Init code

        V_RETURN(m_pDev->GetRenderTargetData(m_pSurface, m_pSysMemSurface));

        D3DLOCKED_RECT rect;
        V_RETURN(m_pSysMemSurface->LockRect(&rect, nullptr, 0));

        _height = ((float*)rect.pBits)[0];
        m_pSysMemSurface->UnlockRect();