kqmlgraphplugin -- a QML plugin to render beautiful and interactive graphs
sebastiangottfried at web.de
Thu Jan 30 08:24:53 GMT 2014
> Cool project, I really missed such a component a while back (I actually
> wrote my own back then, which was less nice than yours). The code looks
> sane too from a quick look, so I'm all for moving it to extragear (although
> I'm not exactly an expert for sane code).
> It doesn't seem to be designed for lots of data (since each point is an
> object, etc.), which is understandable; but eventually it would be a nice
> feature to add API designed towards such data in the future?
The line chart isn't suited at all for big data sets right now. Not only it
use multiple QML items per data point but the line connecting the data points
is drawn into one huge buffer, even for the parts of the line clipped by the
The bar chart behaves better. It is based on a ListView item, so only the
items actually visible on screen (which is a fairly limited number) are
created at a given time.
I think API-wise both chart types are fine. There is no inherent problem with
QTableModels for large data sets I know of. But the line chart definitely
needs a more efficient implementation. This is one of the points I hope I can
resolve when porting to Qt Quick 2.
> On Wednesday 29 January 2014 12:41:22 Inge Wallin wrote:
> > Regarding 3D charts, I have no idea if this is even possible using QML
> > alone or if you need to do something else for that.
> I assume you're talking about the "usual" 3D charts, such as 3D-looking pie
> charts and bar graphs? For drawing those, I would not use any kind of 3D API
> at all. Just drawing some rectangles and ellipses clipping each other will
> be way easier for that purpose, which is very easy even with QtQuick 1.
> (Apart from that, those 3D effects are bad for a chart's readability
> anyways ;)
This is no near-future stuff anyways.
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