Hello everyone.

I am making a shot'em up game, and now i am programming the weapons. I make a class for a weapon, and the class have an ALLEGRO_BITMAP for the sprite of the shoot. My question is if it's better to load the bitmap one time as a static const member, or loading and destroying it every time the bullet is fired and destroyed.

I had try first without the static member, and it was ok, but now i try the static const way and i get and error:

class Weapon1{
private:
static const ALLEGRO_BITMAP *sprite = al_load_bitmap("sprites/bullet1.png");

......

"error C2864: 'Weapon1::sprite' : only static const integral data members can be initialized within a class"

Then i create "sprite" as static, not const, and i initialized it before the main class but i get a memory error:
"Unhandled exception at 0x00000000 in Thunder Force IV.exe: 0xC0000005: Access violation reading location 0x00000000."

class Weapon1{
private:
static ALLEGRO_BITMAP *sprite;

.....

ALLEGRO_BITMAP *Weapon1::sprite = al_load_bitmap("sprites/bullet1.png");

int main(void)
{

....

Thanks for reading, i'm awaiting your help.

You cannot load an image before you initialize Allegro.

I like to do one more thing: Only load each image file once, and then have many ALLEGRO_BITMAP pointers point to the same image.

In other words, only load the ALLEGRO_BITMAP for your bullet once, and make every bullet object use the same ALLEGRO_BITMAP.

I discovered many years ago that doing it this way gave me much better performance. I assume it's still true.

You'd use new and a loop to allocate your array of bitmaps, something like:

weapon_sprites = new ALLEGRO_BITMAP*[number_of_sprites];
for(int i = 0; i < number_of_sprites; i++) { weapon_sprites = load_sprite(...); }

If you find performance isn't as good as you like it, you may want to consider storing as many sprites as possible in a single bitmap, and use the al_hold_bitmap_drawing function to group all sprites from the same bitmap together.

A matrix is a 2D array, or if you're allocating it dynamically, you have to do the y * width + x thing.

A matrix just adds an extra *...

something like:

ALLEGRO_BITMAP ***weapon_sprites = new ALLEGRO_BITMAP**[rows];
for(int i = 0; i < rows; i++) {
   weapon_sprites[i] = new ALLEGRO_BITMAP*[columns];
   for(int j = 0; j < columns; j++) {
      weapon_sprites[i][j] = load_sprite(...);
   }
}

Thats just pseudo code. You'll have to figure out how to fit it into your own setup.

Thanks for the code. I discover what i was doing wrong and why it returned a costructor error. That confused me and it makes me crazy. I'm very grateful for your help.

I will try that functions you suggest me, but i feel a bit overwhelmed because i'm still beggining with Allegro, but i promise to learn and use these functions.

Thanks to all people that help begginers like me.