.. index:: single: Graphics and Game Programming; Introduction =================================================== Graphics and 2D Games programming using RingAllegro =================================================== In this chapter we will learn how to use the allegro game programming library in our Ring applications. We have the file gamelib.ring that load the DLL library that contains wrappers for the Allegro functions .. code-block:: ring Load "allegro.rh" if iswindows() LoadLib("ring_allegro.dll") but ismacosx() LoadLib("libringallegro.dylib") else LoadLib("libringallegro.so") ok The file gamelib.ring uses the Load instruction to execute the file allegro.rh which is a ring source code file contains constants to be used in our programs. Then using the function LoadLib() we can load the DLL library "ring_allegro.dll". To write portable code we can change the gamelib.ring to check the platform before loading the DLL/So file. .. index:: pair: Graphics and Game Programming; Drawing, Animation and Input Drawing, Animation and Input ============================ The next example uses the Allegro library for drawing, moving objects on the screen and getting input from the keyboard and the mouse. .. code-block:: ring Load "gamelib.ring" al_init() al_init_image_addon() display = al_create_display(640,480) al_show_native_message_box(display, "Hello", "Welcome", "Using Allegro from the Ring programming language", "", 0); al_clear_to_color(al_map_rgb(0,0,255)) BOUNCER_SIZE = 40 bouncer_x = 10 bouncer_y = 20 bouncer = al_create_bitmap(BOUNCER_SIZE, BOUNCER_SIZE) al_set_target_bitmap(bouncer) al_clear_to_color(al_map_rgb(255,0,255)) for x = 1 to 30 bouncer_x += x bouncer_y += x al_set_target_bitmap(al_get_backbuffer(display)) al_clear_to_color(al_map_rgb(0,0,0)) al_draw_bitmap(bouncer, bouncer_x, bouncer_y, 0) al_draw_bitmap(bouncer, 200+bouncer_x,200+ bouncer_y, 0) al_flip_display() al_rest(0.1) next al_clear_to_color(al_map_rgb(255,255,255)) image = al_load_bitmap("man2.jpg") al_draw_bitmap(image,200,200,0) al_flip_display() al_rest(2) event_queue = al_create_event_queue() al_register_event_source(event_queue, al_get_display_event_source(display)) ev = al_new_allegro_event() timeout = al_new_allegro_timeout() al_init_timeout(timeout, 0.06) FPS = 60 timer = al_create_timer(1.0 / FPS) al_register_event_source(event_queue, al_get_timer_event_source(timer)) al_start_timer(timer) redraw = true SCREEN_W = 640 SCREEN_H = 480 BOUNCER_SIZE = 32 bouncer_x = SCREEN_W / 2.0 - BOUNCER_SIZE / 2.0 bouncer_y = SCREEN_H / 2.0 - BOUNCER_SIZE / 2.0 bouncer_dx = -4.0 bouncer_dy = 4.0 al_install_mouse() al_register_event_source(event_queue, al_get_mouse_event_source()) al_install_keyboard() al_register_event_source(event_queue, al_get_keyboard_event_source()) KEY_UP = 1 KEY_DOWN = 2 KEY_LEFT = 3 KEY_RIGHT = 4 Key = [false,false,false,false] while true al_wait_for_event_until(event_queue, ev, timeout) switch al_get_allegro_event_type(ev) on ALLEGRO_EVENT_DISPLAY_CLOSE exit on ALLEGRO_EVENT_TIMER # Animation if bouncer_x < 0 or bouncer_x > SCREEN_W - BOUNCER_SIZE bouncer_dx = -bouncer_dx ok if bouncer_y < 0 or bouncer_y > SCREEN_H - BOUNCER_SIZE bouncer_dy = -bouncer_dy ok bouncer_x += bouncer_dx bouncer_y += bouncer_dy # Keyboard if key[KEY_UP] and bouncer_y >= 4.0 bouncer_y -= 4.0 ok if key[KEY_DOWN] and