Merge: A2b graphics geometry (0x208 keystone + blit compositor)

Opening event-CG sequence now renders correctly. 0x208 get-texture-size
implemented as a real VM op; faithful 800x600 immediate-mode blit compositor;
gfx + --shot diagnostics. Post-opening background/sprite anchor drift is
characterized and deferred to the anchor-record subsystem (next chunk).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/opcode-reference.md

@@ -81,6 +81,11 @@
 - **grounding:** source=inference, confidence=med
 - **evidence:** confirm via frida
 
+### 0x208 `get-texture-size` (get-texture-size, argc 3)
+- **summary:** 0x208 (slot)(out_w)(out_h) — writes the loaded texture's width/height into two output globals; keystone for bytecode-computed sprite/bg geometry (SC0000 label_12649)
+- **grounding:** source=inference, confidence=med
+- **evidence:** SC0000 label_12649: set-texture(resId,slot) then 0x208(slot)->w,h feeds w/2 horizontal-center + foot-anchor subtraction into draw-texture dst; stubbing yields 0x0 sizes / off-center draws
+
 ### 0x217 `gfx-geom?` (u004211E0, argc 4)
 - **summary:** 4 global-ints; part of a 0x217/0x218/0x21a geometry chain
 - **grounding:** source=inference, confidence=low
@@ -840,10 +845,6 @@ op 0x90 (u0041BEB0, argc 7): `0x90 x y w h tgt_a tgt_b tgt_c`. Kelebek left it "
 - **summary:** —
 - **grounding:** source=kelebek, confidence=low
 
-### 0x208 `u00420BF0` (u00420BF0, argc 3)
-- **summary:** —
-- **grounding:** source=kelebek, confidence=low
-
 ### 0x20a `u00420CE0` (u00420CE0, argc 1)
 - **summary:** —
 - **grounding:** source=kelebek, confidence=low

docs/phase-a-slice-plan.md

@@ -245,6 +245,40 @@ of the above. **Watch-items:** BGM looping is whole-file for now (Eushully OGGs
 `LOOPLENGTH` Vorbis comments — refine later); `play-sound-effect`(0xb4, argc 2) left stubbed (arg roles
 unconfirmed).
 
+### A2b-Geometry — `0x208` keystone + blit compositor (2026-07-06)
+
+Spec/plan: `docs/superpowers/{specs,plans}/2026-07-06-a2b-graphics-geometry*.md`. **Shipped & verified:**
+the CG-load subroutine (`SC0000.asm` `label_12649`) computes all sprite/background geometry **in
+bytecode** (`add`/`sub`/`div`/`lookup-array`); the only missing native primitive was **`0x208 =
+get-texture-size(slot) → (out_w, out_h)`**. Implemented as a real VM op (`IHost.GetTextureSize`, writes
+the two output globals); non-Godot hosts return `(0,0)` so trace/selftest parity holds (engine 11/11,
+`--selftest` byte-identical). Replaced the TextureRect-per-slot approximation with a faithful **800×600
+immediate-mode blit compositor** (`Main.BlitSlot`: `_screen.BlitRect(src rect → dst)` in execution order,
+one displayed `TextureRect`; source dims read from the pre-converted BMP header on the VM thread via
+`BmpHeader.ReadDims`, so the bytecode's geometry math sees real sizes synchronously). New diagnostics:
+`Age.Cli gfx <SCENE>` (headless numeric oracle — dumps per-draw resolved file + computed geometry) and
+`godot … -- --shot <png> [--shot-page N]` (page-gated screenshot capture). **The opening event-CG sequence
+renders correctly** — full-screen CG at `(0,0)` with dialogue over it (verified by screenshot, SC0000
+pages 1/3).
+
+**Slot-0 seed (bug found & fixed via the gfx oracle + user eyeball):** slot 0 is the **primary/screen
+surface** (800×600), normally created by engine-boot init the single-scene harness skips. Cold, `0x208`
+measured `0×0`, and the anchor-preserve math (`base' = center − (w_new/2, h_new)`) then wrote a corrupted
+`(−400,−600)` into the **persistent base globals** — so the first CG was grey and CG2 inherited the
+corruption. Fix: seed `_slotDims[0] = (800,600)` (and record `create-texture(w,h)` dims) so the first CG's
+anchor stays an identity. This is the faithful stand-in for the skipped boot-time primary-surface creation.
+
+**DEFERRED (next chunk) — the sprite/background anchor-record subsystem.** Everything blits through slot 0
+as an immediate-mode canvas; the anchor-preserve base globals **accumulate drift** across textures of
+*different* sizes (same-size 800×600 CGs stay put; the first `BG*` 800×500 / `AE*` 800×800 / sprite starts
+a drift that accumulates — `BG030A→(300,500)`, next→`(450,100)`, →`(800,350)`…, marching bottom-right).
+The real engine doesn't drift because it stores each element's geometry in a **per-object record** via
+`0x217/0x218/0x21a` (currently no-op) and restores it (the `0x12683` if-branch reading the `0x3239` record
+table). Implementing that store/restore (+ the record layout, likely Frida-confirmed) is the fix for
+backgrounds **and** sprites together. Fades/alpha (`AE*`, `0x202/0x203`) and green chromakey remain
+deferred as before (the compositor is built to accept alpha later). Also out: true multi-surface (dest
+handle is collapsed onto the screen). The full-screen opening path is unaffected by any of these.
+
 ---
 
