Allegro 5 Audio Assertion Fail - c++

Question

I'm wondering if anyone can point me in the right direction for this error.
I am learning 2D game programming using Allegro 5 installed in Visual Studio 2010.
I have been following a tutorial series and everything has been fine until the last lesson.
The final code will build successfully. The executable will load but will crash out when I hit the space bar to fire a bullet (it's a side shooter game). I get the following error:
"Assertion failed: spl, file allegro-git\addons\audio\kgm_sample.c line 321"
It obviously has something to do with the bullet sample sound linked in with the key press.
If I comment out the line: al_play_sample(shot, 1, 0, 1, ALLEGRO_PLAYMODE_ONCE, 0); in the FireBullet() function, then the game will play fine (without the bullet sound).
I have searched everywhere and cannot find a solution.
Here is the complete code for the game:
#include <allegro5\allegro.h>
#include <allegro5\allegro_primitives.h>
#include <allegro5\allegro_font.h>
#include <allegro5\allegro_ttf.h>
#include <allegro5\allegro_image.h>
#include <allegro5\allegro_audio.h>
#include <allegro5\allegro_acodec.h>
#include "objects.h"
//GLOBALS==============================
const int WIDTH = 800;
const int HEIGHT = 400;
const int NUM_BULLETS = 5;
const int NUM_COMETS = 10;
const int NUM_EXPLOSIONS = 5;
enum STATE{TITLE, PLAYING, LOST};
enum KEYS{UP, DOWN, LEFT, RIGHT, SPACE};
bool keys[5] = {false, false, false, false, false};
SpaceShip ship;
Bullet bullets[NUM_BULLETS];
Comet comets[NUM_COMETS];
Explosion explosions[NUM_EXPLOSIONS];
ALLEGRO_SAMPLE *shot = NULL;
ALLEGRO_SAMPLE *boom = NULL;
ALLEGRO_SAMPLE *song = NULL;
ALLEGRO_SAMPLE_INSTANCE *songInstance = NULL;
//prototypes
void InitShip(SpaceShip &ship, ALLEGRO_BITMAP *image);
void ResetShipAnimation(SpaceShip &ship, int position);
void DrawShip(SpaceShip &ship);
void MoveShipUp(SpaceShip &ship);
void MoveShipDown(SpaceShip &ship);
void MoveShipLeft(SpaceShip &ship);
void MoveShipRight(SpaceShip &ship);
void InitBullet(Bullet bullet[], int size);
void DrawBullet(Bullet bullet[], int size);
void FireBullet(Bullet bullet[], int size, SpaceShip &ship);
void UpdateBullet(Bullet bullet[], int size);
void CollideBullet(Bullet bullet[], int bSize, Comet comets[], int cSize, SpaceShip &ship, Explosion explosions[], int eSize);
void InitComet(Comet comets[], int size, ALLEGRO_BITMAP *image);
void DrawComet(Comet comets[], int size);
void StartComet(Comet comets[], int size);
void UpdateComet(Comet comets[], int size);
void CollideComet(Comet comets[], int cSize, SpaceShip &ship, Explosion explosions[], int eSize);
void InitExplosions(Explosion explosions[], int size, ALLEGRO_BITMAP *image);
void DrawExplosions(Explosion explosions[], int size);
void StartExplosions(Explosion explosions[], int size, int x, int y);
void UpdateExplosions(Explosion explosions[], int size);
void InitBackground(Background &back, float x, float y, float velX, float velY, int width, int height, int dirX, int dirY, ALLEGRO_BITMAP *image);
void UpdateBackground(Background &back);
void DrawBackground(Background &back);
void ChangeState(int &state, int newState);
int main(void)
{
//primitive variable
bool done = false;
bool redraw = true;
const int FPS = 60;
int state = -1;
//object variables
Background BG;
Background MG;
Background FG;
