[WorldWind学习]12.WavingFlags和WavingFlagLayer

WW目前的服务器似乎都连不上了，不知道Java版的是不是可以！

WW实现了旗帜标注，鼠标移动到旗帜的位置，旗帜会高亮显示。点击，探出对话框显示标注的信息。

1.WavingFlagLayer对象

public class WavingFlagLayer : RenderableObject

WavingFlagLayer继承自RenderableObject，定义了三个事件如下：

1         public event System.EventHandler OnMouseEnterEvent;
2         public event System.EventHandler OnMouseLeaveEvent;
3         public event System.Windows.Forms.MouseEventHandler OnMouseUpEvent;

string highlightTexturePath = System.IO.Path.GetDirectoryName(System.Windows.Forms.Application.ExecutablePath) + "\\Data\\ring.dds";

//高亮显示采用的图片路径

该对象重点查看PerformSelectionAction(DrawArgs drawArgs)方法，重载了RenderableObject的PerformSelectionAction方法。

 1 public override bool PerformSelectionAction(DrawArgs drawArgs)
 2         {
 3             Vector3 surfacePos = MathEngine.SphericalToCartesian(m_latitude, m_longitude, World.EquatorialRadius);
 4             Vector3 rc = new Vector3(
 5                 (float)drawArgs.WorldCamera.ReferenceCenter.X,
 6                 (float)drawArgs.WorldCamera.ReferenceCenter.Y,
 7                 (float)drawArgs.WorldCamera.ReferenceCenter.Z
 8                 );
 9             Vector3 projectedPoint = drawArgs.WorldCamera.Project(surfacePos - rc);
10             int mouseBuffer = 15;
11             if (projectedPoint.X > DrawArgs.LastMousePosition.X - mouseBuffer &&
12                     projectedPoint.X < DrawArgs.LastMousePosition.X + mouseBuffer &&
13                     projectedPoint.Y > DrawArgs.LastMousePosition.Y - mouseBuffer &&
14                     projectedPoint.Y < DrawArgs.LastMousePosition.Y + mouseBuffer)//通过包围盒判断是否选中，转换到屏幕坐标来判断
15             {
16                 if (OnMouseUpEvent != null)//如果委托链不为空，执行事件委托链中的方法
17                 {
18                     OnMouseUpEvent(this, new System.Windows.Forms.MouseEventArgs(System.Windows.Forms.MouseButtons.Left, 1, DrawArgs.LastMousePosition.X, DrawArgs.LastMousePosition.Y, 0));
19                 }
20                 return true;
21             }
22             return false;
23         }

