Thread: Pointer Passing Problems/ General Confusion

Hi, I'm nearly finished on this little project (a maze game) I've been working on, but have come up against a stumbling block. I'll try to explain it the best I can without just posting all of the code.

Right, it all started with a simple few IF statements in the key function:

Code:

#define PLAYER '@'
#define MONSTER '#'
#define EMPTY ' '
#define OWALL '£'
#define IWALL '&'

void keyTest()
{
.......
.......
while(!done)
	{
        switcher = _getch(); 
        switch(switcher)
        {
        case UPKEY:
                            
              if(board[x][y - 1] == OWALL)
	        break;
				
	if(board[x][y - 1] == EXIT)
	{
                system("CLS");
                gotoxy(70, 25);
	         printf("YOU WIN!!!");
	         done = TRUE;
	        _getch();
	        break;
	}
			
              if(board[x][y - 1] == MONSTER)
	{             
               system("CLS");
               gotoxy(70, 25);
	     printf("YOU LOSE!!!");
	     done = TRUE;
	       _getch();
	      break;
	}
	else
		{
		board[x][y] = EMPTY;
		printf("%c", EMPTY);
		y--;
		board[x][y] = PLAYER;
		gotoxy(x, y);
		printf("%c", PLAYER);
              }
              break;
.......
.......
}

The board[x][y] is a char array that I'm using to try and randomly generate content (instead of drawing ASCII art in a text file and using a pointer).

Now the problem I had there was that the collision detection wasn't really performing and was detecting a monster hit when I was nowhere near it. I eventually figured that because I was using gotoxy for the screen positioning, the array co-ordinates were different from the values of X and Y.

To get around this, I used this:

Code:

void initBoard()
{
.......
.........
for(i = 0 ; i< XRES; i++)
	{
		for(j = 0; j< YRES; j++)
		{
			if((board[i][j]) == PLAYER)
			{
				x = i; 
				y = j;
			}
		}
	}
.....
.......
}

The next problem was passing X and Y from the initBoard function into the keyTest function. Long story short, my main function looked like this:

Code:

int main(void)
{
conWindow();
/* Seed rand */
srand(time(NULL));
title();
initBoard();
gotoxy(2, 2);
keyTest();
 return 0;
}

which meant that I had to not only pass a value into the keyTest function from the initBoard function, but also had to give it another value from main. This was messing up my program.
So my somewhat contrived solution was to pass the values from the initBoard function, into the main function, then from there into the keyTest function, which I achieved like this:

Code:

void initBoard()
{
.......................................
main(&x, &y);
..................
}

//////////////////////////////////////////////////////////
int main(int *ref, int *ref2)
{
.........
ref = &x;
ref2 = &y;
keyTest(&ref,&ref2);
.........
}

/////////////////////////////////////////////////////

void keyTest(int *pass, int *pass2)
{
..........
	x = &pass;
	y = &pass2;
..........
}

As you can probably tell, now I'm just really confused and I know that has to be a better way of doing this but can't think of a way around it.

NOTE: The ............... inside the code is to signify that there is more code there, but I'm not sure that it's relevant.

Any help/comments/musings would be greatly appreciated.

Thanks

SM

Well, the standard already lays out exactly how main() needs to be defined. One way to achieve what you're trying to do might be:

Declare x and y inside main(), pass pointers to them to your initBoard() function. Then pass them (their values, not pointers) from main() to your keyTest() function:

Code:

void initBoard(int *x, int *y)
{
.............
			if((board[i][j]) == PLAYER)
			{
				*x = i; 
				*y = j;
			}
..............
}
int main(void)
{
  int x, y;
  initBoard(&x, &y);
  keyTest(x, y);
  return 0;
}

Thanks very much for that, I can't believe that I didn't think about that first.
Much cleaner and tidier now, cheers

Is your array maybe not being initialized correctly? I imagine that you print the entire screen at some point early on. Does that show the monsters correctly? Do you maybe have an "= MONSTER" test instead of "== MONSTER" for one of the other directions?

Code:

#define PLAYER '@'
#define MONSTER '#'
#define EMPTY ' '
#define OWALL '£'
#define IWALL '&'

Walls are usually '#'s, and monsters are usually letters . . . </roguelike>

Also, I'm not sure if the pound sign is ANSI standard. http://www.fileformat.info/info/unic...00a3/index.htm It may exist in the extended ASCII. You'd have to check.

It seems to me that your code could make use of a switch statement, and definitely a function too, as mentioned.

Originally Posted by Swordsman

Well, I'm trying to say that if board[i][j] == IWALL,
make board[i+1][j] OR board[i][j+1] = IWALL.

I'm using this to look through the array for IWALLs, then place another next to them on either the X or Y axis. If that makes even a lick of sense.



Dammit!
Thought I had the answer there. Why should I only seed it once (I'm using the system clock)?

Thanks again guys

Because once the (pseudo) Random number generator is "seeded", it has a starting point. From then on, it will deliver it's best shot at random number selections. Seeding it again, is a waste of time & code - it can not improve it's performance in any way.

I'm using this to look through the array for IWALLs, then place another next to them on either the X or Y axis. If that makes even a lick of sense.

If it makes sense to you, it makes sense to me - i've never seen your game at all, so have only a slightly out of focus, idea of it.

OK, so our algo for this is:

Code:

Scan every array element
   if an IWALL is found then {
      get a random number
      
      if that random number is even,   
          put another IWALL adjacent to the first one, along the x axis
      else  /* the random number is odd */
          put another IWALL adjacent to the first one, along the y axis
      
   } /* end of if an IWALL */
} /* end of scan

That's how I understand what you're saying now. Scan would be a for loop, usually.

Sound about right?

Adak