 ## Risks / open questions for A0

engine/Age.Cli/Program.cs

@@ -42,6 +42,28 @@ if (args[0] == "audio")
     return 0;
 }
 
+if (args[0] == "gfx")
+{
+    // gfx <SCENE.BIN> [0xADDR=VAL ...] — run the scene and dump executed texture ops in order with
+    // resolved file + computed geometry (set-texture / get-texture-size / draw-texture). Diagnostic only.
+    var sceneName = args[1];
+    var sceneKey = Path.GetFileNameWithoutExtension(sceneName).ToUpperInvariant();
+    var res = ResourceMap.Load();
+    var host = new GfxTraceHost(res, sceneKey);
+    var vm = new VirtualMachine(Sys4Loader.Load(Paths.Scripts()[sceneName.ToUpperInvariant()], table), table, host);
+    foreach (var s in args.Skip(2))
+    {
+        var kv = s.Split('=');
+        int k = kv[0].StartsWith("0x") ? Convert.ToInt32(kv[0], 16) : int.Parse(kv[0]);
+        long v = kv[1].StartsWith("0x") ? Convert.ToInt64(kv[1], 16) : long.Parse(kv[1]);
+        vm.Globals[k] = v;
+    }
+    vm.Run();
+    Console.WriteLine($"{sceneName}: {host.Events.Count} texture ops (halt: {vm.HaltReason})");
+    foreach (var line in host.Events) Console.WriteLine("  " + line);
+    return 0;
+}
+
 if (args[0] == "trace")
 {
     var scene = new Regex(@"^S[CP]\d{4}\.BIN$");
@@ -84,4 +106,53 @@ sealed class AudioTraceHost : IHost
     public void CreateTexture(int slot, int width, int height) { }
     public void SetTexture(long resourceId, int slot) { }
     public void DrawTexture(int slot, int srcX, int srcY, int width, int height, int dstX, int dstY) { }
+    public (int Width, int Height) GetTextureSize(int slot) => (0, 0);
+}
+
+sealed class GfxTraceHost : IHost
+{
+    private readonly ResourceMap _res;
+    private readonly string _scene;
+    private readonly Dictionary<int, string?> _slotBmp = new();   // slot -> resolved BMP path (or null)
+    // slot -> dims. Slot 0 is the primary/screen surface (800x600), normally created at engine boot which
+    // the single-scene harness skips; seed it so the first CG's anchor math stays correct (not 0x0).
+    private readonly Dictionary<int, (int W, int H)> _slotDims = new() { { 0, (800, 600) } };
+    public List<string> Events { get; } = new();
+    public GfxTraceHost(ResourceMap res, string scene) { _res = res; _scene = scene; }
+
+    public (int Width, int Height) GetTextureSize(int slot)
+    {
+        var d = _slotDims.TryGetValue(slot, out var v) ? v : (0, 0);
+        Events.Add($"get-tex-size slot={slot} -> {d.Item1}x{d.Item2}");
+        return d;
+    }
+
+    public void SetTexture(long resId, int slot)
+    {
+        var e = _res.Resolve(_scene, resId);
+        var bmp = e != null ? ResourceMap.TexturePath(e) : null;
+        _slotBmp[slot] = bmp;
+        _slotDims[slot] = BmpHeader.ReadDims(bmp);
+        Events.Add($"set-texture slot={slot} res=0x{resId:x} -> {(e?.Name ?? "<unresolved>")}"
+                   + (bmp == null ? " [NO BMP]" : ""));
+    }
+
+    public void DrawTexture(int slot, int sx, int sy, int w, int h, int dx, int dy)
+    {
+        _slotBmp.TryGetValue(slot, out var bmp);
+        Events.Add($"draw-texture slot={slot} src=({sx},{sy} {w}x{h}) dst=({dx},{dy}) "
+                   + $"file={(bmp != null ? System.IO.Path.GetFileName(bmp) : "<none>")}");
+    }
+
+    public void CreateTexture(int slot, int width, int height)
+    {
+        _slotDims[slot] = (width, height);
+        Events.Add($"create-texture slot={slot} {width}x{height}");
+    }
+    public void ShowText(int offset, string text) { }
+    public void CallScript(long id) { }
+    public void OnStub(int opcode) { }
+    public void WaitForInput() { }
+    public void PlayBgm(long id) { }
+    public void PlayVoice(long id) { }
 }

