FIXED: Slowdown issue with DrawAni when drawing multiple Line charts - Official support forum

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RGraph is a JavaScript charts library based on HTML5 SVG and canvas. RGraph is mature (over 18 years old) and has a wealth of features making it an ideal choice to use for showing charts on your website.

Version 7.20

Version 7.20 (released in June 2026) is the latest version of RGraph and the major change in this version is an update to the default values of properties making for better looking charts without having to set any properties. Read more about this and other changes in the changelog.

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16th June, Rachel
I have a question about the 3D Bar chart

12th June, Marco
Should I use SVG or canvas for the charts on my website?

9th June, Richard
New version of RGraph: version 7.20

3rd June, Patrick
Question about installing RGraph

1st June, Ouja
How do I add a click event to a bar in my Bar chart?

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Slowdown issue with DrawAni when drawing multiple Line charts

When drawing multiple line charts, a speed degradation issue occurs during drawAni. In RGraph.common.core.js, within the RGraph.Background.draw function:

// Reset the line dash
if (typeof args.object.context.setLineDash == 'function') {
args.object.context.setLineDash([1,0]);
}

This part takes a long time. Setting it to the default value like this:

args.object.context.setLineDash([]);

restores the speed to normal.

Please confirm.

Thank you."

Thanks very much for identifying the issue. I've added the fix into the code and it will be a part of version 6.17. The updated library is available on GitHub if you want it:

https://raw.githubusercontent.com/heyesr/rgraph/main/libraries/RGraph.common.core.js

The difference is quite pronounced!

And with the background grid code being shared between a few libraries (eg bar/line/gantt/hbar/scatter) this is unlikely to just affect the Line chart animations - but those other charts too.

Cheers.