Functions Taking Dif. Numbers of Arguments at Dif. Times?

Hi,

I've been programming a few months. Basically, I've been looking at some code for this bot in Quake 2 recently, and I've noticed that at one point in the code for it, in p_client.c, a function is declared with three arguments:

Code:

void	SelectSpawnPoint (edict_t *ent, vec3_t origin, vec3_t angles)
{
...

Yet in a header file, oak.h, it's declared with 2 arguments, ie

Code:

void SelectSpawnPoint(vec3_t origin, vec3_t angles);

And then in another source file, it's called with 2 arguments:

Code:

SelectSpawnPoint(spawn_origin, spawn_angles);

So what's going on? I thought once you'd declared your function, it had a set number of arguments to it?

Thanks.

You're probably seeing what's called function overloading.

Thanks mate. But I dunno about this. Surely if it's function overloading I should be able to call the function with 3 arguments as well as 2?

ie by doing this:

void SelectSpawnPoint(ent, vec3_t origin, vec3_t angles);

But that doesn't work. It won't compile if I do that. It tells me there are too few arguments.

Originally Posted by bengreenwood

Thanks mate. But I dunno about this. Surely if it's function overloading I should be able to call the function with 3 arguments as well as 2?

ie by doing this:

void SelectSpawnPoint(ent, vec3_t origin, vec3_t angles);

But that doesn't work. It won't compile if I do that. It tells me there are too few arguments.

The code you provided is not a call, but a prototype. Yes, you should be able to call the function using 2 or 3 arguments provided they are the correct type for that function.

Oh oops I mean... when I called it in the game I did it like this:

SelectSpawnPoint (newOak, spawn_origin, spawn_angles);

But that doesn't work. It tells me there are too few arguments for the function. I don't understand why.

The code I'm dealing with is from this zip here if you're willing to take a look:

http://www.quake2.com/dll/tutorials/bot/src.zip

In the file called oak.c, the selectspawnpoint function is called with 2 arguments. In the file p_client.c, it's called with 3 arguments.

Thanks for your help.

Originally Posted by bengreenwood

Oh oops I mean... when I called it in the game I did it like this:

SelectSpawnPoint (newOak, spawn_origin, spawn_angles);

But that doesn't work. It tells me there are too few arguments for the function. I don't understand why.

The code I'm dealing with is from this zip here if you're willing to take a look:

http://www.quake2.com/dll/tutorials/bot/src.zip

In the file called oak.c, the selectspawnpoint function is called with 2 arguments. In the file p_client.c, it's called with 3 arguments.

Thanks for your help.

Well I've searched those two files for the SelectSpawnPoint function, and I haven't seen it called with 3 arguments. I've only seen it called and defined as having 2 arguments, unless I'm missing something.

Try posting the exact error message you get from your compiler.

Thanks for doing that.

Actually I just realised something. That source code I gave you the link to is not exactly what I'm using. Basically that is for a bot designed for an old version of Quake 2 (v3.17 I think). I compiled that and when I tried it with my version of Quake 2 (v3.2), the bot didn't work.

Then I realised you can get the source code for the latest version of Quake 2 here:

ftp://ftp.idsoftware.com/idstuff/qua...e/q2src320.exe

Basically the code for the oak bot is pretty much the same as the source code for the 3.17 version of Quake 2, but with a few modifications. So I thought OK, I'll just try sticking those extra files (oak.h, oakai.c, oak.c) in the source code for Quake 2 v 3.2 , and see what happens when I compile that. Oh and I also made a few little changes to some files in the Quake 2 source as in the Quake 2 Oak 2 tutorials that are up on the tutorials section of this:

http://www.quake2.com/dll/

To my amazement it worked and I got the bot running in the game.

But the point is, if you get the source code for Quake 2 v3.2 and look in p_client.c you'll see that selectspawnpoint takes three arguments in there. Whereas in the bot.c file I'm using it only takes 2. I think maybe in 3.17 p_client.c used to have a selectspawnpoint function that only takes 2 arguments whereas in the 3.2 version of Quake 2 it takes 3. Weird because the bot still works anyway though.

Anyway thanks for your help with this. It'd be cool to be able to understand what's going on better...