// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Child wind vane
// Not compiled or tested in-world
// Setup: Use a child arrow whose front is local +X. Owner-touch starts wind tracking once per two seconds.
// Stop / restore: Owner-touch to stop and restore the captured starting pose before removing, resetting, or relinking.
// Notes: Use a small nonphysical rezzed build with clear space. Actual prim transforms change. Original poses live only in script memory. Do not change physical status or link topology during use. Converts a world direction into the root-local frame. Calm wind keeps the last meaningful orientation; the root never rotates.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT. Not compiled or tested in-world.
vector home;
rotation rest;
integer active;
integer valid=TRUE;
default
{
    state_entry()
    {
        home=llGetLocalPos();
        rest=llGetLocalRot();
    }
    touch_start(integer count)
    {
        if(llDetectedKey(0)!=llGetOwner()||!valid||llGetLinkNumber()<2||llGetStatus(STATUS_PHYSICS))return;
        active=!active;
        if(active)
        {
            llResetTime();
            vector wind=llWind(ZERO_VECTOR);
            wind.z=0.0;
            if(llVecMag(wind)>0.01)
            {
                vector local=llVecNorm(wind)/llGetRootRotation();
                llSetLinkPrimitiveParamsFast(LINK_THIS,[PRIM_ROT_LOCAL,llRotBetween(<1.0,0.0,0.0>,local)]);
            }
            llSetTimerEvent(2);
        }
        else
        {
            llSetTimerEvent(0.0);
            llSetLinkPrimitiveParamsFast(LINK_THIS,[PRIM_POS_LOCAL,home,PRIM_ROT_LOCAL,rest]);
        }
    }
    timer()
    {
        if(llGetLinkNumber()<2||llGetStatus(STATUS_PHYSICS))
        {
            llSetTimerEvent(0.0);
            active=FALSE;
            return;
        }
        vector wind=llWind(ZERO_VECTOR);
        wind.z=0.0;
        if(llVecMag(wind)>0.01)
        {
            vector local=llVecNorm(wind)/llGetRootRotation();
            llSetLinkPrimitiveParamsFast(LINK_THIS,[PRIM_ROT_LOCAL,llRotBetween(<1.0,0.0,0.0>,local)]);
        }
    }
    changed(integer change)
    {
        if(change&CHANGED_LINK)
        {
            valid=FALSE;
            active=FALSE;
            llSetTimerEvent(0.0);
            llOwnerSay("Links changed; stopped without restoring. Reposition and reset before reuse.");
        }
    }
}