栅格瓦片-栅格掩模

// https://gw.alipayobjects.com/zos/antvdemo/assets/2019_clip/ndvi_201905.tif
import { RasterLayer, Scene } from '@antv/l7';
import { Map } from '@antv/l7-maps';
import * as GeoTIFF from 'geotiff';
const scene = new Scene({
  id: 'map',
  map: new Map({
    center: [105, 37.5],
    zoom: 2.5,
  }),
});
scene.on('loaded', async () => {
  const tiffdata = await getTiffData();

  const masklayer = new RasterLayer({
    zIndex: 3,
    visible: false,
  });
  masklayer
    .source(tiffdata.data, {
      parser: {
        type: 'raster',
        width: tiffdata.width,
        height: tiffdata.height,
        extent: [
          73.4821902409999979, 3.8150178409999995, 135.1066187319999869, 57.6300459959999998,
        ],
      },
    })
    .style({
      clampLow: false,
      clampHigh: false,
      domain: [10, 60],
      noDataValue: 0,
      rampColors: {
        positions: [0, 0.05, 0.1, 0.25, 0.5, 1.0], // 数据需要换成 0-1
        colors: ['rgba(0,0,0,0)', 'rgba(92,58,16,0)', '#fabd08', '#f1e93f', '#f1ff8f', '#fcfff7'],
      },
    });

  const raster = new RasterLayer({
    zIndex: 2,
    maskLayers: [masklayer],
    visible: true,
    enableMask: true,
  })
    .source(
      'https://tiles{1-3}.geovisearth.com/base/v1/img/{z}/{x}/{y}?format=webp&tmsIds=w&token=b2a0cfc132cd60b61391b9dd63c15711eadb9b38a9943e3f98160d5710aef788',
      {
        parser: {
          type: 'rasterTile',
          tileSize: 256,
        },
      },
    )
    .style({
      opacity: 1,
    });
  scene.addLayer(raster);

  scene.addLayer(masklayer);
  addLayer();
});
async function getTiffData() {
  const response = await fetch(
    'https://gw.alipayobjects.com/zos/antvdemo/assets/light_clip/lightF182013.tiff',
  );
  const arrayBuffer = await response.arrayBuffer();
  const tiff = await GeoTIFF.fromArrayBuffer(arrayBuffer);
  const image = await tiff.getImage();
  const width = image.getWidth();
  const height = image.getHeight();
  const values = await image.readRasters();
  return {
    data: values[0],
    width,
    height,
  };
}

async function addLayer() {}