static void drawTorus(float r, float R, int nsides, int rings) {
float ringDelta = 2.0f * (float) Math.PI / rings;
float sideDelta = 2.0f * (float) Math.PI / nsides;
float theta = 0.0f, cosTheta = 1.0f, sinTheta = 0.0f;
for (int i = rings - 1; i >= 0; i--) {
float theta1 = theta + ringDelta;
float cosTheta1 = (float) Math.cos(theta1);
float sinTheta1 = (float) Math.sin(theta1);
GL11.glBegin(GL11.GL_QUAD_STRIP);
float phi = 0.0f;
for (int j = nsides; j >= 0; j--) {
phi += sideDelta;
float cosPhi = (float) Math.cos(phi);
float sinPhi = (float) Math.sin(phi);
float dist = R + r * cosPhi;
GL11.glNormal3f(cosTheta1 * cosPhi, -sinTheta1 * cosPhi, sinPhi);
GL11.glVertex3f(cosTheta1 * dist, -sinTheta1 * dist, r * sinPhi);
GL11.glNormal3f(cosTheta * cosPhi, -sinTheta * cosPhi, sinPhi);
GL11.glVertex3f(cosTheta * dist, -sinTheta * dist, r * sinPhi);
}
GL11.glEnd();
theta = theta1;
cosTheta = cosTheta1;
sinTheta = sinTheta1;
}
}