I need to make a phase do a ping pong for a sampler.

I'm working on a sampler and I would like to add a ping pong play mode, I need the phase to do a 0-1 and then a 1-0 back down, I tried scaling the phase through a triangle shaper and then cutting the frequancy by half, and this worked, but it had a negative affect on some other parts of the sample engine that need to stay in line with the 0-1 range of the phase counter.

How do I make a phase counter go 0-1 and then climb back down to 0?

 

I got this all sorted out, you can skip this thread.