Gauges: fix blank per-weapon loop/generator lamps (4A/1B/5D boxes)

The SubsystemCluster per-weapon MFD panels render two image-strip lamps in
the TEMP/STATUS area: the cooling-loop number (btploop, 1..6) and the
generator letter (btpbus, A..D). Both drew as completely empty boxes.
Three stacked databinding bugs, all now fixed:

1. Color drop (btl4gau2.cpp): AnimatedSubsystemLamp/AnimatedSourceLamp
   ctors dropped the bg/fg color params the binary passes (bg=0xff,fg=0,
   same as the neighboring temp bar) and hardcoded 0,0 -> OneOfSeveral::
   Execute did SetColor(0)+DrawBitMapOpaque(0), i.e. black-on-black.
   Restored 0xff,0 (verified vs @004c70a4 / caller SubsystemCluster
   @004c8140).

2. Shadow-field trap (btl4gau2.hpp, gotcha #2): both lamp classes
   re-declared `int selected;` while already inheriting it from
   OneOfSeveral (@0xAC). The CoolingLoop/PowerSource connection wrote the
   derived shadow copy while OneOfSeveral::Execute read the base @0xAC
   (always 0) -> every lamp stuck on frame 0 ("OFF"). Removed the
   redeclarations so &selected binds the inherited member. Loop numbers
   now render (verified: PPC->4, Myomers->5, ERMLaser->1/6, etc.).

3. Attribute-table shift (powersub.cpp + btl4gau2.cpp, gotcha #8): the
   generator-letter lamp resolved its source via
   ResolveLink(AttributePointerOf(subsystem,"InputVoltage")), but the
   BT_DEV_GAUGES audio attribute rows shifted the chained attribute ids so
   AttributePointerOf no longer landed on voltageSource@0x1D0 -> the link
   always resolved to 0 (OFF) even though the master PoweredSubsystem ctor
   DID bind voltageSource to its Generator. New BTPowerSourceFrame bridge
   reads the NAMED member via PoweredSubsystem::ResolveVoltageSource() and
   returns Generator::generatorNumber (@0x1E0), bypassing the attribute
   table -- the same pattern as the BTCoolingLoopFrame fix. Generator
   letters now render (verified: PPC_1->GeneratorA="A", Myomers->
   GeneratorD="D", SRM6->GeneratorB="B").

Result: the "4 A / 1 B / 5 D" boxes render with both the loop number and
generator letter, matching the reference. Kept BT_LOOP_LOG-gated
[loopfeed]/[busfeed] feed diagnostics; both pod + glass builds clean.

Awaiting live playtest verification.

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

game/reconstructed/btl4gau2.cpp

@@ -204,9 +204,19 @@ protected:
 
 //
 // PowerSourceConnection -- @004c31ec ctor / @004c3258 sampler (vt 0x518e9c).
-// Resolves the power source (Resolve(source)) and copies its bus-lamp state
+// The binary resolves the subsystem's InputVoltage link and reads
-// (+0x1e0); 0 if unresolved.
+// resolved+0x1E0 == Generator::generatorNumber (1..4 -> the btpbus generator-
+// letter frame A..D; 0 == OFF).
+// DATABINDING FIX 2026-07-20 (gotcha 8, sibling of the CoolingLoop fix above):
+// the binary's path was ResolveLink(AttributePointerOf(subsystem,"InputVoltage"))
+// but the BT_DEV_GAUGES audio attribute rows shifted the chained attribute ids
+// so AttributePointerOf no longer lands on voltageSource@0x1D0 -- the link always
+// resolved to 0 and every generator lamp drew frame 0 ("OFF").  'source' now
+// carries the SUBSYSTEM directly and BTPowerSourceFrame (powersub.cpp) reads the
+// NAMED voltageSource member via ResolveVoltageSource(), bypassing the attribute
+// table.
 //
+extern int BTPowerSourceFrame(void *subsystem);
 class PowerSourceConnection : public GaugeConnection
 {
 public:
@@ -214,8 +224,7 @@ public:
 		: GaugeConnection(0), source(source), destination(destination) {}
 	void Update()								// @004c3258
 	{
-		void *resolved = ResolveLink(source);
+		*destination = BTPowerSourceFrame(source);
-		*destination = (resolved == 0) ? 0 : *(int *)((char *)resolved + 0x1e0);
 	}
 protected:
 	void	*source;							// @0x10
@@ -707,8 +716,13 @@ AnimatedSubsystemLamp::AnimatedSubsystemLamp(
 	void				*subsystem,
 	const char			*identification_string
 ):
+	// COLOR FIX 2026-07-20 (verified vs binary @004c70a4 / caller SubsystemCluster
+	// @004c8140): the ctor DROPPED the background/foreground color params the binary
+	// passes and hardcoded 0,0 -- so Execute's SetColor(0)+DrawBitMapOpaque(0) drew
+	// the loop/gen boxes black-on-black (invisible).  The binary passes bg=0xff,fg=0
+	// (the MFD on-color, same as the neighboring temp bar) -- restored.
 	OneOfSeveral(rate, mode_mask, renderer_in, graphics_port_number,		// FUN_004c4d88
-		x, y, True /*fromImageStrip*/, image, 0, 0, columns, rows,
+		x, y, True /*fromImageStrip*/, image, 0xff, 0, columns, rows,
 		identification_string)
 {
 	selected = 0;												// @0xAC  this[0x2B]
@@ -735,8 +749,10 @@ AnimatedSourceLamp::AnimatedSourceLamp(
 	void				*source,
 	const char			*identification_string
 ):
+	// COLOR FIX 2026-07-20 (same drop as AnimatedSubsystemLamp above): restore the
+	// binary's bg=0xff,fg=0 so the generator-letter bus lamp draws (was 0,0 = blank).
 	OneOfSeveral(rate, mode_mask, renderer_in, graphics_port_number,
-		x, y, True, image, 0, 0, columns, rows, identification_string)
+		x, y, True, image, 0xff, 0, columns, rows, identification_string)
 {
 	selected = 0;
 	AddConnection(new PowerSourceConnection(&selected, source));	// FUN_004c31ec
@@ -1402,7 +1418,9 @@ SubsystemCluster::SubsystemCluster(
 	else
 		powerSourceA = new AnimatedSourceLamp(ChildRate(), mfd_mode, renderer_in,	// @004c7160
 			mfd_port, x + 0x10e, y + 0xe, "btpbus.pcc", 5, 1,
-			inputVoltage, "PowerSource");
+			subsystem_in, "PowerSource");	// pass the SUBSYSTEM -- BTPowerSourceFrame
+											// reads voltageSource by name (attribute-shift
+											// databinding fix); NOT the inputVoltage slot
 
