c++ - 如何在不阻塞 C++ Allegro 中的整个程序的情况下使文本闪烁？

Question

bool running = true;

int width = al_get_display_width(display);
while (running) {

for (;;) {
    al_clear_to_color(al_map_rgb(255, 255, 255));
    al_draw_bitmap(bitmap, 0, 0, 0);
    al_draw_text(font, al_map_rgb(0, 0, 0), 760, 375, 0, "Play (Spacebar)");
    al_flip_display();
    al_rest(1.5);

    al_clear_to_color(al_map_rgb(255, 255, 255));
    al_draw_bitmap(bitmap, 0, 0, 0);
    al_flip_display();
    al_rest(0.5);
}

ALLEGRO_EVENT event;
al_wait_for_event(queue, &event);
if (event.type == ALLEGRO_EVENT_DISPLAY_CLOSE) {
    running = false;
}
}

如您所见，我有一个无限循环，它阻塞了整个程序以使文本闪烁。问题是我如何进行闪烁，以便其他事情像后续事件一样继续工作(当用户点击 X 时窗口关闭)

Answer 1

最好的方法是在绘制文本时检查要绘制的状态(闪烁或关闭)。这可以从当前时间得出。像这样的东西:

while (running) {
    al_clear_to_color(al_map_rgb(255, 255, 255));
    al_draw_bitmap(bitmap, 0, 0, 0);

    if (fmod(al_get_time(), 2) < 1.5) { // Show the text for 1.5 seconds every 2 seconds.
        al_draw_text(font, al_map_rgb(0, 0, 0), 760, 375, 0, "Play (Spacebar)");
    }

    al_flip_display();

    // Handle events in a non-blocking way, for example
    // using al_get_next_event (not al_wait_for_event).
}