How to draw a shape on a graph?

[julietzhang]

I want to draw some shapes on a graph by editing the source code.
Where can I find the class that generates the canvas of graph?

[eduramiba]

Hi,
While you can't extend the OpenGL graph visualization (that is VisualizationModule) with plugins, you can create new renderers for Preview visualization.

Check this http://wiki.gephi.org/index.php/HowTo_w ... w_renderer and some examples https://github.com/gephi/gephi-plugins-bootcamp
Also the default renderers are in Preview Plugin module.

Eduardo

[julietzhang]

Thanks, but I need to draw some shapes under overview perspective...

Is there anyway to get the canvas that those nodes on under overview perspective?

[eduramiba]

Sorry that is not possible. But you always can modify VisualizationModule to draw what you need even though there is no plugin support.

Eduardo

[julietzhang]

So, I can draw on the graph same with those nodes on?
I first try to get the "drawable" by using VizController.getInstance().getDrawable() and then using drawable.getGL() get the GL, draw a triangle on it but nothing shown up.
So, how can I draw?

[eduramiba]

Well remember that if you customize Visualization module you are making a fork of it, not plugins, and the module is quite complex.
About the GL, you can't just retrieve it and use it for drawing anywhere. Looking at the code, I think you should implement your extra graphics at display method of org.gephi.visualization.opengl.compatibility.CompatibilityEngine class.

Eduardo

[julietzhang]

Thanks a lot.
Can you tell me the process, the functions it calls, that when an edge is drawn on the graph? Just the visualization part is OK.

[eduramiba]

You will need to know at least some OpenGL to add new graphics.
It uses JOGL which is simply java bindings to it.

Eduardo