private void DrawDendrogram(Graphics graphics, DendrogramFormat format)
{
var locations = format.LeafLocations.Select(kvp => (kvp.Key + kvp.Value) / 2).ToList();
var lines = format.Data.GetLines(locations, RectilinearLines).ToList();
var pen = new Pen(Color.Black, 1);
var maxHeight = lines.Max(line => line.Item4);
if (maxHeight == 0)
{
// TODO: Draw a degenerate tree where all nodes connect at the same point
return;
}
var colorFraction = GetFractionForColors(format);
var treeFraction = 1 - colorFraction;
if (treeFraction > 0)
{
var denominator = maxHeight / treeFraction;
var offset = denominator - maxHeight;
foreach (var line in lines)
{
var start = CoordinatesToPoint(line.Item1, (offset + line.Item2) / denominator);
var end = CoordinatesToPoint(line.Item3, (offset + line.Item4) / denominator);
DrawLine(graphics, pen, start, end);
}
}
if (colorFraction > 0)
{
for (int colorLevel = 0; colorLevel < format.ColorLevelCount; colorLevel++)
{
for (int iLeaf = 0; iLeaf < format.Colors.Count; iLeaf++)
{
var color = format.Colors[iLeaf][colorLevel];
var left = format.LeafLocations[iLeaf].Key;
var right = format.LeafLocations[iLeaf].Value;
var bottom = colorLevel * colorFraction / format.ColorLevelCount;
var top = (colorLevel + 1) * colorFraction / format.ColorLevelCount;
var topLeft = CoordinatesToPoint(left, top);
var bottomRight = CoordinatesToPoint(right, bottom);
var rectangle = new RectangleF(
Math.Min(topLeft.X, bottomRight.X),
Math.Min(topLeft.Y, bottomRight.Y),
Math.Abs(topLeft.X - bottomRight.X),
Math.Abs(topLeft.Y - bottomRight.Y));
graphics.FillRectangle(new SolidBrush(color), rectangle);
}
}
}
}
private double GetFractionForColors(DendrogramFormat dendrogramFormat)
{
if (dendrogramFormat.Colors == null || dendrogramFormat.Colors.Count == 0)
{
return(0);
}
var totalSpace = GetTotalSpace();
var spaceForColors = Math.Max(totalSpace / 10, dendrogramFormat.ColorLevelCount * 5);
if (spaceForColors >= totalSpace)
{
return(1);
}
return(spaceForColors / totalSpace);
}
