README.md

leaflet.latlng-graticule

Create a Canvas as ImageOverlay to draw the Lat/Lon Graticule, and show the grid tick label at the edges of the map.

Check out the demo.

Usage example

    L.latlngGraticule({
        showLabel: true,
        zoomInterval: [
            {start: 2, end: 3, interval: 30},
            {start: 4, end: 4, interval: 10},
            {start: 5, end: 7, interval: 5},
            {start: 8, end: 10, interval: 1}
        ]
    }).addTo(map);

Or

    L.latlngGraticule({
        showLabel: true,
        zoomInterval: [
          {start: 0, end: 1, interval: 90},
          {start: 2, end: 2, interval: 45},
          {start: 3, end: 3, interval: 10},
          {start: 4, end: 5, interval: 5},
          {start: 6, end: 6, interval: 2},
          {start: 7, end: 7, interval: 1},
          {start: 8, end: 8, interval: (30.0 / 60.0)},
          {start: 9, end: 9, interval: (20.0 / 60.0)},
          {start: 10, end: 10, interval: (10.0 / 60.0)},
          {start: 11, end: 11, interval: (5.0 / 60.0)},
          {start: 12, end: 12, interval: (2.0 / 60.0)},
          {start: 13, end: 13, interval: (1.0 / 60.0)},
          {start: 14, end: 15, interval: (0.5 / 60.0)},
          {start: 16, end: 16, interval: (0.2 / 60.0)},
          {start: 17, end: 18, interval: (0.1 / 60.0)},
        ]
    }).addTo(map);

Options

• showLabel: Show the grid tick label at the edges of the map. Default true
• opacity: Opacity of the Graticule and Label. Default 1
• weight: The width of the graticule lines. Default 0.8
• color: The color of the graticule lines. Default #aaa
• font: Font Style for the tick label. Default 12px Verdana
• fontColor: Color of the tick label. Default #aaa
• format: Format of labels. Possible values: dd for Decimal Degrees, dmd for Degrees Decimal Minutes and dms for Degrees Minutes Seconds. Default dd
• precision: Decimal Degrees precision if format is dd. Default 4
• zoomInterval: Use different intervals in different zoom levels. You can set for both latitude and longitude lines as the example, or set different intervals for latitude and longitude like below:

  zoomInterval: {
    latitude: [
      {start: 4, end: 6, interval: 5},
      {start: 7, end: 20, interval: 1}
    ],
    longitude: [
      {start: 4, end: 6, interval: 10},
      {start: 7, end: 20, interval: 2}
    ]
  }

• Default:

  zoomInterval: [
    {start: 2, end: 2, interval: 40},
    {start: 3, end: 3, interval: 20},
    {start: 4, end: 4, interval: 10},
    {start: 5, end: 7, interval: 5},
    {start: 8, end: 20, interval: 1}
  ]

Special Options

Some of the projections (like Lambert) is no straight line, set those options to draw a polyline graticule.

• lngLineCurved: Interval of polyline. Deafult 0
• latLineCurved: Interval of polyline. Deafult 0

Check out the Lambert projection example.