Implement system menu show delay opcodes

engine/Age.Engine.Tests/SystemMenuShowDelayOpcodeTests.cs

@@ -0,0 +1,71 @@
+using Age.Engine.Model;
+using Age.Engine.Sys4;
+using Age.Engine.Vm;
+
+public class SystemMenuShowDelayOpcodeTests
+{
+    private static readonly OpcodeTable Table = OpcodeTableJson.Load(Paths.OpcodesJson);
+    private static Operand I(long value) => new(0, value);
+    private static Operand G(long address) => new(3, address);
+    private static (int, Operand[]) Exit() => (0x2, Array.Empty<Operand>());
+
+    [Fact]
+    public void System4DelayRoundTripsThroughThePairedGetter()
+    {
+        Script system4 = ScriptAssembler.Assemble(Table, "SYSTEM4.BIN",
+        [
+            (0x149, [I(1000)]),
+            (0x148, [G(0x100)]),
+            Exit(),
+        ], []);
+        var vm = new VirtualMachine(system4, Table, new RecordingHost());
+
+        Assert.Equal(0u, vm.SystemMenuShowDelayMilliseconds);
+
+        vm.Run();
+
+        Assert.Equal(1000u, vm.SystemMenuShowDelayMilliseconds);
+        Assert.Equal(1000, vm.Globals[0x100]);
+    }
+
+    [Fact]
+    public void SetterAndGetterPreserveTheCompleteNativeDword()
+    {
+        Script system4 = ScriptAssembler.Assemble(Table, "SYSTEM4.BIN",
+        [
+            (0x149, [I(0x80000001L)]),
+            (0x148, [G(0x100)]),
+            Exit(),
+        ], []);
+        var vm = new VirtualMachine(system4, Table, new RecordingHost());
+
+        vm.Run();
+
+        Assert.Equal(0x80000001u, vm.SystemMenuShowDelayMilliseconds);
+        Assert.Equal(unchecked((int)0x80000001u), vm.Globals[0x100]);
+    }
+
+    [Fact]
+    public void RootSceneReloadRestoresTheZeroDefault()
+    {
+        Script reloadedSystem4 = ScriptAssembler.Assemble(Table, "SYSTEM4.BIN",
+        [
+            (0x148, [G(0x100)]),
+            Exit(),
+        ], []);
+        Script initial = ScriptAssembler.Assemble(Table, "INITIAL",
+        [
+            (0x149, [I(1000)]),
+            (0x9, Array.Empty<Operand>()),
+        ], []);
+        var provider = new MapProvider(new Dictionary<long, Script> { [0] = reloadedSystem4 });
+        var host = new RecordingHost();
+        var vm = new VirtualMachine(initial, Table, host, provider: provider);
+
+        vm.Run();
+
+        Assert.Equal(0u, vm.SystemMenuShowDelayMilliseconds);
+        Assert.Equal(0, vm.Globals[0x100]);
+        Assert.Equal(1, host.SceneContextResets);
+    }
+}

engine/Age.Engine/Vm/VirtualMachine.cs

@@ -91,6 +91,9 @@ public sealed class VirtualMachine
     // EngineCtx +0xa0d10: AGERC queries this through IAGEService to gray its native
     // settings/save menu actions while CONFIG owns the scripted settings screen.
     private int _systemMenuActionsEnabled = 1;
+    // EngineCtx +0x5511c: unsigned TIMER_SHOWMENU dwell threshold. Native op 0x148
+    // returns the same dword through the VM's signed integer-cell representation.
+    private uint _systemMenuShowDelayMilliseconds;
     private readonly Dictionary<string, int> _valueSwitchTargets = new(StringComparer.Ordinal);
     // Native EngineCtx owns 11 lazily allocated integer FIFOs at +0x55130. ATSEEK/MVSEEK use
     // slot zero as their packed-coordinate flood-fill worklist; op 0x132 replaces a slot.
@@ -115,6 +118,7 @@ public sealed class VirtualMachine
     public bool AutoMessageEnabled => _autoMessageEnabled;
     public bool MessageSkipEnabled => _messageSkipEnabled;
     public int SystemMenuActionsEnabled => _systemMenuActionsEnabled;
+    public uint SystemMenuShowDelayMilliseconds => _systemMenuShowDelayMilliseconds;
     public string PendingDiagnosticText => _diagnosticOutput.PendingText;
     /// <summary>
     /// Zero-based active-frame cutoff selected by opcode 0x1ad, or null when no surviving marker
@@ -786,6 +790,7 @@ public sealed class VirtualMachine
         _advReadSkipState = false;
         _advTextStyle = AdvTextStyle.Default;
         _systemMenuActionsEnabled = 1;
+        _systemMenuShowDelayMilliseconds = 0;
         TextHistory.SetRecordingEnabled(true);
         _host.SetMessageSkipActive(false);
         _host.SetPhysicalMessageSkipActive(false);
@@ -2343,6 +2348,14 @@ public sealed class VirtualMachine
             case "u0041FB10": // pre-reference compatibility
                 _systemMenuActionsEnabled = unchecked((int)Read(a[0]));
                 return pc + 1;
+            case "get-system-menu-show-delay": // 0x148: paired TIMER_SHOWMENU getter
+            case "u004160A0": // pre-reference compatibility
+                Write(a[0], unchecked((int)_systemMenuShowDelayMilliseconds));
+                return pc + 1;
+            case "set-system-menu-show-delay": // 0x149: top-edge dwell threshold in milliseconds
+            case "u0041FCE0": // pre-reference compatibility
+                _systemMenuShowDelayMilliseconds = unchecked((uint)Read(a[0]));
+                return pc + 1;
             case "get-message-glyph-delay": // 0x7f
             case "u00414C60":
                 Write(a[0], _messageGlyphDelayMilliseconds); return pc + 1;