If you are wanting to wrap a texture on top of a dynamically generated 'rolling' hill, I don't think this is too difficult, if you use POLYVECTORs.
Take the below screen shot as an example.
The bottom set of red circles would represent your rolling terrain points.
The bottom set of blue circles would be calculated based on the red points.
It should be an easy algorithm to determine these blue dots, somebody on here may provide the technical term for that trig function, I have no idea.
Then repeat this (and reuse the same texture) for all of the terrain points.
Then design your texture like the top texture in the screenshot (but with a even horizontal base, unlike the cut/paste I did from yours).
Using polyvectors, map the red dots from the bottom to the red dots on the texture.
Then do the same for the blue dots.
This will result in the texture 'wrapping' around the terrain.
It will distort a slight bit of course, but experiment and you may be happy.
You could have a longer texture to provide less repeating, each time just pick a point to start mapping from.
Of course you may have to predetermine certain valid starting points so the results flow together with the neighboring terrain nicely. (same concept as a tileable texture)
[Edit] The more reds dots you use along the terrain, the better it may look.