Draw a stand-in for a missing thumbnail, pass the language code to eu07.ini

The file was getting "pl" or "en" whatever the user picked, so a simulator with
its own language file started in English.

StarterNG.Tests/MiniTextureIndexTests.cs

@@ -0,0 +1,76 @@
+using StarterNG.Infrastructure.Adapters;
+using StarterNG.Infrastructure.Vehicles;
+using StarterNG.Tests.Fakes;
+
+namespace StarterNG.Tests;
+
+public class MiniTextureIndexTests
+{
+    private static readonly string[] Names =
+    {
+        "ep07", "et22", "111a", "112a", "203v", "401k", "en57", "sm42", "st44", "412w",
+        "406r", "424z", "621z", "z1kd", "gags", "eaos", "falns", "uacs", "sgs", "kbs"
+    };
+
+    private static MiniTextureIndex Build(int missRate)
+    {
+        var files = new InMemoryFileSystem();
+        foreach (string name in Names)
+            files.WithFile(TestInstallation.At("textures", "mini", name + ".bmp"), "bitmap");
+        files.WithFile(TestInstallation.At("textures", "mini", "other.bmp"), "bitmap");
+
+        var environment = new FakeEnvironment();
+        if (missRate > 0)
+            environment.With(MiniTextureIndex.MissRateVariable, missRate.ToString());
+
+        return new MiniTextureIndex(files, new GamePaths(TestInstallation.Root), environment);
+    }
+
+    [Fact]
+    public void Without_the_debug_variable_every_thumbnail_loads()
+    {
+        var index = Build(missRate: 0);
+
+        Assert.Equal(0, index.SimulatedMissRate);
+        Assert.All(Names, name => Assert.True(index.Has(name)));
+    }
+
+    [Fact]
+    public void The_debug_variable_hides_roughly_the_share_it_names()
+    {
+        var index = Build(missRate: 50);
+
+        int hidden = Names.Count(name => !index.Has(name));
+
+        // Twenty names is a small sample, so this only asserts that the switch
+        // bites and does not take everything with it.
+        Assert.InRange(hidden, 3, Names.Length - 3);
+    }
+
+    [Fact]
+    public void A_hidden_thumbnail_stays_hidden_rather_than_flickering()
+    {
+        var index = Build(missRate: 50);
+        string hidden = Names.First(name => !index.Has(name));
+
+        for (int i = 0; i < 20; i++)
+            Assert.False(index.Has(hidden));
+    }
+
+    [Fact]
+    public void A_hidden_thumbnail_falls_back_to_other_bmp_like_an_unknown_one()
+    {
+        var index = Build(missRate: 50);
+        string hidden = Names.First(name => !index.Has(name));
+
+        Assert.EndsWith("other.bmp", index.PathFor(hidden));
+    }
+
+    [Fact]
+    public void An_unknown_name_still_falls_back_to_other_bmp_in_a_normal_run()
+    {
+        var index = Build(missRate: 0);
+
+        Assert.EndsWith("other.bmp", index.PathFor("nie-ma-takiej"));
+    }
+}

StarterNG.Tests/SettingsStoreTests.cs

@@ -26,11 +26,50 @@ public class SettingsStoreTests
         Assert.Equal(1920, settings.Width);
         Assert.Equal(1080, settings.Height);
         Assert.True(settings.Fullscreen);
-        Assert.Equal("Polski", settings.Language);
+        Assert.Equal("pl", settings.LanguageCode);
         Assert.True(settings.LanguageWasSet);
         Assert.Equal(UserIni, installation.SettingsStore.LoadedFrom);
     }
 
