// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Four-panel image wall
// Not compiled or tested in-world
// Setup: Add texture art to root. Name four children tile00, tile10, tile01, tile11. Use face0/default mapping with matching face orientations.
// Stop / restore: Owner-touch applies/restores the four saved diffuse mappings.
// Notes: Use a spare modifiable build. Snapshot state is held only in script memory; restore before reset/removal. Do not relink during a preview. Names encode column,row with row0 at bottom in UV space. Duplicate or missing names reject the preview.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT. Not compiled or tested in-world.
list links;
list saved;
integer preview;
integer valid=TRUE;
default
{
    touch_start(integer n)
    {
        if(llDetectedKey(0)!=llGetOwner()||llGetLinkNumber()>1||!valid)return;
        integer i;
        if(preview)
        {
            for(i=0;i<4;++i)llSetLinkPrimitiveParamsFast(llList2Integer(links,i),[PRIM_TEXTURE,0]+llList2List(saved,i*4,i*4+3));
            preview=FALSE;
            return;
        }
        if(llGetInventoryType("art")!=INVENTORY_TEXTURE)return;
        links=[];
        saved=[];
        list names=["tile00","tile10","tile01","tile11"];
        for(i=0;i<4;++i)
        {
            integer j;
            integer found;
            integer count;
            for(j=2;j<=llGetObjectPrimCount(llGetKey());++j)if(llGetLinkName(j)==llList2String(names,i))
            {
                found=j;
                ++count;
            }
            if(count!=1)
            {
                llOwnerSay("Need four unique tile names.");
                return;
            }
            links+=[found];
        }
        for(i=0;i<4;++i)
        {
            integer link=llList2Integer(links,i);
            saved+=llGetLinkPrimitiveParams(link,[PRIM_TEXTURE,0]);
            vector offset=<-0.25,-0.25,0.0>;
            if(i%2)offset.x=0.25;
            if(i/2)offset.y=0.25;
            llSetLinkPrimitiveParamsFast(link,[PRIM_TEXTURE,0,"art",<0.5,0.5,0.0>,offset,0.0]);
        }
        preview=TRUE;
    }
    changed(integer change)
    {
        if(change&CHANGED_LINK)valid=FALSE;
    }
}