First baby steps

 Thanks Jornmo - That's pretty cool.
It will give me a basis for something to play with and see if I can attempt some of the things I need in a game.

To expand on my objective to draw a grid of say 10 X 10 X 10 with each (25 Max) star as a circular object of the size & colour to match the start type.
To be able to plot a point between one star and another… and your draw line routine gives me the basis of that.
To be able to rotate the matrix of stars to show relative distance in the 3 dimensions.

I can draw the grid and show the stars in a DrawingArea control but being able to rotate them around an arbitrary central point involves some very complex drawing math and that's a bit beyond me.
My compromise was to to be able to see the grind in any iso direction by 'flipping' the grid up, down, left and right to show the relative position of the stars.
I'm hopeful that the OpenGl processes will make the outcome much more better looking and less clumsy.

As soon as I have something, I'll post it up.

Nice vector graphics!