engine/Age.Engine.Tests/BmpHeaderTests.cs

@@ -0,0 +1,33 @@
+using System.IO;
+using Age.Engine.Sys4;
+using Xunit;
+
+public class BmpHeaderTests
+{
+    [Fact]
+    public void ReadDimsReadsWidthAndHeightFromBmpHeader()
+    {
+        // Minimal 54-byte BMP header (BITMAPFILEHEADER 14 + BITMAPINFOHEADER 40); width=4, height=3.
+        var b = new byte[54];
+        b[0] = (byte)'B'; b[1] = (byte)'M';
+        System.BitConverter.GetBytes(40).CopyTo(b, 14);   // header size
+        System.BitConverter.GetBytes(4).CopyTo(b, 18);    // width
+        System.BitConverter.GetBytes(3).CopyTo(b, 22);    // height
+        var tmp = Path.Combine(Path.GetTempPath(), "agehdr_test.bmp");
+        File.WriteAllBytes(tmp, b);
+        try
+        {
+            var (w, h) = BmpHeader.ReadDims(tmp);
+            Assert.Equal(4, w);
+            Assert.Equal(3, h);
+        }
+        finally { File.Delete(tmp); }
+    }
+
+    [Fact]
+    public void ReadDimsReturnsZeroForMissingFile()
+    {
+        var (w, h) = BmpHeader.ReadDims(Path.Combine(Path.GetTempPath(), "does_not_exist_agehdr.bmp"));
+        Assert.Equal((0, 0), (w, h));
+    }
+}

engine/Age.Engine.Tests/TextureGeometryTests.cs

@@ -0,0 +1,46 @@
+using System.Collections.Generic;
+using Age.Engine.Hosting;
+using Age.Engine.Model;
+using Age.Engine.Sys4;
+using Age.Engine.Vm;
+using Xunit;
+
+public class TextureGeometryTests
+{
+    private sealed class FakeSizeHost : IHost
+    {
+        public void ShowText(int o, string t) { }
+        public void CallScript(long id) { }
+        public void OnStub(int op) { }
+        public void WaitForInput() { }
+        public void CreateTexture(int slot, int w, int h) { }
+        public void SetTexture(long resId, int slot) { }
+        public void DrawTexture(int slot, int sx, int sy, int w, int h, int dx, int dy) { }
+        public void PlayBgm(long id) { }
+        public void PlayVoice(long id) { }
+        public (int Width, int Height) GetTextureSize(int slot) => (0x140, 0xC8);
+    }
+
+    [Fact]
+    public void GetTextureSizeWritesHostDimsIntoOutputGlobals()
+    {
+        var table = OpcodeTableJson.Load(Paths.OpcodesJson);
+        // 0x208 (global-int 50)(global-int 60)(global-int 61): slot=50, out_w=G[60], out_h=G[61]
+        const int T_GINT = 3;
+        var ins = new Instruction(0, 0x208, new[]
+        {
+            new Operand(T_GINT, 50), new Operand(T_GINT, 60), new Operand(T_GINT, 61),
+        });
+        var script = new Script
+        {
+            Header = new ScriptHeader(0, 0, 0, 0, 0, 0),
+            Instructions = new[] { ins },
+            IndexByOffset = new Dictionary<int, int> { { 0, 0 } },
+            Strings = new Dictionary<int, string>(),
+        };
+        var vm = new VirtualMachine(script, table, new FakeSizeHost());
+        vm.Run();
+        Assert.Equal(0x140, vm.Globals[60]);
+        Assert.Equal(0xC8, vm.Globals[61]);
+    }
+}

