Eurogeo 1.1.0 – name a country from its outline

Most of us know the flags. Far fewer could pick out North Macedonia with the borders unlabelled and the colours taken away.

Eurogeo is an offline quiz app for Android and iOS about the countries of Europe, and version 1.1.0 adds their outlines as a subject in their own right. You get the bare shape and name the country – or the reverse, where you are given the country and pick its outline from several. Outlines also cross with flags, so a shape can ask for a flag and a flag can ask for a shape.

Where the country outlines come from

The shapes are not pictures. They are coordinates generated from Natural Earth by a Python tool, written into the content seed as plain numbers and drawn natively on each platform – Jetpack Compose on Android, SwiftUI on iOS. One source of geometry, two renderers, and no image to duplicate from one platform to the other.

That paid off somewhere I had not expected: the launcher icon is generated from the same data, so the app's own silhouette of Europe cannot drift from the one inside the game.

Drawing the smallest countries

Natural Earth's resolution runs out at the small end – small entities like Monaco, San Marino or Vatican City come out as a few unusable points. The smallest countries are drawn from a second, finer source instead – see the app's About screen to learn about their respective licences.

Getting the coastlines to close was most of the work, and all of it happens before the app is built. The generator refuses a coastline it cannot join and names the country whose source data came back wrong, rather than quietly producing a lumpy Ireland. What ships is the finished coordinates, so the app itself has nothing to fetch.

Try out Eurogeo on Google Play Store!

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