// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Reflect a direction from a plane
// Not compiled or tested in-world
// Setup: Put in a spare prim you own. Set incoming DIRECTION and surface NORMAL, then touch.
// 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: The normal is normalized internally. The reflection preserves the original vector magnitude; this is not a physics collision response.
// License: see LICENSE in this distribution.
// Original Incoprea example. MIT. Owner-only calculation; no scene changes.
vector DIRECTION = <1.0, -2.0, -3.0>;
vector NORMAL = <0.0, 0.0, 1.0>;
default
{
    touch_start(integer detectedCount)
    {
        if (llDetectedKey(0) != llGetOwner()) return;
        if (llVecMag(NORMAL) < 0.000001)
        {
            llOwnerSay("Normal is zero.");
            return;
        }
        vector n = llVecNorm(NORMAL);
        vector reflected = DIRECTION - 2.0 * (DIRECTION * n) * n;
        llOwnerSay("Reflected direction: " + (string)reflected);
    }
    changed(integer change)
    {
        if (change & CHANGED_OWNER) llResetScript();
    }
}