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| 1 | +import type { MapGeoJSONFeature, QueryRenderedFeaturesOptions } from 'maplibre-gl' |
| 2 | +import type { FrameState } from 'ol/Map.js' |
| 3 | +import { toDegrees } from 'ol/math.js' |
| 4 | +import { toLonLat } from 'ol/proj.js' |
| 5 | +import LayerRenderer from 'ol/renderer/Layer.js' |
| 6 | +import GeoJSON from 'ol/format/GeoJSON.js' |
| 7 | +import type { Coordinate } from 'ol/coordinate.js' |
| 8 | +import type { FeatureCallback } from 'ol/renderer/vector.js' |
| 9 | +import type { Feature } from 'ol' |
| 10 | +import type { Geometry } from 'ol/geom.js' |
| 11 | +import { SimpleGeometry } from 'ol/geom.js' |
| 12 | +import type { Pixel } from 'ol/pixel.js' |
| 13 | +import type MapLibreLayer from './MapLibreLayer.js' |
| 14 | + |
| 15 | +const VECTOR_TILE_FEATURE_PROPERTY = 'vectorTileFeature'; |
| 16 | + |
| 17 | +const formats: { |
| 18 | + [key: string]: GeoJSON; |
| 19 | +} = { |
| 20 | + 'EPSG:3857': new GeoJSON({ |
| 21 | + featureProjection: 'EPSG:3857', |
| 22 | + }), |
| 23 | +}; |
| 24 | + |
| 25 | +/** |
| 26 | + * This class is a renderer for MapLibre Layer to be able to use the native ol |
| 27 | + * functionalities like map.getFeaturesAtPixel or map.hasFeatureAtPixel. |
| 28 | + */ |
| 29 | +export default class MapLibreLayerRenderer extends LayerRenderer<MapLibreLayer> { |
| 30 | + private readonly translateZoom: Function | undefined |
| 31 | + |
| 32 | + constructor(layer: MapLibreLayer, translateZoom: Function | undefined) { |
| 33 | + super(layer) |
| 34 | + this.translateZoom = translateZoom |
| 35 | + } |
| 36 | + |
| 37 | + getFeaturesAtCoordinate( |
| 38 | + coordinate: Coordinate | undefined, |
| 39 | + hitTolerance: number = 5 |
| 40 | + ): Feature<Geometry>[] { |
| 41 | + const pixels = this.getMapLibrePixels(coordinate, hitTolerance); |
| 42 | + |
| 43 | + if (!pixels) { |
| 44 | + return []; |
| 45 | + } |
| 46 | + |
| 47 | + const queryRenderedFeaturesOptions = |
| 48 | + (this.getLayer().get( |
| 49 | + 'queryRenderedFeaturesOptions', |
| 50 | + ) as QueryRenderedFeaturesOptions) || {}; |
| 51 | + |
| 52 | + // At this point we get GeoJSON MapLibre feature, we transform it to an OpenLayers |
| 53 | + // feature to be consistent with other layers. |
| 54 | + const features = this.getLayer() |
| 55 | + .mapLibreMap?.queryRenderedFeatures(pixels, queryRenderedFeaturesOptions) |
| 56 | + .map((feature) => { |
| 57 | + return this.toOlFeature(feature); |
| 58 | + }); |
| 59 | + |
| 60 | + return features || []; |
| 61 | + } |
| 62 | + |
| 63 | + override prepareFrame(): boolean { |
| 64 | + return true; |
| 65 | + } |
| 66 | + |
| 67 | + override renderFrame(frameState: FrameState): HTMLElement { |
| 68 | + const layer = this.getLayer(); |
| 69 | + const {mapLibreMap} = layer; |
| 70 | + const map = layer.getMapInternal(); |
| 71 | + if (!layer || !map || !mapLibreMap) { |
| 72 | + return null; |
| 73 | + } |
| 74 | + |
| 75 | + const mapLibreCanvas = mapLibreMap.getCanvas(); |
| 76 | + const {viewState} = frameState; |
| 77 | + // adjust view parameters in MapLibre |
| 78 | + mapLibreMap.jumpTo({ |
| 79 | + center: toLonLat(viewState.center, viewState.projection) as [number, number], |
| 80 | + zoom: (this.translateZoom ? this.translateZoom(viewState.zoom) : viewState.zoom) - 1 , |
| 81 | + bearing: toDegrees(-viewState.rotation), |
| 82 | + }); |
| 83 | + |
| 84 | + const opacity = layer.getOpacity().toString(); |
| 85 | + if (mapLibreCanvas && opacity !== mapLibreCanvas.style.opacity) { |
| 86 | + mapLibreCanvas.style.opacity = opacity; |
| 87 | + } |
| 88 | + |
| 89 | + if (!mapLibreCanvas.isConnected) { |
