leaflet-baidu: This plugin in no longer maintained nor enchanced

An on-going plugin for leaflet with Baidu Map.

Why this plugin?

Baidu map is using a different coordinate system and a different algorithm to calculate tile coordinate. Inspired by another leaflet plugin by Pavel Shramov and Bruno B. It is dedicated for Google, Bing, and Yandex map.

Contributing to the code

I have created several tickets in the issue list with "help wanted" labels. If you have any idea, please do not hesitate leave a comment or make a pull request. All advices are appreciated.
It would be great if you create the branch accordingly: fix_number of issue.
It would also be great if you create commit message accordingly: re #number of issue: your commit message

How Does Baidu Map Work?

Basically, there are 4 kinds of coordinate need to know: Longitude and Latitude, point coordinate, pixel coordiante, tile coordinate. In the following demostration, I will use the coordinate of Tian'an Men(116.404, 39.915) in Baidu coordinate system.

Longitude and Latitude

The coordinate Baidu Map using is different from WGS84, which is general international standards. One layer encryption is required by the Chinese goverment, which is called GCJ-02. Moreover, Baidu Map encrypts another layer called BD-09 based on GCJ-02. Here's an interface to convert those coordinates.

Point Coordinate

Baidu Map uses Mercator projection. The difference between Baidu Map and other maps in projection is the range of latitude. Google map will project the earth to a square, latitude is roughly from -85 to 85; whereas baidu map projects the earth from -71.988531 to 74.000022. This coordinate convertion is managed by a class called BMap from Baidu.

var projection = new BMap.MercatorProjection();
var point = projection.lngLatToPoint(new BMap.Point(116.404, 39.915));
alert(point.x + ", " + point.y);
//results: 12958175, 4825923.77

An image to show point coordinate:

Pixel Coordinate

Formula: pixel_coordinate = |point_coordinate * 2^(zoom-18)|. If you how to make math equation in markdown feel free to make a pull request.
18 is the Max Zoom level of Baidu map. The pixel coordinate of Tian'an Men in Zoom Level 4 in Baidu Map is 790, 294.

Tile Coordinate

Formula: tile_coordinate = |pixel_coordinate/256|
256 is the size of the tile height and width in Baidu Map. For instance, the tile coordinate of Tian'an Men in zoom level 4 is 3,1, and 50617, 18851 in zoom level 18.

Chinese Documentation

The coordinate system is cited from Here. Here's more details in Chinese.

Contact

My email is surezeroleo@gmail.com. Again, all advices are appreciated.