我可以估计每个国家在两个或多个航路点之间的旅行距离吗

Question

我希望能够通过谷歌地图API估计每个国家的旅行距离。

示例：我的路线起点是阿姆斯特丹(荷兰(，然后我在柏林(德国(有一个航路点，最终目的地是华沙(波兰(。

我想估计一下每个国家的公里数。

我已经搜索了谷歌地图API，但我找不到一个方法来做到这一点。

软件程序输出应该类似于：

• 荷兰：53公里
• 德国504公里
• 波兰304公里

Answer 1

在自己折腾了一番之后，我找到了以下解决方案：

import turf from '@turf/turf'
import polyline from '@mapbox/polyline'
import shapefile from 'shapefile'
// The google routes api result
import data from './coords.js';
// The compete route polyline
const polydata = polyline.toGeoJSON(data.routes[0].overview_polyline.points);
async function fetchWorldData() {
let worldData = [];
try {
let overBorder = false;
// Load country borders shapeFile
const source = await shapefile.open("TM_WORLD_BORDERS-0.3.shp");
// Loop over all countries
while (true) {
// Read the source for a specific country
const result = await source.read();
if (result.done) break;
// Check if the trip will cross any borders, if they do, set overBorder to true
if (turf.lineIntersect(polydata, result.value.geometry).features.length !== 0) {
overBorder = true;
// Append intersected borders
worldData.push(result.value);
}
}

// Return a list with all the country data
return worldData;
} catch (e) {
console.log(e);
}
}
async function makePrediction() {
console.time("execution time");
// Object to returned
let countries = []
// When leaving a border you will intersect with it(1) You will then intersect with the next border (2) causing another intersect.
// This bool ignores the entering intersect.
let ignoreNextBorder = false;
try {
// Fetch the world data
let worldData = await fetchWorldData();
worldData.map(async border => {
// Store distance and duration per country
let distance = 0;
let duration = 0;
data.routes[0].legs[0].steps.map(async (step) => {
// Get the step starting point
let pt = turf.point([step.start_location.lng, step.start_location.lat]);
const pointInCountry = turf.booleanPointInPolygon(pt, border.geometry);
// Check if the step starting point is in the current country
if (pointInCountry) {
// Add the step distance to the total
distance += step.distance.value;
duration += step.duration.value;
}
});
countries[border.properties.NAME] = {
duration: duration,
distance: distance
}
});
console.timeEnd("execution time");
return countries;
} catch (e) {
console.log(e)
}
}
makePrediction().then(console.log);

如果愿意，可以传递其他形状文件。它显示的结果如下：示例结果

不利的一面是，国家没有秩序。但这很适合我的需求。