// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Triangle winding and area vector
// Not compiled or tested in-world
// Setup: Use a spare owned prim. Set three noncollinear vectors A/B/C. Touch for owner-only results.
// Stop / restore: Disable/remove. No scene properties change.
// Notes: Swapping two vertices reverses the normal; this does not inspect or change an actual mesh face.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT.
vector A=<0.0,0.0,0.0>;
vector B=<4.0,0.0,1.0>;
vector C=<1.0,3.0,2.0>;
default
{
    touch_start(integer detectedCount)
    {
        if(llDetectedKey(0)!=llGetOwner())return;
        vector cross=(B-A)%(C-A);
        float magnitude=llVecMag(cross);
        if(magnitude<0.000001)
        {
            llOwnerSay("Degenerate triangle.");
            return;
        }
        llOwnerSay("Unit normal="+(string)(cross/magnitude)+"; area="+(string)(magnitude*0.5));
    }
}