2.WavingFlags是一个插件对象。

public class WavingFlags : WorldWind.PluginEngine.Plugin

WavingFlags的Load方法从文件中读取WavingFlagLayer信息，加载。绑定事件关联的方法。

  1   /// <summary>
  2         /// Plugin entry point - All plugins must implement this function
  3         /// </summary>
  4         public override void Load()
  5         {
  6             FileInfo savedFile = new FileInfo(SavedFilePath);
  7             if (!savedFile.Exists)
  8             {
  9                 if (!savedFile.Directory.Exists)
 10                     savedFile.Directory.Create();
 11 
 12                 try
 13                 {
 14                     WorldWind.Net.WebDownload download = new WorldWind.Net.WebDownload(DataFileUri);
 15                     download.DownloadFile(savedFile.FullName);
 16                     download.Dispose();
 17                 }
 18                 catch { }
 19             }
 20 
 21             m_wavingFlagsList = new RenderableObjectList("Waving Flags");
 22             m_wavingFlagsList.IsOn = false;
 23             System.Collections.Hashtable countryHash = new System.Collections.Hashtable();
 24 
 25             using (StreamReader reader = savedFile.OpenText())
 26             {
 27                 string header = reader.ReadLine();
 28                 string[] headers = header.Split('\t');
 29 
 30                 string line = reader.ReadLine();
 31                 while (line != null)
 32                 {
 33                     System.Collections.Hashtable fieldHash = new System.Collections.Hashtable();
 34                     string[] lineParts = line.Split('\t');
 35 
 36                     //Log.Write(string.Format("{0}\t{1}", lineParts[0], lineParts[1]));
 37                     try
 38                     {
 39                         double latitude = double.Parse(lineParts[3], System.Globalization.CultureInfo.InvariantCulture);
 40                         double longitude = double.Parse(lineParts[4], System.Globalization.CultureInfo.InvariantCulture);
 41 
 42                         if (lineParts[1].Length == 2)
 43                         {
 44                             string flagFileUri = FlagTextureDirectoryUri + "/" + lineParts[1] + FlagSuffix;
 45                             FileInfo savedFlagFile = new FileInfo(SavedFlagsDirectory + "\\" + lineParts[1] + ".dds");
 46 
 47                             WavingFlagLayer flag = new WavingFlagLayer(
 48                                 lineParts[0],
 49                                 ParentApplication.WorldWindow.CurrentWorld,
 50                                 latitude,
 51                                 longitude,
 52                                 flagFileUri);
 53 
 54                             flag.SavedImagePath = savedFlagFile.FullName;
 55                             flag.ScaleX = 100000;
 56                             flag.ScaleY = 100000;
 57                             flag.ScaleZ = 100000;
 58                             flag.Bar3D = new Bar3D(flag.Name, flag.World, latitude, longitude, 0, flag.ScaleZ, System.Drawing.Color.Red);
 59                             flag.Bar3D.ScaleX = 0.3f * flag.ScaleX;
 60                             flag.Bar3D.ScaleY = 0.3f * flag.ScaleY;
 61                             flag.Bar3D.IsOn = false;
 62                             flag.RenderPriority = RenderPriority.Custom;
 63 
 64                             flag.OnMouseEnterEvent += new EventHandler(flag_OnMouseEnterEvent);
 65                             flag.OnMouseLeaveEvent += new EventHandler(flag_OnMouseLeaveEvent);
 66                             flag.OnMouseUpEvent += new System.Windows.Forms.MouseEventHandler(flag_OnMouseUpEvent);
 67                             m_wavingFlagsList.Add(flag);
 68 
 69                             for (int i = 0; i < lineParts.Length; i++)
 70                             {
 71                                 try
 72                                 {
 73                                     double value = double.Parse(lineParts[i], System.Globalization.CultureInfo.InvariantCulture);
 74                                     fieldHash.Add(headers[i], value);
 75                                 }
 76                                 catch
 77                                 {
 78                                     fieldHash.Add(headers[i], lineParts[i]);
 79                                 }
 80                             }
 81                             countryHash.Add(lineParts[0], fieldHash);
 82                         }
 83                         else
 84                         {
 85                             //Log.Write(Log.Levels.Debug, "blank: " + lineParts[0]);
 86                         }
 87                     }
 88                     catch(Exception ex)
 89                     {
 90                         Log.Write(Log.Levels.Warning, string.Format("Exception: {0} - {1}", lineParts[0], ex.ToString()));
 91                     }
 92 
 93                     line = reader.ReadLine();
 94                 }
 95                 Headers = headers;
 96             }
 97             
 98             CountryHash = countryHash;
 99             
100             InitializeCiaForm();
101 
102             ParentApplication.WorldWindow.CurrentWorld.RenderableObjects.Add(m_wavingFlagsList);
103         }

