// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Evaluate a custom piecewise response curve
// Not compiled or tested in-world
// Setup: Place in a spare owned prim. Set paired KNOTS in strictly increasing input order and VALUE. Touch to run; output is private to the owner.
// Stop / restore: Disable/remove. No scene changes or external calls.
// Notes: Each interval is linear. The table is validated before lookup; this differs from a smooth spline.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT.
list KNOTS=[0.0,0.0,0.2,0.05,0.6,0.8,1.0,1.0];
float VALUE=0.45;
default
{
    touch_start(integer detectedCount)
    {
        if(llDetectedKey(0)!=llGetOwner())return;
        integer n=llGetListLength(KNOTS);
        if(n<4||n%2)
        {
            llOwnerSay("Need at least two input/output pairs.");
            return;
        }
        integer i;
        for(i=2;i<n;i+=2)if(llList2Float(KNOTS,i)<=llList2Float(KNOTS,i-2))
        {
            llOwnerSay("Inputs must strictly increase.");
            return;
        }
        if(VALUE<=llList2Float(KNOTS,0))
        {
            llOwnerSay((string)llList2Float(KNOTS,1));
            return;
        }
        for(i=2;i<n;i+=2)
        {
            float right=llList2Float(KNOTS,i);
            if(VALUE<=right)
            {
                float left=llList2Float(KNOTS,i-2);
                float t=(VALUE-left)/(right-left);
                float y=llList2Float(KNOTS,i-1);
                llOwnerSay("Output="+(string)(y+t*(llList2Float(KNOTS,i+1)-y)));
                return;
            }
        }
        llOwnerSay("Clamped="+(string)llList2Float(KNOTS,-1));
    }
}