+    [Fact]
+    public void A_language_the_starter_does_not_ship_survives_a_round_trip()
+    {
+        // A user-supplied translation must reach the simulator as written; folding
+        // every unknown code into "en" is what forced eu07.exe into English.
+        var installation = WithHome(new InMemoryFileSystem().WithFile(UserIni, "lang zh\n"));
+        installation.SettingsStore.Load();
+
+        Assert.Equal("zh", installation.SettingsStore.Settings.LanguageCode);
+
+        installation.SettingsStore.Save();
+
+        Assert.Contains("lang zh", installation.Files.ReadAllText(UserIni));
+    }
+
+    [Fact]
+    public void A_language_chosen_in_the_picker_is_written_as_its_own_code()
+    {
+        var installation = WithHome();
+        installation.SettingsStore.Load();
+        installation.SettingsStore.Settings.Language = "中文";
+        installation.SettingsStore.Settings.LanguageCode = "zh";
+
+        installation.SettingsStore.Save();
+
+        Assert.Contains("lang zh", installation.Files.ReadAllText(UserIni));
+    }
+
+    [Fact]
+    public void With_no_language_recorded_the_file_still_names_one()
+    {
+        var installation = WithHome();
+        installation.SettingsStore.Load();
+
+        installation.SettingsStore.Save();
+
+        Assert.Contains("lang en", installation.Files.ReadAllText(UserIni));
+    }
+
     [Fact]
     public void A_first_run_falls_back_to_the_ini_shipped_with_the_installation()
     {

StarterNG/App.axaml.cs

@@ -51,7 +51,12 @@ public partial class App : Avalonia.Application
     {
 
         var resolvedName = Loc.Load(langNameOrCode);
+
+        // The service is the authority on which language actually loaded: the code
+        // goes to eu07.ini for the simulator, the name to the picker.
         AppServices.Current.Settings.Language = resolvedName;
+        AppServices.Current.Settings.LanguageCode = Loc.CurrentLangCode;
+
         ApplyCulture(Loc.CurrentLangCode);
     }
 

StarterNG/Application/AppServices.cs

@@ -43,13 +43,19 @@ public sealed class AppServices
         Localization = new LocalizationService(log);
         Sceneries = new SceneryRepository(files, paths, log, new SceneryParser(clock, Random));
         SceneryImages = new SceneryImageLocator(files);
-        MiniTextures = new MiniTextureIndex(files, paths);
+        MiniTextures = new MiniTextureIndex(files, paths, environment);
         Vehicles = new TexturesTxtVehicleRepository(files, paths, log, new TexturesTxtParser());
         Physics = new FizPhysicsRepository(files, paths, log);
         MissingAssets = new MissingAssetScanner(files, paths);
         SceneryTexts = new SceneryTranslations(files, log);
         Timetables = new TimetableLocator(files);
         LoadWeights = new LoadWeightsRepository(files, paths, log);
+        // Leaves a trail when the thumbnail debug switch is on, so a run with
+        // missing minis is never mistaken for a broken installation.
+        if (MiniTextures is MiniTextureIndex { SimulatedMissRate: > 0 } debugMinis)
+            log.Log($"{MiniTextureIndex.MissRateVariable}={debugMinis.SimulatedMissRate}: " +
+                    "ukrywam ten procent miniatur pojazdow");
+
         Library = new GameLibrary(Vehicles, Sceneries, MiniTextures, Physics, log);
         State = new AppState();
 

StarterNG/Domain/Settings/SimulatorSettings.cs

@@ -27,7 +27,19 @@ public sealed class SimulatorSettings
     /// </summary>
     public bool LanguageWasSet { get; internal set; }
 
+    /// <summary>
+    /// Display name of the starter's language, as the picker shows it ("Polski",
+    /// "English", "中文"). Resolved from <see cref="LanguageCode"/> at startup.
+    /// </summary>
     public string Language = "English";
+
+    /// <summary>
+    /// The language's code, as its startercfg/lang/*.xml declares it and as
+    /// eu07.ini stores it. This is what the simulator reads, so it has to carry
+    /// whatever language the user actually picked rather than being folded into
+    /// one of two known ones.
+    /// </summary>
+    public string LanguageCode = "";
     public bool Fullscreen;
     public bool PauseWhenInactive = true;
     public bool PauseOnStart;