//Allegro variables
ALLEGRO_DISPLAY *display = NULL;
ALLEGRO_EVENT_QUEUE *event_queue = NULL;
ALLEGRO_TIMER *timer = NULL;
ALLEGRO_FONT *font18 = NULL;
ALLEGRO_BITMAP *shipImage;
ALLEGRO_BITMAP *cometImage;
ALLEGRO_BITMAP *expImage;
ALLEGRO_BITMAP *title = NULL;
ALLEGRO_BITMAP *lost = NULL;
ALLEGRO_BITMAP *bgImage = NULL;
ALLEGRO_BITMAP *mgImage = NULL;
ALLEGRO_BITMAP *fgImage = NULL;
//Initialization Functions
if(!al_init()) //initialize Allegro
return -1;
display = al_create_display(WIDTH, HEIGHT); //create our display object
if(!display) //test display object
return -1;
al_init_primitives_addon();
al_install_keyboard();
al_init_font_addon();
al_init_ttf_addon();
al_init_image_addon();
al_install_audio();
al_init_acodec_addon();
event_queue = al_create_event_queue();
timer = al_create_timer(1.0 / FPS);
shipImage = al_load_bitmap("spaceship_by_arboris.png");
al_convert_mask_to_alpha(shipImage, al_map_rgb(255, 0, 255));
cometImage = al_load_bitmap("asteroids.png");
expImage = al_load_bitmap("explosion.png");
title = al_load_bitmap("Shooter_Title.png");
lost = al_load_bitmap("Shooter_Lose.png");
bgImage = al_load_bitmap("starBG.png");
mgImage = al_load_bitmap("starMG.png");
fgImage = al_load_bitmap("starFG.png");
al_reserve_samples(10);
shot = al_load_sample("shot.ogg");
boom = al_load_sample("explosion.wav");
song = al_load_sample("war.wav");
songInstance = al_create_sample_instance(song);
al_set_sample_instance_playmode(songInstance, ALLEGRO_PLAYMODE_LOOP);
al_attach_sample_instance_to_mixer(songInstance, al_get_default_mixer());
srand(time(NULL));
ChangeState(state, TITLE);
InitShip(ship, shipImage);
InitBullet(bullets, NUM_BULLETS);
InitComet(comets, NUM_COMETS, cometImage);
InitExplosions(explosions, NUM_EXPLOSIONS, expImage);
InitBackground(BG, 0, 0, 1, 0, 800, 400, -1, 1, bgImage);
InitBackground(MG, 0, 0, 2, 0, 2400, 400, -1, 1, mgImage);
InitBackground(FG, 0, 0, 4, 0, 2400, 400, -1, 1, fgImage);
font18 = al_load_font("arial.ttf", 18, 0);
al_register_event_source(event_queue, al_get_keyboard_event_source());
al_register_event_source(event_queue, al_get_timer_event_source(timer));
al_register_event_source(event_queue, al_get_display_event_source(display));
al_start_timer(timer);
while(!done)
{
ALLEGRO_EVENT ev;
al_wait_for_event(event_queue, &ev);
if(ev.type == ALLEGRO_EVENT_TIMER)
{
redraw = true;
if(keys[UP])
MoveShipUp(ship);
else if(keys[DOWN])
MoveShipDown(ship);
else
ResetShipAnimation(ship, 1);
if(keys[LEFT])
MoveShipLeft(ship);
else if(keys[RIGHT])
MoveShipRight(ship);
else
ResetShipAnimation(ship, 2);
if(state == TITLE)
{}
else if(state == PLAYING)
{
UpdateBackground(BG);
UpdateBackground(MG);
UpdateBackground(FG);
UpdateExplosions(explosions, NUM_EXPLOSIONS);
UpdateBullet(bullets, NUM_BULLETS);
StartComet(comets, NUM_COMETS);
UpdateComet(comets, NUM_COMETS);
CollideBullet(bullets, NUM_BULLETS, comets, NUM_COMETS, ship, explosions, NUM_EXPLOSIONS);
CollideComet(comets, NUM_COMETS, ship, explosions, NUM_EXPLOSIONS);
if(ship.lives <= 0)
ChangeState(state, LOST);
}
else if(state == LOST)
{}
}
else if(ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
{
done = true;
}
else if(ev.type == ALLEGRO_EVENT_KEY_DOWN)
{
switch(ev.keyboard.keycode)
{
case ALLEGRO_KEY_ESCAPE:
done = true;
break;
case ALLEGRO_KEY_UP:
keys[UP] = true;
break;
case ALLEGRO_KEY_DOWN:
keys[DOWN] = true;
