LlSitTarget/GetSitTarget

<lsl> list GetSitTarget(integer prim, key av) {//WARNING: This function is very good but not perfect. Do not repeatedly pass GetSitTarget to llSitTarget or UpdateSitTarget.

//Do not use this on moving avatars or objects, the results will very likely be wrong.
   vector tp = llGetAgentSize(av);
   if(tp)
   {//llGetObjectDetails is used so the av is not required to be seated on the object with the sit target.
       list details = llGetLinkPrimitiveParams(prim, [PRIM_POSITION, PRIM_ROTATION]) + llGetObjectDetails(av, [OBJECT_POS, OBJECT_ROT]);
       rotation f = llList2Rot(details, 1);
       rotation r = llList2Rot(details, 3) / f;
       float fAdjust = ((((0.008906 * tp.z) + -0.049831) * tp.z) + 0.088967) * tp.z;
       return [((llList2Vector(details, 2) - llList2Vector(details, 0)) / f) + (llRot2Up(r) * fAdjust) - <0.0, 0.0, 0.4>, r];
   }
   return [];

}//Written by Strife Onizuka, size adjustment provided by Talarus Luan

//Sets / Updates the sit target moving the avatar on it if necessary. UpdateLinkSitTarget(integer link, vector pos, rotation rot) {//Using this while the object is moving may give unpredictable results.

   llLinkSitTarget(link, pos, rot);//Set the sit target
   key user = llAvatarOnLinkSitTarget(link);
   if(user)//true if there is a user seated on the sittarget, if so update their position
   {
       vector size = llGetAgentSize(user);
       if(size)//This tests to make sure the user really exists.
       {
           integer linkNum = llGetNumberOfPrims();
           do
           {
               if(user == llGetLinkKey( linkNum ))//just checking to make sure the index is valid.
               {
                   //We need to make the position and rotation local to the current prim
                   list local;
                   if(llGetLinkKey(link) != llGetLinkKey(1))//only need the local rot if it's not the root.
                       local = llGetLinkPrimitiveParams(link, [PRIM_POS_LOCAL, PRIM_ROT_LOCAL]);
                   float fAdjust = ((((0.008906 * size.z) + -0.049831) * size.z) + 0.088967) * size.z;
                   llSetLinkPrimitiveParamsFast(linkNum, [
                           PRIM_POS_LOCAL, ((pos + <0.0,0.0,0.4> - (llRot2Up(rot) * fAdjust)) * llList2Rot(local, 1)) + llList2Vector(local, 0),
                           PRIM_ROT_LOCAL, rot * llList2Rot(local, 1)
                       ]);
                   jump end;//cheaper but a tad slower then return
               }
           }while( --linkNum );
       }
       else
       {//It is rare that the sit target will bork but it does happen, this can help to fix it.
           llUnSit(user);
       }
   }
   @end;

}//Written by Strife Onizuka, size adjustment provided by Talarus Luan

default {

   touch_start(integer c) {
       integer link = llDetectedLinkNumber(0);
       list vr = GetSitTarget(link, llDetectedKey(0));
       if(vr != []) {
           UpdateLinkSitTarget(link, llList2Vec(vr, 0), llList2Rot(vr, 1));
       }
   }

} </lsl>