Selectively disable drawAltitude for compound markers

[joric]

First of all, I've managed to solve a bunch of problems already.

• Sorting markers by distance (Marker 3D depth #2097, using sortByDistanceToCamera: true, still doesn't sort across layers).
• Drawing lower shape for drawAltitude (Possibility of drawing LineStrings drawAltitude floating? #2320, using additional markers).
• Switching between 2d and 3d modes (to get rid of the parallax effect) with enableAltitude/setOptions, Broken redraw in 2d is fixable with forceRenderOnMoving.

But there's an unsolvable with drawAltitude - when you use compound markers, i.e. symbol: [ {..}, {..} ] with different markerDy, it draws SEVERAL vertical lines, one for each marker.

I CANNOT use separate layers, because Z-sorting doesn't work across layers, and I need Z-sorting for markers.

It would be great to disable altitude by symbol, because separating markers into different layers cause all sorts of issues (weird overlap, etc. as depth sorting doesn't work across layers).

Example: https://joric.github.io/supraland/3d

var marker = new maptalks.Marker([o.lng, o.lat, o.alt],{
  symbol: [
    {
      markerWidth: 75,
      markerHeight: 75,
      markerType: 'pin',
    },
    {
      markerFile: 'icon.png',
      markerWidth  : 32,
      markerHeight : 32,
      markerDy: -22,
    },
  ],
}).addTo(vectorLayer);

It draws two altitude lines for the marker. I think it should allow customizing altitude display (and color) for each symbol.
I thought maybe options could be callable, so we could use dynamic colors, but it doesn't work this way.

//    vectorLayer.setOptions({drawAltitude : {lineWidth : 3, lineColor : '#888' }});
    vectorLayer.setOptions({drawAltitude : (e)=>{lineWidth : 3, lineColor : getColor(e) }});

Also it may be useful to customize altitude drawing for lineString, I need only the last point. It is fixable with multiple layers, because Z-sorting doesn't matter for lines, but it would need an extra layer for endpoints only.

Upd. OK I realized I can do that with just 1 extra layer because I don't really need to sort lines by depth. Closing.