I've been learning some game programming with allegro lately and I've run into a problem. My "game" is a compile type of the many tutorials I learnt uptil now. Anyway, I ran into a function problem with Allegro. My first code was this:
#include <allegro.h>
#include <sstream>
#include <string>
#include <cstring>
#include <fstream>
volatile bool Close = false;
void handler(){
Close = true;}
/*timer*/
volatile long speed_counter = 0;
void increment_speed_counter(){
speed_counter++;
}
END_OF_FUNCTION(increment_speed_counter);
using namespace std;
int main()
{
if(!allegro_init()){
fstream error;
error.open("error_log.txt", ios::ate);
error << "ERROR: Failed to initialized allegro!!\n";
error.close();
}
install_keyboard();
install_timer();
LOCK_VARIABLE(speed_counter);
LOCK_FUNCTION(increment_speed_counter);
install_int_ex(increment_speed_counter, BPS_TO_TIMER(120));
set_color_depth(24);
set_gfx_mode(GFX_AUTODETECT_WINDOWED, 640, 480, 0, 0);
BITMAP *buffer = create_bitmap(640, 480);
BITMAP *spaceship = load_bitmap("ship.bmp", NULL); //up
BITMAP *spaceship2 = load_bitmap("ship2.bmp", NULL); //down
BITMAP *spaceship3 = load_bitmap("ship3.bmp", NULL); //right
BITMAP *spaceship4 = load_bitmap("ship4.bmp", NULL); //left
FONT *myriad = load_font("myriad.pcx", NULL, NULL);
BITMAP *meteor = load_bitmap("meteor.bmp", NULL);
BITMAP *options = create_bitmap(640, 480);
//srand(time(NULL));
LOCK_FUNCTION(handler);
//int mx = rand() % 100;
//int my = rand() % 100;
long int ship_x = 300;
long int ship_y = 200;
int Bx [1000];
int By [1000];
bool done = false;
set_close_button_callback(handler);
while(!Close){
while(speed_counter > 0){
textprintf_ex(screen, font, 200,10, makecol(255,100,200), -1, "Space Void: Asonomia");
if(ship_x >= 620){
ship_x = 620;
}
if(ship_y >= 460){
ship_y = 460;
}
if(ship_x <= 0){
ship_x = 0;
}
if(ship_y <= 0){
ship_y = 0;
}
if(key[KEY_ESC]){
Close = true;
}
if(key[KEY_LEFT]){
ship_x -=5;
clear(buffer);
draw_sprite(buffer, spaceship4, ship_x, ship_y);
blit(buffer, screen, 0,0,0,0, 640, 480);
rest(20);
}
if(key[KEY_RIGHT]){
ship_x +=5;
clear(buffer);
draw_sprite(buffer, spaceship3, ship_x, ship_y);
blit(buffer, screen, 0,0,0,0, 640, 480);
rest(20);
}
if(key[KEY_UP]){
ship_y -= 5;
clear(buffer);
draw_sprite(buffer, spaceship, ship_x, ship_y);
blit(buffer, screen, 0,0,0,0, 640, 480);
rest(20);
}
if(key[KEY_DOWN]){
ship_y += 5;
clear(buffer);
draw_sprite(buffer, spaceship2, ship_x, ship_y);
blit(buffer, screen, 0,0,0,0, 640, 480);
rest(20);
}
speed_counter--;
}
}
destroy_bitmap(spaceship);
destroy_bitmap(spaceship2);
destroy_bitmap(spaceship3);
destroy_bitmap(spaceship4);
destroy_bitmap(buffer);
return 0;
}
END_OF_MAIN()
It was very messy so I decided to clean it up a bit by adding functions.
So now it's this:
#include <allegro.h>
#include <sstream>
#include <string>
#include <cstring>
#include <fstream>
//X Button
volatile bool Close = false;
void handler(){
Close = true;}
//FPS
volatile long speed_counter = 0;
void increment_speed_counter(){
speed_counter++;
}
void initialize(){
if(!allegro_init()){
allegro_message("Error Initializing Allegro");
}
install_keyboard();
install_timer();
LOCK_VARIABLE(speed_counter);
LOCK_FUNCTION(increment_speed_counter);
install_int_ex(increment_speed_counter, BPS_TO_TIMER(60));
//Video Mode
set_color_depth(24);
set_gfx_mode(GFX_AUTODETECT_WINDOWED, 640, 480, 0,0);
}
void load_externs(){
BITMAP *buffer = create_bitmap(640, 480);
BITMAP *spaceship = load_bitmap("ship.bmp", NULL); //up
BITMAP *spaceship2 = load_bitmap("ship2.bmp", NULL); //down
BITMAP *spaceship3 = load_bitmap("ship3.bmp", NULL); //right
BITMAP *spaceship4 = load_bitmap("ship4.bmp", NULL); //left
BITMAP *meteor = load_bitmap("meteor.bmp", NULL);
BITMAP *options = create_bitmap(640, 480);
}
int main(){
initialize();
load_externs();
long int ship_x = 300;
long int ship_y = 200;
bool done = false;
set_close_button_callback(handler);
while(!Close){
while(speed_counter > 0){
textprintf_ex(screen, font, 200,10, makecol(255,100,200), -1, "Space Void: Asonomia");
if(ship_x >= 620){
ship_x = 620;
}
if(ship_y >= 460){
ship_y = 460;
}
if(ship_x <= 0){
ship_x = 0;
}
if(ship_y <= 0){
ship_y = 0;
}
if(key[KEY_ESC]){
Close = true;
}
if(key[KEY_LEFT]){
ship_x -=5;
clear(buffer);
draw_sprite(buffer, spaceship4, ship_x, ship_y);
blit(buffer, screen, 0,0,0,0, 640, 480);
rest(20);
}
if(key[KEY_RIGHT]){
ship_x +=5;
clear(buffer);
draw_sprite(buffer, spaceship3, ship_x, ship_y);
blit(buffer, screen, 0,0,0,0, 640, 480);
rest(20);
}
if(key[KEY_UP]){
ship_y -= 5;
clear(buffer);
draw_sprite(buffer, spaceship, ship_x, ship_y);
blit(buffer, screen, 0,0,0,0, 640, 480);
rest(20);
}
if(key[KEY_DOWN]){
ship_y += 5;
clear(buffer);
draw_sprite(buffer, spaceship2, ship_x, ship_y);
blit(buffer, screen, 0,0,0,0, 640, 480);
rest(20);
}
speed_counter--;
}
}
destroy_bitmap(spaceship);
destroy_bitmap(spaceship2);
destroy_bitmap(spaceship3);
destroy_bitmap(spaceship4);
destroy_bitmap(buffer);
return 0;
}
END_OF_MAIN()
I added two new functions which were "load_externs" which would load the bitmaps and "initialize" which would initialize allegro, graphics etc. Now, when I compiled it it game me the error that there were no define BITMAPs, like spaceship, buffer etc. Although, I had added the function in int main: load_externs(); and top of that it wasnt initializing allegro, which meant that it wasn't reading the functions I added in int main(), but why? I'm probably missing something out here, I'd appreciate some help, thanks. :)
EDIT: I couldn't ask this on allegro.cc as well as I already made an account there and I couldn't log in with it, same happened when I made another account. I keep getting login errors... :/ But... I know stackoverflow's awesome members are always here to help. :D
You have made the bitmaps local variables in load_externs, they won't be be visible in other functions like main.
The quickest solution is to make buffer, spaceship etc global.