PdfSharp.Drawing.XGraphics.Initialize C# (CSharp) Method

    void Initialize()
    {
      this.pageOrigin = new XPoint();
      XMatrix matrix = new XMatrix();  //XMatrix.Identity;

      double pageHeight = this.pageSize.height;
      PdfPage targetPage = PdfPage;
      XPoint trimOffset = new XPoint();
      if (targetPage != null && targetPage.TrimMargins.AreSet)
      {
        pageHeight += targetPage.TrimMargins.Top.Point + targetPage.TrimMargins.Bottom.Point;
        trimOffset = new XPoint(targetPage.TrimMargins.Left.Point, targetPage.TrimMargins.Top.Point);
      }

#if GDI
      if (this.targetContext == XGraphicTargetContext.GDI)
      {
        if (this.gfx != null)
          matrix = (XMatrix)gfx.Transform;

        if (this.pageUnit != XGraphicsUnit.Point)
        {
          switch (this.pageUnit)
          {
            case XGraphicsUnit.Inch:
              matrix.ScalePrepend(XUnit.InchFactor);
              break;

            case XGraphicsUnit.Millimeter:
              matrix.ScalePrepend(XUnit.MillimeterFactor);
              break;

            case XGraphicsUnit.Centimeter:
              matrix.ScalePrepend(XUnit.CentimeterFactor);
              break;

            case XGraphicsUnit.Presentation:
              matrix.ScalePrepend(XUnit.PresentationFactor);
              break;
          }
        }
      }
#endif
#if WPF
      if (this.targetContext == XGraphicTargetContext.WPF)
      {
        if (this.pageUnit != XGraphicsUnit.Presentation)
        {
          switch (this.pageUnit)
          {
            case XGraphicsUnit.Point:
              matrix.ScalePrepend(XUnit.PointFactorWpf);
              break;

            case XGraphicsUnit.Inch:
              matrix.ScalePrepend(XUnit.InchFactorWpf);
              break;

            case XGraphicsUnit.Millimeter:
              matrix.ScalePrepend(XUnit.MillimeterFactorWpf);
              break;

            case XGraphicsUnit.Centimeter:
              matrix.ScalePrepend(XUnit.CentimeterFactorWpf);
              break;
          }
          if (!matrix.IsIdentity)
          {
#if !SILVERLIGHT
            MatrixTransform transform = new MatrixTransform((System.Windows.Media.Matrix)matrix);
            dc.PushTransform(transform);
#else
            MatrixTransform transform2 = new MatrixTransform();
            transform2.Matrix = (System.Windows.Media.Matrix)matrix;
            dc.PushTransform(transform2);
#endif
          }
        }
      }
#endif
      if (this.pageDirection == XPageDirection.Upwards)
        matrix.Prepend(new XMatrix(1, 0, 0, -1, 0, pageHeight));

      if (trimOffset != new XPoint())
        matrix.TranslatePrepend(trimOffset.x, trimOffset.y);

      this.defaultViewMatrix = matrix;
      this.transform = new XMatrix();  //XMatrix.Identity;
    }