break;
case ALLEGRO_KEY_LEFT:
keys[LEFT] = true;
break;
case ALLEGRO_KEY_RIGHT:
keys[RIGHT] = true;
break;
case ALLEGRO_KEY_SPACE:
keys[SPACE] = true;
if(state == TITLE)
ChangeState(state, PLAYING);
else if(state ==PLAYING)
FireBullet(bullets, NUM_BULLETS, ship);
else if(state == LOST)
ChangeState(state, PLAYING);
break;
}
}
else if(ev.type == ALLEGRO_EVENT_KEY_UP)
{
switch(ev.keyboard.keycode)
{
case ALLEGRO_KEY_ESCAPE:
done = true;
break;
case ALLEGRO_KEY_UP:
keys[UP] = false;
break;
case ALLEGRO_KEY_DOWN:
keys[DOWN] = false;
break;
case ALLEGRO_KEY_LEFT:
keys[LEFT] = false;
break;
case ALLEGRO_KEY_RIGHT:
keys[RIGHT] = false;
break;
case ALLEGRO_KEY_SPACE:
keys[SPACE] = false;
break;
}
}
if(redraw && al_is_event_queue_empty(event_queue))
{
redraw = false;
if(state == TITLE)
{
al_draw_bitmap(title, 0, 0, 0);
}
else if(state == PLAYING)
{
DrawBackground(BG);
DrawBackground(MG);
DrawBackground(FG);
DrawShip(ship);
DrawBullet(bullets, NUM_BULLETS);
DrawComet(comets, NUM_COMETS);
DrawExplosions(explosions, NUM_EXPLOSIONS);
al_draw_textf(font18, al_map_rgb(255, 0, 255), 5, 5, 0, "Player has %i lives left. Player has destroyed %i objects", ship.lives, ship.score);
}
else if(state == LOST)
{
al_draw_bitmap(lost, 0, 0, 0);
al_draw_textf(font18, al_map_rgb(0, 255, 255), WIDTH - 10, 20, ALLEGRO_ALIGN_RIGHT, "Final Score: %i", ship.score);
}
al_flip_display();
al_clear_to_color(al_map_rgb(0,0,0));
}
}
al_destroy_sample(shot);
al_destroy_sample(boom);
al_destroy_sample(song);
al_destroy_sample_instance(songInstance);
al_destroy_bitmap(bgImage);
al_destroy_bitmap(mgImage);
al_destroy_bitmap(fgImage);
al_destroy_bitmap(title);
al_destroy_bitmap(lost);
al_destroy_bitmap(expImage);
al_destroy_bitmap(cometImage);
al_destroy_bitmap(shipImage);
al_destroy_event_queue(event_queue);
al_destroy_timer(timer);
al_destroy_font(font18);
al_destroy_display(display); //destroy our display object
return 0;
}
void InitShip(SpaceShip &ship, ALLEGRO_BITMAP *image = NULL) {
ship.x = 20;
ship.y = HEIGHT / 2;
ship.ID = PLAYER;
ship.lives = 3;
ship.speed = 6;
ship.boundx = 10;
ship.boundy = 12;
ship.score = 0;
ship.maxFrame = 3;
ship.curFrame = 0;
ship.frameCount = 0;
ship.frameDelay = 50;
ship.frameWidth = 44;
ship.frameHeight = 41;
ship.animationColumns = 3;
ship.animationDirection = 1;
ship.animationRow = 1;
if(image != NULL)
ship.image = image;
}
void ResetShipAnimation(SpaceShip &ship, int position)
{
if(position == 1)
ship.animationRow = 1;
else
ship.curFrame = 0;
}
void DrawShip(SpaceShip &ship)
{
int fx =(ship.curFrame % ship.animationColumns) * ship.frameWidth;
int fy = ship.animationRow * ship.frameHeight;
al_draw_bitmap_region(ship.image, fx, fy, ship.frameWidth,
ship.frameHeight, ship.x - ship.frameWidth / 2, ship.y - ship.frameHeight / 2, 0);
/*al_draw_filled_rectangle(ship.x - ship.boundx, ship.y - ship.boundy, ship.x + ship.boundx,
ship.y + ship.boundy, al_map_rgba(255, 0, 255, 100));*/
}
void MoveShipUp(SpaceShip &ship)
{
ship.animationRow = 0;
ship.y -= ship.speed;
if(ship.y < 0)
ship.y = 0;
}
void MoveShipDown(SpaceShip &ship)
{
ship.animationRow = 2;
ship.y += ship.speed;
if(ship.y > HEIGHT)
ship.y = HEIGHT;
}
void MoveShipLeft(SpaceShip &ship)
{
ship.curFrame = 2;
ship.x -= ship.speed;
if(ship.x < 0)
ship.x = 0;
}
void MoveShipRight(SpaceShip &ship)
{
ship.curFrame = 1;
ship.x += ship.speed;
