Rotating Vertices About Point

I'm reverse engineering a level map for a game. Each object within the level has 3 floats for positioning (x,y,z) and 3 floats for rotation (x,y,z). A lot of the objects, when pull

Solution 1:

Have you tried translating the object center to the world axis, applying your rotation, and then translating back by the opposite amount?

In your 2D example you would do a translation of (-7.5,-7.5), apply your rotation, and then translate by (7.5,7.5).