// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Signed horizontal turn angle
// Not compiled or tested in-world
// Setup: Put in a spare prim you own. Edit FROM and TO direction vectors. Touch to see degrees.
// Stop / restore: Disable or remove the script. It only reports to its owner and does not change prim properties. Reset clears its temporary state.
// Notes: Ignores Z. Positive means counterclockwise viewed from above; a zero horizontal heading is rejected.
// License: see LICENSE in this distribution.
// Original Incoprea example. MIT. Owner-only calculation; no scene changes.
vector FROM = <1.0, 0.0, 0.0>;
vector TO = <-1.0, 1.0, 0.0>;
default
{
    touch_start(integer detectedCount)
    {
        if (llDetectedKey(0) != llGetOwner()) return;
        if ((FROM.x * FROM.x + FROM.y * FROM.y < 0.000001) ||
        (TO.x * TO.x + TO.y * TO.y < 0.000001))
        {
            llOwnerSay("Headings must be nonzero.");
            return;
        }
        float crossZ = FROM.x * TO.y - FROM.y * TO.x;
        float dot = FROM.x * TO.x + FROM.y * TO.y;
        llOwnerSay("Signed turn: " + (string)(llAtan2(crossZ, dot) * RAD_TO_DEG) + " degrees");
    }
    changed(integer change)
    {
        if (change & CHANGED_OWNER) llResetScript();
    }
}