dmd: support DMD Studio colorization bypass

VisualPinball.Engine.DMD.Unity/Runtime/AssemblyInfo.cs

@@ -0,0 +1,3 @@
+using System.Runtime.CompilerServices;
+
+[assembly: InternalsVisibleTo("VisualPinball.Engine.DMD.Unity.Test")]

VisualPinball.Engine.DMD.Unity/Runtime/DmdBridgePlayer.cs

@@ -97,6 +97,7 @@ public class DmdBridgePlayer : MonoBehaviour
 		private DmdBridgeSettings _settings;
 		private DmdBridgeSettings _appliedSettings;
 		private DmdBridgeSettings _lastFallbackSettings;
+		private readonly DmdColorizationPolicy _colorizationPolicy = new DmdColorizationPolicy();
 		private DateTime _appliedConfigWriteTimeUtc;
 		private string _appliedConfigPath;
 		private bool _missingDisplayWarningLogged;
@@ -196,8 +197,9 @@ private void HandleDisplaysRequested(object sender, RequestedDisplays requestedD
 					continue;
 				}
 
-				EnsurePipeline(display);
-				_pipeline?.Clear();
+				if (EnsurePipeline(display)) {
+					_pipeline?.Clear();
+				}
 				return;
 			}
 		}
@@ -231,7 +233,24 @@ private void HandleDisplayUpdateFrame(object sender, DisplayFrameData frame)
 				}
 			}
 
-			_pipeline.Push(frame);
+			// This handler runs on Unity's main thread. Rebuilding here is intentional: the pipeline
+			// worker cannot dispose itself because disposal waits for that worker to finish.
+			var colorizationAction = _colorizationPolicy.ObserveFrame(frame.Format,
+				_pipeline != null && _pipeline.UsesColorization, out var shouldWarn);
+			if (colorizationAction == DmdColorizationPipelineAction.Bypass) {
+				if (shouldWarn) {
+					var recovery = _colorizationPolicy.AwaitingSupportedColorizedFrame
+						? " temporarily; colorization will resume when Dmd2/Dmd4 arrives"
+						: string.Empty;
+					Logger.Warn($"[DMD] Unsupported colorization source format {frame.Format} — bypassing colorization{recovery} for display \"{frame.Id}\".");
+				}
+				EnsurePipeline(_currentDisplay, force: true);
+			} else if (colorizationAction == DmdColorizationPipelineAction.Restore) {
+				Logger.Info($"[DMD] Supported colorization format {frame.Format} arrived — restoring colorization for display \"{frame.Id}\".");
+				EnsurePipeline(_currentDisplay, force: true);
+			}
+
+			_pipeline?.Push(frame);
 		}
 
 		private bool IsTargetDisplay(string id)
@@ -242,7 +261,7 @@ private bool IsTargetDisplay(string id)
 				: string.Equals(id, targetDisplayId, StringComparison.OrdinalIgnoreCase);
 		}
 
-		private static bool TryInferDisplayConfig(DisplayFrameData frame, out DisplayConfig display)
+		internal static bool TryInferDisplayConfig(DisplayFrameData frame, out DisplayConfig display)
 		{
 			display = null;
 			if (frame?.Data == null) {
@@ -290,11 +309,12 @@ private static bool TryInferDimensions(int pixelCount, out int width, out int he
 			}
 		}
 
-		private void EnsurePipeline(DisplayConfig display, bool force = false)
+		private bool EnsurePipeline(DisplayConfig display, bool force = false)
 		{
+			_colorizationPolicy.SelectDisplay(display);
 			_currentDisplay = display;
 			if (!force && _pipeline != null && _pipeline.Matches(display)) {
-				return;
+				return false;
 			}
 
 			_pipeline?.Dispose();
@@ -303,14 +323,25 @@ private void EnsurePipeline(DisplayConfig display, bool force = false)
 			if (destinations.Count == 0) {
 				Logger.Warn("[DMD] No DMD destinations are available; bridge will ignore frames.");
 				_pipeline = null;
-				return;
+				return true;
 			}
 
-			var converter = CreateConverter();
-			_resolvedConverter = converter?.Name ?? "none";
-			RequestSourceFrameFormat(converter != null ? DisplayFrameFormat.Dmd4 : DisplayFrameFormat.Dmd8);
+			var converter = _colorizationPolicy.BypassColorization ? null : CreateConverter();
+			_resolvedConverter = _colorizationPolicy.BypassColorization
+				? "bypassed (unsupported source format)"
+				: converter?.Name ?? "none";
+			RequestSourceFrameFormat(PreferredSourceFormat(converter != null, _colorizationPolicy));
 			_pipeline = new DmdPipeline(display, destinations, converter, _settings.FlipHorizontally);
 			Logger.Info($"[DMD] Pipeline for \"{display.Id}\" created with {destinations.Count} destination(s).");
+			return true;
+		}
+
+		internal static DisplayFrameFormat PreferredSourceFormat(bool converterAvailable,
+			DmdColorizationPolicy policy)
+		{
+			return converterAvailable || policy != null && policy.AwaitingSupportedColorizedFrame
+				? DisplayFrameFormat.Dmd4
+				: DisplayFrameFormat.Dmd8;
 		}
 
 		private void RequestSourceFrameFormat(DisplayFrameFormat format)