engine/Age.Engine.Tests/TextureOpsTests.cs

@@ -18,6 +18,7 @@ public class TextureOpsTests
         public void CreateTexture(int slot, int w, int h) => Creates++;
         public void SetTexture(long resId, int slot) => Sets.Add((resId, slot));
         public void DrawTexture(int slot, int srcX, int srcY, int w, int h, int dstX, int dstY) => Draws.Add((slot, w, h));
+        public (int Width, int Height) GetTextureSize(int slot) => (0, 0);
         public void PlayBgm(long id) { }
         public void PlayVoice(long id) { }
     }

engine/Age.Engine.Tests/WaitForInputTests.cs

@@ -17,6 +17,7 @@ public class WaitForInputTests
         public void CreateTexture(int slot, int w, int h) { }
         public void SetTexture(long resId, int slot) { }
         public void DrawTexture(int slot, int srcX, int srcY, int w, int h, int dstX, int dstY) { }
+        public (int Width, int Height) GetTextureSize(int slot) => (0, 0);
         public void PlayBgm(long id) { }
         public void PlayVoice(long id) { }
     }

engine/Age.Engine/Hosting/CaptureHost.cs

@@ -11,6 +11,7 @@ public sealed class CaptureHost : IHost
     public void CreateTexture(int slot, int width, int height) { }
     public void SetTexture(long resourceId, int slot) { }
     public void DrawTexture(int slot, int srcX, int srcY, int width, int height, int dstX, int dstY) { }
+    public (int Width, int Height) GetTextureSize(int slot) => (0, 0);
     public void PlayBgm(long id) { }
     public void PlayVoice(long id) { }
 }

engine/Age.Engine/Hosting/IHost.cs

@@ -8,6 +8,7 @@ public interface IHost
     void CreateTexture(int slot, int width, int height);
     void SetTexture(long resourceId, int slot);
     void DrawTexture(int slot, int srcX, int srcY, int width, int height, int dstX, int dstY);
+    (int Width, int Height) GetTextureSize(int slot);
     void PlayBgm(long id);
     void PlayVoice(long id);
 }

engine/Age.Engine/Sys4/BmpHeader.cs

@@ -0,0 +1,25 @@
+namespace Age.Engine.Sys4;
+
+/// <summary>
+/// Reads pixel dimensions from a BMP file header (BITMAPINFOHEADER: width at byte 18, height at byte 22,
+/// both little-endian int32; height may be negative for top-down bitmaps). Used to give the VM the
+/// texture size that opcode 0x208 (get-texture-size) needs, without decoding pixels. Our textures are
+/// pre-converted BMPs (tools/convert_agf.py).
+/// </summary>
+public static class BmpHeader
+{
+    public static (int Width, int Height) ReadDims(string? path)
+    {
+        if (string.IsNullOrEmpty(path) || !File.Exists(path)) return (0, 0);
+        try
+        {
+            var b = new byte[26];
+            using var fs = File.OpenRead(path);
+            if (fs.Read(b, 0, 26) < 26 || b[0] != (byte)'B' || b[1] != (byte)'M') return (0, 0);
+            int w = System.BitConverter.ToInt32(b, 18);
+            int h = System.BitConverter.ToInt32(b, 22);
+            return (System.Math.Abs(w), System.Math.Abs(h));
+        }
+        catch { return (0, 0); }
+    }
+}

