public void draw(float innerRadius,
renders a disk on the z = 0 plane. The disk has a radius of
outerRadius, and contains a concentric circular hole with a radius of
innerRadius. If innerRadius is 0, then no hole is generated. The disk is
subdivided around the z axis into slices (like pizza slices), and also
about the z axis into rings (as specified by slices and loops,
With respect to orientation, the +z side of the disk is considered to be
"outside" (see glu.quadricOrientation). This means that if the orientation
is set to GLU.OUTSIDE, then any normals generated point along the +z axis.
Otherwise, they point along the -z axis.
If texturing is turned on (with glu.quadricTexture), texture coordinates are
generated linearly such that where r=outerRadius, the value at (r, 0, 0) is
(1, 0.5), at (0, r, 0) it is (0.5, 1), at (-r, 0, 0) it is (0, 0.5), and at
(0, -r, 0) it is (0.5, 0).