glVertex3f (x[4], y[3], 0); glVertex3f (x[4], y[3], dc->frame_depth/2);
glVertex3f (x[5], y[2], 0); glVertex3f (x[5], y[2], dc->frame_depth/2);
glVertex3f (x[6], y[2], 0); glVertex3f (x[6], y[2], dc->frame_depth/2);
glVertex3f (x[4], y[3], 0); glVertex3f (x[4], y[3], dc->frame_depth/2);
glVertex3f (x[5], y[2], 0); glVertex3f (x[5], y[2], dc->frame_depth/2);
glVertex3f (x[6], y[2], 0); glVertex3f (x[6], y[2], dc->frame_depth/2);