2D mesh rotation

Hi!

Build the mesh exactly the way you have, but before the rendering of the mesh do:

Move the center of height map to (0,0,0).
glTranslatef(-64, 0, -64);
Rotate around the y-axis.
glRotatef(angleInDegree, 0,1,0);
Move back to the original position.
glTranslate(64, 0, 64);

Okay… and since we are in OpenGL land, you actually have to do it in the reverse order.
glTranslate(64, 0, 64);
glRotatef(angleInDegree, 0,1,0);
glTranslatef(-64, 0, -64);

(The matrices are pushed on a stack. What came last is executed first.)

Cheers!