Functions for Working with GeoSpatial Canvas Elements
npm install geocanvasbash
npm install geocanvas
`basic usage
// this function is mutable
// modifying the original canvas
maskCanvas({
// required
// an HTML Canvas Element
canvas,
// required
// bounding box of the canvas
// as [xmin, ymin, xmax, ymax]
// or [west, south, east, north]
canvas_bbox: [7698736.857788673, 163239.83797837645, 10066450.245949661, 1325082.6679127468],
// required
// spatial reference system of the canvas image
canvas_srs: 3857,
// optional
canvas_pixel_height: 2445.98490512499,
// optional
canvas_pixel_width: 2445.98490512499,
// required
// a GeoJSON Feature, FeatureCollection, Polygon, or MultiPolygon
mask: { type: "FeatureCollection", features: [ / ... / ] },
// required
// spatial reference system of the mask geometry
mask_srs: 4326,
// optional parameter
// accepts "outside" or "inside"
// default is outside
// choose whether to make the inside or outside
// of the mask geometry transparent
strategy: "outside"
});