openlayer point symbol from wkt string

Question

I'd like to represent a series of points each associated with their own wkt string representing the shape of that point at a certain zoom level.

With geoserver, I can do that pretty easily. Something like this for example:

* {
   mark: symbol("wkt://MULTILINESTRING((-0.25 -0.25, -0.125 -0.25), (0.125 -0.25, 0.25 -0.25), (-0.25 0.25, -0.125 0.25), (0.125 0.25, 0.25 0.25))");
}

This symbol is relative to the actual coordinate of a point and can be sized up or down with another property.

Is there anything similar with openlayer ? How can I represent a point with a dynamic polygon shape ?

I'd be interesting to know how to do this with webGL in Openlayer, if it's possible as the data I'm working with contains thousands of points on the map.

Answer 1

OpenLayers styles have a geometry property (defaults to the feature's geometry but can be overridden) so if you had a WKT geometry string as a property of a point feature you could parse that, translate it relative to the feature's position and use it to style the point:

var features = [
  new Feature({
    geometry: new Point([50, 50]),
    mark: "MULTILINESTRING((-0.25 -0.25, -0.125 -0.25), (0.125 -0.25, 0.25 -0.25), (-0.25 0.25, -0.125 0.25), (0.125 0.25, 0.25 0.25))"
  })
];

var parser = new WKT();

var style = new Style({
  stroke = new Stroke({
    width: 2,
    color: 'black'
});

var layer = new VectorLayer({
  source : new VectorSource({
    features: features,
  }),
  style: function(feature) {
    var point = feature.getGeometry().getCoordinates();
    var mark = parser.readGeometry(feature.get('mark'));
    mark.translate(point[0], [point[1]);
    style.setGeometry(mark);
    return style;
  }
});