engine/Age.Engine/Vm/VirtualMachine.cs

@@ -175,6 +175,12 @@ public sealed class VirtualMachine
             case "draw-texture":   // (handle, slot, srcX, srcY, w, h, dstX, dstY)
                 _host.DrawTexture((int)Read(a[1]), (int)Read(a[2]), (int)Read(a[3]), (int)Read(a[4]),
                                   (int)Read(a[5]), (int)Read(a[6]), (int)Read(a[7])); return pc + 1;
+            case "get-texture-size":   // 0x208 (slot) (out_w) (out_h)
+            {
+                var (gw, gh) = _host.GetTextureSize((int)Read(a[0]));
+                Write(a[1], gw); Write(a[2], gh);
+                return pc + 1;
+            }
             case "play-bgm":   _host.PlayBgm(Read(a[0])); return pc + 1;
             case "play-voice": _host.PlayVoice(Read(a[0])); return pc + 1;
             default:

godot/GodotAdvHost.cs

@@ -9,6 +9,9 @@ public sealed class GodotAdvHost : IHost
     private readonly ResourceMap _res;
     private readonly string _scene;                       // e.g. "SC0000" — for section_base
     private readonly Dictionary<int, string?> _slotBmp = new();          // slot -> pre-converted BMP path
+    // slot -> dims. Slot 0 is the primary/screen surface (800x600), normally created at engine boot which
+    // the single-scene harness skips; seed it so the first CG's anchor math stays correct (not 0x0).
+    private readonly Dictionary<int, (int W, int H)> _slotDims = new() { { 0, (800, 600) } };
     private readonly SemaphoreSlim _gate = new(0, 1);
     public volatile bool IsWaiting;
     public readonly List<(int Offset, string Text)> Captured = new();
@@ -24,8 +27,11 @@ public sealed class GodotAdvHost : IHost
         _main.CallDeferred("AppendLine", text);
     }
 
+    public volatile int Pages;   // VM-thread page counter (incremented before IsWaiting so shot-gating can't race)
+
     public void WaitForInput()
     {
+        Pages++;
         _main.CallDeferred("PageBreak");
         IsWaiting = true;
         _gate.Wait();
@@ -40,18 +46,25 @@ public sealed class GodotAdvHost : IHost
     public void OnStub(int opcode) { }
 
     // ---- texture ops (run on the VM thread; marshal Godot node work to the main thread) ----
-    public void CreateTexture(int slot, int width, int height) => _slotBmp[slot] = null;
+    public void CreateTexture(int slot, int width, int height) { _slotBmp[slot] = null; _slotDims[slot] = (width, height); }
 
     public void SetTexture(long resourceId, int slot)
     {
         var asset = _res.Resolve(_scene, resourceId);
-        _slotBmp[slot] = asset != null ? ResourceMap.TexturePath(asset) : null;
+        var bmp = asset != null ? ResourceMap.TexturePath(asset) : null;
+        _slotBmp[slot] = bmp;
+        _slotDims[slot] = BmpHeader.ReadDims(bmp);   // synchronous: dims from the header, no Godot Image
     }
 
+    // Dims are read from the BMP header on the VM thread so the bytecode's geometry math (which calls this
+    // synchronously right after set-texture) sees the real size. Pixels are blitted later on the main thread.
+    public (int Width, int Height) GetTextureSize(int slot)
+        => _slotDims.TryGetValue(slot, out var d) ? (d.W, d.H) : (0, 0);
+
     public void DrawTexture(int slot, int srcX, int srcY, int width, int height, int dstX, int dstY)
     {
         if (_slotBmp.TryGetValue(slot, out var bmp) && bmp != null)
-            _main.CallDeferred("DrawSlot", slot, bmp, dstX, dstY, width, height);
+            _main.CallDeferred("BlitSlot", bmp, srcX, srcY, width, height, dstX, dstY);
     }
 
     // ---- audio ops (OGG plays natively in Godot) ----

godot/Main.cs

@@ -7,8 +7,9 @@ using Age.Engine.Vm;
 
 public partial class Main : Godot.Control
 {
-    private Control _stage = null!;                       // texture layer (behind the text)
+    private TextureRect _screenView = null!;              // shows the composited screen backbuffer
-    private readonly Dictionary<int, TextureRect> _slots = new();
+    private Image _screen = null!;                        // 800x600 immediate-mode canvas
+    private ImageTexture _screenTex = null!;
     private Label _text = null!;
     private Label _status = null!;
     private AudioStreamPlayer _bgm = null!;                // looping background music
@@ -18,14 +19,26 @@ public partial class Main : Godot.Control
     private volatile bool _done;
     private bool _ended;
     private bool _selftest;
+    private string? _shotPath;                 // --shot <png>: capture a page then quit (dev tool)
+    private int _shotPage = 1;                  // --shot-page <n>: which page to capture (default 1)
+    private volatile int _pageCount;
+    private int _shotSettle;
+    private bool _shotDone;
 
