namespace AcDream.App.Streaming;

/// <summary>
/// Immutable world-origin center captured by the update thread when a
/// landblock load is admitted. Worker construction and render publication use
/// this same value, so a later recenter cannot combine two coordinate frames.
/// </summary>
public readonly record struct LandblockBuildOrigin
{
    public LandblockBuildOrigin(int centerX, int centerY)
    {
        CenterX = centerX;
        CenterY = centerY;
        IsSpecified = true;
    }

    public int CenterX { get; }
    public int CenterY { get; }

    /// <summary>
    /// Distinguishes a captured origin at the valid map coordinate (0,0)
    /// from an old compatibility request that carries no origin at all.
    /// </summary>
    public bool IsSpecified { get; }
}

/// <summary>
/// Complete immutable input to one CPU-side landblock build.
/// <see cref="Generation"/> is carried for matching and diagnostics only;
/// residency policy remains owned by <see cref="StreamingController"/>.
/// </summary>
public readonly record struct LandblockBuildRequest(
    uint LandblockId,
    LandblockStreamJobKind Kind,
    ulong Generation,
    LandblockBuildOrigin Origin);