// controls for navigating ship using arrow keys
void SpecialInput(int key, int x, int y) {
    switch (key) {
    case GLUT_KEY_UP:
        myWorld.shipType[selection]->translate(0, -7);
        break;
    case GLUT_KEY_LEFT:
        //rotate ship given center point of the ship
        myWorld.shipType[selection]->rotate(
                myWorld.shipType[selection]->center[0],
                myWorld.shipType[selection]->center[1], -2);
        break;
    case GLUT_KEY_RIGHT:
        myWorld.shipType[selection]->rotate(
                myWorld.shipType[selection]->center[0],
                myWorld.shipType[selection]->center[1], 2);
        break;
    }
    glutPostRedisplay();
}

void Shape2D::rotate(GLfloat rx, GLfloat ry, GLfloat angle){
    glTranslatef(rx, ry, 0);
    glRotatef(angle, 0., 0., 1.);
    glTranslatef(-rx, -ry, 0);
}

switch (key) {
case GLUT_KEY_UP:
    myWorld.shipType[selection]->translate(0, -7);
    break;
case GLUT_KEY_LEFT:
    glPushMatrix();
    myWorld.shipType[selection]->rotate(
            myWorld.shipType[selection]->center[0],
            myWorld.shipType[selection]->center[1], -2);
    myWorld.shipType[selection]->draw();
    glutPostRedisplay();
    glPopMatrix();
    break;
case GLUT_KEY_RIGHT:
    myWorld.shipType[selection]->rotate(
            myWorld.shipType[selection]->center[0],
            myWorld.shipType[selection]->center[1], 2);
    break;
}
//glutPostRedisplay();