Rewrite TreeMap generated C # to C++

advanced
#1

I’d like to write TreeMap generated code, but I do not know how to write in Openframeworks.

But I found C # source code, but I do not have knowledge.

How can I rewrite this source code for C ++?


Slice calculation 
public Slice<T> GetSlice<T>(IEnumerable<Element<T>> elements, double totalSize, double sliceWidth)
{
 if (!elements.Any()) return null;
 if (elements.Count() == 1) return new Slice<T> 
  { Elements = elements, Size = totalSize };

 var sliceResult = GetElementsForSlice(elements, sliceWidth);

 return new Slice<T>
 {
  Elements = elements,
  Size = totalSize,
  SubSlices = new[]
  { 
   GetSlice(sliceResult.Elements, sliceResult.ElementsSize, sliceWidth),
   GetSlice(sliceResult.RemainingElements, 1 - sliceResult.ElementsSize, 
sliceWidth)
  }
 };
}

private SliceResult<T> GetElementsForSlice<T>(IEnumerable<Element<T>> elements,double sliceWidth)
{
 var elementsInSlice = new List<Element<T>>();
 var remainingElements = new List<Element<T>>();
 double current = 0;
 double total = elements.Sum(x => x.Value);

 foreach (var element in elements)
 {
  if (current > sliceWidth)
   remainingElements.Add(element);
  else
  {
   elementsInSlice.Add(element);
   current += element.Value / total;
  }
 }

 return new SliceResult<T> 
 { 
  Elements = elementsInSlice, 
  ElementsSize = current,
  RemainingElements = remainingElements
 };
}

public class SliceResult<T>
{
 public IEnumerable<Element<T>> Elements { get; set; }
 public double ElementsSize { get; set; }
 public IEnumerable<Element<T>> RemainingElements { get; set; }
}

public class Slice<T>
{
 public double Size { get; set; }
 public IEnumerable<Element<T>> Elements { get; set; }
 public IEnumerable<Slice<T>> SubSlices { get; set; }
}

public class Element<T>
{
 public T Object { get; set; }
 public double Value { get; set; }
}

Generating rectangles using leaf slice (slice with only one element in it) 
public IEnumerable<SliceRectangle<T>> GetRectangles<T>(Slice<T> slice, int width, 
 int height)
{
 var area = new SliceRectangle<T>
  { Slice = slice, Width = width, Height = height };
  
 foreach (var rect in GetRectangles(area))
 {
  // Make sure no rectangle go outside the original area
  if (rect.X + rect.Width > area.Width) rect.Width = area.Width - rect.X;
  if (rect.Y + rect.Height > area.Height) rect.Height = area.Height - rect.Y;
   
  yield return rect;
 }
}
 
private IEnumerable<SliceRectangle<T>> GetRectangles<T>(
 SliceRectangle<T> sliceRectangle)
{
 var isHorizontalSplit = sliceRectangle.Width >= sliceRectangle.Height;
 var currentPos = 0;
 foreach (var subSlice in sliceRectangle.Slice.SubSlices)
 {
  var subRect = new SliceRectangle<T> { Slice = subSlice };
  int rectSize;
   
  if (isHorizontalSplit)
  {
   rectSize = (int)Math.Round(sliceRectangle.Width * subSlice.Size);
   subRect.X = sliceRectangle.X + currentPos;
   subRect.Y = sliceRectangle.Y;
   subRect.Width = rectSize;
   subRect.Height = sliceRectangle.Height;
  }
  else
  {
   rectSize = (int)Math.Round(sliceRectangle.Height * subSlice.Size);
   subRect.X = sliceRectangle.X;
   subRect.Y = sliceRectangle.Y + currentPos;
   subRect.Width = sliceRectangle.Width;
   subRect.Height = rectSize;
  }
   
  currentPos += rectSize;
   
  if (subSlice.Elements.Count() > 1)
  {
   foreach (var sr in GetRectangles(subRect))
    yield return sr;
  }
  else if (subSlice.Elements.Count() == 1)
   yield return subRect;
 }
}
 
public class SliceRectangle<T>
{
 public Slice<T> Slice { get; set; }
 public int X { get; set; }
 public int Y { get; set; }
 public int Width { get; set; }
 public int Height { get; set; }
}

Drawing the rectangles in WinForm 
public void DrawTreemap<T>(IEnumerable<SliceRectangle<T>> rectangles, int width, 
 int height)
{
 var font = new Font("Arial", 8 );
 
 var bmp = new Bitmap(width, height);
 var gfx = Graphics.FromImage(bmp);
  
 gfx.FillRectangle(Brushes.Blue, new RectangleF(0, 0, width, height));
 
 foreach (var r in rectangles)
 {
  gfx.DrawRectangle(Pens.Black, 
   new Rectangle(r.X, r.Y, r.Width - 1, r.Height - 1));
 
  gfx.DrawString(r.Slice.Elements.First().Object.ToString(), font, 
   Brushes.White, r.X, r.Y);
 }
 
 var form = new Form() { AutoSize = true };
 form.Controls.Add(new PictureBox()
  { Width = width, Height = height, Image = bmp });
 form.ShowDialog();
}

And finally to generate a Treemap in LinqPad 
void Main()
{
 const int Width = 400;
 const int Height = 300;
 const double MinSliceRatio = 0.35;
 
 var elements = new[] { 24, 45, 32, 87, 34, 58, 10, 4, 5, 9, 52, 34 }
  .Select (x => new Element<string> { Object = x.ToString(), Value = x })
  .OrderByDescending (x => x.Value)
  .ToList();
 
 var slice = GetSlice(elements, 1, MinSliceRatio).Dump("Slices");
  
 var rectangles = GetRectangles(slice, Width, Height)
  .ToList().Dump("Rectangles");
  
 DrawTreemap(rectangles, Width, Height);
}