Вращение фигуры вокруг своей оси в движении в Opengl(glut)

Смог сделать обычное движение фигуры треугольник:

Rectanglee::Rectanglee() {
    float temp_x = rand() % 100 / 1000.f;
    float temp_y = rand() % 100 / 1000.f;

    this->point[0].x = temp_x;
    this->point[0].y = temp_y;

    this->point[1].x = -temp_x;
    this->point[1].y = temp_y;

    this->point[2].x = -temp_x;
    this->point[2].y = -temp_y;

    this->point[3].x = temp_x;
    this->point[3].y = -temp_y;

    printf("constructor Rectanglee\n");
}

void Rectanglee::Draw()
{
    glPushMatrix();
    glBegin(GL_QUADS);
    glColor3ub(point[0].r, point[0].g, point[0].b);
    glVertex2d(point[0].x, point[0].y);
    glColor3ub(point[1].r, point[1].g, point[1].b);
    glVertex2d(point[1].x, point[1].y);
    glColor3ub(point[2].r, point[2].g, point[2].b);
    glVertex2d(point[2].x, point[2].y);
    glColor3ub(point[3].r, point[3].g, point[3].b);
    glVertex2d(point[3].x, point[3].y);
    glEnd();
    glPopMatrix();
}

void Rectanglee::Move() {
    point[0].x += speedX;
    point[0].y += speedY;
    point[1].x += speedX;
    point[1].y += speedY;
    point[2].x += speedX;
    point[2].y += speedY;
    point[3].x += speedX;
    point[3].y += speedY;

    if (point[0].x > ballXMax || point[1].x > ballXMax || point[2].x > ballXMax || point[3].x > ballXMax) {
        speedX = -speedX;
    }
    else if (point[0].x < ballXMin || point[1].x < ballXMin || point[2].x < ballXMin || point[3].x < ballXMin) {
        speedX = -speedX;
    }
    if (point[0].y > ballYMax || point[1].y > ballYMax || point[2].y > ballYMax || point[3].y > ballYMax) {
        speedY = -speedY;
    }
    else if (point[0].y < ballYMin || point[1].y < ballYMin || point[2].y < ballYMin || point[3].y < ballYMin) {
        speedY = -speedY;
    }
}

Как можно добавить вращение вокруг своей оси в движении?