// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Touch-sampled smooth value noise
// Not compiled or tested in-world
// Setup: Put in a spare ordinary cube you own. Touch different places on one face to sample the procedural pattern at live surface coordinates. Edit the constants to design a pattern.
// Stop / restore: Disable/remove. Only private owner messages are produced; no texture or tint is applied.
// Notes: The sine hash is decorative and may vary slightly across floating-point implementations; it is not secure randomness. Surface coordinates depend on the viewer and mesh; ordinary prim faces are the clearest test surface.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT. Live surface-coordinate sampler.
float FREQUENCY=6.0;
float hash(float x,float y)
{
    float n=llSin(x*127.1+y*311.7)*43758.5453;
    return n-llFloor(n);
}
float noise(vector q)
{
    integer x=llFloor(q.x);
    integer y=llFloor(q.y);
    float u=q.x-x;
    float v=q.y-y;
    u=u*u*(3.0-2.0*u);
    v=v*v*(3.0-2.0*v);
    float a=hash(x,y);
    float b=hash(x+1,y);
    float c=hash(x,y+1);
    float d=hash(x+1,y+1);
    return (a+(b-a)*u)*(1.0-v)+(c+(d-c)*u)*v;
}
default
{
    touch_start(integer detectedCount)
    {
        if(llDetectedKey(0)!=llGetOwner())return;
        vector uv=llDetectedTouchST(0);
        if(llDetectedTouchFace(0)<0||uv==TOUCH_INVALID_TEXCOORD)
        {
            llOwnerSay("Surface coordinates unavailable.");
            return;
        }
        vector p=2.0*uv-<1.0,1.0,0.0>;
        if(FREQUENCY<=0.0)
        {
            llOwnerSay("Positive frequency required.");
            return;
        }
        llOwnerSay("Smooth noise="+(string)noise(uv*FREQUENCY));
    }
}