| 90 | + // The canvas is not connected to the DOM, request a map rendering at the next animation frame |
| 91 | + // to set the canvas size. |
| 92 | + map.render(); |
| 93 | + } else if (!sameSize(mapLibreCanvas, frameState)) { |
| 94 | + mapLibreMap.resize(); |
| 95 | + } |
| 96 | + |
| 97 | + mapLibreMap.redraw(); |
| 98 | + |
| 99 | + return mapLibreMap.getContainer(); |
| 100 | + } |
| 101 | + |
| 102 | + override getFeatures(pixel: Pixel): Promise<Feature<Geometry>[]> { |
| 103 | + const coordinate = this.getLayer() |
| 104 | + .getMapInternal() |
| 105 | + ?.getCoordinateFromPixel(pixel); |
| 106 | + return Promise.resolve(this.getFeaturesAtCoordinate(coordinate)); |
| 107 | + } |
| 108 | + |
| 109 | + override forEachFeatureAtCoordinate<Feature>( |
| 110 | + coordinate: Coordinate, |
| 111 | + _frameState: FrameState, |
| 112 | + hitTolerance: number, |
| 113 | + callback: FeatureCallback<Feature>, |
| 114 | + ): Feature | undefined { |
| 115 | + const features = this.getFeaturesAtCoordinate(coordinate, hitTolerance); |
| 116 | + features.forEach((feature) => { |
| 117 | + const geometry = feature.getGeometry(); |
| 118 | + if (geometry instanceof SimpleGeometry) { |
| 119 | + callback(feature, this.getLayer(), geometry); |
| 120 | + } |
| 121 | + }); |
| 122 | + return features?.[0] as Feature; |
| 123 | + } |
| 124 | + |
| 125 | + private getMapLibrePixels( |
| 126 | + coordinate?: Coordinate, |
| 127 | + hitTolerance?: number, |
| 128 | + ): [[number, number], [number, number]] | [number, number] | undefined { |
| 129 | + if (!coordinate) { |
| 130 | + return undefined; |
| 131 | + } |
| 132 | + |
| 133 | + const pixel = this.getLayer().mapLibreMap?.project( |
| 134 | + toLonLat(coordinate) as [number, number], |
| 135 | + ); |
| 136 | + |
| 137 | + if (pixel?.x === undefined || pixel?.y === undefined) { |
| 138 | + return undefined; |
| 139 | + } |
| 140 | + |
| 141 | + let pixels: [[number, number], [number, number]] | [number, number] = [ |
| 142 | + pixel.x, |
| 143 | + pixel.y, |
| 144 | + ]; |
| 145 | + |
| 146 | + if (hitTolerance) { |
| 147 | + const [x, y] = pixels as [number, number]; |
| 148 | + pixels = [ |
| 149 | + [x - hitTolerance, y - hitTolerance], |
| 150 | + [x + hitTolerance, y + hitTolerance], |
| 151 | + ]; |
| 152 | + } |
| 153 | + return pixels; |
| 154 | + } |
| 155 | + |
| 156 | + private toOlFeature(feature: MapGeoJSONFeature): Feature<Geometry> { |
| 157 | + const layer = this.getLayer(); |
| 158 | + const map = layer.getMapInternal(); |
| 159 | + |
| 160 | + const projection = |
| 161 | + map?.getView()?.getProjection()?.getCode() || 'EPSG:3857'; |
| 162 | + |
| 163 | + if (!formats[projection]) { |
| 164 | + formats[projection] = new GeoJSON({ |
| 165 | + featureProjection: projection, |
| 166 | + }); |
| 167 | + } |
| 168 | + |
| 169 | + const olFeature = formats[projection].readFeature(feature) as Feature; |
| 170 | + if (olFeature) { |
| 171 | + // We save the original MapLibre feature to avoid losing information |
| 172 | + // potentially needed for others functionalities like highlighting |
| 173 | + // (id, layer id, source, sourceLayer ...) |
| 174 | + olFeature.set(VECTOR_TILE_FEATURE_PROPERTY, feature, true); |
| 175 | + } |
| 176 | + return olFeature; |
| 177 | + } |
| 178 | +} |
| 179 | + |
| 180 | +function sameSize(canvas: HTMLCanvasElement, frameState: FrameState): boolean { |
| 181 | + return ( |
| 182 | + canvas.width === Math.floor(frameState.size[0] * frameState.pixelRatio) && |
| 183 | + canvas.height === Math.floor(frameState.size[1] * frameState.pixelRatio) |
| 184 | + ); |
| 185 | +} |
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