[Swixel]

This snippet friendly fire on the pyro's flamethrower, if mp_friendlyfire is set to 1. This is because Valve are doing a check further down and line and I'm not going to break half the game to give friendlyfire to one weapon. (Okay, I might, but not now.)

As a disclaimer, I'm putting this here for others who are looking for it. I am working on something with it in it, whether I finish it or get bored by something else shiny, I don't know ...

I didn't even find this request until I'd been hacking away on something totally unrelated (duel related), but I'm set

Game Data ... works as of ... well, now.

PHP Code:

// CTFFlameEntity::OnCollide(CBaseEntity *)
"CTFFlameEntity_OnCollide"
{
    "library" "server"
    "windows" "\x81\xEC\xA8\x00\x00\x00\x56\x8B\xF1\x8B\x86\xFC\x00\x00\x00\xC1\xE8\x0B\xA8\x01\x57"
    "linux" "@_ZN14CTFFlameEntity9OnCollideEP11CBaseEntity"
}

// CTFFlameEntity::OnCollideWithTeammate(CTFPlayer *)
"CTFFlameEntity_OnCollideWithTeammate"
{
    "library" "server"
    "windows" "\x56\x8B\x74\x24\x08\x57\x8B\xF9\x6A\x2A\x8B\xCE\x2A\x2A\x2A\x2A\x2A\x84\xC0\x2A\x2A\x2A\x2A\x2A\x2A\x85\xF6\x2A\x2A\x8B\x06\x8B\x50\x08\x8B\xCE\xFF\xD2\x8B\x00\x89\x44\x24\x0C\x2A\x2A"
    "linux" "@_ZN14CTFFlameEntity21OnCollideWithTeammateEP9CTFPlayer"
} 


The detour...

PHP Code:

DETOUR_DECL_MEMBER1(CTFFlameEntity_OnCollideWithTeammate, int, CBaseEntity*, pPlayer)
{
    /* Get the original result */
    int TeamCollision = DETOUR_MEMBER_CALL(CTFFlameEntity_OnCollideWithTeammate)(pPlayer);

    char *addr;
    if(!g_pGameConf->GetMemSig("CTFFlameEntity_OnCollide", (void **)&addr) || !addr)
    {
        // If it goes pear-shaped, bail by performing the default function
        META_CONPRINTF("Could not find signature for 'CTFFlameEntity_OnCollide'.\n");
        return TeamCollision;
    }
    /* predcrab to the rescue -- this calls CTFFlameEntity::OnCollide using |this|, with platform specific code. */
    union
    {
        int (VEmptyClass::*mfpOnCollide)(CBaseEntity *pPlayer);
#ifndef PLATFORM_POSIX
        void *addr;
    } u;
    u.addr = addr;
#else
        struct  
        {
            void *addr;
            intptr_t adjustor;
        } s;
    } u;
    u.s.addr = addr;
    u.s.adjustor = 0;
#endif
    return (reinterpret_cast<VEmptyClass *>(this)->*u.mfpOnCollide)(pPlayer);
    /* end predcrab to the rescue */
} 


If you want to do what I'm doing in my extension then you need a cvar (enable/disable) or two (enable/disable flamethrower "modes"). You can then check for the cvar values and do whatever you want based on that.

If my extension is disabled it kills all cvars (atm), though I'm thinking of working out a mode of individual functions (based on mode cvars and callbacks).

You can additionally detour OnCollide, if you wish to disable all damage, and just return 0 on both.

While I did find the sigs on my own, there are some people who deserve thanks...

• predcrab - for providing a large chunk of the code and helping me get the detour working;
• asherkin - for basically re-teaching me more than I've forgotten about C++, and helping me debug various parts of this, and teaching me to find sigs;
• psychonic, and Wazz - for explaining things to me and teaching me to find sigs in a sensible way.

[Thraka]

Cooooool. If someone can turn this into an extension that can be used by other plugins, that would be awesome.

[Swixel]

Originally Posted by Thraka Cooooool. If someone can turn this into an extension that can be used by other plugins, that would be awesome.

It gets a little too difficult to call detours on the fly C++ <-> Pawn... globally you can enable/disable them, you could probably even use a config (with pawn writing to it, C++ reading/updating from it), but it'd get ugly pretty quickly, and I hate file i/o

[Sir Jake]

This would be great with the warmup rounds.

[Swixel]

Well Valve checks block it from working outside of friendlyfire *anyway*, so that detour (as is) just enables the flamethrower whenever mp_friendlyfire is on. Otherwise Valve's later check (done by the CTFFlamethrower itself) disables it ...

If you're worried you could always do what I'm doing, and check against an enable cvar (or even check the detour status against mp_friendlyfire):

PHP Code:

// Somewhere up the top, nicely, to declare it
ConVar *cv_FF;

// Within the SDK_OnLoad function
    cv_FF = g_pCVar->FindVar("mp_friendlyfire");

// Within the detour
if(cv_FF->GetBool())
{
/* rest of the detour code */
}
else
{
  return TeamCollision;
} 


Or you could just destroy the detour every time cv_FF changes...

PHP Code:

// Declare this somewhere
static void FFCallback( IConVar *var, const char *pOldValue, float flOldValue )
{
    if(cv_FF->GetBool())
    {
        uradetour->EnableDetour();
    }
    else
    {
        uradetour->DisableDetour();
    }
}

// within OnLoad, after cv_FF is "found"
cv_FF->InstallChangeCallback(FFCallBack); 


* shrugs *

[asherkin]

Few short notes:

Originally Posted by Swixel PHP Code: cv_FF = g_pCVar->FindVar("mp_friendlyfire");

Make sure to check this isn't NULL.
I have had some really nasty crashes forgetting that in the past, even for valve cvars that should be there for sure.

Originally Posted by Swixel PHP Code: uradetour->Destroy();

Probably meant DisableDetour() here, destroy would free the CDetour structure, requiring you to call CreateDetour again

[Swixel]

Originally Posted by asherkin Few short notes: Make sure to check this isn't NULL. I have had some really nasty crashes forgetting that in the past, even for valve cvars that should be there for sure. Probably meant DisableDetour() here, destroy would free the CDetour structure, requiring you to call CreateDetour again

Both good points ... *edits the above*

[El Diablo War3Evo]

I know this is an old post, but I am dieing to see this working!

I would love to see this working either as a plugin or a extension.

I did find: https://www.openhub.net/p/wtff .. but i haven't learned c++ good enough to figure out how to compile it and get it going.. plus it is years old and who knows if it is any good still?

Other links:
https://forums.alliedmods.net/showthread.php?t=133740
https://bitbucket.org/aws/wtff/wiki/browse/

[friagram]

Did you check to see if it is picked up in ontakedamage_alive ?