[WorldWind学习]2.WorldWindow控件

首先查看WorldWindow 的构造函数，接着查看InitializeGraphics()函数。

 1 public WorldWindow()

 2         {

 3             this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.Opaque, true);

 4 

 5             // The m_Device3d can't be created unless the control is at least 1 x 1 pixels in size

 6             this.Size = new Size(1,1);

 7 

 8             try

 9             {

10                 // Now perform the rendering m_Device3d initialization

11                 // Skip DirectX initialization in design mode

12                 if(!IsInDesignMode()) 13                     this.InitializeGraphics();//初始化设备Device 14 

15                 //Post m_Device3d creation initialization

16                 this.drawArgs = new DrawArgs(m_Device3d, this );

17                 this.m_RootWidget = new WorldWind.Widgets.RootWidget(this);

18                 this.m_NewRootWidget = new WorldWind.NewWidgets.RootWidget(this);

19 

20                 //this.m_RootWidget.ChildWidgets.Add(layerManager);

21                 DrawArgs.RootWidget = this.m_RootWidget;

22                 DrawArgs.NewRootWidget = this.m_NewRootWidget;

23 

24                 m_FpsTimer.Elapsed += new System.Timers.ElapsedEventHandler(m_FpsTimer_Elapsed);

25                 m_FpsTimer.Start();

26 

27                 TimeKeeper.Start();

28             //    WorldWind.Widgets.LayerManager layerManager = new WorldWind.Widgets.LayerManager();

29             //    m_RootWidget.ChildWidgets.Add(layerManager);

30 

31             }

32             catch (InvalidCallException caught)

33             {

34                 throw new InvalidCallException(

35                     "Unable to locate a compatible graphics adapter. Make sure you are running the latest version of DirectX.", caught );

36             }

37             catch (NotAvailableException caught)

38             {

39                 throw new NotAvailableException(

40                     "Unable to locate a compatible graphics adapter. Make sure you are running the latest version of DirectX.", caught );

41             }

42         }

View Code

 1 private void InitializeGraphics()

 2         {

 3             // Set up our presentation parameters

 4             m_presentParams = new PresentParameters();

 5 

 6             m_presentParams.Windowed = true;

 7             m_presentParams.SwapEffect = SwapEffect.Discard;

 8             m_presentParams.AutoDepthStencilFormat = DepthFormat.D16;

 9             m_presentParams.EnableAutoDepthStencil = true;

10             

11             if(!World.Settings.VSync)

12                 // Disable wait for vertical retrace (higher frame rate at the expense of tearing)

13                 m_presentParams.PresentationInterval = PresentInterval.Immediate;

14 

15             int adapterOrdinal = 0;

16             try

17             {

18                 // Store the default adapter

19                 adapterOrdinal = Manager.Adapters.Default.Adapter;

20             }

21             catch

22             {

23                 // User probably needs to upgrade DirectX or install a 3D capable graphics adapter

24                 throw new NotAvailableException();

25             }

26 

27             DeviceType dType = DeviceType.Hardware;

28 

29             foreach(AdapterInformation ai in Manager.Adapters)

30             {

31                 if(ai.Information.Description.IndexOf("NVPerfHUD") >= 0)

32                 {

33                     adapterOrdinal = ai.Adapter;

34                     dType = DeviceType.Reference;

35                 }

36             }

37             CreateFlags flags = CreateFlags.SoftwareVertexProcessing;

38 

39             // Check to see if we can use a pure hardware m_Device3d

40             Caps caps = Manager.GetDeviceCaps(adapterOrdinal, DeviceType.Hardware);

41 

42             // Do we support hardware vertex processing?

43             if(caps.DeviceCaps.SupportsHardwareTransformAndLight)

44                 //    // Replace the software vertex processing

45                 flags = CreateFlags.HardwareVertexProcessing;

46 

47             // Use multi-threading for now - TODO: See if the code can be changed such that this isn't necessary (Texture Loading for example)

48             flags |= CreateFlags.MultiThreaded | CreateFlags.FpuPreserve;

49 

50             try

51             {

52                 // Create our m_Device3d

53                 m_Device3d = new Device(adapterOrdinal, dType, this, flags, m_presentParams);

54             }

55             catch( Microsoft.DirectX.DirectXException    )

56             {

57                 throw new NotSupportedException("Unable to create the Direct3D m_Device3d.");

58             }

59 

60             // Hook the m_Device3d reset event

61             m_Device3d.DeviceReset += new EventHandler(OnDeviceReset);

62             m_Device3d.DeviceResizing += new CancelEventHandler(m_Device3d_DeviceResizing);

63             OnDeviceReset(m_Device3d, null);

64         }

控件重要的方法：

OnApplicationIdle函数定义：

public void OnApplicationIdle(object sender, EventArgs e)//The world render loop.实现世界的渲染循环

OnPaint函数定义：

protected override void OnPaint(PaintEventArgs e)    // Occurs when the control is redrawn and m_isRenderDisabled=true.

protected override void OnMouseWheel(MouseEventArgs e)  //处理鼠标滚轮事件

protected override void OnKeyDown(KeyEventArgs e)  //重载处理键盘按下的事件

protected override void OnKeyUp(KeyEventArgs e)     //重载处理键盘弹起事件

protected override void OnMouseDoubleClick(MouseEventArgs e)

protected override void OnMouseUp(MouseEventArgs e)

控件几个重要的属性和字段：

  private Device m_Device3d;

  private DrawArgs drawArgs;

  private World m_World;

  private Cache m_Cache;

  private Thread m_WorkerThread;