绘制PointPlacemarks

Question

有没有办法在World Wind中修复PointPlacemarks的绘制顺序？

即使在<{>>地标B 的Placemarks example排序中，只需在特定缩放级别移动鼠标即可更改音频地标：

到目前为止，我已经尝试过：

• 将PointPlacemarks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）

gov.nasa.worldwind.render.DrawContextImpl从

更改orderedRenderables

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;
        }
    });

到

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

（或修改比较器以做你想要的）。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);
        }
    }
}