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Matrix.Reset Metoda

Definice

Resetuje tuto Matrix tak, aby měly prvky matice identit.

public:
 void Reset();
public void Reset ();
member this.Reset : unit -> unit
Public Sub Reset ()

Příklady

Následující příklad kódu je určen pro použití s Windows Forms a vyžaduje PaintEventArgse, Paint objekt události. Kód provede následující akce:

  • Vytvoří matici škálování.

  • Zobrazí seznam prvků matice na obrazovku.

  • Obnoví matici na identitu.

  • Zobrazí seznam prvků na obrazovku.

  • Přeloží matici o 50 bodů na ose x a 40 bodů na ose y.

  • Zobrazí seznam prvků přeložené matice na obrazovku.

  • Nakreslí obdélník na obrazovku před použitím transformace matice (modrý obdélník).

  • Použije transformaci na obdélník.

  • Nakreslí transformovaný obdélník na obrazovku (červený obdélník) pomocí stejných souřadnic jako předchozí obdélník.

Všimněte si, že červený obdélník nebyl škálován (z důvodu resetování), ale byl přeložen na osu x a osu y.

public:
   void ResetExample( PaintEventArgs^ e )
   {
      Pen^ myPen = gcnew Pen( Color::Blue,1.0f );
      Pen^ myPen2 = gcnew Pen( Color::Red,1.0f );

      // Create a matrix that scales by 5 in the x direction and
      // by 3 in the y direction.
      Matrix^ myMatrix = gcnew Matrix( 5.0f,0.0f,0.0f,3.0f,0.0f,0.0f );

      // List the matrix elements to the screen.
      ListMatrixElements( e, myMatrix, "Beginning Matrix", 6, 20 );

      // Reset the matrix to identity.
      myMatrix->Reset();

      // Again list the matrix elements to the screen.
      ListMatrixElements2( e, myMatrix, "Matrix After Reset", 6, 40 );

      // Translate the matrix by 50 points in the x-axis and 40 points
      // in the y-axis.
      myMatrix->Translate( 50.0f, 40.0f );

      // List the matrix elements to the screen.
      ListMatrixElements1( e, myMatrix, "Matrix After Translation", 6, 60 );

      // Draw a rectangle to the screen.
      e->Graphics->DrawRectangle( myPen, 0, 0, 100, 100 );

      // Apply the matrix transform to the Graphics.
      e->Graphics->Transform = myMatrix;

      // Draw another rectangle to the screen that has the transform
      // applied.
      e->Graphics->DrawRectangle( myPen2, 0, 0, 100, 100 );
   }

   //-------------------------------------------------------
   // This function is a helper function to
   // list the contents of a matrix.
   //-------------------------------------------------------
   void ListMatrixElements2( PaintEventArgs^ e, Matrix^ matrix, String^ matrixName, int numElements, int y )
   {
      // Set up variables for drawing the array
      // of points to the screen.
      int i;
      float x = 20,X = 200;
      System::Drawing::Font^ myFont = gcnew System::Drawing::Font( "Arial",8 );
      SolidBrush^ myBrush = gcnew SolidBrush( Color::Black );

      // Draw the matrix name to the screen.
      e->Graphics->DrawString( String::Concat( matrixName, ":  " ), myFont, myBrush, (float)x, (float)y );

      // Draw the set of path points and types to the screen.
      for ( i = 0; i < numElements; i++ )
      {
         e->Graphics->DrawString( String::Concat( matrix->Elements[ i ], ", " ), myFont, myBrush, (float)X, (float)y );
         X += 30;
      }
   }
public void ResetExample(PaintEventArgs e)
{
    Pen myPen = new Pen(Color.Blue, 1);
    Pen myPen2 = new Pen(Color.Red, 1);
             
    // Create a matrix that scales by 5 in the x direction and
    // by 3 in the y direction.
    Matrix myMatrix = new Matrix(
        5.0f, 0.0f, 0.0f, 3.0f, 0.0f, 0.0f); 
             
