Rotate SVG at the center for Google maps custom icon

Question

I have this code for drawing a rotated icon on a google map:

    function createMarker(device) {
        var wtf = new google.maps.Marker({
        map: window.map_,
        position: new google.maps.LatLng(device.lat, device.lng),
        icon: {
            path: 'M350,0 700,700 350,550 0,700',
            fillColor: "limegreen",
            fillOpacity: 0.8,
            scale: 0.04,
            strokeColor: 'limegreen',
            strokeWeight: 1,
            anchor: new google.maps.Point(800, 800),
            rotation: device.head,
        }
      });
      return wtf;
}

The problem is the rotation rotates on one of the corners of the SVG - not the center. I found the svg path somewhere, scaled it by trial and error, and guessed at the anchor. When I add a label, instead of the label being under the icon it is all messed up. The label uses the same lat/long as the marker.

See example:

I'm finding it impossible to get the icon to rotate "on the spot" above the label. Any ideas on how to get this to work? Thanks

Answer 1

This isn't ideal but it works okay. This is TypeScript code. You can't go back to JavaScript after writing in TypeScript, it is just too painful.

Given that pos is a LatLng:

let pos = new this.google.maps.LatLng(lat, lng);

Methods:

public createMarker(heading: number, pos: any) {
    let marky = new this.google.maps.Marker({
        position: pos,
        map: this.google_map,
        icon: {
            path: this.google.maps.SymbolPath.FORWARD_CLOSED_ARROW,
            fillOpacity: 1,
            fillColor: 'orange',
            strokeWeight: 1.5,
            scale: 2,
            strokeColor: 'darkblue',
            rotation: heading,
            anchor: this.getRotation(heading),
        },
    });
    return marky;
}

public createLabel(name: string, pos: any) {
    let label = new MapLabel({
        text: name,
        position: pos,
        map: this.google_map,
        fontSize: 17,
        fontColor: 'darkred',
        align: 'center'
    });
    return label;
}

public getRotation(angle: number) {
    if (angle <= 30) return new this.google.maps.Point(0, 5);
    if (angle <= 45) return new this.google.maps.Point(0, 5);
    if (angle <= 60) return new this.google.maps.Point(2, 4);
    if (angle <= 120) return new this.google.maps.Point(3, 0);
    if (angle <= 150) return new this.google.maps.Point(0, 0);
    if (angle <= 210) return new this.google.maps.Point(0, 0);
    if (angle <= 220) return new this.google.maps.Point(-1, 0);
    if (angle <= 240) return new this.google.maps.Point(-3, 0);
    if (angle <= 280) return new this.google.maps.Point(-3, -3);
    return new this.google.maps.Point(0, 5);
}