        }
        if (this.handler) {
            this.handler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_CLICK)
            this.handler.removeInputAction(Cesium.ScreenSpaceEventType.MOUSE_MOVE)
            this.handler.destroy()
            this.handler = null
        }
        this.tooltip?.destroy()
        this.tooltip = null
        this.startPosition = null
        this.endPosition = null
        this.isDrawing = false
    }
}