Messages

1

Graphics / Re: sf::Texture::~Texture() Crashes App On Exit

« on: November 17, 2016, 12:00:18 am »

Some code to help with how to use callbacks in a thread-safe manner:

typedef std::function<void(const std::string &data, bool success)> DownloadCallback;

struct DownloadItem {
    std::string data;
    DownloadCallback callback;
    bool success;
};

class Downloader {
public:
    void downloadItem(const std::string &itemUrl, const DownloadCallback &itemCallback) {
        _mutex.lock();
        // save itemUrl and itemCallback
        _mutex.unlock();
        // items get processed in background thread
    }

    void update() {
        DownloadItem item;
        bool gotItem = false;

        _mutex.lock();
        if (!_completedList.empty()) {
            item = _completedList[0];
            gotItem = true;
            _completedList.erase(_completedList.begin());
        }
        _mutex.unlock();

        if (gotItem) {
            item.callback(item.data, item.success);
        }
    }
private:
    // could use a queue instead of vector
    std::vector<DownloadItem> _completedList;
    std::mutex _mutex;
};

// UI thread
MyApp::run() {

    downloader.downloadItem("http://mysite.com/image.png", [&](const std::string &data, bool success) {
       
        if (success) {
            texture.loadFromMemory(data.c_str(), data.size());
        } else {
            sf::err() << "Failed to download image.\n";
        }
    });

    while (window.isOpen()) {

        // poll the downloader for completions
        downloader.update();

        // draw stuff
    }
}
 

2

Window / Re: No touch events on Surface devices

« on: October 21, 2016, 04:41:47 pm »

Thanks for the reply, Laurent.  *Please* add that to the documentation.  I spent about 16 hours on this unnecessarily.

3

Window / Re: No touch events on Surface devices

« on: October 21, 2016, 01:24:04 am »

Hi Mario,

Yes, I did step through with a debugger, and set breakpoints.  That is how I verified that only mouse events are coming in.  Besides events, the sf::Touch class is not returning any activity at all.  Am I missing an SFML setup or initialization call for touchscreen?

Thanks.

4

Window / No touch events on Surface devices

« on: October 20, 2016, 05:51:07 pm »

On a MS Surface 3, all touch events come in as mouse events:

- sf::EventType::MouseButtonPressed
- sf::EventType::MouseButtonReleased  <-- rarely receive this one
- sf::EventType::MouseMoved

This would be okay if the Released messages were reliable, but rarely receive them.

Also tried using sf::Touch::isDown() but it never returns true.  It's like SFML is completely unable to hook the touchscreen at all on these Surface devices.

I searched the forum before posting this.  Does anyone know of a reliable workaround?

Thanks.