GitHub - jorelosorio/web-mercator-projection: A Go project to explore the math to calculate and present data in a map using the `Web Mercator Projection` (original) (raw)

Web Mercator Projection

A Go project to explore the Math to calculate and present data in a map using the Web Mercator Projection.

To get more information about this topic, please look at the following references:

How does this project work?

In the main example project, there is a file main.go that contains the following actions available:

Convert a LonLat into a Point coordinates and vice versa.
A function to add a Red-Marker into a map image. (The coordinates must be setted manually in the code)

The resultant image will be stored in a folder named data.

This is how the main.go will print out the information:

LonLat: {-74.92010258781309 11.045882360336755}
Point: {298.8939304168872 480.38414652354516 2}
Tile: {1 1 2}
LonLat from Point: {-74.9201025878131 11.045882360336744}

Structs definitions

LonLat: A location in the map using angles in degrees.
Point: A pixel in the map for a specific zoom or scale.
Tile: Represent at which (tile/block) a Point or LonLat is.

If you are curious about how the maps where built using the data in OpenStreetMap please take a look at this Gist https://gist.github.com/jorelosorio/7042bd27e4b2bb03865215d6a5607266

Tools

GoLang 1.17
Docker
ImageMagick 6.9.11-60
Visual Studio Code Optional!

It requires a Remote - Containers extension. for more information please refers to: https://code.visualstudio.com/docs/remote/containers#_getting-started

Development

This project contains a Dockerfile file with all required dependencies to run it using Visual Studio Code + Remote - Containers extension. However, if you want to make it run locally in your development machine, please follow the instructions below.

Install Go

Install it from https://go.dev/dl/

Install ImageMagick

Install it using the following instructions https://imagemagick.org/script/download.php

Build the executable

go build ./examples/main.go

The binary file depends on the assets folder to build the map, make sure to have it on the same directory.

Licences and assets

OpenStreetMap data is licenced under the Open Data Commons Open Database Licence (ODbL). https://opendatacommons.org/licenses/odbl/1-0/
Red marker icon https://www.iconfinder.com/icons/299087/marker_map_icon Creative Commons (Attribution 3.0 Unported) http://creativecommons.org/licenses/by/3.0/

GitHub - jorelosorio/web-mercator-projection: A Go project to explore the math to calculate and present data in a map using the Web Mercator Projection (original) (raw)