glMatrixMode(GL_TEXTURE);
    glLoadIdentity();
    glRotatef(tb.angle, 0.0, 0.0, 1.0);

    glBindTexture(GL_TEXTURE_2D, tb.tex);
    glBegin(GL_QUADS);
    {
        glColor4f(1.0, 1.0, 1.0, 1.0/(50.0)*(float)m_i);
        glTexCoord2f(0, 0);
        glVertex3f(-tb.cx, -tb.cy, 0);

        glTexCoord2f(1, 0);
        glVertex3f(tb.cx, -tb.cy, 0);

        glTexCoord2f(1, 1);
        glVertex3f(tb.cx, tb.cy, 0);

        glTexCoord2f(0, 1);
        glVertex3f(-tb.cx, tb.cy, 0);
    }
    glEnd();