Alternate sprite animation

#include <allegro5/allegro.h>
#include <allegro5/allegro_native_dialog.h>
#include <allegro5/allegro_image.h>
#include <allegro5/allegro_audio.h>
#include <allegro5/allegro_acodec.h>
#include <sstream>
#include <vector>

#define ScreenWidth 800
#define ScreenHeight 600

int main()
{
    const int FPS = 8;
    const int interval = 4;
    enum direction { S = 0, A = 4, W = 8, D = 12 };

    if(!al_init()){
        al_show_native_message_box(NULL, NULL, NULL, "Could not initialize allegro!", NULL, 0);
        return -1;
    }

    al_set_new_display_flags(ALLEGRO_WINDOWED);
    ALLEGRO_DISPLAY *display = al_create_display(ScreenWidth, ScreenHeight);
    al_set_window_position(display, 200, 100);
    al_set_window_title(display, "Greverus");

    if(!display){
        al_show_native_message_box(display, "Simple Title", "Display Settings", "Display window was not created successfully!", NULL, ALLEGRO_MESSAGEBOX_QUESTION);
        return -1;
    }

    bool done = false, draw = true, active = false;
    float x = 10, y = 10, moveSpeed = 10;
    int dir = S, prevDir, index = 0;

    int imageNumber = -1;
    bool startAnimation = false;

    al_install_keyboard();
    al_install_mouse();
    al_init_image_addon();

    ALLEGRO_BITMAP *person = al_load_bitmap("Data/textures/human/Ganondorf/ganondorf_sprite_att.png");

    std::vector<int> source;
    std::vector<int> width;

    ALLEGRO_COLOR pixel, lastPixel, color;

    source.push_back(0);
    width.push_back(0);

    for(int i = 0; i < al_get_bitmap_width(person); i++){
        color = al_map_rgba(255, 7, 49, 255);
        pixel = al_get_pixel(person, i, 0);

        if(memcmp(&pixel, &lastPixel, sizeof(ALLEGRO_COLOR))){
            if(!memcmp(&pixel, &color, sizeof(ALLEGRO_COLOR))){
                source.push_back(i);
                if(source.size() == 2)
                    width.push_back(i);
                else
                    width.push_back(i - width[width.size() - 1]);
            }
        }else if(i == al_get_bitmap_width(person) - 1){
            width.push_back(i - width[width.size() - 1]);
        }

        lastPixel = pixel;
    }

    al_convert_mask_to_alpha(person, al_map_rgba(255, 7, 49, 255));

    ALLEGRO_KEYBOARD_STATE keyState;

    ALLEGRO_TIMER *timer = al_create_timer(1.0 / FPS);
    ALLEGRO_EVENT_QUEUE *event_queue = al_create_event_queue();
    al_register_event_source(event_queue, al_get_keyboard_event_source());
    al_register_event_source(event_queue, al_get_timer_event_source(timer));
    al_register_event_source(event_queue, al_get_display_event_source(display));
    al_register_event_source(event_queue, al_get_mouse_event_source());

    al_start_timer(timer);

    while(!done){
        ALLEGRO_EVENT events;
        al_wait_for_event(event_queue, &events);
        al_get_keyboard_state(&keyState);

        if(events.type == ALLEGRO_EVENT_KEY_UP){
            switch(events.keyboard.keycode)
            {
            case ALLEGRO_KEY_ESCAPE:
                done = true;
            }
        }else if(events.type == ALLEGRO_EVENT_DISPLAY_CLOSE){
            done = true;
        }else if(events.type == ALLEGRO_EVENT_TIMER){
            active = true;
            prevDir = dir;
            if(al_key_down(&keyState, ALLEGRO_KEY_S)){
                y += moveSpeed;
                dir = S;
            }else if(al_key_down(&keyState, ALLEGRO_KEY_W)){
                y -= moveSpeed;
                dir = W;
            }else if(al_key_down(&keyState, ALLEGRO_KEY_D)){
                x += moveSpeed;
                dir = D;
            }else if(al_key_down(&keyState, ALLEGRO_KEY_A)){
                x -= moveSpeed;
                dir = A;
            }else if(al_key_down(&keyState, ALLEGRO_KEY_SPACE) && !startAnimation){
                startAnimation = true;
            }else{
                active = false;
            }

            if(startAnimation){
                imageNumber++;
                if(imageNumber >= source.size()){
                    imageNumber = -1;
                    startAnimation = false;
                }
            }
            draw = true;
        }

        if(draw){
            if(!startAnimation){
                al_draw_bitmap(person, x, y, 0);
            }else{
                al_draw_bitmap_region(person, source[imageNumber], 0, width[imageNumber], al_get_bitmap_height(person), x, y, 0);
            }
            al_flip_display();
            al_clear_to_color(al_map_rgb(0, 0, 0));
        }
    }
    al_destroy_display(display);
    al_destroy_timer(timer);
    //for(int i = 0; i < 16; i++){
    //    al_destroy_bitmap(playerWalk[i]);
    //}
    al_destroy_event_queue(event_queue);
    return 0;
}