Question

所以我有这段代码：

void Engine::Run() {
    // initialize all components
    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK))
        throw Exception("couldn't initialize SDL\n" + string(SDL_GetError()), 1);

    // other code

    run = true;
    SDL_Event event;

    while (run) {
        // other code

        uint32 timeout = SDL_GetTicks() + 50;
        while (SDL_PollEvent(&event) && timeout - SDL_GetTicks() > 0)
            HandleEvent(event);
    }
}

void Engine::HandleEvent(const SDL_Event& event) {
    switch (event.type) {
    case SDL_KEYDOWN:
        inputSys->KeyDownEvent(event.key);
        break;
    case SDL_KEYUP:
        inputSys->KeyUpEvent(event.key);
        break;
    case SDL_JOYBUTTONDOWN:
        cout << "button" << endl;
        break;
    case SDL_JOYHATMOTION:
        cout << "hat" << endl;
        break;
    case SDL_JOYAXISMOTION:
        cout << "axis" << endl;
        break;
    case SDL_JOYDEVICEADDED: case SDL_JOYDEVICEREMOVED:
        inputSys->UpdateControllers();
        break;
    // other code
    }
}

问题在于，唯一未被调用的事件是操纵杆按钮，帽子和轴事件。另外两个与操纵杆相关的事件工作得很好我在一个不同的项目中使用完全相同的代码，其中所有操纵杆事件都被调用而没有问题，但是因为我将代码移动到我的新项目中，所以它们不再被调用。
SDL确实识别插入的控制器，我可以使用SDL_JoystickGetAxis之类的功能，但由于某些原因，这三个事件似乎不起作用。知道为什么会这样吗？

Answer 1

您必须致电SDL_JoystickOpen才能获得这些活动。这是他们的例子：

SDL_Joystick *joy;

// Initialize the joystick subsystem
SDL_InitSubSystem(SDL_INIT_JOYSTICK);

// Check for joystick
if (SDL_NumJoysticks() > 0) {
    // Open joystick
    joy = SDL_JoystickOpen(0);

    if (joy) {
        printf("Opened Joystick 0\n");
        printf("Name: %s\n", SDL_JoystickNameForIndex(0));
        printf("Number of Axes: %d\n", SDL_JoystickNumAxes(joy));
        printf("Number of Buttons: %d\n", SDL_JoystickNumButtons(joy));
        printf("Number of Balls: %d\n", SDL_JoystickNumBalls(joy));
    } else {
        printf("Couldn't open Joystick 0\n");
    }

    // Close if opened
    if (SDL_JoystickGetAttached(joy)) {
        SDL_JoystickClose(joy);
    }
}

SDL2操纵杆事件未触发

1 个答案: