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我試圖在美國宇航局的Worldwind中實現自己的雜波濾波器，它引起了一個奇怪的問題 - 雜波濾波器還沒有做很多，但我會用它來移動東西當我通過了「閃爍」的問題。每當鼠標移動時，GlobeAnnotation渲染器都會閃爍。當我將雜波濾鏡設置爲空時，閃爍似乎不會發生。WorldWind Java中的閃爍註釋
這裏是一個GIF圖片，展示了我的意思：https://media.giphy.com/media/xT9IgFiZwYZ3VJHQU8/giphy.gif
我從這裏克隆NASA世界風代碼：https://github.com/NASAWorldWind/WorldWindJava。我做了一些改變，使我的最終過濾器的工作。需要注意的是，我希望GlobeAnnotations顯示爲始終位於其他位置之上。
我該如何讓GlobeAnnotations不會互相爭鬥並且閃爍，但仍然會出現在其他任何事物的頂部 - 同時開啓雜波濾波器？
請注意，以下代碼僅僅是一個示例，我將它們放在一起以顯示我在「真實」應用程序中看到的問題。我希望GlobeAnnotations始終處於一切領先地位 - 但不會閃爍並與對方交戰。
這裏是我的測試車手：
package gov.nasa.worldwindx.examples;
import java.awt.Color;
import gov.nasa.worldwind.geom.LatLon;
import gov.nasa.worldwind.geom.Position;
import gov.nasa.worldwind.layers.AnnotationLayer;
import gov.nasa.worldwind.layers.RenderableLayer;
import gov.nasa.worldwind.render.GlobeAnnotation;
import gov.nasa.worldwind.render.Material;
import gov.nasa.worldwind.render.airspaces.CappedCylinder;
public class FlashyAnnotations extends ApplicationTemplate {
@SuppressWarnings("unchecked")
private static class AppFrame extends ApplicationTemplate.AppFrame {
private AnnotationLayer layer;
public AppFrame() {
this.getWwd().getSceneController().setClutterFilter(new SimpleClutterFilter());
CappedCylinder cappedCyl = new CappedCylinder(LatLon.fromDegrees(27, -100), 3000000);
cappedCyl.getAttributes().setDrawInterior(true);
cappedCyl.getAttributes().setInteriorMaterial(Material.GREEN);
cappedCyl.getAttributes().setInteriorOpacity(.75f);
cappedCyl.setAltitudes(10, 100000);
RenderableLayer renderLayer = new RenderableLayer();
renderLayer.addRenderable(cappedCyl);
insertBeforeCompass(this.getWwd(), renderLayer);
// Create example annotations
this.setupAnnotations();
}
private void setupAnnotations() {
// Create an AnnotationLayer with lots of annotations
this.layer = new AnnotationLayer();
GlobeAnnotation ga = new GlobeAnnotation("Annotation", Position.fromDegrees(20, -100.9, 1000));
ga.getAttributes().setTextColor(Color.white);
ga.getAttributes().setBackgroundColor(Color.BLACK);
ga.getAttributes().setOpacity(.75f);
ga.setAlwaysOnTop(true);
layer.addAnnotation(ga);
ga = new GlobeAnnotation("Annotation", Position.fromDegrees(25, -100.9, 1000));
ga.getAttributes().setTextColor(Color.white);
ga.getAttributes().setBackgroundColor(Color.BLACK);
ga.getAttributes().setOpacity(.75f);
ga.setAlwaysOnTop(true);
layer.addAnnotation(ga);
// Add layer to the layer list and update the layer panel
insertBeforeCompass(this.getWwd(), layer);
}
}
public static void main(String[] args) {
ApplicationTemplate.start("WorldWind Annotations", AppFrame.class);
}
}
這裏是我的（基本上沒有-OP）雜波濾除：
package gov.nasa.worldwindx.examples;
import java.util.List;
import gov.nasa.worldwind.render.Declutterable;
import gov.nasa.worldwind.render.DrawContext;
import gov.nasa.worldwind.util.ClutterFilter;
public class SimpleClutterFilter implements ClutterFilter{
@Override
public void apply(DrawContext dc, List<Declutterable> shapes) {
for(Declutterable shape: shapes) {
dc.addOrderedRenderable(shape);
}
}
}
而且我也不得不更新gov.nasa.worldwind.render .BasicAnnotationRenderer將它創建的OrderedAnnotations實現爲Declutterable。 （這個內部類的唯一變化是添加isEnableDecluttering和getBounds）：
public class OrderedAnnotation implements OrderedRenderable, Declutterable
{
protected Annotation annotation;
protected double eyeDistance;
protected Layer layer;
public OrderedAnnotation(Annotation annotation, double eyeDistance)
{
this.annotation = annotation;
this.eyeDistance = eyeDistance;
}
public OrderedAnnotation(Annotation annotation, Layer layer, double eyeDistance)
{
this.annotation = annotation;
this.eyeDistance = eyeDistance;
this.layer = layer;
}
public double getDistanceFromEye()
{
return this.eyeDistance;
}
public void render(DrawContext dc)
{
OGLStackHandler stackHandler = new OGLStackHandler();
BasicAnnotationRenderer.this.beginDrawAnnotations(dc, stackHandler);
try
{
this.doRender(dc, this);
// Draw as many as we can in a batch to save ogl state switching.