 WavingFlagLayer事件关联的方法。

 1  void flag_OnMouseUpEvent(object sender, System.Windows.Forms.MouseEventArgs e)
 2         {
 3             if (DrawArgs.NewRootWidget.OnMouseMove(e) || DrawArgs.RootWidget.OnMouseMove(e))
 4                 return;
 5 
 6             m_ciaForm.Visible = true;
 7         }
 8 
 9         void flag_OnMouseLeaveEvent(object sender, EventArgs e)
10         {
11             WavingFlagLayer wavingFlag = (WavingFlagLayer)sender;
12             wavingFlag.ShowHighlight = false;
13             
14         }
15 
16         void flag_OnMouseEnterEvent(object sender, EventArgs e)
17         {
18             System.Windows.Forms.MouseEventArgs mea = new System.Windows.Forms.MouseEventArgs(
19                 System.Windows.Forms.MouseButtons.None,
20                 0, 
21                 DrawArgs.LastMousePosition.X, 
22                 DrawArgs.LastMousePosition.Y, 
23                 0);
24 
25             // hack check to make sure that a widget isn't in the way
26             if (DrawArgs.NewRootWidget.OnMouseMove(mea) || DrawArgs.RootWidget.OnMouseMove(mea))
27                 return;
28 
29             WavingFlagLayer flag = (WavingFlagLayer)sender;
30             if (m_wavingFlagsList.IsOn && flag.Initialized && flag.IsOn)
31             {
32                 ChangeForm(flag.Name, m_currentCategoryIndex);
33                 //m_ciaForm.Visible = true;
34             }
35 
36             for (int i = 0; i < m_wavingFlagsList.ChildObjects.Count; i++)
37             {
38                 if (m_wavingFlagsList.ChildObjects[i] is WavingFlagLayer)
39                 {
40                     WavingFlagLayer wavingFlag = (WavingFlagLayer)m_wavingFlagsList.ChildObjects[i];
41                     if (wavingFlag.Name != flag.Name)
42                         wavingFlag.ShowHighlight = false;
43                     else
44                         wavingFlag.ShowHighlight = true;
45                 }
46             }
47         }

