So here's the problem-
I've made a background fluid grid for my current project (see Geometry Wars for an example). It works, but it eats up the CPU and knocks my previous perfect framerate down to ~5 fps on an iPad. The grid is very efficient, and has nothing to do with the actual fluid simulation. The problem is drawing it. In order to redraw the changes in the grid, I have to remove every line that was changed, then redraw them per frame. That can be anywhere from 10-60 vector lines destroyed and recreated per frame. To make it efficient, I have ensured that only the lines that have changed are rebuilt. But, it's still dreadfully slow.

Any suggestions?

Please keep in mind that if you rotate and scale vector lines it cause the line width to stretch, and it looks very poor.