Get size of the layout

**How to get size of the layout **

Issue: How to get size of the layout (CADNET-438).

Tips: To do this, the example below demonstrates how the size is calculated for non-empty layers for different file formats.

Example:

string extension = Path.GetExtension(fileName);
using (CadImage cadImage = (CadImage)Image.Load(fileName))
{
  List<string> layouts = GetNotEmptyLayouts(cadImage, extension);
  const double Epsilon = 0.00001;
  double dpi = 300;
  foreach (string layout in layouts)
  {
      System.Console.WriteLine("Layout= " + layout);
      using (FileStream fs = new FileStream(outDir + "layout_" + layout + ".jpg", FileMode.Create))
      {
          JpegOptions jpegOptions = new JpegOptions();
          CadRasterizationOptions options = new CadRasterizationOptions();
          options.Layouts = new string[] { layout };

          CadLayout l = cadImage.Layouts[layout];

          if ((Math.Abs(l.MaxExtents.Y) < Epsilon && Math.Abs(l.MaxExtents.X) < Epsilon) || (Math.Abs(l.MaxExtents.Y + 1E+20) < Epsilon || Math.Abs(l.MaxExtents.X + 1E+20) < Epsilon) || (Math.Abs(l.MinExtents.Y - 1E+20) < Epsilon || Math.Abs(l.MinExtents.X - 1E+20) < Epsilon))
          {
              // do nothing, we can automatically detect size
              // we can not rely on PlotPaperUnits here too because it is PlotInInches by default
          }
          else
          {
              double sizeExtX = l.MaxExtents.X - l.MinExtents.X;
              double sizeExtY = l.MaxExtents.Y - l.MinExtents.Y;

              if (l.PlotPaperUnits == CadPlotPaperUnits.PlotInInches)
              {
                  options.PageHeight = INtoPixels(sizeExtY, dpi);
                  options.PageWidth = INtoPixels(sizeExtX, dpi);
              }
              else
              {
                  if (l.PlotPaperUnits == CadPlotPaperUnits.PlotInMillimeters)
                  {
                      options.PageHeight = MMtoPixels(sizeExtY, dpi);
                      options.PageWidth = MMtoPixels(sizeExtX, dpi);
                  }
                  else
                  {
                      options.PageHeight = (float)sizeExtY;
                      options.PageWidth = (float)sizeExtX;
                  }
              }
          }

          System.Console.WriteLine("Layout= " + layout + " height= " + options.PageHeight + " width= " + options.PageWidth);
         jpegOptions.VectorRasterizationOptions = options;

          cadImage.Save(fs, jpegOptions);
      }
  }
}

private static List<string> GetNotEmptyLayouts(Image cadImage, string extension)
{
    List<string> nonEmptyLayouts = new List<string>();
    if (cadImage == null)
        return nonEmptyLayouts;

    switch (extension)
    {
        case ".dwg":
            nonEmptyLayouts = GetNotEmptyLayoutsForDwg((CadImage)cadImage);
            break;
        case ".dxf":
            nonEmptyLayouts = GetNotEmptyLayoutsForDxf((CadImage)cadImage);
            break;
    }

    return nonEmptyLayouts;
}

private static int MMtoPixels(double mm, double dpi)
{
    double inches = mm * 0.0393701;
    double pixels = dpi * inches;

    return (int)(pixels + 0.5);
}

private static int INtoPixels(double inches, double dpi)
{
    double pixels = dpi * inches;
    return (int)(pixels + 0.5);
}

private static List<string> GetNotEmptyLayoutsForDxf(CadImage cadImage)
{
    List<string> notEmptyLayouts = new List<string>();

    Dictionary<string, string> layoutBlockHandles = new Dictionary<string, string>();
    foreach (CadLayout layout in cadImage.Layouts.Values)
    {
        if (layout.BlockTableRecordHandle != null)
            layoutBlockHandles.Add(layout.BlockTableRecordHandle, layout.LayoutName);
    }

    foreach (CadBaseEntity entity in cadImage.Entities)
    {
        if (layoutBlockHandles.ContainsKey(entity.SoftOwner))
        {
            string layoutName = layoutBlockHandles[entity.SoftOwner];
            if (!notEmptyLayouts.Contains(layoutName))
                notEmptyLayouts.Add(layoutName);
        }
    }

    return notEmptyLayouts;
}

private static List<string> GetNotEmptyLayoutsForDwg(CadImage cadImage)
{
    List<string> notEmptyLayouts = new List<string>();

    foreach (CadLayout layout in cadImage.Layouts.Values)
    {
        foreach (CadBlockTableObject tableObject in cadImage.BlocksTables)
        {
            if (string.Equals(tableObject.HardPointerToLayout, layout.ObjectHandle))
            {
                if (cadImage.BlockEntities.ContainsKey(tableObject.BlockName))
                {
                    CadBlockEntity cadBlockEntity = cadImage.BlockEntities[tableObject.BlockName];
                    if (cadBlockEntity.Entities.Length > 0)
                        notEmptyLayouts.Add(layout.LayoutName);
                }
                break;
            }
        }
    }

    return notEmptyLayouts;
}