矢量绘图叠加 C#

Question

I want to draw vector lines and text on a overlay thats located in front of a picture. At the moment i'm painting on a transparent descaled bitmap via drawings.graphic, but since im refreshing it on Mouse_move it's quite ressource heavy. Now i want to display my vectors directly via some svg viewer. Does anybody know a good package to use? It just has to be performant, can be integrated in my xaml, use a transparent background and draw text and lines. The NuGet packages i found, were either poorly documented or didn't work. (VectSharp, SVG)

Answer 1

As far as I know, nothing built in plays nicely with SVG. Assuming you are not married to the idea of SVG there might be some other way to do it:

1. Use windows forms and do manual drawing in the paint-event. This may be slow if you have lots of graphics to draw.
2. Draw to a bitmap and draw this to the screen (as you are currently seem to do). Assuming you are not changing everything in each mouse move it might be possible to separate the bitmap in a foreground and background bitmap and only redraw the foreground on mouse move.
3. Convert the svg graphics to xaml. Programs like inkscape can do this, but it might require some manual adjustments to get the correct enclosing elements etc.
4. Convert the vector graphics objects to corresponding WPF graphics object and bind this to some suitable container object in the xaml code.
5. Use something like SharpDX to get a lower level access to the graphics hardware.

You mentions performance issues, but performance for things like this is ensuring you do not redo work unnecessarily and ensuring the graphics primitives are sent to the hardware as efficiently as possible. It might for example be more efficient to draw a single GraphicsPath than drawing each line individually.

It would also be helpful if you could specify how many vectors you are attempting to draw. If we are talking about millions of lines it might be expected to be a bit slow unless you have a well optimized rendering pipeline.