+ trackball_state *trackball;
+ Bool button_down_p;
+
+ GLfloat show_colors[4];
+ GLfloat stretch_val_x, stretch_val_y;
+ GLfloat stretch_val_dx, stretch_val_dy;
+
+ GLfloat curx, cury, curz;
+
+ GLfloat rx, ry, rz;
+ GLfloat rot, drot, odrot, ddrot, orot;
+ float theta, rho, dtheta, drho, gamma, dgamma;