java - PointPlacemarks 的绘制顺序

Question

是否有办法修复 World Wind 中 PointPlacemarks 的绘制顺序？

即使在 Placemarks example只需在特定缩放级别移动鼠标即可更改地标 B 和音频地标的顺序:

到目前为止我已经尝试过:

• 将 PointPlacemark 添加到单独的图层
• 使用 RenderableLayer.setRenderables 而不是 RenderableLayer.addRenderable
• Related question on World Wind forums

Answer 1

Hacky解决方案(需要修改World Wind源代码)

在gov.nasa.worldwind.render.DrawContextImpl中将orderedRenderables从

protected PriorityQueue<OrderedRenderableEntry> orderedRenderables =
    new PriorityQueue<OrderedRenderableEntry>(100, new Comparator<OrderedRenderableEntry>()
    {
        public int compare(OrderedRenderableEntry orA, OrderedRenderableEntry orB)
        {
            double eA = orA.distanceFromEye;
            double eB = orB.distanceFromEye;

            return eA > eB ? -1 : eA == eB ? (orA.time < orB.time ? -1 : orA.time == orB.time ? 0 : 1) : 1;
        }
    });

至

protected Queue<OrderedRenderableEntry> orderedRenderables = new ArrayDeque<>();

(或修改比较器以执行您想要的操作)。这将修复绘图顺序。

替代解决方案(不需要修改 World Wind 源代码)

扩展PointPlacemark并覆盖makeOrderedRenderable():

public class OrderedPointPlacemark extends PointPlacemark {
    public OrderedPointPlacemark(Position position) {
        super(position);
    }
    @Override
    protected void makeOrderedRenderable(DrawContext dc) {
        super.makeOrderedRenderable(dc);

        if (this.intersectsFrustum(dc) || this.isDrawLine(dc)) {
            dc.pollOrderedRenderables();
            dc.addOrderedSurfaceRenderable(this);
        }
    }
}