This visualization compares French legislative electoral districts between 2012 and 2017, showing how commune boundaries and canton assignments shifted across the two years. It displays two side-by-side maps, likely using Three.js with WebGL rendering to animate or morph between the two configurations. The data comes from CSV files containing commune-to-canton and commune-to-district correspondences for both years. The visualization relies on the Vue framework to manage the interface and handle state transitions, with the geographic comparisons rendered through WebGL for smooth interactive exploration.