fix(ui): keep spellbook tab captions above chrome

docs/research/2026-07-15-retail-magic-ui-and-casting-pseudocode.md

@@ -202,6 +202,9 @@ The two top-level tabs are not `UIElement_Button` instances. They resolve from
 base `0x1000043A` as `UIElement_Text` (type 12), with state 11 `Closed` and
 state 12 `Open`. Both states set `PassToChildren`; the three child chrome
 elements carry the left/center/right Closed/Open RenderSurface media.
+Their direct string property `0x17` resolves through the installed string
+tables to `Spellbook` (string id `49867858`) and `Components` (string id
+`79360818`).
 
 Retail state and text construction used by these tabs:
 
@@ -227,8 +230,21 @@ UIElement::SetState @ 0x00464E70
                 child.SetState(stateId)
         diff old/new effective properties
         call OnSetAttribute for changed properties
+
+Retained rendering reduction:
+    draw the UIElement_Text background
+    draw its three stateful chrome children
+    draw the authored glyph content as the parent's foreground
 ```
 
+Retail `UIElement_Text::DrawSelf @ 0x00467AA0` owns the glyphs while the child
+regions own the state chrome. acdream's sprites and DAT glyphs share one
+submission-ordered batch, so submitting the glyphs in the parent's foreground
+pass preserves that same visible composition; submitting the entire parent
+before its retained children lets the center chrome overpaint the caption.
+This rule is derived structurally from `PassToChildren`, not from the two
+spellbook element ids.
+
 The Magic-combat favorite tab captions are authored text (`I` through `VIII`)
 and intentionally omit property `0x20`. Their small rectangles still render
 because retail begins with zero text margins. A generic four-pixel inset on

src/AcDream.App/UI/UiText.cs

@@ -165,6 +165,7 @@ public sealed class UiText : UiElement, IUiDatStateful
     private ElementInfo? _datInfo;
     private uint _activeRetailStateId = UiStateInfo.DirectStateId;
     private string _activeDatStateName = "";
+    private bool _drawTextAfterChildren;
 
     // ── Selection state ──────────────────────────────────────────────────
     private Pos? _selAnchor;   // where the drag started
@@ -205,10 +206,25 @@ public sealed class UiText : UiElement, IUiDatStateful
     internal void ConfigureDatState(ElementInfo info)
     {
         _datInfo = info;
+        // Retail spellbook tabs are UIElement_Text parents whose Open/Closed
+        // PassToChildren states drive three authored chrome pieces. In retail's
+        // software surface those pieces form the tab background while the text
+        // remains the foreground. Our retained renderer submits parent and child
+        // sprites into one painter-ordered batch, so submit only the glyph content
+        // in the parent's foreground pass after those chrome children.
+        _drawTextAfterChildren = false;
+        foreach (UiStateInfo state in info.States.Values)
+        {
+            if (!state.PassToChildren) continue;
+            _drawTextAfterChildren = true;
+            break;
+        }
         _activeRetailStateId = info.EffectiveDefaultStateId();
         ApplyDatState(_activeRetailStateId, propagate: false);
     }
 
+    internal bool DrawTextAfterChildren => _drawTextAfterChildren;
+
     public bool TrySetRetailState(uint stateId)
         => ApplyDatState(stateId, propagate: true);
 
@@ -307,6 +323,18 @@ public sealed class UiText : UiElement, IUiDatStateful
         // submitted first → text on top.
         ctx.DrawFill(0, 0, Width, Height, BackgroundColor);
 
+        if (!_drawTextAfterChildren)
+            DrawText(ctx);
+    }
+
+    protected override void OnDrawAfterChildren(UiRenderContext ctx)
+    {
+        if (_drawTextAfterChildren)
+            DrawText(ctx);
+    }
+
+    private void DrawText(UiRenderContext ctx)
+    {
         // Static centered single-line mode (vitals cur/max numbers etc.): draw the first
         // line centered H+V (or H+Top/Bottom per VerticalJustify) with the SAME formula
         // UIElement_Meter used for its label, then skip the scroll/selection machinery entirely.

tests/AcDream.App.Tests/UI/Layout/SpellbookRowStyleTests.cs

@@ -29,4 +29,36 @@ public sealed class SpellbookRowStyleTests
         Assert.Equal(0x06001396u, style.BackgroundSprite);
         Assert.Equal(0x06001397u, style.SelectedSprite);
     }
+
+    [Fact]
+    public void InstalledDat_ResolvesAuthoredSpellbookTabCaptions()
+    {
+        string datDir = System.Environment.GetEnvironmentVariable("ACDREAM_DAT_DIR")
+            ?? Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.UserProfile),
+                "Documents", "Asheron's Call");
+        if (!Directory.Exists(datDir)) return;
+
+        using var dats = new DatCollection(datDir, DatAccessType.Read);
+        ElementInfo root = Assert.IsType<ElementInfo>(LayoutImporter.ImportInfos(
+            dats, SpellbookWindowController.LayoutId, SpellbookWindowController.RootId));
+        var strings = new DatStringResolver(dats);
+
+        Assert.Equal("Spellbook", ResolveCaption(SpellbookWindowController.SpellTabId));
+        Assert.Equal("Components", ResolveCaption(SpellbookWindowController.ComponentTabId));
+
+        string? ResolveCaption(uint id)
+        {
+            ElementInfo node = Assert.IsType<ElementInfo>(Find(root, id));
+            Assert.True(node.TryGetEffectiveProperty(0x17u, out UiPropertyValue label));
+            return strings.Resolve(label.StringInfoValue);
+        }
+    }
+
+    private static ElementInfo? Find(ElementInfo root, uint id)
+    {
+        if (root.Id == id) return root;
+        foreach (ElementInfo child in root.Children)
+            if (Find(child, id) is { } found) return found;
+        return null;
+    }
 }

tests/AcDream.App.Tests/UI/Layout/SpellbookWindowControllerTests.cs

@@ -26,7 +26,16 @@ public sealed class SpellbookWindowControllerTests
     [Fact]
     public void RetailFixture_BindsTextTabs_AndPropagatesOpenClosedState()
     {
-        ImportedLayout layout = FixtureLoader.LoadSpellbook();
+        ImportedLayout layout = LayoutImporter.Build(
+            FixtureLoader.LoadSpellbookInfos(),
+            _ => (0u, 0, 0),
+            datFont: null,
+            stringResolve: value => value.StringId switch
+            {
+                49867858u => "Spellbook",
+                79360818u => "Components",
+                _ => null,
+            });
         var closed = new List<uint>();
         using SpellbookWindowController? controller = Bind(
             layout, new Spellbook(), close: () => closed.Add(1u));
@@ -37,6 +46,11 @@ public sealed class SpellbookWindowControllerTests
         UiElement spellPage = Assert.IsAssignableFrom<UiElement>(layout.FindElement(SpellbookWindowController.SpellPageId));
         UiElement componentPage = Assert.IsAssignableFrom<UiElement>(layout.FindElement(SpellbookWindowController.ComponentPageId));
 
+        Assert.Equal("Spellbook", Assert.Single(spellTab.LinesProvider()).Text);
+        Assert.Equal("Components", Assert.Single(componentTab.LinesProvider()).Text);
+        Assert.True(spellTab.DrawTextAfterChildren);
+        Assert.True(componentTab.DrawTextAfterChildren);
+
         Assert.Equal(RetailUiStateIds.Open, spellTab.ActiveRetailStateId);
         Assert.Equal(RetailUiStateIds.Closed, componentTab.ActiveRetailStateId);
         Assert.True(spellPage.Visible);