Player Movement Problem

Player Movement Problem

edwin velasquez

Member #5,578

March 2005

i am new to game problem with allegro and i cannot get my object to move without seeing the objects remain as a move. Here is my code

1#include <allegro.h>
2 
3volatile long speed_counter = 0;
4 
5void increment_speed_counter() 
6{
7  speed_counter++; 
8}
9END_OF_FUNCTION(increment_speed_counter);
10      
11int start()
12{
13    allegro_init();
14    install_keyboard();
15    if (set_gfx_mode(GFX_AUTODETECT, 320, 240, 0, 0) < 0)
16    {
17       textout(screen, font, "Sorry your comuter does not support 320 x 240.", 0, 0, 0);
18    }
19}
20    
21void game()
22{
23     int x, y;
24     x = 0;
25     y = 0;
26     BITMAP *smallship;
27     BITMAP *buffer;
28     buffer = create_bitmap(SCREEN_W, SCREEN_H);
29     smallship = load_bitmap("airplane.bmp",0);
30     install_timer();
31     LOCK_VARIABLE(speed_counter);
32     LOCK_FUNCTION(increment_speed_counter);
33     install_int_ex(increment_speed_counter, BPS_TO_TIMER(60));
34     while (!key[KEY_ESC])
35     {
36     while (speed_counter > 0) 
37     {
38     if (key[KEY_UP])
39     y = y - 1;
40     if (key[KEY_DOWN])
41     y = y + 1;
42     if (key[KEY_LEFT])
43     x = x - 1;
44     if (key[KEY_RIGHT])
45     x = x + 1;  
46     speed_counter--;
47     }  
48     acquire_screen();
49     draw_sprite(buffer, smallship, x, y);
50     blit(buffer, screen, 0,0,0,0,320,240);
51     release_screen();               
52}    
53}
54 
55void exit()
56{
57     allegro_exit();
58}
59 
60int main(void)
61{
62    start();
63    game();
64    return 0;
65}
66END_OF_MAIN()

Can anyone tell me how i can fix this code. Thank you in advance.

Kitty Cat

Member #2,815

October 2002

Callclear_bitmap(buffer);after blitting it to the screen. Also, you shouldn't acquire the screen while you're not drawing to it. Since you're only blitting to the screen, Allegro will take care of it fine for you.

--
"Do not meddle in the affairs of cats, for they are subtle and will pee on your computer." -- Bruce Graham

edwin velasquez

Member #5,578

March 2005

thx i got it to work.

Ceagon Xylas

Member #5,495

February 2005

just a quick note: you do know that you can use the simple math operations like y+=1; right? or if you're doing increments by 1, use y++; or y--; It works exactly the same, just saves ya a little time in coding. Good luck with the game!