OpenGL线框模式``` #if (CC_TARGET_PLATFORM == CC_PLATFORM_MAC) ||

#if (CC_TARGET_PLATFORM == CC_PLATFORM_MAC) || (CC_TARGET_PLATFORM == CC_PLATFORM_WIN32) || (CC_TARGET_PLATFORM == CC_PLATFORM_LINUX)
    if (true)
    {
        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
        // 为了使线看的更明显 , 设置当前线的宽度 5 像素 
        glLineWidth(5.0f);
    }
#endif

// ....

#if (CC_TARGET_PLATFORM == CC_PLATFORM_MAC) || (CC_TARGET_PLATFORM == CC_PLATFORM_WIN32) || (CC_TARGET_PLATFORM == CC_PLATFORM_LINUX)
    // 记得还原
    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
#endif