// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Blend nearby rotations with normalized interpolation
// Not compiled or tested in-world
// Setup: Use a spare owned prim. Set two Euler poses and T0..1. Touch for private calculations.
// Stop / restore: Disable/remove. No camera or object settings are changed.
// Notes: Normalized linear interpolation is not constant angular speed. It is useful for inexpensive blends of nearby orientations.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT. Transform planning only.
vector START=<0.0,0.0,10.0>;
vector END=<20.0,30.0,50.0>;
float T=0.4;
default
{
    touch_start(integer detectedCount)
    {
        if(llDetectedKey(0)!=llGetOwner())return;
        if(T<0.0||T>1.0)
        {
            llOwnerSay("T must be0..1.");
            return;
        }
        rotation a=llEuler2Rot(START*DEG_TO_RAD);
        rotation b=llEuler2Rot(END*DEG_TO_RAD);
        float dot=a.x*b.x+a.y*b.y+a.z*b.z+a.s*b.s;
        if(dot<0.0)b=<-b.x,-b.y,-b.z,-b.s>;
        rotation q=<a.x+(b.x-a.x)*T,a.y+(b.y-a.y)*T,a.z+(b.z-a.z)*T,a.s+(b.s-a.s)*T>;
        float length=llSqrt(q.x*q.x+q.y*q.y+q.z*q.z+q.s*q.s);
        if(length<0.000001)
        {
            llOwnerSay("Degenerate quaternion blend.");
            return;
        }
        q=<q.x/length,q.y/length,q.z/length,q.s/length>;
        llOwnerSay("Normalized blend="+(string)q);
    }
}