152    GLfloat angle, da;  in gear()  local
160    da = 2.0 * M_PI / teeth / 4.0;  in gear()
174          glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),  in gear()
186       glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);  in gear()
187       glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),  in gear()
189       glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),  in gear()
205          glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),  in gear()
214    da = 2.0 * M_PI / teeth / 4.0;  in gear()
218       glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),  in gear()
220       glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),  in gear()
222       glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);  in gear()
236       u = r2 * cos(angle + da) - r1 * cos(angle);  in gear()
237       v = r2 * sin(angle + da) - r1 * sin(angle);  in gear()
242       glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);  in gear()
243       glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);  in gear()
244       glNormal3f(cos(angle + 1.5 * da), sin(angle + 1.5 * da), 0.0);  in gear()
245       glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),  in gear()
247       glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),  in gear()
249       u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da);  in gear()
250       v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da);  in gear()
252       glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),  in gear()
254       glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),  in gear()
256       glNormal3f(cos(angle + 3.5 * da), sin(angle + 3.5 * da), 0.0);  in gear()