// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Spatial checker tile tint
// Not compiled or tested in-world
// Setup: Name up to 32 children checker_tile, set CELL spacing, and align the root-local floor grid. Face0 only.
// Stop / restore: Owner-touch applies/restores saved colors.
// Notes: Use a spare modifiable build. Snapshot state is held only in script memory; restore before reset/removal. Do not relink during a preview. Alternating parity is based on rounded root-local X/Y cell coordinates; uneven or rotated tile centers need their own layout.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT. Not compiled or tested in-world.
float CELL=1.0;
list links;
list saved;
integer preview;
integer valid=TRUE;
default
{
    touch_start(integer n)
    {
        if(llDetectedKey(0)!=llGetOwner()||llGetLinkNumber()>1||!valid||CELL<=0.0)return;
        integer i;
        if(preview)
        {
            for(i=0;i<llGetListLength(links);++i)llSetLinkPrimitiveParamsFast(llList2Integer(links,i),[PRIM_COLOR,0]+llList2List(saved,i*2,i*2+1));
            preview=FALSE;
            return;
        }
        links=[];
        saved=[];
        for(i=2;i<=llGetObjectPrimCount(llGetKey())&&llGetListLength(links)<32;++i)if(llGetLinkName(i)=="checker_tile")
        {
            links+=[i];
            list color=llGetLinkPrimitiveParams(i,[PRIM_COLOR,0]);
            saved+=color;
            vector p=llList2Vector(llGetLinkPrimitiveParams(i,[PRIM_POS_LOCAL]),0);
            integer parity=(llRound(p.x/CELL)+llRound(p.y/CELL))%2;
            vector tint=<0.9,0.9,0.9>;
            if(parity)tint=<0.12,0.12,0.12>;
            llSetLinkPrimitiveParamsFast(i,[PRIM_COLOR,0,tint,llList2Float(color,1)]);
        }
        preview=TRUE;
    }
    changed(integer change)
    {
        if(change&CHANGED_LINK)valid=FALSE;
    }
}