using System.Numerics;

namespace AutoRig.Mesh;

// s&box compat: the engine defines Vector2/Vector3 in the GLOBAL namespace, which
// shadows using-directive imports - alias explicitly to System.Numerics.
using Vector2 = System.Numerics.Vector2;
using Vector3 = System.Numerics.Vector3;


/// <summary>Axis-aligned bounding box.</summary>
public readonly record struct Aabb3( Vector3 Min, Vector3 Max )
{
    public Vector3 Size => Max - Min;
    public Vector3 Center => (Min + Max) * 0.5f;

    public static Aabb3 FromPoints( ReadOnlySpan<Vector3> points )
    {
        if ( points.IsEmpty ) return new( Vector3.Zero, Vector3.Zero );
        var min = points[0]; var max = points[0];
        foreach ( var p in points ) { min = Vector3.Min( min, p ); max = Vector3.Max( max, p ); }
        return new( min, max );
    }

    public bool Intersects( Aabb3 other, float expand )
        => Min.X - expand <= other.Max.X && Max.X + expand >= other.Min.X
        && Min.Y - expand <= other.Max.Y && Max.Y + expand >= other.Min.Y
        && Min.Z - expand <= other.Max.Z && Max.Z + expand >= other.Min.Z;
}