XFEEDToolBox

using System.Numerics;
using Microsoft.UI.Composition;
using Windows.Foundation;
using XFEEDToolBox.Core.Galaxy;
using XFEEDToolBox.Core.Models;

namespace XFEEDToolBox.Controls;

public sealed partial class GalaxyMapView
{
    private GalaxyConstellationResolution constellationResolution = new([], [], 16);
    private readonly List<(LineVisual Line, CompositionColorBrush Brush)> constellationLines = [];
    internal int VisibleConstellationSegments { get; private set; }
    internal int ResolvedConstellationGroupsForProbe => constellationResolution.Groups.Count;
    internal int PendingConstellationGroupsForProbe => constellationResolution.PendingGroupCount;
    internal GalaxyConstellationResolution ConstellationResolutionForProbe => constellationResolution;
    internal int OriginalConstellationSubmittedForProbe=>graphics?.SubmittedOriginalConstellationLines??0;
    internal bool OriginalConstellationWorldStyleForProbe=>graphics?.OriginalConstellationWorldStyleRestored==true;

    private void RebuildConstellations()
    {
        if (Filter?.ShowConstellations != true)
        {
            constellationResolution = new([], [], 16);
            return;
        }
        // Use the same strictly filtered catalogue snapshot as the stellar models.
        // This adds no network/native request and never supplies an estimated position.
        var endpoints = GalaxyOriginalConstellations.EndpointNames.ToHashSet(StringComparer.OrdinalIgnoreCase);
        var facts = new Dictionary<string, Coordinates>(StringComparer.OrdinalIgnoreCase);
        foreach (var sample in ordered)
            if (endpoints.Contains(sample.System.Name)) facts.TryAdd(sample.System.Name, sample.System.Position);
        constellationResolution = GalaxyOriginalConstellations.Resolve(facts.GetValueOrDefault);
    }

    private void DrawConstellations(GalaxyCamera camera, ref int lineCount)
    {
        VisibleConstellationSegments = 0;
        graphics?.SetOriginalConstellations(Filter?.ShowConstellations==true?constellationResolution.Groups:[],camera);
        if (Filter?.ShowConstellations == true)
        foreach (var group in constellationResolution.Groups)
        {
            var alpha = GalaxyOriginalConstellations.Alpha(group, camera.Eye, camera.Focus);
            if (alpha <= GalaxyOriginalConstellations.SubmissionAlpha) continue;
            foreach (var edge in group.Lines)
            {
                if (!GalaxyMapGeometry.TryProjectSegment(camera, edge.From, edge.To, out var segment)) continue;
                var from = new Point(segment.X1, segment.Y1); var to = new Point(segment.X2, segment.Y2);
                var dx = to.X - from.X; var dy = to.Y - from.Y;
                var length = Math.Sqrt(dx * dx + dy * dy);
                if (length < .3) continue;
                // GPU uses the actual world-width StarMapLine pass. Retain a
                // neutral Composition fallback when no D3D renderer is available.
                if (graphics is null)
                {
                    if (constellationLines.Count <= VisibleConstellationSegments)
                    {
                        var brush = compositor!.CreateColorBrush(Windows.UI.Color.FromArgb(255, 255, 255, 255));
                        constellationLines.Add((CreateLine(brush, 1), brush));
                    }
                    var line = constellationLines[VisibleConstellationSegments];
                    line.Brush.Color = Windows.UI.Color.FromArgb((byte)Math.Round(alpha * 255), 255, 255, 255);
                    line.Line.Shape.Scale = Vector2.One;
                    line.Line.Move(from, to);
                }
                VisibleConstellationSegments++;
            }
        }
        for (var i = graphics is null ? VisibleConstellationSegments : 0; i < constellationLines.Count; i++)
            constellationLines[i].Line.Shape.Scale = Vector2.Zero;
    }
}