vue3-openlayers 轨迹回放（历史轨迹），实时轨迹

本篇介绍一下使用vue3-openlayers轨迹回放（历史轨迹），实时轨迹

1 需求

• 轨迹回放（历史轨迹）
• 实时轨迹

2 分析

可以使用和上一篇相同的办法,即主要是利用定时器，不断添加feature

• 轨迹回放（历史轨迹），一般是一次性拿到所有坐标点，按照时间间隔不断循环添加feature
• 实时轨迹，一般是通过websocket监听，不断获取最新坐标点，根据上报的频率，可能需要抽样

也可以使用ol-animation-path(下篇介绍,其实openlayers也有类似的方法)

3 实现

<template>
  <ol-map
    :loadTilesWhileAnimating="true"
    :loadTilesWhileInteracting="true"
    style="width: 100%; height: 100%"
    ref="mapRef"
  >
    <ol-view
      ref="view"
      :center="center"
      :zoom="zoom"
      :projection="projection"
    />

    <ol-tile-layer>
      <ol-source-tianditu
        layerType="img"
        :projection="projection"
        :tk="key"
        :hidpi="true"
        ref="sourceRef"
      ></ol-source-tianditu>
    </ol-tile-layer>
    <ol-tile-layer>
      <ol-source-tianditu
        :isLabel="true"
        layerType="img"
        :projection="projection"
        :tk="key"
        :hidpi="true"
      ></ol-source-tianditu>
    </ol-tile-layer>
    <ol-vector-layer>
      <ol-source-vector>
				<ol-feature  v-if="trace.length" >
          <ol-geom-point :coordinates="trace[trace.length-1][1]" ></ol-geom-point>
          <ol-style>
            <ol-style-icon  :src="iconSrc" :width="30" :height="30" :rotation="angle"></ol-style-icon>
          </ol-style>
        </ol-feature>
        <ol-feature v-for="(item, index) in trace" :key="index">
          <ol-geom-line-string :coordinates="item"></ol-geom-line-string>
          <ol-style>
            <ol-style-stroke color="rgba(228, 147, 87, 1)" :width="3"></ol-style-stroke>
          </ol-style>
        </ol-feature>
      </ol-source-vector>
    </ol-vector-layer>
  </ol-map>
</template>

<script setup lang="ts">
import iconSrc from '@/assets/image/truck.png';

const center = ref([121, 31]);
const projection = ref('EPSG:4326');
const zoom = ref(5);
const mapRef = ref();
const key = '替换为天地图key';
const sourceRef = ref(null);
const data = ref([
  [110, 30],
  [110.2, 30],
  [110.4, 30.2],
  [110.8, 30.4],
  [111, 31],
  [111.3, 31],
  [111.6, 31],
  [111.9, 31],
  [112, 31],
  [112.3, 31],
  [112.5, 31],
  [112.8, 31],
  [113, 31],
  [114, 31],
  [115.3, 32],
  [115.5, 32],
  [115.8, 31.8],
  [116, 31.4],
  [116.2, 31.1],
  [116.5, 30.5],
  [115, 30.2],
  [114, 29.8],
  [113, 29.6],
  [112, 29.4],
  [111, 30.2],
  [110, 30.4],
  [109, 30.6],
  [108, 31]
]);
const trace = ref([]);
const angle=ref(0);

onMounted(() => {
  let i = 0;
  const interval = setInterval(() => {
    if (data.value[i + 1]) {
      let arc = 0;
      if (
        (data.value[i + 1][0] - data.value[i][0] >= 0 &&
				data.value[i + 1][1] - data.value[i][1] >= 0) ||
        (data.value[i + 1][0] - data.value[i][0] < 0 &&
          data.value[i + 1][1] - data.value[i][1] > 0)
      ) {
        arc = Math.atan(
          (data.value[i + 1][0] - data.value[i][0]) / (data.value[i + 1][1] - data.value[i][1])
        );
      } else if (
        (data.value[i + 1][0] - data.value[i][0] > 0 &&
          data.value[i + 1][1] - data.value[i][1] < 0) ||
        (data.value[i + 1][0] - data.value[i][0] < 0 &&
          data.value[i + 1][1] - data.value[i][1] < 0)
      ) {
        arc =
          Math.PI +
          Math.atan(
            (data.value[i + 1][0] - data.value[i][0]) /
              (data.value[i + 1][1] - data.value[i][1])
          );
      }
			angle.value=arc
      trace.value.push([data.value[i], data.value[i + 1]]);
      i++;
    } else {
      clearInterval(interval);
    }
  }, 200);
});
</script>
<style scoped lang="scss">
.overlay-content {
  background: rgba(255, 255, 255, 0.7);
  box-shadow: 0 5px 10px rgb(2 2 2 / 20%);
  padding: 10px 20px;
  font-size: 16px;
  color: black;
}
</style>