Ok so a triangle is nice and all but we want a sine wave.

Just integrating and filtering the triangle gives us a pretty nasty distorted sine, so i added a preshaper stage whith makes the triangle trapezoidal.

So i cut off the top (here 1V limit, in real its controlled with a poti), flip it, cut off the other half, and done.

The result:

The original triangle in blue, the resulting trapezoid in yellow.

The 180° phaseshift is due to the flipping to cut off the top half. I didnt flip it back because it doesnt matter and i use quad-opamp IC´s ... so this part is neatly done with one IC.