Scrolling Text with Allegro

#include <allegro5/allegro.h>
#include <allegro5/allegro_image.h>
#include <allegro5/allegro_font.h>
#include <allegro5/allegro_ttf.h>
#include <allegro5/allegro_primitives.h>

#include <iostream>
#include <string>
#include <fstream>

using namespace std;

const int SCREEN_W = 640;
const int SCREEN_H = 480;
const float FPS = 60.0;
const int yVel = 50;

int main()
{
    int fps = 0, fps_accum = 0;
    double fps_time = 0;
    int lvlX = SCREEN_W / 2 - 24, lvlY = 0, lvlNum = 1;
    string level = "Level ";
    ofstream outfile;
    outfile.open("level.out");
    if(!al_init())
    {
        cout << "Failed to init allegro\n";
    }
    if(!al_install_keyboard())
    {
        cout << "Failed to install keyboad\n";
    }

    if(!al_init_primitives_addon())
    {
        cout << "Failed to init primitives addon\n";
    }

    if(!al_init_image_addon())
    {
        cout << "Failed to init image addon\n";
    }

    al_init_font_addon();
    al_init_ttf_addon();

    ALLEGRO_DISPLAY *display;
    ALLEGRO_EVENT_QUEUE *event_queue;
    ALLEGRO_TIMER *timer;
    ALLEGRO_FONT *fnt, *lvltxt;

        fnt = al_load_ttf_font("pirulen.ttf", 12, 0);
        lvltxt = fnt;

    bool doexit = false;
    bool redraw = false;

    timer = al_create_timer(1.0/FPS);
    display = al_create_display(SCREEN_W, SCREEN_H);
    event_queue = al_create_event_queue();
    //al_set_display_flag(display, ALLEGRO_FULLSCREEN_WINDOW, 1);
    al_set_window_title(display, "Scrolling Text");
    al_set_window_position(display, 20, 20);

    al_register_event_source(event_queue, al_get_display_event_source(display));
    al_register_event_source(event_queue, al_get_timer_event_source(timer));
    al_register_event_source(event_queue, al_get_keyboard_event_source());

    al_clear_to_color(al_map_rgb(0, 0, 0));
    al_flip_display();
    al_start_timer(timer);

    while(!doexit)
    {
        ALLEGRO_EVENT ev;
        al_wait_for_event(event_queue, &ev);

        if(ev.type == ALLEGRO_EVENT_TIMER)
        {
            // logic
            if(lvlY < 0 || lvlY > SCREEN_H)
            {
                lvlY = 0;
                outfile << level << " " << lvlNum << endl;
                lvlNum++;
            }
            else lvlY += yVel;


            redraw = true;
        }
        else if(ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
        {
            break;
        }
        else if(ev.type == ALLEGRO_EVENT_KEY_DOWN)
        {
            switch(ev.keyboard.keycode)
            {
                break;
            }
        }
        else if(ev.type == ALLEGRO_EVENT_KEY_UP)
        {
            switch(ev.keyboard.keycode)
            {
                case ALLEGRO_KEY_ESCAPE:
                    doexit = true;
                    break;
            }
        }

        if(redraw && al_is_event_queue_empty(event_queue))
        {
            redraw = false;
            al_clear_to_color(al_map_rgb(0, 0, 0));
            double t = al_get_time();
            // draw map code here
            al_draw_filled_rounded_rectangle(4, 4, 100, 22, 8, 8, al_map_rgb(255, 0, 255));
            al_draw_textf(fnt, al_map_rgb(255, 255, 255),  8,  8, 0, "FPS: %d", fps);
            al_draw_textf(lvltxt, al_map_rgb(255, 255, 255), lvlX, lvlY, 0, "Level %d", lvlNum);
            al_flip_display();

            fps_accum++;
            if(t - fps_time >= 1)
            {
                fps = fps_accum;
                fps_accum = 0;
                fps_time = t;
            }
        }
    }

    outfile.close();

    return 0;

}