[RadCartesianChart] Weird rendering

[Sébastien]

Hi,

My very short list of data is ordered by time. You will see that the rendering does not make sense.

You can run the sample: ChartBug.

As I understand, we can set the ItemSources of a SeriesSpline for like 1 month of data and control what is shown with the DateTimeContinuousAxis.Minimum and DateTimeContinuousAxis.Maximum values to set the visible range.

Thank you in advance
Sébastien

[Yana]

Hello Sebastien,

The Chart rendering is correct per the provided ItemsSource.  Let me explain - in general, Minimum and Maximum values of the axis limit the axis points, it does not mean the Chart outside these minimum and maximum is not considered at all.

To make the Chart clearer,  please just for a test replace SplineSeries with LineSeries and set its ShowLabels to "True":

<chart:LineSeries x:Name="SplineSeries1" ShowLabels="True">
    <chart:LineSeries.CategoryBinding>
        <chart:PropertyNameDataPointBinding PropertyName="Date" />
    </chart:LineSeries.CategoryBinding>
    <chart:LineSeries.ValueBinding>
        <chart:PropertyNameDataPointBinding PropertyName="Value" />
    </chart:LineSeries.ValueBinding>
</chart:LineSeries>

The result will be the following:

As you can see, exactly 4 points are rendered as the first points from the ItemsSource have Date value earlier than the DateTimeContinuousAxis.Minimum value. Still, the Chart takes into account the value before the Minimum as it does not start with its first point after the axis minimum.

I hope I clear things up. Let me know if you have any additional questions on this.

Regards,
Yana
Progress Telerik

[Sébastien]

Hi, thanks for the answer.

My remaining question is in the new provided image.

Sébastien

[Sébastien]

Hi,

I have a new sample with data to show you the rendering spline bug. While resizing the app, the spline is rendered correctly, but you can see in the video that it does not work at all size.

In my app, I see even worse rendering.

Good luck!
Sébastien

[Sébastien]

Hi,

For WinUI 3, I had my hypothesis that your team didn't reinvent the "world" when it comes to the rendering engine since this is mostly just C# code that is compatible with UWP and WInUI3.

I created a new WinUI3 app and the bug is also present. Open the app and resize the window.

Bonus: when exiting the app, there is a catastrophic failure. It happens with WinUI 3 only, but not UWP.

Good luck

[Yana]

Hi Sebastien,

Thank you for the detailed report.

Indeed, it seems there is an issue in the rendering engine of the spline chart - in general, spline chart should use curves instead of straight lines, still, in this case, there are two edges when the window is resized.

I've logged a public bug report on your behalf in our feedback portal for the Telerik UI for UWP, here is the direct link:

Chart: SplineSeries rendering is not correct in certain scenarios

I've updated your points as a small sign of gratitude for your involvement on this. I am so sorry for any inconvenience caused.

Regards,
Yana
Progress Telerik