using Unity.Mathematics;

namespace ProjectM.Simulation
{
    /// <summary>
    /// Pure helpers for the LANTERN "light is territory" relevancy prototype (Build Spec Phase 1 step 8): an entity
    /// outside a player's lamp radius isn't replicated to that player. The decision is a planar (XZ) distance test
    /// so it's Burst-safe + unit-testable independent of the netcode <c>GhostRelevancy</c> set manipulation.
    /// </summary>
    public static class LightRelevancyMath
    {
        /// <summary>Prototype lamp radius (world units). Per-player dim/bright (a variable radius = the quiet/blind
        /// trade) is the tuning follow-up; the prototype uses one fixed radius to prove the gamma test.</summary>
        public const float LampRadiusDefault = 25f;

        /// <summary>True when the ghost at <paramref name="ghostPos"/> is OUTSIDE the lamp centred on
        /// <paramref name="playerPos"/> (planar XZ distance beyond the radius) — i.e. hidden from that player.</summary>
        public static bool IsHidden(float3 playerPos, float3 ghostPos, float radiusSq)
            => math.distancesq(playerPos.xz, ghostPos.xz) > radiusSq;
    }
}