VisualPinball.Engine.DMD.Unity/Runtime/DmdColorizationPolicy.cs

@@ -0,0 +1,88 @@
+using System;
+using VisualPinball.Unity;
+
+namespace VisualPinball.Engine.DMD.Unity
+{
+	internal enum DmdColorizationPipelineAction
+	{
+		None,
+		Bypass,
+		Restore,
+	}
+
+	/// <summary>
+	/// Tracks whether the selected display must bypass a colorization source that cannot consume
+	/// the format emitted by its gamelogic engine.
+	/// </summary>
+	internal sealed class DmdColorizationPolicy
+	{
+		private DisplayConfig _display;
+		private bool _warningIssued;
+
+		public bool BypassColorization { get; private set; }
+		public bool AwaitingSupportedColorizedFrame { get; private set; }
+
+		/// <summary>
+		/// Selects a display topology. An identical re-announcement deliberately preserves the
+		/// bypass latch; selecting a different id, geometry, or horizontal orientation resets it.
+		/// </summary>
+		public void SelectDisplay(DisplayConfig display)
+		{
+			if (SameTopology(_display, display)) {
+				return;
+			}
+
+			_display = display;
+			BypassColorization = false;
+			AwaitingSupportedColorizedFrame = false;
+			_warningIssued = false;
+		}
+
+		/// <summary>
+		/// Decides whether the bridge must rebuild its pipeline. A Dmd8 frame may be the transient
+		/// pre-preference frame from a missed display announcement, so its bypass recovers when the
+		/// requested Dmd2/Dmd4 stream arrives. Dmd24 is RGB-authored and remains a sticky bypass.
+		/// </summary>
+		public DmdColorizationPipelineAction ObserveFrame(DisplayFrameFormat format,
+			bool pipelineUsesColorization, out bool shouldWarn)
+		{
+			if (!pipelineUsesColorization) {
+				if (BypassColorization && AwaitingSupportedColorizedFrame && SupportsColorization(format)) {
+					BypassColorization = false;
+					AwaitingSupportedColorizedFrame = false;
+					_warningIssued = false;
+					shouldWarn = false;
+					return DmdColorizationPipelineAction.Restore;
+				}
+				shouldWarn = false;
+				return DmdColorizationPipelineAction.None;
+			}
+
+			if (SupportsColorization(format)) {
+				shouldWarn = false;
+				return DmdColorizationPipelineAction.None;
+			}
+
+			BypassColorization = true;
+			AwaitingSupportedColorizedFrame = format == DisplayFrameFormat.Dmd8;
+			shouldWarn = !_warningIssued;
+			_warningIssued = true;
+			return DmdColorizationPipelineAction.Bypass;
+		}
+
+		public static bool SupportsColorization(DisplayFrameFormat format)
+		{
+			return format == DisplayFrameFormat.Dmd2 || format == DisplayFrameFormat.Dmd4;
+		}
+
+		private static bool SameTopology(DisplayConfig first, DisplayConfig second)
+		{
+			if (ReferenceEquals(first, second)) {
+				return true;
+			}
+			return first != null && second != null &&
+			       string.Equals(first.Id, second.Id, StringComparison.OrdinalIgnoreCase) &&
+			       first.Width == second.Width && first.Height == second.Height && first.FlipX == second.FlipX;
+		}
+	}
+}

VisualPinball.Engine.DMD.Unity/Runtime/DmdPipeline.cs

@@ -49,11 +49,13 @@ internal sealed class DmdPipeline : IDisposable
 		private volatile bool _running = true;
 
 		private static readonly Logger Logger = LogManager.GetCurrentClassLogger();
+		public bool UsesColorization { get; }
 
 		public DmdPipeline(DisplayConfig display, List<IDestination> destinations, AbstractConverter converter, bool flipHorizontally)
 		{
 			_display = display;
 			_destinations = destinations;
+			UsesColorization = converter != null;
 			_source = VpeGleSource.Create(display, converter != null);
 			_renderGraph = new RenderGraph(new UndisposedReferences(), runOnMainThread: true) {
 				Name = $"VPE DMD ({display.Id})",

VisualPinball.Engine.DMD.Unity/Runtime/VpeGleSource.cs

@@ -3,7 +3,9 @@
 using System.Reactive.Subjects;
 using LibDmd.Frame;
 using LibDmd.Input;
+using NLog;
 using VisualPinball.Unity;
+using Logger = NLog.Logger;
 
 namespace VisualPinball.Engine.DMD.Unity
 {
@@ -17,6 +19,7 @@ internal abstract class VpeGleSource : AbstractSource, ISource
 
 		private readonly Subject<Unit> _onResume = new Subject<Unit>();
 		private readonly Subject<Unit> _onPause = new Subject<Unit>();
+		private static readonly Logger Logger = LogManager.GetCurrentClassLogger();
 
 		protected VpeGleSource(string displayId, int width, int height)
 		{
@@ -104,6 +107,7 @@ private sealed class ColorizableVpeGleSource : VpeGleSource, IGray2Source, IGray
 		{
 			private readonly Subject<DmdFrame> _gray2Frames = new Subject<DmdFrame>();
 			private readonly Subject<DmdFrame> _gray4Frames = new Subject<DmdFrame>();
+			private bool _unsupportedFormatWarningLogged;
 
 			public ColorizableVpeGleSource(string displayId, int width, int height) : base(displayId, width, height)
 			{
@@ -118,6 +122,12 @@ public override void Push(DisplayFrameFormat format, byte[] data, int length)
 					case DisplayFrameFormat.Dmd4:
 						_gray4Frames.OnNext(CreateFrame(data, length, 4));
 						break;
+					default:
+						if (!_unsupportedFormatWarningLogged) {
+							Logger.Warn($"[DMD] Colorization source cannot consume {format}; frame ignored while the main-thread bridge switches to passthrough.");
+							_unsupportedFormatWarningLogged = true;
+						}
+						break;
 				}
 			}