passing pointer to change its value but stay still

Question

passing pointer to change its value but stay still

I am working on C++ with allegro library.

there is draw_tiles function.

void draw_tiles(def_sm         


        

Answer 1

You need to pass a pointer to pointer to achieve that:

void loadTilemap(int i,BITMAP ** tileLayer){
   char c[128];
   sprintf(c,TILEPATHFORMAT,i);
   *tileLayer= load_bitmap(c,NULL); 
}

loadTilemap(s_world->tilemap, &TileMap); 

That's assuming TileMap is of type BITMAP *.

Alternatively, you could simply return the BITMAP* pointer as a result of loadTilemap:

 BITMAP* loadTilemap(int i,BITMAP * tileLayer){
   char c[128];
   sprintf(c,TILEPATHFORMAT,i);
   return load_bitmap(c,NULL); 
}

TileMap = loadTilemap(s_world->tilemap, TileMap);

This would allow you to get rid of tileLayer parameter altogether, as you don't seem to be using it for anything else in loadTileMap (i.e. it's only an output parameter).