if(ship.x > 300)
ship.x = 300;
}
void InitBullet(Bullet bullet[], int size)
{
for(int i = 0; i < size; i++)
{
bullet[i].ID = BULLET;
bullet[i].speed = 10;
bullet[i].live = false;
}
}
void DrawBullet(Bullet bullet[], int size)
{
for( int i = 0; i < size; i++)
{
if(bullet[i].live)
al_draw_filled_circle(bullet[i].x, bullet[i].y, 2, al_map_rgb(255, 255, 255));
}
}
void FireBullet(Bullet bullet[], int size, SpaceShip &ship)
{
for( int i = 0; i < size; i++)
{
if(!bullet[i].live)
{
bullet[i].x = ship.x + 17;
bullet[i].y = ship.y;
bullet[i].live = true;
al_play_sample(shot, 1, 0, 1, ALLEGRO_PLAYMODE_ONCE, 0);
break;
}
}
}
void UpdateBullet(Bullet bullet[], int size)
{
for(int i = 0; i < size; i++)
{
if(bullet[i].live)
{
bullet[i].x += bullet[i].speed;
if(bullet[i].x > WIDTH)
bullet[i].live = false;
}
}
}
void CollideBullet(Bullet bullet[], int bSize, Comet comets[], int cSize, SpaceShip &ship, Explosion explosions[], int eSize)
{
for(int i = 0; i < bSize; i++)
{
if(bullet[i].live)
{
for(int j =0; j < cSize; j++)
{
if(comets[j].live)
{
if(bullet[i].x > (comets[j].x - comets[j].boundx) &&
bullet[i].x < (comets[j].x + comets[j].boundx) &&
bullet[i].y > (comets[j].y - comets[j].boundy) &&
bullet[i].y < (comets[j].y + comets[j].boundy))
{
bullet[i].live = false;
comets[j].live = false;
ship.score++;
StartExplosions(explosions, eSize, bullet[i].x, bullet[i].y);
al_play_sample(boom, 1, 0, 1, ALLEGRO_PLAYMODE_ONCE, 0);
}
}
}
}
}
}
void InitComet(Comet comets[], int size, ALLEGRO_BITMAP *image = NULL)
{
for(int i = 0; i < size; i++)
{
comets[i].ID = ENEMY;
comets[i].live = false;
comets[i].speed = 5;
comets[i].boundx = 35;
comets[i].boundy = 35;
comets[i].maxFrame = 143;
comets[i].curFrame = 0;
comets[i].frameCount = 0;
comets[i].frameDelay = 2;
comets[i].frameWidth = 96;
comets[i].frameHeight = 96;
comets[i].animationColumns = 21;
if(rand() % 2)
comets[i].animationDirection = 1;
else
comets[i].animationDirection = -1;
if(image != NULL)
comets[i].image = image;
}
}
void DrawComet(Comet comets[], int size)
{
for(int i = 0; i < size; i++)
{
if(comets[i].live)
{
int fx = (comets[i].curFrame % comets[i].animationColumns) * comets[i].frameWidth;
int fy = (comets[i].curFrame / comets[i].animationColumns) * comets[i].frameHeight;
al_draw_bitmap_region(comets[i].image, fx, fy, comets[i].frameWidth,
comets[i].frameHeight, comets[i].x - comets[i].frameWidth / 2, comets[i].y - comets[i].frameHeight / 2, 0);
/*al_draw_filled_rectangle(comets[i].x - comets[i].boundx, comets[i].y - comets[i].boundy, comets[i].x + comets[i].boundx,
comets[i].y + comets[i].boundy, al_map_rgba(255, 0, 255, 100));*/
}
}
}
void StartComet(Comet comets[], int size)
{
for(int i = 0; i < size; i++)
{
if(!comets[i].live)
{
if(rand() % 500 == 0)
{
comets[i].live = true;
comets[i].x = WIDTH;
comets[i].y = 30 + rand() % (HEIGHT - 60);
break;
}
}
}
}
void UpdateComet(Comet comets[], int size)
{
for(int i = 0; i < size; i++)
{
if(comets[i].live)
{
if(++comets[i].frameCount >= comets[i].frameDelay)
{
comets[i].curFrame += comets[i].animationDirection;
if(comets[i].curFrame >= comets[i].maxFrame)
comets[i].curFrame = 0;
else if( comets[i].curFrame <= 0)
comets[i].curFrame = comets[i].maxFrame - 1;
comets[i].frameCount = 0;
}
comets[i].x -= comets[i].speed;
}
}
}
void CollideComet(Comet comets[], int cSize, SpaceShip &ship, Explosion explosions[], int eSize)
