mirror of https://gitee.com/antv-l7/antv-l7
89 lines
2.2 KiB
Markdown
89 lines
2.2 KiB
Markdown
---
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title: 掩模图层 - 直接使用
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order: 0
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---
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<embed src="@/docs/common/style.md"></embed>
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我们可以直接创建一个 `MaskLayer` 添加到场景中用于裁剪支持掩模的图层。
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```js
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const mask = new MaskLayer();
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mask.source(...);
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const layer = new PointLayer({
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mask: true,
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});
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scene.addLayer(mask);
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scene.addLayer(layer);
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```
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<div>
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<div style="width:60%;float:left; margin: 10px;">
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<img width="80%" alt="案例" src='https://gw.alipayobjects.com/mdn/rms_816329/afts/img/A*jhWWS6dhKhYAAAAAAAAAAAAAARQnAQ'>
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</div>
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</div>
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### 实现
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下面我们来介绍如何直接创建一个 `MaskLayer` 进行使用。
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```javascript
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import { RasterLayer, Scene, MaskLayer } from '@antv/l7';
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import { GaodeMap } from '@antv/l7-maps';
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import * as GeoTIFF from 'geotiff';
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const scene = new Scene({
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id: 'map',
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stencil: true,
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map: new GaodeMap({
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style: 'dark',
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center: [ 105, 37.5 ],
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zoom: 2.5
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})
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});
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scene.on('loaded', () => {
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fetch('https://gw.alipayobjects.com/os/basement_prod/d2e0e930-fd44-4fca-8872-c1037b0fee7b.json')
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.then(res => res.json())
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.then(data => {
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const layer = new MaskLayer({}).source(data)
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scene.addLayer(layer);
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});
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addLayer();
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});
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async function getTiffData() {
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const response = await fetch('https://gw.alipayobjects.com/os/rmsportal/XKgkjjGaAzRyKupCBiYW.dat');
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const arrayBuffer = await response.arrayBuffer();
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const tiff = await GeoTIFF.fromArrayBuffer(arrayBuffer);
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const image = await tiff.getImage();
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const width = image.getWidth();
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const height = image.getHeight();
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const values = await image.readRasters();
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return {
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data: values[0],
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width,
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height,
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min: 0,
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max: 8000
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};
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}
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async function addLayer() {
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const tiffdata = await getTiffData();
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const layer = new RasterLayer({ mask: true }).source(tiffdata.data, {
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parser: {
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type: 'raster',
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width: tiffdata.width,
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height: tiffdata.height,
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extent: [ 73.482190241, 3.82501784112, 135.106618732, 57.6300459963 ]
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}
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})
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.style({
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domain: [ 0, 8000 ],
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rampColors: {
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colors: [ '#FF4818', '#F7B74A', '#FFF598', '#91EABC', '#2EA9A1', '#206C7C' ].reverse(),
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positions: [ 0, 0.2, 0.4, 0.6, 0.8, 1.0 ]
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}
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});
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scene.addLayer(layer);
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}
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``` |