// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Frame a flat artwork with a perspective view
// Not compiled or tested in-world
// Setup: Use a spare owned prim. Set width/height, vertical FOV and aspect ratio. Touch for private calculations.
// Stop / restore: Disable/remove. No camera or object settings are changed.
// Notes: The artwork must face the camera directly. Unlike spherical fitting, it uses tangent rather than sine.
// License: see LICENSE in this distribution.
// Original Incoprea. MIT. Transform planning only.
float WIDTH=6.0;
float HEIGHT=4.0;
float VERTICAL_FOV=50.0;
float ASPECT=1.7777778;
default
{
    touch_start(integer detectedCount)
    {
        if(llDetectedKey(0)!=llGetOwner())return;
        if(WIDTH<=0.0||HEIGHT<=0.0||VERTICAL_FOV<=1.0||VERTICAL_FOV>=170.0||ASPECT<=0.0)
        {
            llOwnerSay("Invalid inputs.");
            return;
        }
        float t=llTan(VERTICAL_FOV*DEG_TO_RAD*0.5);
        float d=HEIGHT*0.5/t;
        float horizontal=WIDTH*0.5/(t*ASPECT);
        if(horizontal>d)d=horizontal;
        llOwnerSay("Minimum frontal distance="+(string)d);
    }
}