bouncer_y <= SCREEN_H - BOUNCER_SIZE - 4.0 bouncer_y += 4.0 ok if key[KEY_LEFT] and bouncer_x >= 4.0 bouncer_x -= 4.0 ok if key[KEY_RIGHT] and bouncer_x <= SCREEN_W - BOUNCER_SIZE - 4.0 bouncer_x += 4.0 ok redraw = true on ALLEGRO_EVENT_MOUSE_AXES bouncer_x = al_get_allegro_event_mouse_x(ev) bouncer_y = al_get_allegro_event_mouse_y(ev) on ALLEGRO_EVENT_MOUSE_ENTER_DISPLAY bouncer_x = al_get_allegro_event_mouse_x(ev) bouncer_y = al_get_allegro_event_mouse_y(ev) on ALLEGRO_EVENT_MOUSE_BUTTON_UP exit on ALLEGRO_EVENT_KEY_DOWN switch al_get_allegro_event_keyboard_keycode(ev) on ALLEGRO_KEY_UP key[KEY_UP] = true on ALLEGRO_KEY_DOWN key[KEY_DOWN] = true on ALLEGRO_KEY_LEFT key[KEY_LEFT] = true on ALLEGRO_KEY_RIGHT key[KEY_RIGHT] = true off on ALLEGRO_EVENT_KEY_UP switch al_get_allegro_event_keyboard_keycode(ev) on ALLEGRO_KEY_UP key[KEY_UP] = false on ALLEGRO_KEY_DOWN key[KEY_DOWN] = false on ALLEGRO_KEY_LEFT key[KEY_LEFT] = false on ALLEGRO_KEY_RIGHT key[KEY_RIGHT] = false on ALLEGRO_KEY_ESCAPE exit off off if redraw and al_is_event_queue_empty(event_queue) redraw = false al_clear_to_color(al_map_rgb(0,0,0)) al_draw_bitmap(bouncer, bouncer_x, bouncer_y, 0) al_flip_display() ok callgc() end al_destroy_timer(timer) al_destroy_allegro_event(ev) al_destroy_allegro_timeout(timeout) al_destroy_event_queue(event_queue) al_destroy_bitmap(bouncer) al_destroy_bitmap(image) al_destroy_display(display) .. note:: In the previous example we used the function callgc() which is a Ring function to force calling the Garbage collector inside the While/End loop. Program Output: At first the program display a messagebox .. image:: ringalleg_shot1.jpg :alt: Displaying a messagebox from our program Then we see two rectangles are moving on the screen .. image:: ringalleg_shot2.jpg :alt: Animation - Moving two rectangles in the screen Then we see an image displayed on the screen .. image:: ringalleg_shot3.jpg :alt: Displaying an image on the screen Finally we have one rectangle, and we see it moving all of the time on the screen but we can control it using the Mouse and/or the Keyborad .. image:: ringalleg_shot4.jpg :alt: Animation and Getting Input from keyboard and the mouse to move the object .. index:: pair: Graphics and Game Programming; TrueType Fonts Using TrueType Fonts ==================== In this example we will see how to use TrueType Fonts *.ttf in our Games using Allegro .. code-block:: ring Load "gamelib.ring" al_init() al_init_font_addon() al_init_ttf_addon() display = al_create_display(800,600) al_clear_to_color(al_map_rgb(0,0,255)) font = al_load_ttf_font("pirulen.ttf",14,0 ) al_draw_text(font, al_map_rgb(255,255,255), 10, 10,ALLEGRO_ALIGN_LEFT, "Welcome to the Ring programming language") al_flip_display() al_rest(2) al_destroy_display(display) Screen Shot: .. image:: ringalleg_shot5.jpg :alt: Using TrueType Fonts .. index:: pair: Graphics and Game Programming; Playing Sound Playing Sound Files =================== The next example play a sound file .. code-block:: ring Load "gamelib.ring" al_init() al_install_audio() al_init_acodec_addon() al_reserve_samples(1) sample = al_load_sample( "footstep.wav" ) sampleid = al_new_allegro_sample_id() al_play_sample(sample, 1.0, 0.0,1.0,ALLEGRO_PLAYMODE_LOOP,sampleid) display = al_create_display(640,480) al_clear_to_color(al_map_rgb(0,0,255)) al_flip_display() al_rest(10) al_destroy_allegro_sample_id(sampleid) al_destroy_sample(sample) al_destroy_display(display) al_exit() .. index:: pair: Graphics and Game Programming; Scaling and Rotating Images Scaling and Rotating Images =========================== The next example display and rotate an image .. code-block:: ring Load "gamelib.ring" al_init() al_init_image_addon() display = al_create_display(640,480) al_set_target_bitmap(al_get_backbuffer(display)) al_clear_to_color(al_map_rgb(255,255,255)) image = al_load_bitmap("man2.jpg") al_draw_rotated_bitmap(image,0,0,250,250,150,0) al_draw_scaled_bitmap(image,0,0,250,250,20,20,400,400,0) al_flip_display() al_rest(2) al_destroy_bitmap(image) al_destroy_display(display) Screen Shot: .. image:: ringalleg_shot6.jpg :alt: Scaling and Rotating Images .. index:: pair: Graphics and Game Programming; Transparent Image Display Transparent Image ========================= The next example display image with white background on another image .. code-block:: ring Load "gamelib.ring" al_init() al_init_image_addon() display = al_create_display(640,480) imageback = al_load_bitmap("palace.jpg") al_draw_bitmap(imageback,0,0,0) image = al_load_bitmap("man4.png") al_convert_mask_to_alpha(image,al_map_rgb(255,255,255)) al_draw_bitmap(image,0,0,0) al_flip_display() al_rest(10) al_destroy_bitmap(image) al_destroy_display(display) Screen Shot: .. image:: ringalleg_shot7.jpg :alt: Transparent Image .. index:: pair: Graphics and Game Programming; Threads Using Threads ============= In this example we will learn how to use threads from the Allegro library .. code-block:: ring Load "gamelib.ring" o1 = new mythreads Func Main al_init() for k = 1 to 5 al_create_thread("o1.thread1()") al_create_thread("o1.thread2()") al_create_thread("o1.thread3()") next al_rest(2) Class Mythreads cAppName = "Threads Application" Func Thread1 for x = 1 to 5 see x + nl next See 'Thread(1) : Application Name : ' + cAppName + nl Func Thread2 for x = 1 to 5 see '*****' + x + nl next See 'Thread(2) : Application Name : ' + cAppName + nl Func Thread3 for x = 1 to 5 see '!!!!' + x + nl next See 'Thread(3) : Application Name : ' + cAppName + nl Output: .. code-block:: ring 1 2 3 4 5 Thread(1) : Application Name : Threads Application *****1 *****2 *****3 *****4 *****5 Thread(2) : Application Name : Threads Application !!!!1 !!!!2 !!!!3 !!!!4 !!!!5 Thread(3) : Application Name : Threads Application 1 2 3 4 5 Thread(1) : Application Name : Threads Application !!!!1 !!!!2 !!!!3 !!!!4 !!!!5 Thread(3) : Application Name : Threads Application *****1 *****2 *****3 *****4 *****5 Thread(2) : Application Name : Threads Application *****1 *****2 *****3 *****4 *****5 Thread(2) : Application Name : Threads Application !!!!1 !!!!2 !!!!3 !!!!4 !!!!5 Thread(3) : Application Name : Threads Application 1 2 3 4 5 Thread(1) : Application Name : Threads Application *****1 *****2 *****3 *****1 *****4 *****2 !!!!1 *****5 *****3 1 !!!!2 Thread(2) : Application Name : Threads Application 1 *****4 !!!!1 2 !!!!3 !!!!4 *****5 !!!!2 3 2 !!!!5 Thread(2) : Application Name : Threads Application !!!!3 4 3 Thread(3) : Application Name : Threads Application !!!!4 5 4 !!!!5 Thread(1) : Application Name : Threads Application 5 Thread(3) : Application Name : Threads Application Thread(1) : Application Name : Threads Application