Question

I need to get the tile number (x, y, z) for a clicked marker using the Google Maps API v3.

There is little documentation available which discusses this. How would I even start?

Answer 1

1. Get the marker lat lng which is a property of to the marker click event object.
2. Use the map projection (map.getProjection()) to convert to world coordinates (also known as point plane).
3. Using the current map zoom level (which is your ‘z’ coordinate), calculate the pixel coordinates from the world coordinates:
   pixelCoordinateX = parseInt(worldCoordinateX * Math.pow(2, zoom), 10). Same concept for the ‘y’ coordinate.
4. Divide the pixelCoordinate by the tile size (256) and take the integer portion. This is the tile number.
   x = parseInt(pixelCoordinateX / 256, 10).

See the Map Types concepts in the Google Maps API Reference.