Calibrate native text weight and advances

docs/engine-re.md

@@ -2515,12 +2515,24 @@ backend-native approximation for every shipped mode-3 call because Himegari alwa
 `(1,1)` radii. The same style applicator covers live ADV, retained History, and surface text. Mode 2
 remains unimplemented and is unused by this game.
 
-The remaining raster behavior is still an approximation: weight 700 uses Godot
+A 2026-07-28 Windows calibration compared exact-profile GDI
-`VariationEmbolden=1.2`, and mode 3 does not reproduce AGE's exact sampled coverage at each ellipse
+`CreateFontIndirectW`/`GetTextExtentPoint32W`/`GetGlyphOutlineW(GGO_GRAY4_BITMAP)` results with Godot's
-angle. Exact GDI-compatible advances, grayscale coverage, and edge pixels require a dedicated glyph
+loaded TTCs. Six mixed kanji, kana, punctuation, full-width digit, and Latin samples found exact
-backend (or a deliberately calibrated approximation) behind the existing engine-owned layout/style
+horizontal agreement for regular 24px Mincho and regular 16px Gothic. GDI also produced identical
-contract. Portable configurable face substitutions/defaults are intentionally deferred to the broader
+measurements with the native negative half-height `lfWidth` and `lfWidth=0`; no horizontal scaling is
-runtime configuration design.
+needed for those profiles on this installation.
+
+The old `VariationEmbolden=1.2` was not a good weight-700 approximation: the sample glyph `魔` had
+coverage sum 6,651 versus native 4,615 (+44%), while complete strings remained as much as 9 pixels
+narrower than native. `VariationEmbolden=0.53` plus one pixel of glyph spacing yields coverage 4,600
+(-0.3%) and bounds all six complete-string errors to 0..3 pixels. Godot reports a 25px/17px line box
+for the native 24px/16px profiles, so presentation subtracts that one-pixel backend excess from the
+script's extra line spacing, retaining AGE's requested total line advance. The calibration is applied
+per bold font variation and through the common live/History/surface style path.
+
+Mode 3 still does not reproduce AGE's exact sampled coverage at each ellipse angle. Exact per-pixel
+parity beyond the calibrated profiles requires a dedicated glyph backend. Portable configurable face
+substitutions/defaults are intentionally deferred to the broader runtime configuration design.
 
 #### ADV wait indicator -- ops `0x73` / `0x72` (2026-07-11)
 

docs/phase-a-slice-plan.md

@@ -3357,6 +3357,25 @@ records, and the Godot self-test applies both modes to a real Label and checks i
 state. Validation: engine **431/431**, zero-warning Godot build, and threaded `SELFTEST OK` with
 `text-effect-modes=ok`. User visual acceptance passed on 2026-07-28.
 
+## ADV font weight and advance calibrated (2026-07-28)
+
+A disposable Windows GDI oracle measured six representative strings and the grayscale `魔` glyph
+against Godot's actual `msmincho.ttc`/`msgothic.ttc` presentation. Regular 24px Mincho and 16px Gothic
+advances match exactly, so neither face receives speculative horizontal scaling. The former
+`VariationEmbolden=1.2` overshot native weight-700 glyph coverage by 44% while remaining up to 9 pixels
+narrow across a complete sample string.
+
+The bold variation now uses measured `VariationEmbolden=0.53` plus one pixel of glyph spacing. Its
+grayscale coverage is within 0.3% of GDI and the six measured string widths are within 0..3 pixels.
+The shared style path also compensates for Godot reporting the two fonts' line boxes one pixel taller
+than AGE's explicit requested heights, preserving native total line advance during wrapping. The Godot
+self-test checks the calibrated variation and both 24px/16px spacing examples.
+
+Validation: engine **431/431**, zero-warning Godot build, and threaded `SELFTEST OK` with
+`font-calibration=ok`. The probes were deliberately disposable; the canonical measurements live in
+`docs/engine-re.md` rather than adding a Windows-only runtime/tool dependency. User visual acceptance
+passed on 2026-07-28.
+
 ## Persistence native-format reconnaissance complete (2026-07-24)
 