while (dc.peekOrderedRenderables() instanceof OrderedAnnotation)
{
OrderedAnnotation oa = (OrderedAnnotation) dc.pollOrderedRenderables();
this.doRender(dc, oa);
}
}
catch (WWRuntimeException e)
{
Logging.logger().log(Level.SEVERE, "generic.ExceptionWhileRenderingAnnotation", e);
}
catch (Exception e)
{
Logging.logger().log(Level.SEVERE, "generic.ExceptionWhileRenderingAnnotation", e);
}
finally
{
BasicAnnotationRenderer.this.endDrawAnnotations(dc, stackHandler);
}
}
public void pick(DrawContext dc, java.awt.Point pickPoint)
{
OGLStackHandler stackHandler = new OGLStackHandler();
BasicAnnotationRenderer.this.pickSupport.clearPickList();
BasicAnnotationRenderer.this.beginDrawAnnotations(dc, stackHandler);
try
{
this.annotation.setPickSupport(BasicAnnotationRenderer.this.pickSupport);
this.doRender(dc, this);
// Draw as many as we can in a batch to save ogl state switching.
while (dc.peekOrderedRenderables() instanceof OrderedAnnotation)
{
OrderedAnnotation oa = (OrderedAnnotation) dc.pollOrderedRenderables();
oa.annotation.setPickSupport(BasicAnnotationRenderer.this.pickSupport);
this.doRender(dc, oa);
}
}
catch (WWRuntimeException e)
{
Logging.logger().log(Level.SEVERE, "generic.ExceptionWhilePickingAnnotation", e);
}
catch (Exception e)
{
Logging.logger().log(Level.SEVERE, "generic.ExceptionWhilePickingAnnotation", e);
}
finally
{
BasicAnnotationRenderer.this.endDrawAnnotations(dc, stackHandler);
BasicAnnotationRenderer.this.pickSupport.resolvePick(dc, pickPoint, this.layer);
BasicAnnotationRenderer.this.pickSupport.clearPickList(); // to ensure entries can be garbage collected
}
}
protected void doRender(DrawContext dc, OrderedAnnotation oa)
{
// Swap the draw context's current layer with that of the ordered annotation
Layer previousCurrentLayer = dc.getCurrentLayer();
try
{
dc.setCurrentLayer(oa.layer);
oa.annotation.renderNow(dc);
}
finally
{
dc.setCurrentLayer(previousCurrentLayer); // restore the original layer
}
}
@Override
public boolean isEnableDecluttering() {
return (annotation instanceof GlobeAnnotation);
}
@Override
public Rectangle2D getBounds(DrawContext dc) {
if(annotation instanceof GlobeAnnotation) {
return ((GlobeAnnotation) annotation).computeBounds(dc);
}
return null;
}
}
看起來像z緩衝渲染閃爍，這發生在多個對象呈現與攝像機相同的距離時。難道你不能手動設置距離（高度邊際差異），以擺脫這一點？ – Caramiriel
我認爲既然我想「永遠在上面」設置，眼睛的距離可能會被worldwind邏輯忽略？ – systemoutprintln