StarterNG/Infrastructure/Settings/SettingsSerializer.cs

@@ -23,7 +23,13 @@ public sealed class SettingsSerializer
     {
 
         s.LanguageWasSet = c.Has("lang");
-        s.Language = c.GetString("lang", "en").ToLowerInvariant() == "pl" ? "Polski" : "English";
+        // Kept as the code the file holds. Startup hands it to the localisation
+        // service, which resolves it to a display name and writes that back; the
+        // starter must not decide here that an unrecognised code means English,
+        // because the same key is what tells the simulator which language to run
+        // in.
+        s.LanguageCode = c.GetString("lang", "");
+        s.Language = s.LanguageCode;
         s.Fullscreen = c.GetBool("fullscreen", false);
         s.PauseWhenInactive = c.GetBool("inactivepause", true);
         s.PauseOnStart = c.GetBool("pause", false);
@@ -165,7 +171,7 @@ public sealed class SettingsSerializer
         foreach (string key in ObsoleteKeys)
             c.Remove(key);
 
-        c.Set("lang", s.Language == "Polski" ? "pl" : "en");
+        c.Set("lang", string.IsNullOrWhiteSpace(s.LanguageCode) ? "en" : s.LanguageCode);
         c.SetBool("fullscreen", s.Fullscreen);
         c.SetBool("inactivepause", s.PauseWhenInactive);
         c.SetBool("pause", s.PauseOnStart);

StarterNG/Infrastructure/Vehicles/MiniTextureIndex.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.IO;
 using StarterNG.Application.Abstractions;
 
@@ -18,26 +19,45 @@ public sealed class MiniTextureIndex : IMiniTextureIndex
     /// <summary>Thumbnail shown when a vehicle names one we do not have.</summary>
     private const string FallbackName = "other";
 
+    /// <summary>
+    /// Set to 1-100 to make that percentage of thumbnails behave as if the
+    /// installation did not have their file - the vehicle then falls back to
+    /// other.bmp exactly as one naming an unknown thumbnail would. For checking
+    /// how a consist looks when some of its stock has no picture of its own.
+    /// Off unless the variable is set.
+    /// </summary>
+    public const string MissRateVariable = "STARTER_DEBUG_MISSING_MINI";
+
     private readonly IFileSystem _files;
     private readonly IGamePaths _paths;
+    private readonly int _missRate;
     private readonly object _gate = new();
 
     private Dictionary<string, string>? _index;
 
-    public MiniTextureIndex(IFileSystem files, IGamePaths paths)
+    public MiniTextureIndex(IFileSystem files, IGamePaths paths, IEnvironment? environment = null)
     {
         _files = files;
         _paths = paths;
+        _missRate = ReadMissRate(environment);
     }
 
+    /// <summary>
+    /// Percentage of thumbnails currently being hidden on purpose; 0 in a normal
+    /// run.
+    /// </summary>
+    public int SimulatedMissRate => _missRate;
+
     public void Preload() => Index();
 
     public bool Has(string? miniName) =>
-        !string.IsNullOrEmpty(miniName) && Index().ContainsKey(miniName.ToLowerInvariant());
+        !string.IsNullOrEmpty(miniName) &&
+        !IsSimulatedMiss(miniName) &&
+        Index().ContainsKey(miniName.ToLowerInvariant());
 
     public string? PathFor(string? miniName)
     {
-        if (!string.IsNullOrEmpty(miniName) &&
+        if (!IsSimulatedMiss(miniName) && !string.IsNullOrEmpty(miniName) &&
             Index().TryGetValue(miniName.ToLowerInvariant(), out string? path))
             return path;
 
@@ -47,6 +67,35 @@ public sealed class MiniTextureIndex : IMiniTextureIndex
     public string? FallbackPath =>
         Index().TryGetValue(FallbackName, out string? path) ? path : null;
 
+    /// <summary>
+    /// Whether this name is one of the thumbnails the debug switch is hiding.
+    /// Decided from the name itself rather than a random draw, so a vehicle keeps
+    /// the same answer every time the strip is rebuilt and can actually be looked
+    /// at.
+    /// </summary>
+    private bool IsSimulatedMiss(string? miniName) =>
+        _missRate > 0 && !string.IsNullOrEmpty(miniName) && Bucket(miniName) < _missRate;
+
+    /// <summary>FNV-1a over the lower-cased name, folded into 0-99.</summary>
+    private static int Bucket(string name)
+    {
+        uint hash = 2166136261;
+        foreach (char c in name.ToLowerInvariant())
+        {
+            hash ^= c;
+            hash *= 16777619;
+        }
+        return (int)(hash % 100);
+    }
+
+    private static int ReadMissRate(IEnvironment? environment)
+    {
+        string? raw = environment?.GetVariable(MissRateVariable);
+        return int.TryParse(raw, NumberStyles.Integer, CultureInfo.InvariantCulture, out int rate)
+            ? Math.Clamp(rate, 0, 100)
+            : 0;
+    }
+
     private Dictionary<string, string> Index()
     {
         lock (_gate)