 The deferred save/profile ownership question now has a compatibility-mode answer. The remaining native

docs/platform-portability.md

@@ -31,7 +31,7 @@ or replaced before claiming portable exports.
 | AGE movie decode (`0x236` scene movies; `0x20f` modal LOGO/OP/ED) | `FfmpegMovieDecoder` is the sole factory over the project-owned `native/age_movie_ffmpeg` ABI | Windows-x64 passes the complete 213-payload installed video/audio corpus gate plus audible LOGO/OP/CHAPTER playback | Add target-specific native builds and export packaging |
 | Movie integration | Each surface owns a unique playback-instance id; `MovieRuntime` owns `IMovieDecoder` from an injected factory; video-only streams use monotonic pacing while audio-bearing streams use the Godot output clock | Concurrent/restarted uses of one asset have independent frame/audio/completion/teardown state; managed code is no longer Windows-annotated, while only the win-x64 native bundle exists today | Add Linux/macOS native builds and smoke gates |
 | Movie audio | ABI v2 returns timestamped stereo float PCM; bounded managed buffering feeds a per-playback Godot `AudioStreamGenerator` and routes native movie flags to engine buses | All 29 installed audio-bearing streams decode with signal; synchronized LOGO/OP/CHAPTER playback is audibly accepted | Treat absent, distorted, or unsynchronized audio from an audio-bearing movie as a runtime bug |
-| ADV font discovery/raster fidelity | Opcode `0x1a5` reaches presentation; `godot/Main.cs` loads Windows `ＭＳ 明朝`/`ＭＳ ゴシック` from their known TTC files when available, otherwise uses the existing Japanese-font/default fallback; native mode 1 maps to one Godot shadow glyph and shipped `(1,1)` mode 3 maps to a one-pixel outline | A normal Windows install preserves Himegari's face distinction and separate displaced-effect/outline profiles; Linux/macOS normally lack the proprietary fonts, while advances, wrapping, boldness, and exact grayscale coverage still depend on the substitute/backend | Add configurable default and requested-face substitutions as part of the broader runtime configuration design; for portable distribution bundle licensed metric-compatible faces or define profile substitutions, then decide whether exact AGE grayscale rasterization warrants a custom glyph backend |
+| ADV font discovery/raster fidelity | Opcode `0x1a5` reaches presentation; `godot/Main.cs` loads Windows `ＭＳ 明朝`/`ＭＳ ゴシック` from their known TTC files when available, otherwise uses the existing Japanese-font/default fallback; native mode 1 maps to one Godot shadow glyph and shipped `(1,1)` mode 3 maps to a one-pixel outline | On the reference Windows install, regular 24px Mincho/16px Gothic advances match GDI exactly; calibrated bold coverage is within 0.3%, six-sample string drift is at most 3px, and backend line-box excess is compensated. Other platforms normally lack the proprietary faces, so substitute metrics remain profile-dependent | Add configurable default and requested-face substitutions as part of the broader runtime configuration design; for portable distribution bundle licensed metric-compatible faces or define profile substitutions, then decide whether broader exact AGE grayscale rasterization warrants a custom glyph backend |
 | Filesystem semantics | Several filename and containment comparisons use `OrdinalIgnoreCase`; installed assets are conventionally uppercase | Needs validation on case-sensitive filesystems; may hide casing or containment mistakes | Add Linux/macOS tests with mixed-case synthetic roots and use filesystem-appropriate containment rules |
 | Save/profile storage | Managed `DirectoryNativeDatStore` under Godot `user://SAVE`; native S3SD/S4SD/S3RT files and 24-bit BMP thumbnails | No Win32 path API at runtime; port saves remain isolated from the original installation | Validate replace/flush, case, permissions, and interrupted-write behavior on each export target |
 | Install/repository discovery | `engine/Age.Engine/Sys4/Paths.cs` finds `age-reimpl` above `AppContext.BaseDirectory` and assumes the current workspace sibling layout | Suitable for development, not packaged exports on any OS | Replace runtime discovery with a user-selected game root/profile; retain repository paths only for developer tools/tests |

