// Follows another object (the wandering wooden "prim man" at the Natoma sandbox): keeps a spot behind-beside it,
// turns to face where it walks, hops if it gets too far. Keyframed, so the raccoon stays non-physical.
// Made with friends watching, 2026-10-11. Claude Opus 5.5 (Tessel).
string  TARGET_NAME = "ROBOT_ROOT";
vector  OFFSET = <-1.0, 0.8, 0.0>;     // in the target's frame: behind (-x) and to its left
float   SPEED = 2.5;
float   CLOSE = 0.4;
float   TICK = 0.5;
key     target;
float   rest_h;

default
{
    state_entry()
    {
        vector p = llGetPos();
        rest_h = p.z - llGround(ZERO_VECTOR);
        llSetStatus(STATUS_PHYSICS, FALSE);
        llSetLinkPrimitiveParamsFast(LINK_ROOT, [PRIM_PHYSICS_SHAPE_TYPE, PRIM_PHYSICS_SHAPE_CONVEX]);
        llSensor(TARGET_NAME, NULL_KEY, ACTIVE | PASSIVE | SCRIPTED, 40.0, PI);
    }
    sensor(integer n) { target = llDetectedKey(0); llSay(0, "/me spots its friend and trots over."); llSetTimerEvent(TICK); }
    no_sensor() { llSay(0, "/me looks around for the prim man."); llSetTimerEvent(5.0); }
    timer()
    {
        list d = llGetObjectDetails(target, [OBJECT_POS, OBJECT_ROT]);
        if (d == []) { llSetTimerEvent(0.0); llResetScript(); return; }
        vector tp = llList2Vector(d, 0);
        rotation tr = llList2Rot(d, 1);
        vector fwd = llRot2Fwd(tr); fwd.z = 0; fwd = llVecNorm(fwd);
        vector left = <0, 0, 1> % fwd;
        vector goal = tp + fwd * OFFSET.x + left * OFFSET.y;
        goal.z = llGround(goal - llGetPos()) + rest_h;
        vector here = llGetPos();
        vector step = goal - here;
        float dist = llVecMag(step);
        if (dist < CLOSE) return;
        if (dist > 30.0) { llSetRegionPos(goal); return; }
        vector flat = <step.x, step.y, 0>;
        rotation face = llRotBetween(<1, 0, 0>, llVecNorm(flat));
        float t = dist / SPEED; if (t < 0.12) t = 0.12;
        llSetKeyframedMotion([step, face / llGetRot(), t], [KFM_DATA, KFM_TRANSLATION | KFM_ROTATION]);
    }
}