将d3地理图块中的缩放限制为“最大”

Question

When you use certain tile-sets (eg .tiles.mapbox.com/v3/mapbox.natural-earth-2/ ) the zoom on d3 geo tiles should be limited to a maximum, otherwise those tiles do not exist, cannot be found, and end up displaying an ugly 'cannot be found' background image.

I have created a fiddle (courtesy of user Lex ) to show you exactly what I mean. Try clicking on a small country to replicate the issue. No tiles exist at that zoom level. The following two solutions would be acceptable.

1. How would I set about limiting the zoom in function clicked that calculates the zoom-to-bounding-box?
2. How would I amend the script such that function clicked continues to zoom into the most detailed tile available?

Answer 1

One easy approach to this is to limit the zoom by setting a maximum scaling factor.

For instance in clicked you could add a line like this:

scale = Math.min(1 << 14, scale);

(based your previous scale extent of [1 << 11, 1 << 14] )

Here's the updated fiddle: https://jsfiddle.net/5Lf0w3sm/17/