    // List the matrix elements to the screen.
    ListMatrixElements(e, myMatrix, "Beginning Matrix", 6, 20);
             
    // Reset the matrix to identity.
    myMatrix.Reset();
             
    // Again list the matrix elements to the screen.
    ListMatrixElements2(e, myMatrix, "Matrix After Reset", 6, 40);
             
    // Translate the matrix by 50 points in the x-axis and 40 points
    // in the y-axis.
    myMatrix.Translate(50.0f, 40.0f); 
  
    // List the matrix elements to the screen.
    ListMatrixElements1(e, myMatrix, "Matrix After Translation", 6, 60);
             
    // Draw a rectangle to the screen.
    e.Graphics.DrawRectangle(myPen, 0, 0, 100, 100);
             
    // Apply the matrix transform to the Graphics.
    e.Graphics.Transform = myMatrix;
             
    // Draw another rectangle to the screen that has the transform
    // applied.
    e.Graphics.DrawRectangle(myPen2, 0, 0, 100, 100);
}
             
//-------------------------------------------------------
// This function is a helper function to
// list the contents of a matrix.
//-------------------------------------------------------
public void ListMatrixElements2(
    PaintEventArgs e,
    Matrix matrix,
    string matrixName,
    int numElements,
    int y)
{
             
    // Set up variables for drawing the array
    // of points to the screen.
    int i;
    float x = 20, X = 200;
    Font myFont = new Font("Arial", 8);
    SolidBrush myBrush = new SolidBrush(Color.Black);
             
    // Draw the matrix name to the screen.
    e.Graphics.DrawString(
        matrixName + ":  ",
        myFont,
        myBrush,
        x,
        y);
             
    // Draw the set of path points and types to the screen.
    for(i=0; i < numElements; i++)
    {
        e.Graphics.DrawString(
            matrix.Elements[i].ToString() + ", ",
            myFont,
            myBrush,
            X,
            y);
        X += 30;
    }
}
Public Sub ResetExample(ByVal e As PaintEventArgs)
    Dim myPen As New Pen(Color.Blue, 1)
    Dim myPen2 As New Pen(Color.Red, 1)
    Dim myMatrix As New Matrix(5.0F, 0.0F, 0.0F, 3.0F, 0.0F, 0.0F)

    ListMatrixElementsHelper2(e, myMatrix, "Beginning Matrix", 6, 20)
    myMatrix.Reset()
    ListMatrixElementsHelper(e, myMatrix, "Matrix After Reset", 6, 40)

    ' Translate.
    myMatrix.Translate(50.0F, 40.0F)

    ListMatrixElementsHelper(e, myMatrix, "Matrix After Translation", _
        6, 60)
    e.Graphics.DrawRectangle(myPen, 0, 0, 100, 100)
    e.Graphics.Transform = myMatrix
    e.Graphics.DrawRectangle(myPen2, 0, 0, 100, 100)
End Sub

' A helper function to list the contents of a matrix.
Public Sub ListMatrixElementsHelper2(ByVal e As PaintEventArgs, _
ByVal matrix As Matrix, ByVal matrixName As String, ByVal numElements As Integer, _
ByVal y As Integer)

    ' Set up variables for drawing the array
    ' of points to the screen.
    Dim i As Integer
    Dim x As Single = 20
    Dim j As Single = 200
    Dim myFont As New Font("Arial", 8)
    Dim myBrush As New SolidBrush(Color.Black)

    ' Draw the matrix name to the screen.
    e.Graphics.DrawString(matrixName + ":  ", myFont, myBrush, x, y)

    ' Draw the set of path points and types to the screen.
    For i = 0 To numElements - 1
        e.Graphics.DrawString(matrix.Elements(i).ToString() + ", ", _
        myFont, myBrush, j, y)
        j += 30
    Next i
End Sub

Poznámky

Prvky na hlavní diagonální matici identity jsou 1. Všechny ostatní prvky matice identit jsou 0.

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