Question

我最近遇到了一个奇怪的问题。我写了一个应用程序类，它使用一个非常简单的渲染器在屏幕上绘制一些模型。相机是可移动的。

我在笔记本电脑上运行程序。最初我注意到屏幕上没有任何东西被绘制（然而，屏幕被正确的颜色清除）。然后我注意到，如果我点击装饰框并移动窗口，屏幕会自动更新：这样，模型变得可见，但除非我再次单击并移动装饰框，否则不会移动。

我在台式电脑上测试了我的程序，一切正常;相机移动顺畅。

最终，我让程序在我的笔记本电脑上运行，但我必须设置SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 0 );并禁用缓冲区交换。

以下是主要的应用程序类。在执行循环中，我将应用程序状态堆调用为循环＆amp;渲染（应用程序状态实际上拥有渲染器）。

如果有任何后果，我的笔记本电脑有intel HD 4000显卡，桌面有GTX 670.

App::App() : _running( false ),
             _deltaTime( 0u ),
             _elapsedTime( 0u ),
             _mainWindow( nullptr ),
             _glContext(),
             _stack() {
    //ctor
}

App::~App() {
    SDL_GL_DeleteContext( _glContext );
    SDL_DestroyWindow( _mainWindow );
    SDL_Quit();
}

void App::execute() {
    _initialize();

    static const float millisecondsPerFrame = 17;

    while ( _running ) {
        //get the delta time & update elapsed time
        uint32_t oldTime = _elapsedTime;
        _elapsedTime = SDL_GetTicks();
        _deltaTime = _elapsedTime - oldTime;

        _processEvents();

        _loop( _deltaTime / 1000.0f );
        _render();

        //apply possible state changes made to the stack
        _stack.applyPendingChanges();

        int usedTime = SDL_GetTicks() - int ( _elapsedTime );

        //sleep the remainder of the cycle if we didn't use the entire update cycle
        if ( millisecondsPerFrame - usedTime > 0 ) {
            SDL_Delay( uint32_t ( millisecondsPerFrame - usedTime ) );
        }
    }
}

void App::_initialize() {

    //initialize random number generator
    nge::srand();

    _running = true;

    _initializeSDL();
    _initializeOpenGL();

    SDL_GL_MakeCurrent( _mainWindow, _glContext );

    //attempt to set late swap tearing
    int res = SDL_GL_SetSwapInterval( -1 );
    //returns 0 on success
    //returns -1 if swap interval is not supported
    if ( res == -1 ) {
        std::cout << "App::_initializeSDL> " << SDL_GetError() << "\n\n";
        SDL_GL_SetSwapInterval( 1 );
    }

    _stack.registerState<GameState>( AppStateID::Game );
    _stack.pushState( AppStateID::Game );
    _stack.applyPendingChanges();
}

void App::_initializeSDL() {
    SDL_Init( SDL_INIT_VIDEO );
    SDL_Init( SDL_INIT_TIMER );

    SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 3 );
    SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 3 );

    SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK,
                        SDL_GL_CONTEXT_PROFILE_CORE );

    SDL_GL_SetAttribute( SDL_GL_ACCELERATED_VISUAL, 1 );

    /**
    For some reason, on my Samsung Series 9, double buffering does not
    work.
    */
    SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 0 );
    SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
    SDL_GL_SetAttribute( SDL_GL_STENCIL_SIZE, 8 );
    //anti-aliasing
    SDL_GL_SetAttribute( SDL_GL_MULTISAMPLEBUFFERS, 1 );
    SDL_GL_SetAttribute( SDL_GL_MULTISAMPLESAMPLES, 4 );

    _mainWindow =  SDL_CreateWindow( "window",
                               SDL_WINDOWPOS_UNDEFINED,
                               SDL_WINDOWPOS_UNDEFINED,
                               800,
                               600,
                               SDL_WINDOW_OPENGL |
                               SDL_WINDOW_RESIZABLE |
                               SDL_WINDOW_MAXIMIZED |
                               SDL_WINDOW_SHOWN );

    _glContext = SDL_GL_CreateContext( _mainWindow );
}

void App::_initializeOpenGL() {
    //initialize GLEW
    glewExperimental = GL_TRUE;

    if ( glewInit() != GLEW_OK ) {
        std::cerr << "glewInit failed." << std::endl;
        std::exit( EXIT_FAILURE );
    }

    glEnable( GL_DEPTH_TEST );
    //enable culling
    glEnable( GL_CULL_FACE );
    glCullFace( GL_BACK );

    glDepthFunc( GL_LEQUAL );
    glEnable( GL_TEXTURE_CUBE_MAP_SEAMLESS );

    std::cout << "OpenGL version: " << glGetString( GL_VERSION ) << std::endl;
    std::cout << "GLSL version: " << glGetString( GL_SHADING_LANGUAGE_VERSION ) << std::endl;
    std::cout << "Vendor: " << glGetString( GL_VENDOR ) << std::endl;
    std::cout << "Renderer: " << glGetString( GL_RENDERER ) << std::endl << std::endl;

    //make sure OpenGL 3.3 is available
    ASSERT( GLEW_VERSION_3_3, "OpenGL 3.3 API is not available" );
}

void App::_processEvents() {
    SDL_Event event;
        while ( SDL_PollEvent( &event ) ) {

            if ( event.type == SDL_QUIT ) {
                _running = false;
            }
        }
}

void App::_loop( float delta ) {
    _stack.loop( delta );
}

void App::_render() {
    _stack.render();
    //SDL_GL_SwapWindow( _mainWindow );
}

Answer 1

我要检查的第一件事是笔记本电脑上的GPU驱动程序。确保驱动程序版本与桌面上的驱动程序版本匹配。

第二件事是添加错误打印。来自here：

window = SDL_CreateWindow("OpenGL Window", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 480, SDL_WINDOW_OPENGL);
if (!window) {
    fprintf(stderr, "Couldn't create window: %s\n", SDL_GetError());
    return;
}

context = SDL_GL_CreateContext(window);
if (!context) {
    fprintf(stderr, "Couldn't create context: %s\n", SDL_GetError());
    return;
}

要检查的第三件事是请求的缓冲区。也许GPU或驱动程序不支持双缓冲，或16位深度，或您请求的其他一些参数。因此，使用initializeSDL()功能中的参数进行播放，找到可在笔记本电脑上使用的参数。

双缓冲在笔记本电脑上不起作用，在桌面上也不起作用

1 个答案: