// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Calibrate a slider from two actual touches
// Not compiled or tested in-world
// Setup: Use a spare ordinary cube owned by you. Tap the intended minimum and maximum positions; subsequent touches read the calibrated range. Reset to recalibrate. Surface mapping can differ on meshes; test one face first.
// Stop / restore: Disable/remove; these controllers report privately and do not alter scene properties. Reset clears gesture/session state.
// Notes: References must be on the same link/face and have distinctS coordinates.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT. Owner input only.
integer stage;
integer face;
integer link;
float low;
float high;
integer ownerTouch()
{
    return llDetectedKey(0)==llGetOwner();
}
integer usable(vector uv)
{
    return llDetectedTouchFace(0)>=0&&uv!=TOUCH_INVALID_TEXCOORD;
}
default
{
    touch_start(integer n)
    {
        if(!ownerTouch())return;
        vector uv=llDetectedTouchST(0);
        if(!usable(uv))return;
        integer f=llDetectedTouchFace(0);
        integer l=llDetectedLinkNumber(0);
        if(stage==0)
        {
            face=f;
            link=l;
            low=uv.x;
            stage=1;
            llOwnerSay("Minimum captured; tap maximum.");
            return;
        }
        if(f!=face||l!=link)
        {
            llOwnerSay("Use the calibrated face.");
            return;
        }
        if(stage==1)
        {
            high=uv.x;
            if(llFabs(high-low)<0.01)
            {
                llOwnerSay("Endpoints too close; try maximum again.");
                return;
            }
            stage=2;
            llOwnerSay("Calibrated; tap to read.");
            return;
        }
        float value=(uv.x-low)/(high-low);
        if(value<0.0)value=0.0;
        if(value>1.0)value=1.0;
        llOwnerSay("Calibrated value="+(string)value);
    }
    changed(integer flags)
    {
        if(flags&CHANGED_OWNER)llResetScript();
    }
}