StarterNG/Views/Depot/MiniTextures.cs

@@ -1,6 +1,10 @@
+using System;
 using System.Collections.Generic;
 using System.IO;
+using Avalonia;
 using Avalonia.Controls;
+using Avalonia.Controls.Shapes;
+using Avalonia.Layout;
 using Avalonia.Media;
 using Avalonia.Media.Imaging;
 
@@ -25,6 +29,75 @@ public sealed class MiniTextures
         return image;
     }
 
+    /// <summary>Body of the drawn stand-in; the black wagon of the old starter.</summary>
+    private static readonly IBrush MissingBody = new SolidColorBrush(Color.Parse("#0B0C0D"));
+
+    private static readonly IBrush MissingEdge = new SolidColorBrush(Color.Parse("#3A424A"));
+
+    private static readonly IBrush MissingMark = new SolidColorBrush(Color.Parse("#E6E8EA"));
+
+    /// <summary>Real minis are about 80x30, and the stand-in keeps that shape.</summary>
+    private const double MiniAspect = 80.0 / 30.0;
+
+    /// <summary>
+    /// The stand-in for a vehicle with no thumbnail: a dark wagon marked with
+    /// question marks, the way the old starter drew textures/mini/other.bmp.
+    /// </summary>
+    /// <remarks>
+    /// Reached only when the installation has no other.bmp either - a vehicle
+    /// naming a thumbnail we do not have already falls back to that file. Drawn
+    /// rather than loaded so the consist keeps its length whatever is missing;
+    /// a vehicle that is simply absent from the strip reads as a shorter train.
+    /// </remarks>
+    public static Control MissingVisual(string? label, int height)
+    {
+        double width = height * MiniAspect;
+        double bodyTop = height * 0.23;
+        double bodyHeight = height * 0.47;
+        double wheelRadius = height * 0.13;
+
+        var canvas = new Canvas { Width = width, Height = height };
+
+        var body = new Border
+        {
+            Width = width - 4,
+            Height = bodyHeight,
+            Background = MissingBody,
+            BorderBrush = MissingEdge,
+            BorderThickness = new Thickness(1),
+            Child = new TextBlock
+            {
+                Text = "? ?",
+                FontSize = Math.Max(9, height * 0.34),
+                FontWeight = FontWeight.SemiBold,
+                Foreground = MissingMark,
+                HorizontalAlignment = HorizontalAlignment.Center,
+                VerticalAlignment = VerticalAlignment.Center
+            }
+        };
+        Canvas.SetLeft(body, 2);
+        Canvas.SetTop(body, bodyTop);
+        canvas.Children.Add(body);
+
+        foreach (double centre in new[] { width * 0.22, width * 0.78 })
+        {
+            var wheel = new Ellipse
+            {
+                Width = wheelRadius * 2,
+                Height = wheelRadius * 2,
+                Fill = MissingBody
+            };
+            Canvas.SetLeft(wheel, centre - wheelRadius);
+            Canvas.SetTop(wheel, bodyTop + bodyHeight - wheelRadius);
+            canvas.Children.Add(wheel);
+        }
+
+        if (!string.IsNullOrWhiteSpace(label))
+            ToolTip.SetTip(canvas, label);
+
+        return canvas;
+    }
+
     public Bitmap? Get(string? name, int height, bool strict = false)
     {
         if (string.IsNullOrEmpty(name))

