Initial commit: bt411 -- standalone Windows BattleTech (Tesla 4.10 port)

Clean, self-contained extraction of the BattleTech-specific work from the
reverse-engineering workspace -- engine + game + content + build, with nothing
from Red Planet or the raw archive dumps. Builds green (Win32) and runs the
single-player drive->animate->target->fire->damage->destroy loop out of the box.

Layout:
  engine/   MUNGA + MUNGA_L4 shared 2007 engine, carrying our BT render/loader
            work (bgfload/L4D3D/L4VIDEO: BSL bit-slice decode, LOD/ground/shadow
            models) + image codec; the minimal rp/ headers the audio HAL needs
  game/     reconstructed BT logic + surviving-original BT source + fwd shims
            + WinMain launcher
  content/  full runtime tree (BTL4.RES, VIDEO/, GAUGE/, AUDIO/, eggs, BTDPL.INI)
  docs/     format specs + reconstruction ledgers
  reference/ raw Ghidra pseudocode (recon source-of-truth) + decomp exporter
  tools/    MP console emulator + map/resource scanners

One top-level CMake builds munga_engine lib + bt410_l4 game lib + btl4.exe.
All paths relativized (186 fwd shims + ~437 CMake abs paths -> repo-relative);
DXSDK is the one external, overridable via -DDXSDK. Verified: builds to a
byte-identical 2.27MB exe and runs combat (TARGET DESTROYED, 0 crashes) against
the bundled content.

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

engine/MUNGA/SET.cpp

@@ -0,0 +1,144 @@
+#include "munga.h"
+#include "set.h"
+
+//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Set ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+//
+//#############################################################################
+// Set
+//#############################################################################
+//
+Set::Set(Node *node):
+	 Socket(node),
+	 contents(NULL)
+{
+
+}
+
+
+
+
+//
+//#############################################################################
+// ~Set
+//#############################################################################
+//
+Set::~Set()
+{
+	SetReleaseNode(NULL);
+	if (contents)
+	{
+		delete contents;
+	}
+}
+
+//
+//#############################################################################
+// TestInstance
+//#############################################################################
+//
+Logical
+	Set::TestInstance() const
+{
+	Socket::TestInstance();
+	Check(contents);
+	return True;
+}
+
+
+//
+//#############################################################################
+// Union
+//
+// Merge contents of this with rhs.   Items that occur in either set are placed
+// in the resulting set, with no duplication.  It is assumed that both operands
+// are proper sets, ie. they contain no duplicates.
+//#############################################################################
+//
+
+Set
+	Set::Union(const Set &) const
+{
+	Check(this);
+
+
+	Set result(NULL);
+
+	return result;
+}
+
+
+//
+//#############################################################################
+// Intersection
+//
+// Merge contents of this with rhs.   Items that occur in both sets are placed
+// only once in the resulting set.  It is assumed that both operands are proper
+// sets, ie. they contain no duplicates.
+//
+// This implementation of set intersection is dumb and slow.
+//#############################################################################
+//
+
+Set
+	Set::Intersection(const Set &rhs) const
+{
+	Check(this);
+	Check(rhs);
+
+	// Contents iterator is a SetIterator and not a ChainIterator in order to
+	// have access to the ChainIterator::ReadAndNextImplentation.
+	// We circumvent encapsulation protections by declaring Set a friend of SetIterator
+	// (which derives from ChainIterator).  Set is not a friend of ChainIterator.
+
+	SetIterator contents_iterator(contents);
+
+	// Casting away const is safe since our local iterator is not going to insert or
+	// remove items from rhs.
+	SetIterator rhs_iterator((Set *) &rhs);
+	Plug *lhs_plug;
+	Plug *rhs_plug;
+	Set result(NULL);
+
+
+	while ((lhs_plug = Cast_Object(Plug *, contents_iterator.ReadAndNextImplementation())) != NULL)
+	{
+		while ((rhs_plug = Cast_Object(Plug *,rhs_iterator.ReadAndNextImplementation())) != NULL)
+		{
+			if (lhs_plug == rhs_plug)
+			{
+				result.AddImplementation(lhs_plug);
+			}
+		}
+	}
+	return result;
+}
+
+//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SetIterator ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+//
+//#############################################################################
+// SetIterator
+//#############################################################################
+//
+SetIterator::SetIterator(Set *set):
+	ChainIterator(set->contents)
+{
+	Check(set);
+}
+
+SetIterator::SetIterator(const SetIterator &iterator):
+	ChainIterator(Cast_Object(Chain*, (Cast_Object(Set *,iterator.socket)->contents)))
+{
+	Check(&iterator);
+}
+
+SetIterator::SetIterator(Chain *chain):
+	ChainIterator(chain)
+{
+	Check(chain);
+}
+
+SetIterator::~SetIterator()
+{
+}