DPI awareness

Hi Ben,

I’ve discussed this with the team today, for the benefit of the community I’ve attached a couple of screenshots showing SciChart WPF v7 at 200% DPI:

Bear in mind – view these images at 1:1 because they are very large and scaling in the browser will introduce extra blurring / scaling
issues.

I have changed the theme to light to make it clearer the effect on gridlines and pasted a 2x window of the series and text over the chart so you can see the difference. I also put a stroke around the scatter points so you can see the defined edge more clearly.

In my opinion these images are OK. They could be better but the lines, text are clear, do scale with DPI and have high enough quality to be readable.

However, there is room for improvement.

SciChart WPF at it’s core uses DirectX and textures (raster technology) not vector to draw, so at 1.5x scale we are rendering to a texture which is say 1.5x and scaling it down. As a result you’re never going to get pixel perfect images at DPI other than 100% because there’s no such thing as 1/2 a pixel on the monitor.

What you see in WPF is ‘as good as it gets’ at the moment. There may be some additional workarounds that we can apply to get the image sharper.

We are also able to achieve sharper imagery on our JavaScript charts using a different technique. Take a look at https://demo.scichart.com/javascript-scatter-chart and https://demo.scichart.com/javascript-line-chart

At 200% DPI these look fantastic, take a look at below:

Now to achieve the same thing in WPF we have to do quite a big deep refactor of the layout & rendering in SciChart WPF. It can be done (without sacrificing performance) but not something we can deliver immediately.

I’m going to discuss further with the WPF team and across our organisation to see what we can do – as we would like to improve this, but no promises on timing just yet

Best regards
Andrew

In regards to the DpiAware_SciChartSurface demo, as mentioned in the comment above, it seems to work for the chart itself, but not the Axes or the annotations, which render at the wrong scale.

<Grid>
<Grid.ColumnDefinitions>
    <ColumnDefinition Width="Auto" />
    <ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>

<ext:SciChartInteractionToolbar TargetSurface="{Binding Source={x:Reference Name=sciChart}}" />

<!-- Please notice that DpiAwareSciChartSurface requires a default style -->
<!-- It is declared above in UserControl.Resources -->
<sciChartScatterChart:DpiAwareSciChartSurface x:Name="sciChart"
                                              Grid.Column="1"
                                              Padding="0"
                                              BorderThickness="0"
                                              ShowLicensingWarnings="False">
    <s:SciChartSurface.Annotations>
        <s:TextAnnotation Text="Hello world! Annotation"
                          FontSize="14"
                          X1="5.0"
                          Y1="5" />
    </s:SciChartSurface.Annotations>
</sciChartScatterChart:DpiAwareSciChartSurface>

<TextBlock Text="Hello World! WPF"
           Foreground="White"
           FontSize="14"
           Grid.ColumnSpan="2"
           VerticalAlignment="Center"
           HorizontalAlignment="Center" />