StarterNG/Views/Depot/VehicleCards.cs

@@ -92,18 +92,9 @@ public sealed class VehicleCards
             }
             else
             {
-                minis.Children.Add(MemberFrame(new Border
+                minis.Children.Add(MemberFrame(
-                {
+                    MiniTextures.MissingVisual(car.SkinFile, VehicleCardStyle.ThumbHeight),
-                    Height = VehicleCardStyle.ThumbHeight, Width = 90, Background = VehicleCardStyle.Placeholder,
+                    item, car, CardCaption(item, car, index)));
-                    CornerRadius = new CornerRadius(4),
-                    Child = new TextBlock
-                    {
-                        Text = car.SkinFile, FontSize = 10, TextWrapping = TextWrapping.Wrap,
-                        HorizontalAlignment = HorizontalAlignment.Center,
-                        VerticalAlignment = VerticalAlignment.Center,
-                        TextAlignment = TextAlignment.Center
-                    }
-                }, item, car, CardCaption(item, car, index)));
             }
         }
 

StarterNG/Views/Scenarios.axaml.cs

@@ -427,26 +427,6 @@ public partial class Scenarios : UserControl
     private static readonly Avalonia.Media.IBrush SelectedVehicleBrush =
         new Avalonia.Media.SolidColorBrush(Avalonia.Media.Color.Parse("#41C400"));
 
-    private static readonly Avalonia.Media.IBrush MissingMiniBrush =
-        new Avalonia.Media.SolidColorBrush(Avalonia.Media.Color.Parse("#22808080"));
-
-    private static Control MissingMiniBox(string? label, int height) => new Border
-    {
-        Height = height,
-        Width = height * 2,
-        Background = MissingMiniBrush,
-        CornerRadius = new Avalonia.CornerRadius(4),
-        Child = new TextBlock
-        {
-            Text = label,
-            FontSize = 10,
-            TextWrapping = Avalonia.Media.TextWrapping.Wrap,
-            HorizontalAlignment = HorizontalAlignment.Center,
-            VerticalAlignment = VerticalAlignment.Center,
-            TextAlignment = Avalonia.Media.TextAlignment.Center
-        }
-    };
-
     private readonly Dictionary<string, Bitmap?> _miniCache = new();
 
     private Bitmap? LoadMini(string? name, int height)
@@ -834,7 +814,7 @@ public partial class Scenarios : UserControl
                     Stretch = Avalonia.Media.Stretch.Uniform,
                     Margin = new Thickness(0)
                 })
-                : MissingMiniBox(train.SkinFile, thumbH);
+                : MiniTextures.MissingVisual(train.SkinFile, thumbH);
 
             bool selected = !string.IsNullOrEmpty(train.Name) &&
                 string.Equals(train.Name, AppServices.Current.State.StartingVehicleName,
@@ -1025,14 +1005,11 @@ public partial class Scenarios : UserControl
         for (int i = _dragBlockStart; i < _dragBlockStart + _dragBlockLength; i++)
         {
             var source = consistStack.Children[i];
+            // The ghost mirrors what the slot shows, stand-in wagons included, so
+            // dragging a vehicle with no thumbnail still carries something visible.
             Control copy = source is Border { Child: Image image }
                 ? new Image { Source = image.Source, Height = image.Height, Stretch = image.Stretch }
-                : new Border
+                : MiniTextures.MissingVisual(null, (int)source.Bounds.Height);
-                {
-                    Width = source.Bounds.Width,
-                    Height = source.Bounds.Height,
-                    Background = MissingMiniBrush
-                };
             panel.Children.Add(copy);
         }
 

StarterNG/Views/Settings.axaml.cs

@@ -277,8 +277,9 @@ public partial class Settings : UserControl, ISettingsCapture
     public void CaptureInto(SimulatorSettings s)
     {
 
-        s.Language = (ChangeLanguageCb.SelectedItem as ComboBoxItem)?.Content?.ToString()
+        var language = ChangeLanguageCb.SelectedItem as ComboBoxItem;
-                     ?? App.Loc.CurrentLanguage;
+        s.Language = language?.Content?.ToString() ?? App.Loc.CurrentLanguage;
+        s.LanguageCode = language?.Tag as string ?? App.Loc.CurrentLangCode;
         s.Fullscreen = IsChecked(FullscreenCb);
         s.PauseWhenInactive = IsChecked(PauseInactiveCb);
         s.PauseOnStart = IsChecked(PauseStartCb);