godot/Main.cs

@@ -16,6 +16,11 @@ public partial class Main : Godot.Control
 {
     private const int ScreenWidth = 800;
     private const int ScreenHeight = 600;
+    // Calibrated against GDI GetGlyphOutlineW(GGO_GRAY4_BITMAP) for Himegari's 24px MS Mincho
+    // weight-700 profile. This matches native glyph coverage while one pixel of spacing approximates
+    // GDI's synthetic-bold advance expansion; see docs/engine-re.md.
+    private const float NativeBoldEmbolden = 0.53f;
+    private const int NativeBoldGlyphSpacing = 1;
     private TextureRect _screenView = null!;              // shows the composited screen backbuffer
     private Image _screen = null!;                        // 800x600 immediate-mode canvas
     private ImageTexture _screenTex = null!;
@@ -1374,6 +1379,7 @@ public partial class Main : Godot.Control
     {
         int fontSize = style.PrimaryFontSize > 0 ? style.PrimaryFontSize : 24;
         Font regularFont = ResolvePresentationFont(style.FontFace, out string fontKey);
+        Font presentationFont = regularFont;
         if (style.Bold)
         {
             if (!_presentationBoldFonts.TryGetValue(fontKey, out FontVariation? boldFont))
@@ -1381,26 +1387,31 @@ public partial class Main : Godot.Control
                 boldFont = new FontVariation
                 {
                     BaseFont = regularFont,
-                    VariationEmbolden = 1.2f,
+                    VariationEmbolden = NativeBoldEmbolden,
+                    SpacingGlyph = NativeBoldGlyphSpacing,
                 };
                 _presentationBoldFonts.Add(fontKey, boldFont);
             }
-            label.AddThemeFontOverride("font", boldFont);
+            presentationFont = boldFont;
         }
-        else label.AddThemeFontOverride("font", regularFont);
+        label.AddThemeFontOverride("font", presentationFont);
         label.AddThemeFontSizeOverride("font_size", fontSize);
         label.AddThemeColorOverride("font_color", RgbColor(style.TextColor, Colors.White));
         Color effectColor = RgbColor(style.EffectColor, new Color(0.38f, 0.38f, 0.38f));
         AdvTextEffectTheme effect = ResolveAdvTextEffectTheme(style);
         label.AddThemeColorOverride("font_outline_color", effectColor);
         label.AddThemeColorOverride("font_shadow_color", effect.ShadowEnabled ? effectColor : Colors.Transparent);
-        label.AddThemeConstantOverride("line_spacing", style.LineSpacing);
+        label.AddThemeConstantOverride("line_spacing",
+            CalibratedLineSpacing(style.LineSpacing, fontSize, presentationFont.GetHeight(fontSize)));
         label.AddThemeConstantOverride("outline_size", effect.OutlineSize);
         label.AddThemeConstantOverride("shadow_offset_x", effect.ShadowOffsetX);
         label.AddThemeConstantOverride("shadow_offset_y", effect.ShadowOffsetY);
         label.AddThemeConstantOverride("shadow_outline_size", 0);
     }
 
+    private static int CalibratedLineSpacing(int nativeSpacing, int nativeFontHeight, float backendFontHeight)
+        => nativeSpacing + nativeFontHeight - System.Math.Max(1, (int)System.MathF.Round(backendFontHeight));
+
     private readonly record struct AdvTextEffectTheme(
         int OutlineSize,
         bool ShadowEnabled,
@@ -2104,18 +2115,35 @@ public partial class Main : Godot.Control
         });
         textEffectModesOk &= textEffectSmoke.GetThemeConstant("outline_size") == 1
                              && textEffectSmoke.GetThemeColor("font_shadow_color").A < 0.01f;
+        ApplyAdvTextStyle(textEffectSmoke, AdvTextStyle.Default with
+        {
+            PrimaryFontSize = 24,
+            Bold = true,
+            FontFace = "ＭＳ 明朝",
+            LineSpacing = 8,
+        });
+        var calibratedBold = textEffectSmoke.GetThemeFont("font") as FontVariation;
+        bool fontCalibrationOk = calibratedBold != null
+                                 && System.Math.Abs(calibratedBold.VariationEmbolden
+                                                    - NativeBoldEmbolden) < 0.001f
+                                 && calibratedBold.SpacingGlyph == NativeBoldGlyphSpacing
+                                 && CalibratedLineSpacing(8, 24, 25) == 7
+                                 && CalibratedLineSpacing(9, 16, 17) == 8
+                                 && textEffectSmoke.GetThemeConstant("line_spacing")
+                                    == CalibratedLineSpacing(
+                                        8, 24, calibratedBold.GetHeight(24));
         textEffectSmoke.QueueFree();
         ok &= launcherOk && sleepMinimumOk && inputTranslationOk && cp932WavMetadataOk
-              && bgmReplacementCancelsFade && textEffectModesOk;
+              && bgmReplacementCancelsFade && textEffectModesOk && fontCalibrationOk;
         if (ok) GD.Print($"SELFTEST OK: threaded host matches headless ({actual.Count} lines, full handling); " +
                          $"debug launcher catalog/UI smoke ({debugEntries.Count} packed scripts); " +
                          $"sleep-min=1ms; native-key-translation=ok; cp932-wav-info=ok; " +
-                         $"bgm-fade-replacement=ok; text-effect-modes=ok");
+                         $"bgm-fade-replacement=ok; text-effect-modes=ok; font-calibration=ok");
         else GD.Print($"SELFTEST FAIL: threaded={actual.Count} vs headless={expected.Count}; " +
                       $"debug-launcher={launcherOk}; sleep-min={sleepMinimumOk}; " +
                       $"native-key-translation={inputTranslationOk}; cp932-wav-info={cp932WavMetadataOk}; " +
                       $"bgm-fade-replacement={bgmReplacementCancelsFade}; " +
-                      $"text-effect-modes={textEffectModesOk}");
+                      $"text-effect-modes={textEffectModesOk}; font-calibration={fontCalibrationOk}");
         GetTree().Quit(ok ? 0 : 1);
     }