[el hippo]

Warning: I am a total noob when it comes to C++ virtual functions and vtables. So please don't be too hard on me.

I have searched the internet (using all the nice search engines) and these forums without any luck. I can call things like Teleport and EyeAngles using the vtable offsets described by L Duke at http://wiki.tcwonline.org/index.php/...%28SourceMM%29 . I have also used the dlsym method of hooking functions in linux. Unfortunately both of these fail to give me access to CBaseEntity::SetGravity().

My guess is that the SetGravity function is not assessable because it is not virtual. I am assuming that I have to do the variable offset method to access and set the gravity. Unfortunately I have no idea how to come up with this offset.

Any help would be greatly appreciated.

Hippo

[c0ldfyr3]

Originally Posted by el hippo My guess is that the SetGravity function is not assessable because it is not virtual. I am assuming that I have to do the variable offset method to access and set the gravity. Unfortunately I have no idea how to come up with this offset. Any help would be greatly appreciated. Hippo

Search for signature scanning, its how you will need to access this function!

[L. Duke]

SetGravity(float) is just an inline that changes m_flGravity so a sig scan wouldn't help. I was using it directly until the last update, but now I'm using the data description map to get the offset.

void UTIL_SetGravity(edict_t *pEntity, float Gravity)
{
    //CBasePlayer *pPlayer = (CBasePlayer *)pEntity->GetUnknown()->GetBaseEntity();
    //pPlayer->SetGravity(Gravity);
    
    static int GravityOffset = 0;

    if (GravityOffset==0)
    {
        datamap_t *dmap = gVFunc.GetDataDescMap(pEntity->GetUnknown()->GetBaseEntity());
        if (dmap)
        {
            GravityOffset = UTIL_FindOffsetDMap(dmap, "m_flGravity");
        }
        else
        {
            META_LOG(g_PLAPI, "*** error *** did not obtain datamap\n");
        }
    }

    if (GravityOffset!=0)
    {
        *(float *)((char *)pEntity->GetUnknown()->GetBaseEntity() + GravityOffset ) = Gravity;
    }
    else
    {
        META_LOG(g_PLAPI, "*** error *** could not find GravityOffset\n");
    }

}

[Knagg0]

And this is what you need:

typedescription_t *FindFieldByName(const char *fieldname, datamap_t *dmap) {

	int c = dmap->dataNumFields;

	for(int i = 0; i < c; i++) {

		typedescription_t *td = &dmap->dataDesc[i];

		if(td->fieldType == FIELD_VOID) continue;

		if(td->fieldType == FIELD_EMBEDDED) {
			typedescription_t *ret = FindFieldByName(fieldname, td->td);
			if(ret) return ret;
		}

		if(!stricmp(td->fieldName, fieldname)) return td;
	}

	if(dmap->baseMap) return FindFieldByName( fieldname, dmap->baseMap );

	return NULL;
}

int UTIL_FindOffsetDMap(datamap_t *dmap, const char *fieldname) {

	typedescription_t *td = FindFieldByName(fieldname, dmap);
	if(td) return td->fieldOffset[0];

	return 0;
}

[el hippo]

L Duke & Knagg,

Thanks for all the help. Your hints and code examples worked perfectly. I always wondered what the datamap was for.

Hippo