Dynamic grid on top of Google Maps

The script will make a layer grid over the google maps. Something similar with what3words [login to view URL] The square size must be declared as a constant and can be changed. Example : gridSize = 10 where 10 means a square by 10 x 10 meters The script must use google maps api (v3) and may use the rectangle primitive: Each grid square must have an click event to it and display something in console when clicked. You can start from this example found on Stackexchange [login to view URL] [login to view URL] The script must be coded in a efficient way - the grid should be written/displayed only for the current viewport, not for the entire world map. It should have the option to hide if a zoom change greater than n + bonus points if the script can work with Openstreetmap in a similar fashion