Imports System.Math
Imports System.Globalization
Imports TestEIn.EgtInterface

Public Class Scene

   Private m_nStatus As Integer
   Private Enum ST As Integer
      NULL = 0
      PAN = 1
      ROT = 2
      ZOOMWIN = 3
   End Enum
   Private m_nGseContext As Integer
   Private m_PrevPoint As Point

   Sub New()
      ' Chiamata richiesta dalla finestra di progettazione.
      InitializeComponent()
      ' Istruzioni di inizializzazione.
      SetStyle(ControlStyles.Opaque, True)
      SetStyle(ControlStyles.UserPaint, True)
      SetStyle(ControlStyles.AllPaintingInWmPaint, True)
      m_nStatus = ST.NULL
      m_nGseContext = 0
      m_PrevPoint = Point.Empty
      Cursor = New Cursor(Me.GetType(), "Pointer.cur")
   End Sub

   Public Sub Init()
      EgtInit(0, "TestEngine.log")
      EgtSetFont("C:\EgtProg\Fonts", "ModernProp.Nfe")
      m_nGseContext = EgtInitGeomDB()
      EgtSetDefaultMaterial(m_nGseContext, 255, 165, 0)
      EgtInitScene(m_nGseContext, Handle, 3, True, 24, 32)
      EgtSetBackground(m_nGseContext, 140, 154, 168, 40, 44, 48, False)
      EgtInitTscExec(m_nGseContext)
   End Sub

   Public Function GetCtx() As Integer
      Return m_nGseContext
   End Function

   Protected Overrides Sub OnHandleDestroyed(e As EventArgs)
      EgtExit()
   End Sub

   Protected Overrides Sub OnPaint(e As PaintEventArgs)
      MyBase.OnPaint(e)
      EgtDraw(m_nGseContext)
   End Sub

   Protected Overrides Sub OnPaintBackground(pevent As PaintEventArgs)
      MyBase.OnPaintBackground(pevent)
   End Sub

   Protected Overrides Sub OnResize(e As System.EventArgs)
      MyBase.OnResize(e)
      EgtResize(m_nGseContext, Width, Height)
   End Sub

   Protected Overrides Sub OnMouseEnter(e As System.EventArgs)
      MyBase.OnMouseEnter(e)
      Focus()
   End Sub

   Protected Overrides Sub OnMouseDown(e As System.Windows.Forms.MouseEventArgs)
      If e.Button = Windows.Forms.MouseButtons.Middle Then
         If (Control.ModifierKeys And Keys.Shift) = Keys.Shift Then
            m_nStatus = ST.ZOOMWIN
            Cursor = New Cursor(Me.GetType(), "ZoomWin.cur")
         ElseIf (Control.ModifierKeys And Keys.Control) = Keys.Control Then
            m_nStatus = ST.ROT
            Cursor = New Cursor(Me.GetType(), "Rotate.cur")
         Else
            m_nStatus = ST.PAN
            Cursor = New Cursor(Me.GetType(), "Pan.cur")
         End If
         m_PrevPoint = e.Location
      Else
         MyBase.OnMouseDown(e)
      End If
      Focus()
   End Sub

   Protected Overrides Sub OnMouseUp(e As System.Windows.Forms.MouseEventArgs)
      If e.Button = Windows.Forms.MouseButtons.Middle Then
         If m_nStatus = ST.ZOOMWIN Then
            EgtResetWinRect(m_nGseContext, False)
            EgtZoomWin(m_nGseContext, m_PrevPoint, e.Location)
         End If
         If m_nStatus <> ST.NULL Then
            m_nStatus = ST.NULL
            Cursor = New Cursor(Me.GetType(), "Pointer.cur")
         End If
      Else
         MyBase.OnMouseUp(e)
      End If
   End Sub

   Protected Overrides Sub OnMouseMove(e As System.Windows.Forms.MouseEventArgs)
      'Visualizzo le coordinate del mouse
      ShowCursorPos(e.Location)
      'Secondo lo stato...
      If e.Button = Windows.Forms.MouseButtons.Middle Then
         If m_nStatus = ST.ZOOMWIN Then
            Cursor = New Cursor(Me.GetType(), "ZoomWin.cur")
            EgtSetWinRect(m_nGseContext, m_PrevPoint, e.Location)
            'Il punto di riferimento deve rimanere quello originale
         ElseIf m_nStatus = ST.ROT Then
            Cursor = New Cursor(Me.GetType(), "Rotate.cur")
            EgtRotateCamera(m_nGseContext, m_PrevPoint, e.Location)
            m_PrevPoint = e.Location
         ElseIf m_nStatus = ST.PAN Then
            Cursor = New Cursor(Me.GetType(), "Pan.cur")
            EgtPanCamera(m_nGseContext, m_PrevPoint, e.Location)
            m_PrevPoint = e.Location
         Else
            m_nStatus = ST.NULL
            Cursor = New Cursor(Me.GetType(), "Pointer.cur")
         End If
      Else
         MyBase.OnMouseMove(e)
      End If
   End Sub

   Protected Overrides Sub OnMouseWheel(e As System.Windows.Forms.MouseEventArgs)
      If Abs(e.Delta) < 30 Then
         Return
      End If
     ' calcolo coefficiente
      Const WHEEL_DELTA As Double = 120
      Dim dCoeff As Double = 1 - 0.1 * Abs(e.Delta) / WHEEL_DELTA
      If e.Delta < 0 Then
         dCoeff = 1 / dCoeff
      End If
     ' eseguo zoom
      EgtZoomOnPoint(m_nGseContext, e.Location, dCoeff)
   End Sub

   Private Sub ShowCursorPos(ByVal WinXY As Point)
      'ricavo punto 3d
      Dim ptWorld As Point3d
      EgtUnProjectPoint(m_nGseContext, WinXY, ptWorld)
      'ricavo direzione di vista
      Dim nDir As Integer
      EgtGetCameraDir(m_nGseContext, nDir)
      'costruisco stringa con dati
      Dim sCursorPos As New System.Text.StringBuilder
      Select Case nDir
      Case CT_TOP, CT_BOTTOM
         sCursorPos.Append("X=")
         sCursorPos.Append(ptWorld.x.ToString("F4", CultureInfo.InvariantCulture))
         sCursorPos.Append(" Y=")
         sCursorPos.Append(ptWorld.y.ToString("F4", CultureInfo.InvariantCulture))
      Case CT_FRONT, CT_BACK
         sCursorPos.Append("X=")
         sCursorPos.Append(ptWorld.x.ToString("F4", CultureInfo.InvariantCulture))
         sCursorPos.Append(" Z=")
         sCursorPos.Append(ptWorld.z.ToString("F4", CultureInfo.InvariantCulture))
      Case CT_LEFT, CT_RIGHT
         sCursorPos.Append("Y=")
         sCursorPos.Append(ptWorld.y.ToString("F4", CultureInfo.InvariantCulture))
         sCursorPos.Append(" Z=")
         sCursorPos.Append(ptWorld.z.ToString("F4", CultureInfo.InvariantCulture))
      Case Else
         sCursorPos.Append("   ")
      End Select
      ' lancio l'evento per visualizzare la stringa
      RaiseEvent CursorPos(Me, sCursorPos.ToString)
   End Sub

   Public Event CursorPos(ByVal sender As Object, ByVal sCursorPos As String)

End Class