{
for(int i = 0; i < cSize; i++)
{
if(comets[i].live)
{
if(comets[i].x - comets[i].boundx < ship.x + ship.boundx &&
comets[i].x + comets[i].boundx > ship.x - ship.boundx &&
comets[i].y - comets[i].boundy < ship.y + ship.boundy &&
comets[i].y + comets[i].boundy > ship.y - ship.boundy)
{
ship.lives--;
comets[i].live = false;
StartExplosions(explosions, eSize, ship.x, ship.y);
al_play_sample(boom, 1, 0, 1, ALLEGRO_PLAYMODE_ONCE, 0);
}
else if(comets[i].x < 0)
{
comets[i].live = false;
ship.lives--;
}
}
}
}
void InitExplosions(Explosion explosions[], int size, ALLEGRO_BITMAP *image = NULL)
{
for(int i = 0; i < size; i++)
{
explosions[i].live = false;
explosions[i].maxFrame = 31;
explosions[i].curFrame = 0;
explosions[i].frameCount = 0;
explosions[i].frameDelay = 1;
explosions[i].frameWidth = 128;
explosions[i].frameHeight = 128;
explosions[i].animationColumns = 8;
explosions[i].animationDirection = 1;
if(image != NULL)
explosions[i].image = image;
}
}
void DrawExplosions(Explosion explosions[], int size)
{
for(int i = 0; i < size; i++)
{
if(explosions[i].live)
{
int fx = (explosions[i].curFrame % explosions[i].animationColumns) * explosions[i].frameWidth;
int fy = (explosions[i].curFrame / explosions[i].animationColumns) * explosions[i].frameHeight;
al_draw_bitmap_region(explosions[i].image, fx, fy, explosions[i].frameWidth,
explosions[i].frameHeight, explosions[i].x - explosions[i].frameWidth / 2, explosions[i].y - explosions[i].frameHeight / 2, 0);
}
}
}
void StartExplosions(Explosion explosions[], int size, int x, int y)
{
for(int i = 0; i < size; i++)
{
if(!explosions[i].live)
{
explosions[i].live = true;
explosions[i].x = x;
explosions[i].y = y;
break;
}
}
}
void UpdateExplosions(Explosion explosions[], int size)
{
for(int i = 0; i < size; i++)
{
if(explosions[i].live)
{
if(++explosions[i].frameCount >= explosions[i].frameDelay)
{
explosions[i].curFrame += explosions[i].animationDirection;
if(explosions[i].curFrame >= explosions[i].maxFrame)
{
explosions[i].curFrame = 0;
explosions[i].live = false;
}
explosions[i].frameCount = 0;
}
}
}
}
void InitBackground(Background &back, float x, float y, float velx, float vely, int width, int height, int dirX, int dirY, ALLEGRO_BITMAP *image)
{
back.x = x;
back.y = y;
back.velX = velx;
back.velY = vely;
back.width = width;
back.height = height;
back.dirX = dirX;
back.dirY = dirY;
back.image = image;
}
void UpdateBackground(Background &back)
{
back.x += back.velX * back.dirX;
if(back.x + back.width <= 0)
back.x = 0;
}
void DrawBackground(Background &back)
{
al_draw_bitmap(back.image, back.x, back.y, 0);
if(back.x + back.width < WIDTH)
al_draw_bitmap(back.image, back.x + back.width, back.y, 0);
}
void ChangeState(int &state, int newState)
{
if(state == TITLE)
{}
else if(state == PLAYING)
{
al_stop_sample_instance(songInstance);
}
else if(state == LOST)
{}
state = newState;
if(state == TITLE)
{}
else if(state == PLAYING)
{
InitShip(ship);
InitBullet(bullets, NUM_BULLETS);
InitComet(comets, NUM_COMETS);
InitExplosions(explosions, NUM_EXPLOSIONS);
al_play_sample_instance(songInstance);
}
else if(state == LOST)
{}
}

Answer 1

Check that a pointer you are using is not NULL when you try to load the file. If it stays NULL then that exception is always thrown because the system will try to read from memory address 0x0 which frankly does not exist