Game object interact distance

[~Unknown~]

I searched this form for any information about this but didn't anything all that helpful aside from ways to interact with objects. My question is do game objects (ie Flag in WSG) have some property that will let the client know how close you need to be to interact with said object. Currently, I'm only using memory reads/writes but will probably use an Endscene hook eventually so all solutions are welcome.


Thanks.

[DarkLinux]

Looks at mouse over interact...

[~Unknown~]

Looks at mouse over interact...

Hmm...So I tried to look at the now restricted function InteractUnit in the wow api. Hex Rays has it shown like this:

signed int __cdecl Script_InteractUnit(int a1)
{
  signed int result; // eax@2
  char *v2; // esi@3
  __int64 v3; // qax@4
  int v4; // eax@5
  int v5; // [sp+Ch] [bp-4h]@0

  if ( lua_isstring(a1, 1) )
  {
    v2 = (char *)lua_tolstring(a1, 1, 0);
    if ( strcasecmp(v2, "mouseover") )
    {
      v4 = FrameScript::GetParamValue(a1, 2, 0);
      LODWORD(v3) = CGGameUI::ClosestObjectMatch(v2, 1, 0, v4, COERCE_INT(3.4028235e38), 0);
    }
    else
    {
      v3 = qword_AD5648;
    }
    if ( dword_9366B4 )
    {
      CGGameUI::ShowBlockedActionFeedback(0, 0);
      result = 0;
    }
    else
    {
      if ( sub_4D7480(v3) )
      {
        lua_pushnumber(a1, 1.0);
        result = 1;
      }
      else
      {
        lua_pushnil(a1);
        result = 1;
      }
    }
  }
  else
  {
    luaL_error(a1, "Usage: InteractUnit(unitToken[, exactMatch])", v5);
    result = 0;
  }
  return result;
}

I note that the first check is to see whether or not we are interacting with mouseover and if so to load the closest object match. The next check on dword_9366B4 leads me to believe the code is checking to see if normal code is trying to call this function since it is restricted aside from blizzard code. If not it calls the function sub_4D7480 on the object and if it returns true it will push the value of 1 as success. Looking at the function sub_4D7480 I get this:

void *__cdecl sub_4D7480(__int64 a1)
{
  __int64 v1; // qax@1
  void *v2; // eax@1
  void *result; // eax@2
  void *v4; // esi@4
  int v5; // eax@6

  LODWORD(v1) = ClntObjMgrGetActivePlayer();
  v2 = ClntObjMgrObjectPtr(v1, TYPEMASK_PLAYER);
  if ( !v2 || *((_BYTE *)v2 + 4105) & 0x40 )
  {
    result = (void *)1;
  }
  else
  {
    result = ClntObjMgrObjectPtr(a1, TYPEMASK_OBJECT);
    v4 = result;
    if ( result )
    {
      if ( *(_WORD *)(*((_DWORD *)result + 3) + 16) != 9
        || (v5 = *((_DWORD *)result + 583)) == 0
        || !(*(_DWORD *)(v5 + 12) & 0x20000000) )
        CGGameUI::Target(a1);
      (*(void (__thiscall **)(void *))(*(_DWORD *)v4 + 180))(v4);
      result = (void *)1;
    }
  }
  return result;
}

After studying this mess for quite awhile I couldn't seem to make heads or tails of an actual distance check on the "thing" that is being interacted with. Sorry to request so much spoonfeeding, but my reversing skills aren't quite up to par.

[sitnspinlock]

hey, was porting parts of my debugger to x64 and figured i would trace it for you quick ;p

the conditional jump at 0x59EF1D (400000 imagebase) is taken if you are not within range, and not taken otherwise. so check the scalar single float comparison above it

[~Unknown~]

hey, was porting parts of my debugger to x64 and figured i would trace it for you quick ;p

the conditional jump at 0x59EF1D (400000 imagebase) is taken if you are not within range, and not taken otherwise. so check the scalar single float comparison above it

Heh, I got all excited when someone posted another "hint" to my problem. Then I came to this beast:



Needless to say, I really hope you didn't actually have use that section in any shape or form for your application or perhaps there's some way you smarter people work with it. Anyway thanks for the good laugh.

[Bananenbrot]

The lower part just multiplies the vector (v25, v26, v27) with the inverse matrix of v35 and compares the result vector to a bounding box given by v46 - v51.
Seems that v43 is sth related to the interaction distance.
Could be horribly wrong because I didn't ever mess with WoW's matrix system.

[MaiN]

It's stored in the game object sub obj base class (fishing bobber, goober, fishing pools etc. they all inherit from this). Hint: Reverse the huge switch in the CGGameObject_C ctor.

[sitnspinlock]

forcing that function to return without checking has some interesting side effects ;p

probably works for flags too. didn't check. but you could probably snipe it from across the map