VWAP Drawing Tool, Path Geometry

[Don22Trader1]

Hello,

Been working on a drawing tool that finds the vwap of a user defined range. The user clicks down onto a bar, drags across however many bars they need, then a vwap line is drawn on the range (using Volumetric Bars).

I have logic that correctly finds the bars indexes, and vwap prices for each bar, the issue is rendering it onto the chart. I found on another thread how using pathGeometry can paint a line with arcs, etc.. that can be used to render the vwap line. I used ChatGPT 4 to help me get started with the rendering logic and below is what I have thus far. When I add the tool to a chart nothing appears, my chart glitches by other drawings disappearing and when I hover over that chart my cursor disappears. Hopefully my code snippet isn't too long but If i can get another pair of eyes to maybe point out why the line is not rendering onto the chart I would appreciate it.

List<SharpDX.Vector2> vwapCoordinates = new List<SharpDX.Vector2>();


OnRender()
{
  ///Find bar Index and VWAP price for every bar in highlighted range
  for (int i = startIdx; i <= endIdx; i++)
  {
    // VWAP Calculations
    {
      .....calculations
    }

    //Turn index and vwap prices to appropriate pixel value coordinates
    vwapBarIndex = chartControl.GetXByBarIndex(myBars, i);
    vwapPrice = chartScale.GetYByValue(VWAP);

    //Create a chart point from x and y coordinate
    SharpDX.Vector2 vwapPoint = new SharpDX.Vector2((float)vwapBarIndex, (float)vwapPrice);

    //add points to a list
    vwapCoordinates.Add(vwapPoint);
  }

  ///Line Creation logic
  SharpDX.Direct2D1.Factory d2dFactory = new SharpDX.Direct2D1.Factory();

  using (SharpDX.Direct2D1.PathGeometry pathGeometry = new SharpDX.Direct2D1.PathGeometry(d2dFactory))
  {
    using (SharpDX.Direct2D1.GeometrySink geometrySink = pathGeometry.Open())
    {
      if (vwapCoordinates.Count > 0)
      {
        // Get starting point from vwapCoordinates List
        SharpDX.Vector2 startingPoint = vwapCoordinates[0];

        // Define the starting point of your VWAP line
        geometrySink.BeginFigure(startingPoint, SharpDX.Direct2D1.FigureBegin.Filled);

        //Add each point to the line drawing
        foreach(var vwapPoint in vwapCoordinates)
        {
          geometrySink.AddLine(vwapPoint);
        }

        //End Figure
        geometrySink.EndFigure(SharpDX.Direct2D1.FigureEnd .Open);
        geometrySink.Close();
      }
    }
  
    ///Rendering Logic
    // Set the stroke style
    SharpDX.Direct2D1.StrokeStyleProperties strokeStyleProperties = new SharpDX.Direct2D1.StrokeStyleProperties()
    {
      DashStyle = SharpDX.Direct2D1.DashStyle.Solid
    };

    using (SharpDX.Direct2D1.StrokeStyle strokeStyle = new SharpDX.Direct2D1.StrokeStyle(d2dFactory, strokeStyleProperties))
    {
      using (SharpDX.Direct2D1.SolidColorBrush strokeBrush = new SharpDX.Direct2D1.SolidColorBrush(RenderTarget, SharpDX.Color.White))
      {
        //Render Target
        RenderTarget.DrawGeometry(pathGeometry, strokeBrush, vwapStrokeWidth, strokeStyle);
      }
    }
  }
  d2dFactory.Dispose();
}

[NinjaTrader_BrandonH]

Hello Don22Trader1,

Thanks for your post.

Something standing out in the code you shared is that you likely do not need to call 'using' before defining pathGeometry, geometrySink, strokeStyle, and strokeBrush.

Further, d2dFactory.Dispose() likely does not need to be called in the script.

Always dispose of a PathGeometry when finished and always dispose of a brush when finished.

Correct, PathGeometry and RenderTarget.DrawGeometry would need to be used to accomplish custom rendering of a line like that on the chart.

You could view the Ichimoku Cloud indicator from the NinjaTrader Ecosystem User App Share for an example of using PathGeometry and RenderTarget.DrawGeometry.

Ichimoku Cloud: https://ninjatraderecosystem.com/use...indicator-nt8/

Also, for examples of using PathGeometry, you could see the Region Drawing object, this uses Path Geometry and is a good example of what may be required.

See the help guide documentation below for more information.

RenderTarget.DrawGeometry: https://ninjatrader.com/support/help...awgeometry.htm
PathGeometry: https://ninjatrader.com/support/help...thgeometry.htm
Geometry: https://ninjatrader.com/support/help...thgeometry.htm
StrokeStyle: https://ninjatrader.com/support/help...trokestyle.htm
RenderTarget: https://ninjatrader.com/support/help...ndertarget.htm
SharpDX.Direct2D1: https://ninjatrader.com/support/help..._direct2d1.htm
Using SharpDX for Custom Chart Rendering - SharpDX Lines and Shapes: https://ninjatrader.com/support/help..._rendering.htm



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