Implement modal startup movies

engine/Age.Engine.Tests/MovieOpcodeTests.cs

@@ -8,6 +8,46 @@ using Xunit;
 
 public class MovieOpcodeTests
 {
+    [Fact]
+    public void InitialRootFlagStartsSetAndClearsWhenExitScriptRuns()
+    {
+        var table = OpcodeTableJson.Load(Paths.OpcodesJson);
+        var root = ScriptAssembler.Assemble(table, "ROOT", new List<(int, Operand[])>
+        {
+            (0x130, new[] { new Operand(3, 0x100) }),
+            (0x9, System.Array.Empty<Operand>()),
+        }, System.Array.Empty<string>());
+        var vm = new VirtualMachine(root, table, new RecordingHost());
+
+        vm.Run();
+        Assert.Equal(1, vm.Globals[0x100]);
+
+        vm.Globals[0x100] = -1;
+        vm.Run();
+        Assert.Equal(0, vm.Globals[0x100]);
+    }
+
+    [Fact]
+    public void ModalMovieDispatchesRawResourceSurfaceAndFlags()
+    {
+        var table = OpcodeTableJson.Load(Paths.OpcodesJson);
+        var script = ScriptAssembler.Assemble(table, "MODAL", new List<(int, Operand[])>
+        {
+            (0x20f, new[] { new Operand(0, 0x335f), new Operand(0, 42), new Operand(0, 4) }),
+            (0x55, new[] { new Operand(3, 0x1234), new Operand(0, 0x5678) }),
+            (0x2, System.Array.Empty<Operand>()),
+        }, System.Array.Empty<string>());
+        var host = new RecordingHost();
+        var vm = new VirtualMachine(script, table, host);
+
+        vm.Run();
+
+        Assert.Equal(new[] { (0x335fL, 42, 4L) }, host.ModalMovies);
+        Assert.Equal(0x5678, vm.Globals[0x1234]);
+        vm.Gfx.BindDraw(1, 42, 0, 0, 1, 1, 0, 0);
+        Assert.Equal(0x335f, vm.Gfx.SnapshotVisibleObjects().Single().SurfaceResId);
+    }
+
     [Fact]
     public void Sc0000ResumesImmediatelyAfterMovieOpcodeAtBytecodeOffset13d1()
     {
@@ -68,6 +108,20 @@ public class MovieOpcodeTests
         Assert.Equal(8_194_052, movie.Bytes.Length);
     }
 
+    [Theory]
+    [InlineData(0x335f, "LOGO.AGF")]
+    [InlineData(0x3364, "OP.AGF")]
+    public void ModalMoviePayloadResolvesFromUniversalRawCatalog(int rawId, string expectedName)
+    {
+        var catalog = Sys4AssetCatalog.Load(Paths.Sys4Ini);
+        var resources = new ResourceMap(catalog, new Sys4AssetStore(catalog, Paths.GameDir));
+        var entry = resources.ResolveRawMovie(rawId);
+
+        Assert.Equal(expectedName, entry?.Name);
+        var movie = resources.ReadMovie(entry!);
+        Assert.Equal(new byte[] { 0, 0, 1, 0xba }, movie.Bytes[..4]);
+    }
+
     [Fact]
     public void Sc0000MoviePayloadDecodesAn800By600FrameOnWindows()
     {

engine/Age.Engine.Tests/NaturalBootIntegrationTests.cs

@@ -99,6 +99,13 @@ public class NaturalBootIntegrationTests
         {
             "SYSTEM4.BIN", "INITCONFIG.BIN", "INIT2.BIN",
         }, sink.Entered.Take(3));
+        int logo = sink.Entered.IndexOf("LOGO.BIN");
+        int opening = sink.Entered.IndexOf("OP.BIN");
+        int init = sink.Entered.IndexOf("INIT.BIN");
+        int title = sink.Entered.IndexOf("TITLE.BIN");
+        Assert.True(logo >= 0 && logo < opening && opening < init && init < title,
+            $"entered={string.Join(",", sink.Entered)}");
+        Assert.Equal(new[] { (0x335fL, 42, 4L), (0x3364L, 42, 4L) }, host.ModalMovies);
         Assert.Contains("TITLE.BIN", sink.Entered);
         Assert.Contains("GAMESTART.BIN", sink.Entered);
         Assert.Contains("UNITECH.BIN", sink.Entered);

engine/Age.Engine.Tests/TestSupport.cs

@@ -36,6 +36,7 @@ internal class RecordingHost : IHost
     public readonly List<int> SfxReleases = new();
     public readonly List<(int Target, long Duration)> BgmFades = new();
     public readonly List<(long Resource, int Surface, long Flags, long SyncMask)> Movies = new();
+    public readonly List<(long Resource, int Surface, long Flags)> ModalMovies = new();
     public readonly List<int> ClearedRenderTargets = new();
     public readonly List<(int First, int Count)> ReleasedSurfaceRanges = new();
     public readonly List<bool> MessageSkipChanges = new();
@@ -128,6 +129,8 @@ internal class RecordingHost : IHost
     public void FadeBgm(int targetPercent, long durationMs) => BgmFades.Add((targetPercent, durationMs));
     public void PlayMovieToSurface(long resourceId, int surfaceSlot, long movieFlags, long syncMask)
         => Movies.Add((resourceId, surfaceSlot, movieFlags, syncMask));
+    public void PlayModalMovieToSurface(long rawResourceId, int surfaceSlot, long movieFlags)
+        => ModalMovies.Add((rawResourceId, surfaceSlot, movieFlags));
 }
 
 internal sealed class MapProvider : IScriptProvider