leafletmapnikcartodb

How CartoDB is able to add mouse interaction over PNG image Tiles

I am new to GIS mapping.

I wonder how CartoDB is able to add mouse interaction like(mouse Hover/click) on The generated PNG image tiles. Can anyone explain the background process about how its done. Thank you so much.

Solution

  • This is a very nice question!

    They use a custom implementation of the UTF-GRID specification called Zera.

    You can read a very good explanation here.