WPF Chart Control With Pan, Zoom and More

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.WindowsAPICodePack.DirectX.Direct2D1;
using System.Windows;

namespace Swordfish.NET.Charts {
  internal class ChartPrimitiveXYD2D : ChartPrimitiveXY, IChartRendererD2D {

    /// <summary>
    /// Geometry to render, geometry created by one factory can't be rendered by another factory
    /// </summary>
    protected Dictionary<IntPtr, GeometryAndFlag> _geometryByFactory = new Dictionary<IntPtr, GeometryAndFlag>();

    public ChartPrimitiveXYD2D() {
    }

    public ChartPrimitiveXYD2D(ChartPrimitiveXYD2D chartPrimitiveXY)
      : base(chartPrimitiveXY) {
    }

    public override ChartPrimitiveXY Clone() {
      return new ChartPrimitiveXYD2D(this);
    }

    protected override void Points_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) {
      base.Points_CollectionChanged(sender, e);
      foreach(GeometryAndFlag gnf in _geometryByFactory.Values) {
        gnf.RecalcGeometry = true;
      }
    }

    protected void CalculateGeometry(D2DFactory d2dFactory, System.Windows.Rect rect) {
        Func<bool, bool, System.Windows.Media.Color, GeometryGroup> buildGeometry = (isFilled, isOk, color) => {
          List<Geometry> geometry = new List<Geometry>();
          if(isOk && Points.Count > 0 && color != System.Windows.Media.Colors.Transparent) {

            var childGeometry = d2dFactory.CreatePathGeometry();
            using(GeometrySink ctx = childGeometry.Open()) {

              ctx.BeginFigure(Points.First().ToD2D(), isFilled ? FigureBegin.Filled : FigureBegin.Hollow);
              foreach(Point point in Points.Skip(1)) {
                ctx.AddLine(point.ToD2D());
              }
              ctx.EndFigure(isFilled ? FigureEnd.Closed : FigureEnd.Open);
              ctx.Close();
            }
            geometry.Add(childGeometry);
            return d2dFactory.CreateGeometryGroup(FillMode.Winding, geometry);
          }
          return null;
        };

        _geometryByFactory[d2dFactory.NativeInterface] =  new GeometryAndFlag(
          buildGeometry(false, LineThickness > 0, LineColor),
          buildGeometry(true, true, FillColor),rect);
    }

    public void RenderFilledElements(PlotRendererD2D canvas, System.Windows.Rect chartArea, System.Windows.Media.MatrixTransform PrimitiveTransform) {
      if(this.FillColor != System.Windows.Media.Colors.Transparent) {
        GeometryAndFlag gnf = null;
        if(!_geometryByFactory.TryGetValue(canvas.D2DFactory.NativeInterface, out gnf) || gnf.RecalcGeometry) {
          CalculateGeometry(canvas.D2DFactory, chartArea);
        }
        //Brush brush = IsDashed ? (Brush)(ChartUtilities.CreateHatch50(this.FillColor, new Size(2, 2))) : (Brush)(new SolidColorBrush(this.FillColor));
        if(_geometryByFactory.TryGetValue(canvas.D2DFactory.NativeInterface, out gnf)) {

          var transformedGeometry = canvas.D2DFactory.CreateTransformedGeometry(gnf.FilledGeometry, PrimitiveTransform.ToD2D());
          var brush = canvas.RenderTarget.CreateSolidColorBrush(FillColor.ToD2D());
          canvas.RenderTarget.FillGeometry(transformedGeometry, brush);
        }
      }
    }

    public void RenderUnfilledElements(PlotRendererD2D canvas, System.Windows.Rect chartArea, System.Windows.Media.MatrixTransform PrimitiveTransform) {

      if(this.LineColor != System.Windows.Media.Colors.Transparent && LineThickness > 0) {
        GeometryAndFlag gnf = null;
        if(!_geometryByFactory.TryGetValue(canvas.D2DFactory.NativeInterface, out gnf) || gnf.RecalcGeometry) {
          CalculateGeometry(canvas.D2DFactory, chartArea);
        }
        if(_geometryByFactory.TryGetValue(canvas.D2DFactory.NativeInterface, out gnf)) {

          var transformedGeometry = canvas.D2DFactory.CreateTransformedGeometry(gnf.UnfilledGeometry, PrimitiveTransform.ToD2D());

          var brush = canvas.RenderTarget.CreateSolidColorBrush(LineColor.ToD2D());

          /*
          StrokeStyle strokeStyle;
          if(IsDashed) {
          strokeStyle = canvas.D2DFactory.CreateStrokeStyle(new StrokeStyleProperties(CapStyle.Flat, CapStyle.Flat, CapStyle.Flat, LineJoin.Bevel, 0, DashStyle.Custom,0),new float[] { 2, 2 });
          } else {
            strokeStyle = canvas.D2DFactory.CreateStrokeStyle(new StrokeStyleProperties(CapStyle.Flat, CapStyle.Flat, CapStyle.Flat, LineJoin.Bevel, 0, DashStyle.Custom,0));
          }
          */
          canvas.RenderTarget.DrawGeometry(transformedGeometry, brush, (float)LineThickness);
        }
      }
    }
  }
}