     public override void _Ready()
     {
-        // texture stage, added first so it draws BEHIND the dialogue text
+        // Screen backbuffer: one 800x600 canvas that draw-texture blits into, shown behind the dialogue.
-        _stage = new Control();
+        _screen = Image.CreateEmpty(800, 600, false, Image.Format.Rgba8);
-        _stage.SetAnchorsAndOffsetsPreset(LayoutPreset.FullRect);
+        _screenTex = ImageTexture.CreateFromImage(_screen);
-        _stage.MouseFilter = MouseFilterEnum.Ignore;
+        _screenView = new TextureRect
-        AddChild(_stage);
+        {
+            Texture = _screenTex,
+            ExpandMode = TextureRect.ExpandModeEnum.IgnoreSize,
+            StretchMode = TextureRect.StretchModeEnum.Scale,
+            MouseFilter = MouseFilterEnum.Ignore,
+        };
+        _screenView.SetAnchorsAndOffsetsPreset(LayoutPreset.FullRect);
+        AddChild(_screenView);   // added first -> draws behind the text/status labels
 
         _text = new Label { AutowrapMode = TextServer.AutowrapMode.WordSmart };
         _text.SetAnchorsAndOffsetsPreset(LayoutPreset.FullRect);
@@ -57,7 +70,13 @@ public partial class Main : Godot.Control
         AddChild(_bgm);
         AddChild(_voice);
 
-        _selftest = System.Array.IndexOf(OS.GetCmdlineUserArgs(), "--selftest") >= 0;
+        var userArgs = OS.GetCmdlineUserArgs();
+        _selftest = System.Array.IndexOf(userArgs, "--selftest") >= 0;
+        for (int i = 0; i < userArgs.Length; i++)
+        {
+            if (userArgs[i] == "--shot" && i + 1 < userArgs.Length) _shotPath = userArgs[i + 1];
+            if (userArgs[i] == "--shot-page" && i + 1 < userArgs.Length) int.TryParse(userArgs[i + 1], out _shotPage);
+        }
 
         var table = OpcodeTableJson.Load(Paths.OpcodesJson);
         var script = Sys4Loader.Load(Paths.Scripts()["SC0000.BIN"], table);
@@ -67,10 +86,26 @@ public partial class Main : Godot.Control
 
         if (_selftest)
             _ = Task.Run(async () => { while (!_done) { if (_host.IsWaiting) _host.SignalInput(); await Task.Delay(1); } });
+        // --shot: auto-advance up to (but not past) the target page, then _Process captures + quits.
+        if (_shotPath != null)
+            _ = Task.Run(async () => { while (!_done) { if (_host.IsWaiting && _host.Pages < _shotPage) _host.SignalInput(); await Task.Delay(1); } });
     }
 
     public override void _Process(double delta)
     {
+        // --shot: once the target page is composed and parked at wait-for-input, settle a few frames then grab it.
+        if (_shotPath != null && !_shotDone && (_host.Pages >= _shotPage && _host.IsWaiting || _done))
+        {
+            if (++_shotSettle >= 3)
+            {
+                _shotDone = true;
+                var img = GetViewport().GetTexture().GetImage();
+                img.SavePng(_shotPath);
+                GD.Print($"SHOT saved page {_pageCount} -> {_shotPath}");
+                GetTree().Quit(0);
+            }
+            return;
+        }
         if (_done && !_ended)
         {
             _ended = true;
@@ -92,28 +127,24 @@ public partial class Main : Godot.Control
     public override void _ExitTree() { _host?.SignalInput(); }
 
