exsprite(3alleg4)						  Allegro manual						 exsprite(3alleg4)

NAME

       exsprite - Datafiles access and sprite animation. Allegro game programming library.

SYNOPSIS

       #include <allegro.h>

       Example exsprite

DESCRIPTION

       This example demonstrates how to use datafiles, various sprite drawing routines and flicker-free animation.

       Why  is	the  animate()	routine coded in that way?  As you probably know, VIDEO RAM is much slower than "normal" RAM, so it's advisable to
       reduce VRAM blits to a minimum.	Drawing sprite on the screen (meaning in VRAM) and then clearing a background for it  is  not  very  fast.
       This example uses a different method which is much faster, but require a bit more memory.

       First  the buffer is cleared (it's a normal BITMAP), then the sprite is drawn on it, and when the drawing is finished this buffer is copied
       directly to the screen. So the end result is that there is a single VRAM blit instead of blitting/clearing the  background  and	drawing  a
       sprite on it.  It's a good method even when you have to restore the background. And of course, it completely removes any flickering effect.

       When  one  uses	a  big	(ie.  800x600 background) and draws something on it, it's wise to use a copy of background somewhere in memory and
       restore background using this "virtual background". When blitting from VRAM in SVGA modes, it's probably, that  drawing	routines  have	to
       switch banks on video card. I think, I don't have to remind how slow is it.

       Note that on modern systems, the above isn't true anymore, and you usually get the best performance by caching all your animations in video
       ram and doing only VRAM->VRAM blits, so there is no more RAM->VRAM transfer at all anymore. And usually, such transfers can run in parallel
       on the graphics card's processor as well, costing virtually no main cpu time at all.  See the exaccel example for an example of this.

SEE ALSO

       BITMAP(3alleg4),   DATAFILE(3alleg4),   END_OF_FUNCTION(3alleg4),   END_OF_MAIN(3alleg4),  LOCK_FUNCTION(3alleg4),  LOCK_VARIABLE(3alleg4),
       SCREEN_H(3alleg4),  SCREEN_W(3alleg4),  allegro_error(3alleg4),	allegro_init(3alleg4),	 allegro_message(3alleg4),   blit(3alleg4),   cir-
       cle(3alleg4),   clear_bitmap(3alleg4),	clear_keybuf(3alleg4),	 create_bitmap(3alleg4),   destroy_bitmap(3alleg4),  draw_sprite(3alleg4),
       draw_sprite_h_flip(3alleg4),  draw_sprite_v_flip(3alleg4),  draw_sprite_vh_flip(3alleg4),  fixed(3alleg4),  font(3alleg4),  hline(3alleg4),
       install_int_ex(3alleg4),  install_keyboard(3alleg4),  install_sound(3alleg4),  install_timer(3alleg4),  itofix(3alleg4), key(3alleg4), key-
       pressed(3alleg4), load_datafile(3alleg4), makecol(3alleg4),  palette_color(3alleg4),  pivot_sprite(3alleg4),  pivot_sprite_v_flip(3alleg4),
       play_sample(3alleg4),   rectfill(3alleg4),   replace_filename(3alleg4),	rest(3alleg4),	screen(3alleg4),  set_gfx_mode(3alleg4),  set_pal-
       ette(3alleg4), text_height(3alleg4), textout_centre_ex(3alleg4), unload_datafile(3alleg4), vsync(3alleg4)

Allegro 							   version 4.4.2						 exsprite(3alleg4)