Best option to draw thousands of triangles

Best option to draw thousands of triangles

I'm developing a small 2D triangulation application and I need to draw on
the screen thousands os triangles and points (may reach 500k points) and I
need to be able to pan and zoom using mouse middle button.
The application must be WPF
I found many way to do that, but I would like to ask more experienced
users which would be best:
1) OpenGL (SharpGL or OpenTK): looks like it's the best option so far, but
I never worked with openGL and I'm also not sure how easy it would be to
implement
2) WPF DrawingVisual class: as far as I read I have to implement my won
event handlings for my zoom and pan needs
3) WPF drawing on canvas: tried this first but application stared to loose
performance at 25k points + lines
4) WriteableBitmapEx: could'n find any good examples out there so I'm not
sure of its capabilites. I saw there are some shape drawing features, but
does it have a good performance and the pan and zoom would be easy to
implement?