RenderTools usage

var renderTools = new RenderTools();

// Register gradient brush
renderTools.RegisterTool<Tuple<Color, Color>, Brush>(tuple =>
    new LinearGradientBrush
    {
        GradientStops = new GradientStopCollection(new []
            {
                new GradientStop(tuple.Item1, 0),
                new GradientStop(tuple.Item2, 1)
            })
    });

// Register solid pen.
renderTools.RegisterTool<Tuple<Brush, double>, Pen>(tuple => new Pen(tuple.Item1, tuple.Item2));

// Register pen with dashstyle support.
renderTools.RegisterTool<Tuple<Brush, double, DashStyle>, Pen>(tuple => new Pen(tuple.Item1, tuple.Item2) { DashStyle = tuple.Item3 });

var brush1 = renderTools.GetTool<Brush>(new Tuple<Color, Color>(Colors.Red, Colors.Yellow));
var brush2 = renderTools.GetTool<Brush>(new Tuple<Color, Color>(Colors.Red, Colors.Yellow));
Console.WriteLine(Object.ReferenceEquals(brush1, brush2));

var pen1 = renderTools.GetTool<Pen>(new Tuple<Brush, double>(Brushes.Red, 5));
var pen2 = renderTools.GetTool<Pen>(new Tuple<Brush, double>(Brushes.Red, 5));
Console.WriteLine(Object.ReferenceEquals(pen1, pen2));

var pen3 = renderTools.GetTool<Pen>(new Tuple<Brush, double, DashStyle>(Brushes.Blue, 2, DashStyles.DashDotDot));
var pen4 = renderTools.GetTool<Pen>(new Tuple<Brush, double, DashStyle>(Brushes.Blue, 2, DashStyles.DashDotDot));
Console.WriteLine(Object.ReferenceEquals(pen3, pen4));