 	// Background: image_names[ auxScreenPlacement ] if present.  (Placement@0x1e0 is
 	// read via the PoweredSubsystem bridge, not the non-byte-exact raw offset.)
@@ -1444,7 +1462,7 @@ SubsystemCluster::SubsystemCluster(
 	else
 	{
 		powerSourceB = new AnimatedSourceLamp(ChildRate(), eng_mode, renderer_in,	// @004c7160
-			engPort, 0x1a, 0xd0, "btebus.pcc", 5, 1, inputVoltage, "PowerSource");
+			engPort, 0x1a, 0xd0, "btebus.pcc", 5, 1, subsystem_in, "PowerSource");	// see powerSourceA
 
 		generatorVoltageBar = new ScalarBarGauge(ChildRate(), eng_mode, renderer_in,	// @004c721c
 			engPort, 0x89, 0x82, 0x93, 0x13b, "evolt.pcc", 0xff, 0,

game/reconstructed/btl4gau2.hpp

@@ -195,8 +195,11 @@
 			int x, int y, const char *image, int columns, int rows,
 			void *subsystem, const char *identification_string);
 		~AnimatedSubsystemLamp();				// @004c7134
-	protected:
+		// SHADOW-FIELD FIX 2026-07-20 (gotcha #2): 'selected' is inherited from
-		int		selected;						// @0xAC  this[0x2B]  (connection dst)
+		// OneOfSeveral (@0xAC).  A redeclared 'int selected;' here shadowed the base
+		// at a higher offset -- the CoolingLoopConnection wrote the shadow while
+		// OneOfSeveral::Execute read the base (always 0) so the loop lamp drew frame
+		// 0 ("OFF").  Removed; the ctor's &selected now binds the inherited member.
 	};
 
 	class AnimatedSourceLamp :					// (best-effort)
@@ -208,8 +211,10 @@
 			int x, int y, const char *image, int columns, int rows,
 			void *source, const char *identification_string);
 		~AnimatedSourceLamp();					// @004c71f0
-	protected:
+		// SHADOW-FIELD FIX 2026-07-20 (gotcha #2): same as AnimatedSubsystemLamp --
-		int		selected;						// @0xAC  this[0x2B]
+		// 'selected' is inherited from OneOfSeveral (@0xAC); the redeclaration here
+		// shadowed it so the PowerSourceConnection wrote a dead copy and the bus lamp
+		// drew frame 0.  Removed; &selected now binds the inherited base member.
 	};
 
 