 该对象用到了Shader编程的知识，Effect类，需要具体查看。

 1  private void RenderFlag(DrawArgs drawArgs, double offset)
 2         {
 3             if (m_effect == null)
 4             {
 5                 string outerrors = "";
 6                 System.Reflection.Assembly assembly = System.Reflection.Assembly.GetExecutingAssembly();
 7                 Stream effectStream = assembly.GetManifestResourceStream("WorldWind.Shaders.flag.fx");
 8                 m_effect =
 9                     Effect.FromStream(
10                     drawArgs.device,
11                     effectStream,
12                     null,
13                     null,
14                     ShaderFlags.None,
15                     null,
16                     out outerrors);
17                 if (outerrors != null && outerrors.Length > 0)
18                     Log.Write(Log.Levels.Error, outerrors);
19             }
20             if (m_vertexBuffer == null)
21             {
22                 drawArgs.device.DeviceReset += new EventHandler(device_DeviceReset);
23                 device_DeviceReset(drawArgs.device, null);
24             }
25             if (m_flagPoleVertices == null)
26             {
27                 CreateFlagPole(drawArgs.device);
28             }
29             Vector3 pos =
30                         MathEngine.SphericalToCartesian(m_latitude, m_longitude, World.EquatorialRadius + World.Settings.VerticalExaggeration * ScaleZ + offset);
31             Vector3 surfacePos = MathEngine.SphericalToCartesian(m_latitude, m_longitude, World.EquatorialRadius + offset);
32             Vector3 rc = new Vector3(
33                 (float)drawArgs.WorldCamera.ReferenceCenter.X,
34                 (float)drawArgs.WorldCamera.ReferenceCenter.Y,
35                 (float)drawArgs.WorldCamera.ReferenceCenter.Z
36                 );
37             drawArgs.device.Transform.World = Matrix.Scaling(World.Settings.VerticalExaggeration * ScaleX * 0.01f, World.Settings.VerticalExaggeration * ScaleY * 0.01f, -World.Settings.VerticalExaggeration * 2 * ScaleZ);
38             drawArgs.device.Transform.World *= Matrix.RotationY((float)-MathEngine.DegreesToRadians(90));
39             drawArgs.device.Transform.World *= Matrix.RotationY((float)-MathEngine.DegreesToRadians(m_latitude));
40             drawArgs.device.Transform.World *= Matrix.RotationZ((float)MathEngine.DegreesToRadians(m_longitude));
41             drawArgs.device.Transform.World *= Matrix.Translation(surfacePos - rc);
42             drawArgs.device.VertexFormat = CustomVertex.PositionColored.Format;
43             drawArgs.device.TextureState[0].ColorOperation = TextureOperation.SelectArg1;
44             drawArgs.device.TextureState[0].ColorArgument1 = TextureArgument.Diffuse;
45             drawArgs.device.TextureState[0].AlphaArgument1 = TextureArgument.Diffuse;
46             drawArgs.device.TextureState[0].AlphaOperation = TextureOperation.SelectArg1;
47             drawArgs.device.DrawIndexedUserPrimitives(PrimitiveType.TriangleList, 0, m_flagPoleVertices.Length, m_flagPoleIndices.Length / 3, m_flagPoleIndices, true, m_flagPoleVertices);
48             drawArgs.device.DrawIndexedUserPrimitives(PrimitiveType.LineList, 0, m_outlineFlagPoleVertices.Length, m_outlineFlagPoleIndices.Length / 2, m_outlineFlagPoleIndices, true, m_outlineFlagPoleVertices);
49             m_angle += .04f;
50             if (m_angle > 360)
51                 m_angle = 0;
52             drawArgs.device.VertexFormat = CustomVertex.PositionNormalTextured.Format;
53             drawArgs.device.Transform.World = Matrix.Scaling(World.Settings.VerticalExaggeration * ScaleX, World.Settings.VerticalExaggeration * ScaleY, World.Settings.VerticalExaggeration * ScaleZ);
54             drawArgs.device.Transform.World *= Matrix.RotationY((float)-MathEngine.DegreesToRadians(m_latitude));
55             drawArgs.device.Transform.World *= Matrix.RotationZ((float)MathEngine.DegreesToRadians(m_longitude));
56             drawArgs.device.Transform.World *= Matrix.Translation(pos - rc);
57 
58             Matrix worldViewProj = drawArgs.device.Transform.World * drawArgs.device.Transform.View * drawArgs.device.Transform.Projection;
59             System.DateTime currentTime = TimeKeeper.CurrentTimeUtc;
60             Point3d sunPosition = SunCalculator.GetGeocentricPosition(currentTime);
61             Vector3 sunVector = new Vector3(
62                 (float)-sunPosition.X,
63                 (float)-sunPosition.Y,
64                 (float)-sunPosition.Z);
65             m_effect.Technique = "VertexAndPixelShader";
66             m_effect.SetValue("angle", (float)m_angle);
67             m_effect.SetValue("attentuation", Attentuation);
68             m_effect.SetValue("World", drawArgs.device.Transform.World);
69             m_effect.SetValue("View", drawArgs.device.Transform.View);
70             m_effect.SetValue("Projection", drawArgs.device.Transform.Projection);
71             m_effect.SetValue("Tex0", m_texture);
72             m_effect.SetValue("lightDir", new Vector4(sunVector.X, sunVector.Y, sunVector.Z, 0));
73             drawArgs.device.Indices = m_indexBuffer;
74             drawArgs.device.SetStreamSource(0, m_vertexBuffer, 0);
75             int numPasses = m_effect.Begin(0);
76             for (int i = 0; i < numPasses; i++)
77             {
78                 m_effect.BeginPass(i);
79                 drawArgs.device.DrawIndexedPrimitives(
80                     PrimitiveType.TriangleList,
81                     0,
82                     0,
83                     m_vertices.Length,
84                     0,
85                     m_indices.Length / 3);
86                 m_effect.EndPass();
87             }
88             m_effect.End();
89             drawArgs.device.Indices = null;
90             drawArgs.device.Transform.World = drawArgs.WorldCamera.WorldMatrix;
91             drawArgs.device.Transform.View = drawArgs.WorldCamera.ViewMatrix;
92         }
View Code
文章未经说明均属原创，学习笔记可能有大段的引用，一般会注明参考文献。 欢迎大家留言交流，转载请注明出处。
【推广】 免费学中医，健康全家人
原文地址：https://www.cnblogs.com/yhlx125/p/3026622.html