leaflet-geojson-proj4-vectortile

It is a open-source leaflet plugin which generate the vector tiles(canvas) for geojson data in proj4 coordinates. (support only for polygon and multipolygon at this time)

Dependency

• [leaflet] (https://leafletjs.com/)
• [proj4js] (https://github.com/proj4js/proj4js)
• [proj4leaflet] (https://kartena.github.io/Proj4Leaflet/)

Demo

[DEMO] (https://hunter3789.github.io/leaflet-geojson-proj4-vectortile/example/demo.html)

• geojson data is from https://geojson-maps.ash.ms/

Installation and setup

• Quick use:

<script src="[path to js]/leaflet-geojson-proj4-vectortile.js"></script>

Usage

0. Slice geojson data by longitude (if needed, for certain projection, usually don't need)

var newGeojson = sliceGeojson(geojson, longitude);

// projection(example) : "+proj=eqc +lat_0=0 +lat_ts=0 +lon_0=126 +x_0=0 +y_0=0 +ellps=WGS84 +units=m +no_defs"

1. Calculate min/max bounds of each polygons from geojson

getGeojsonBounds(map, geojson);

2. Draw Tiles (draw polygons in which boundaries and tiles overlap.)

L.geoJson.projvt(geojson, options).addTo(map);

// options(example) : {tileSize:512, pane:pane, color: "black", fillColor: "#ffffe5", weight: 1, simplify:true, tolerance:1}

• select proper tileSize for better performance
• simplify option is for polyline simplification, tolerance option is smooth parameter.

License

LICENSE