antv-l7/packages/site/examples/raster/single_raster/demo/light_default.js

60 lines
1.5 KiB
JavaScript

// https://gw.alipayobjects.com/zos/antvdemo/assets/2019_clip/ndvi_201905.tif
import { RasterLayer, Scene } from '@antv/l7';
import { GaodeMap } from '@antv/l7-maps';
import * as GeoTIFF from 'geotiff';
const scene = new Scene({
id: 'map',
map: new GaodeMap({
style: 'dark',
center: [ 105, 37.5 ],
zoom: 2.5
})
});
scene.on('loaded', () => {
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() {
const tiffdata = await getTiffData();
const layer = new RasterLayer({});
layer
.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: [ 0, 90 ],
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(92,58,16,0)','rgba(92,58,16,0)', '#fabd08', '#f1e93f', '#f1ff8f', '#fcfff7' ],
}
});
scene.addLayer(layer);
}