Allegro Mouse Events Lesson 5

// gcc -Wall 4.c -o 4 $(pkg-config --libs allegro-5.0 allegro_image-5.0 allegro_primitives-5.0)

#define ALLEGRO_STATICLINK
#include <allegro5/allegro.h>
#include <allegro5/allegro_primitives.h>

int main() {

    ALLEGRO_DISPLAY *display;
    ALLEGRO_EVENT_QUEUE *event_queue = NULL;

    if(!al_init()) {
        return -1;
    }

    int win_x = 400;
    int win_y = 400;

    display = al_create_display(win_x, win_y);

    if(!display) {
        return -1;
    }

    al_init_primitives_addon();
    al_install_mouse();

    event_queue = al_create_event_queue();
    al_register_event_source(event_queue, al_get_mouse_event_source());
    al_register_event_source(event_queue, al_get_display_event_source(display));

    bool user_exit = false;

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

        // to close the program with 'x' button of window, need to initialize al_register_event_source
        if(ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE) {
            user_exit = true;
        }

        int pos_x;
        int pos_y;
        bool draw = true;

        if(ev.type == ALLEGRO_EVENT_MOUSE_AXES) {
            pos_x = ev.mouse.x;
            pos_y = ev.mouse.y;
        } else if(ev.type == ALLEGRO_EVENT_MOUSE_BUTTON_DOWN) {
            if(ev.mouse.button) {
                draw = !draw;
            }
        }

        if(draw) {
            al_hide_mouse_cursor(display);
            al_draw_filled_circle(pos_x, pos_y, 10, al_map_rgb(0, 255,0));
        } else {
            al_show_mouse_cursor(display);
        }

        al_flip_display();
        al_clear_to_color(al_map_rgb(24, 24, 24));
    }

    al_destroy_event_queue(event_queue);
    al_uninstall_keyboard();
    al_destroy_display(display);

    return 0;
}