game/reconstructed/heat.cpp

@@ -1140,14 +1140,43 @@ Subsystem *CreateCondenserSubsystem(Mech *owner, int id, void *seg)
 //===========================================================================//
 int BTCoolingLoopFrame(void *subsystem_v)
 {
+	// [loopfeed] diagnostic (env BT_LOOP_LOG): why does the per-weapon cooling-loop
+	// lamp read 0 (the blank frame)?  Logs the outcome + reason for the first ~80
+	// samples so every weapon prints once.
+	static int s_loopLog = -1;
+	if (s_loopLog < 0) s_loopLog = getenv("BT_LOOP_LOG") ? 1 : 0;
+	static int s_loopN = 0;
+	int trace = s_loopLog && (s_loopN++ < 80);
+
 	Subsystem *sub = (Subsystem *)subsystem_v;
 	if (sub == 0 || !sub->IsDerivedFrom(*HeatSink::GetClassDerivations()))
+	{
+		if (trace) DEBUG_STREAM << "[loopfeed] " << (sub ? sub->GetName() : "(null)")
+			<< " -> 0 (not a HeatSink)\n" << std::flush;
 		return 0;
+	}
 	HeatSink *sink = (HeatSink *)sub;
 	if (sink->coolantAvailable != 1)					// the binary's src+0x134 gate
+	{
+		if (trace) DEBUG_STREAM << "[loopfeed] " << sub->GetName()
+			<< " -> 0 (coolantAvailable=" << sink->coolantAvailable << ")\n" << std::flush;
 		return 0;
+	}
 	Subsystem *master = sink->linkedSinks.Resolve();	// attr id 3 "HeatSink" + FUN_00417ab4
-	if (master == 0 || !master->IsDerivedFrom(*Condenser::GetClassDerivations()))
+	if (master == 0)
+	{
+		if (trace) DEBUG_STREAM << "[loopfeed] " << sub->GetName()
+			<< " -> 0 (linkedSinks EMPTY -- not linked to a condenser)\n" << std::flush;
 		return 0;
-	return ((Condenser *)master)->condenserNumber;		// master+0x1d4 (loop/frame number)
+	}
+	if (!master->IsDerivedFrom(*Condenser::GetClassDerivations()))
+	{
+		if (trace) DEBUG_STREAM << "[loopfeed] " << sub->GetName()
+			<< " -> 0 (linkedSinks='" << master->GetName() << "' is NOT a Condenser)\n" << std::flush;
+		return 0;
+	}
+	int frame = ((Condenser *)master)->condenserNumber;	// master+0x1d4 (loop/frame number)
+	if (trace) DEBUG_STREAM << "[loopfeed] " << sub->GetName() << " -> frame " << frame
+		<< " (condenser '" << master->GetName() << "')\n" << std::flush;
+	return frame;
 }

game/reconstructed/powersub.cpp

@@ -663,6 +663,60 @@ Subsystem *
 }
 
 
+//
+// BTPowerSourceFrame -- complete-type bridge for the AnimatedSourceLamp
+// (btpbus/btebus generator-letter lamp).  The binary's PowerSourceConnection
+// sampler (@004c3258) resolves the subsystem's InputVoltage link and reads
+// resolved+0x1E0 == Generator::generatorNumber (1..4 -> btpbus frames A..D; 0
+// == OFF).
+//
+// The port cannot reproduce the binary's path -- it walked
+//   ResolveLink( AttributePointerOf(subsystem,"InputVoltage") )
+// but AttributePointerOf now returns the WRONG slot: the BT_DEV_GAUGES audio
+// attribute rows shifted the chained attribute ids, so the name->pointer lookup
+// no longer lands on voltageSource@0x1D0 (the same regression that broke the
+// CoolingLoop lamp -- see btl4gau2.cpp).  The link therefore always resolved to
+// 0 and every generator lamp drew frame 0 ("OFF") even though the master
+// PoweredSubsystem ctor DID bind voltageSource to its Generator.
+//
+// This bridge takes the subsystem directly and reads the NAMED member via
+// PoweredSubsystem::ResolveVoltageSource() (voltageSource.Resolve()), bypassing
+// the attribute table entirely -- exactly the BTCoolingLoopFrame pattern.
+//
+int BTPowerSourceFrame(void *subsystem_v)
+{
+	static int s_log = -1;
+	if (s_log < 0) s_log = getenv("BT_LOOP_LOG") ? 1 : 0;
+	static int s_n = 0;
+	int trace = s_log && (s_n++ < 40);
+
+	Subsystem *sub = (Subsystem *)subsystem_v;
+	if (sub == 0 || !sub->IsDerivedFrom(*PoweredSubsystem::GetClassDerivations()))
+	{
+		if (trace) DEBUG_STREAM << "[busfeed] " << (sub ? sub->GetName() : "(null)")
+			<< " -> 0 (not a PoweredSubsystem)\n" << std::flush;
+		return 0;
+	}
+	Generator *gen = (Generator *)((PoweredSubsystem *)sub)->ResolveVoltageSource();
+	if (gen == 0)
+	{
+		if (trace) DEBUG_STREAM << "[busfeed] " << sub->GetName()
+			<< " -> 0 (voltageSource unbound)\n" << std::flush;
+		return 0;
+	}
+	if (gen->GetClassID() != RegisteredClass::GeneratorClassID)
+	{
+		if (trace) DEBUG_STREAM << "[busfeed] " << sub->GetName()
+			<< " -> 0 (source not a Generator)\n" << std::flush;
+		return 0;
+	}
+	int frame = gen->generatorNumber;							// @0x1E0 (A..D)
+	if (trace) DEBUG_STREAM << "[busfeed] " << sub->GetName() << " -> frame " << frame
+		<< " (generator '" << gen->GetName() << "')\n" << std::flush;
+	return frame;
+}
+
+
 //#############################################################################
 // Voltage-source linkage helpers
 //