自定义水位图

import { CanvasLayer, Scene } from '@antv/l7';
import { GaodeMap } from '@antv/l7-maps';
let x = 0;
function draw(option) {
  const { size, ctx, mapService } = option;
  const [width, height] = size;

  const radius = 30,
    rectWidth = radius * 2;
  const rectHeight = rectWidth;

  ctx.clearRect(0, 0, width, height);

  const points = [
    {
      lng: 108.544921875,
      lat: 30.977609093348686,
      level: 85,
      color: 'rgba(	220,20,60, 0.6)',
    },
    {
      lng: 110.654296875,
      lat: 31.090574094954192,
      level: 75,
      color: 'rgba(	255,140,0, 0.6)',
    },
    {
      lng: 112.5,
      lat: 29.80251790576445,
      level: 65,
      color: 'rgba(255,165,0, 0.6)',
    },
    {
      lng: 114.78515624999999,
      lat: 30.64867367928756,
      level: 40,
      color: 'rgba(30,144,255, 0.6)',
    },
    {
      lng: 116.49902343749999,
      lat: 29.84064389983441,
      level: 50,
      color: 'rgba(30,144,255, 0.6)',
    },
    {
      lng: 118.21289062499999,
      lat: 31.16580958786196,
      level: 20,
      color: 'rgba(	127,255,0, 0.6)',
    },
    {
      lng: 119.091796875,
      lat: 32.509761735919426,
      level: 50,
      color: 'rgba(30,144,255, 0.6)',
    },
    {
      lng: 121.0693359374999,
      lat: 31.80289258670676,
      level: 45,
      color: 'rgba(30,144,255, 0.6)',
    },
  ];
  ctx.fillStyle = 'rgb(35,75,225)';
  ctx.font = 'normal small-caps bold 14px arial';
  ctx.textAlign = 'center';
  ctx.textBaseline = 'middle';

  points.map((point) => {
    const pixelCenter = mapService.lngLatToContainer([point.lng, point.lat]);
    pixelCenter.x *= window.devicePixelRatio;
    pixelCenter.y *= window.devicePixelRatio;
    const rectStartX = pixelCenter.x - radius;
    const rectStartY = pixelCenter.y - radius;

    ctx.save();

    ctx.fillText(point.level + '%', pixelCenter.x, pixelCenter.y);

    ctx.beginPath();
    ctx.arc(pixelCenter.x, pixelCenter.y, radius, 0, Math.PI * 2);
    ctx.fillStyle = 'rgba(135,206,250,0.2)';
    ctx.closePath();
    ctx.fill();
    ctx.clip();

    ctx.beginPath();
    ctx.fillStyle = point.color;
    ctx.moveTo(rectStartX, pixelCenter.y);

    const waterheight = rectStartY + ((100 - point.level) / 100) * rectHeight;
    for (let i = 0; i <= rectWidth; i += 10) {
      ctx.lineTo(rectStartX + i, waterheight + Math.sin(Math.PI * 2 * (i / rectWidth) + x) * 3 + 1);
    }

    ctx.lineTo(pixelCenter.x + radius, pixelCenter.y + radius);
    ctx.lineTo(rectStartX, pixelCenter.y + radius);
    ctx.lineTo(rectStartX, pixelCenter.y);
    ctx.closePath();

    ctx.fill();

    ctx.restore();
    return '';
  });
  return '';
}

const scene = new Scene({
  id: 'map',
  map: new GaodeMap({
    style: 'fresh',
    center: [115, 31],
    zoom: 5.0,
  }),
});
scene.on('loaded', () => {
  const layer = new CanvasLayer({
    zIndex: 10,
    trigger: 'change',
  });
  layer.draw(draw);
  scene.addLayer(layer);

  setInterval(() => {
    x += 0.1;
    scene.render();
    return '';
  }, 30);

  layer.on('add', () => {
    layer.getCanvas().addEventListener('click', (e) => {
      console.log(e);
    });
  });
});