     // ---- UI methods invoked on the main thread via CallDeferred ----
-    // Composite a resolved texture into a slot at (x,y) sized (w,h). One TextureRect per slot,
+    // Blit a source BMP (src rect) onto the screen backbuffer at (dstX,dstY), then refresh the display
-    // layered in draw order (backgrounds are drawn before sprites, so they sit behind).
+    // texture. Execution order == paint order, so later draws (sprites) land over earlier ones (bg).
-    public void DrawSlot(int slot, string bmpPath, int x, int y, int w, int h)
+    public void BlitSlot(string bmpPath, int srcX, int srcY, int w, int h, int dstX, int dstY)
     {
-        var img = new Image();
+        var src = new Image();
-        var err = img.LoadBmpFromBuffer(System.IO.File.ReadAllBytes(bmpPath));
+        if (src.LoadBmpFromBuffer(System.IO.File.ReadAllBytes(bmpPath)) != Error.Ok)
-        if (err != Error.Ok) { GD.Print($"BMP load failed {bmpPath}: {err}"); return; }
+        { GD.Print($"BMP load failed {bmpPath}"); return; }
-        if (!_slots.TryGetValue(slot, out var tr))
+        if (src.GetFormat() != Image.Format.Rgba8) src.Convert(Image.Format.Rgba8);
-        {
+
-            tr = new TextureRect
+        // Clamp the source rect to the image; a zero/negative size falls back to the full image.
-            {
+        int sw = w > 0 ? w : src.GetWidth();
-                ExpandMode = TextureRect.ExpandModeEnum.IgnoreSize,
+        int sh = h > 0 ? h : src.GetHeight();
-                StretchMode = TextureRect.StretchModeEnum.Scale,
+        sw = System.Math.Min(sw, src.GetWidth() - srcX);
-                MouseFilter = MouseFilterEnum.Ignore,
+        sh = System.Math.Min(sh, src.GetHeight() - srcY);
-            };
+        if (sw <= 0 || sh <= 0) return;
-            _stage.AddChild(tr);
+
-            _slots[slot] = tr;
+        _screen.BlitRect(src, new Rect2I(srcX, srcY, sw, sh), new Vector2I(dstX, dstY));
-        }
+        _screenTex.Update(_screen);
-        tr.Texture = ImageTexture.CreateFromImage(img);
-        tr.Position = new Vector2(x, y);
-        tr.Size = new Vector2(w > 0 ? w : img.GetWidth(), h > 0 ? h : img.GetHeight());
-        tr.Visible = true;
     }
 
     // Load an OGG off disk and play it. BGM loops; voice plays once, cutting off any prior line.
@@ -136,7 +167,7 @@ public partial class Main : Godot.Control
     }
 
     public void AppendLine(string text) => _text.Text += text + "\n";
-    public void PageBreak() => _status.Text = "▼ click / Enter";
+    public void PageBreak() { _pageCount++; _status.Text = "▼ click / Enter"; }
     public void ClearPage() { _text.Text = ""; _status.Text = ""; }
     public void ShowEnd() => _status.Text = "— end —";
 

vm-map/opcodes.toml

@@ -4978,33 +4978,33 @@ observed_types = ["imm", "l-int"]
 
 [[opcode]]
 op = 0x208
-label = "u00420BF0"
+label = "get-texture-size"
 argc = 3
 abi_source = "kelebek+decode-validated"
 
 [opcode.semantics]
-name = "u00420BF0"
+name = "get-texture-size"
-category = "unknown"
+category = "draw"
-summary = ""
+summary = "0x208 (slot)(out_w)(out_h) — writes the loaded texture's width/height into two output globals; keystone for bytecode-computed sprite/bg geometry (SC0000 label_12649)"
 noop_headless = false
-source = "kelebek"
+source = "inference"
-confidence = "low"
+confidence = "med"
 depends_on = []
-evidence = ""
+evidence = "SC0000 label_12649: set-texture(resId,slot) then 0x208(slot)->w,h feeds w/2 horizontal-center + foot-anchor subtraction into draw-texture dst; stubbing yields 0x0 sizes / off-center draws"
 
 [[opcode.semantics.args]]
 i = 1
-role = ""
+role = "slot"
 observed_types = ["imm", "g-int", "l-int"]
 
 [[opcode.semantics.args]]
 i = 2
-role = ""
+role = "out_width"
 observed_types = ["g-int", "l-int"]
 
 [[opcode.semantics.args]]
 i = 3
-role = ""
+role = "out_height"
 observed_types = ["g-int", "l-int"]
 
 [[opcode]]