# Loctome API
# Terrain Elevation Service
This service provide the functionality to enrich coords with the terrain elevation data
If do you like use this service, please [Contact with us](https://loctome.com/web/english/contact-us) to request an api_key that allow the autentification.
## Who to use it?
This API can be used with two format of input coords data
## With Shapes Coords
https://node.loctome.com/height?json={"shape":[{"lat":40.712431,"lng":-76.504916},{"lat":40.712275,"lng":-76.605259}]}&api_key=elevation_api_key
Test [Link](https://node.loctome.com/height?json={%22shape%22:[{%22lat%22:40.712431,%22lng%22:-76.504916},{%22lat%22:40.712275,%22lng%22:-76.605259}]}&api_key=elevation_api_key)
## With Encoded Coords
You could be send multiple coords as compressed-encoded format
https://node.loctome.com/height?json={"encoded":"morjnAme`eB?`A\\`@f@`A\\`@d@bB\\bBbAbBbB^bB`@~B?hC?`C`@bA`A?dCcAbBaC?gDeCaBiGcBiFcBeDgCcBgD?aCbBcAbB?`A`B`AhC`@bB?bA`@\\^]bAkB^aB_@aCcAkGaAaB`@e@^]bA\\?d@^?`@\\`@?^d@??_@\\cA^_@d@?\\^bA?|@?bA?d@?^??`@\\`@?^?`@?`@\""}&api_key=elevation_api_key
Test [Link](https://node.loctome.com/height?json={%22encoded%22%3A%22morjnAme%60eB%3F%60A%5C%5C%60%40f%40%60A%5C%5C%60%40d%40bB%5C%5CbBbAbBbB%5EbB%60%40~B%3FhC%3F%60C%60%40bA%60A%3FdCcAbBaC%3FgDeCaBiGcBiFcBeDgCcBgD%3FaCbBcAbB%3F%60A%60B%60AhC%60%40bB%3FbA%60%40%5C%5C%5E%5DbAkB%5EaB_%40aCcAkGaAaB%60%40e%40%5E%5DbA%5C%5C%3Fd%40%5E%3F%60%40%5C%5C%60%40%3F%5Ed%40%3F%3F_%40%5C%5CcA%5E_%40d%40%3F%5C%5C%5EbA%3F%7C%40%3FbA%3Fd%40%3F%5E%3F%3F%60%40%5C%5C%60%40%3F%5E%3F%60%40%3F%60%40%5C%22%22}&api_key=elevation_api_key)
## Demo Map
[Try the Map Demo App](https://node.loctome.com/map.html)
## Compress Encode javascript example code:
@points = array of values lat1, lng1, lat2, lng2,...
@precision = Number between 1 and 8, represent the decimal precision. i.e. 6 = 23.412345
function compress(points, precision) {
try {
var oldLat = 0,
oldLng = 0,
len = points.length,
index = 0,
encoded = '';
precision = Math.pow(10, precision);
while (index < len) {
// Round to N decimal places
var lat = Math.round(points[index++] * precision);
var lng = Math.round(points[index++] * precision);
// Encode the differences between the points
encoded += encodeNumber(lat - oldLat);
encoded += encodeNumber(lng - oldLng);
oldLat = lat;
oldLng = lng;
}
return encoded;
} catch (err) {
msg(err);
}
}
function encodeNumber(num) {
try {
var num = num << 1;
if (num < 0) {
num = ~(num);
}
var encoded = '';
while (num >= 0x20) {
encoded += String.fromCharCode((0x20 | (num & 0x1f)) + 63);
num >>= 5;
}
encoded += String.fromCharCode(num + 63);
return encoded;
} catch (err) {
msg(err);
}
}
## Swagger API Definition
Access to the Swagger API defintion in the folow [Link](https://editor.swagger.io/?url=https://node.loctome.com/swagger/elevation.yaml)
