STEP 6 COMPLETE: cylinder hit-location LIVE — unaimed hits resolve to zones

The Mech per-impact hit-location resolver (the cylinder damage table) is now functional, wired, and runtime-verified [T2]. Unaimed (zone==-1) hits — the collision-damage path — now resolve an impact point to a damage zone via the authentic height x angle grid + weighted dice roll, instead of dropping. dmgtable.cpp/.hpp was a non-functional skeleton on no-op ReconTable/stream shims; backed it with real std::vector storage and fixed 5 latent runtime bugs: - ReadEntries now consumes the leading cell name-string ([i32 len][len+1]) - PieSlice ctor reads rotateWithTorso into the correct member - SelectSlice direct-indexes (was int lookup on a float-keyed table) - ResolveHit returns the zone (chains SelectSlice -> SelectZone) - real MemoryStream::ReadBytes (was a variadic no-op) mech.cpp ctor: replaced the empty-name StandingAnimation stub with the real load — FindResourceDescription(dzRes->resourceName, type 0x1d) -> stream -> new DamageLookupTable, cached at mech[0x111]; ~Mech deletes it. Mech::TakeDamageMessageHandler override registered (MESSAGE_ENTRY overlays Entity's by ID): on invalidDamageZone, resolve via the table then base-route; aimed reticle hits pass through unchanged. Three named accessors (no databinding-trap raw reads): WorldToLocal (localToWorld.MultiplyByInverse), CylinderReferenceHeight (standingTemplateMaxY == collisionTemplate->maxY == binary mech+0x2ec[+0xc]), TorsoHeading via a BTGetTorsoTwist bridge in torso.cpp (Torso::CurrentTwist == torso+0x1d8; torso.hpp cannot be included into mech.cpp — subsystem-stub collision). Stream format + geometry + roll + handler were all byte-verified against the shipped BTL4.RES type-29 resources (18 tables, exact consumption) and the disassembly (FUN_0049eb54/e678/de14, glue 0x49ed0c, handler @0x4a037a). Runtime: boots clean, "[cyl] table 'bhk1' layers=7" (exact byte-verified layer count, found by name), mech spawns + walks, no asserts/AV/0xCDCDCDCD. Env gate BT_CYL_LOG=1. Unblocks collision-damage application. KB updated (combat-damage.md STEP 6 COMPLETE, open-questions.md marked done). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-08 08:32:17 -05:00
parent 33fee712e9
commit d07ac7dd49
8 changed files with 504 additions and 557 deletions
@@ -72,6 +72,13 @@
 // AUTHENTIC GROUND MODEL ctor half (task #15): complete BoxedSolid type for the
 // collisionTemplate/collisionVolume extent reads + the template bottom lift.
 #include <BOXSOLID.hpp>
+// STEP 6 cylinder hit-location table.  dmgtable.hpp pulls in no subsystem
+// headers (only Plug + mechrecon + <vector>), so it is safe here -- unlike the
+// real subsystem headers, whose classes collide with mech.cpp's local stubs.
+// The torso twist is reached via a BRIDGE (BTGetTorsoTwist, defined in torso.cpp)
+// for the same reason.
+#include "dmgtable.hpp"
+extern Scalar BTGetTorsoTwist(Subsystem *torso);		// torso.cpp (Torso complete there)
 #if !defined(APP_HPP)
 #	include <app.hpp>
 #endif
@@ -394,14 +401,107 @@ Derivation
 		"Mech"
 	);

-// Chain Mech's handler set to the parent's (Entity's, which Mover/JointedMover use
-// directly -- they add none).  An EMPTY set with no inheritance made Receiver::Receive
-// find NO handler for TakeDamageMessageID (and every other inherited message), so the
-// engine base Entity::TakeDamageMessageHandler -- which routes damageZones[zone]->
-// TakeDamage -- never ran and damage silently dropped.  (Mech's OWN TakeDamage override
-// + cylinder lookup is the later STEP-6 reconstruction; this restores the base routing.)
+// Mech's OWN handler table, chained to the parent's (Entity's, which Mover/
+// JointedMover use directly -- they add none).  It OVERRIDES Entity's TakeDamage
+// with the cylinder hit-location resolver (STEP 6): Build() overlays the derived
+// entry onto the inherited table by message ID (RECEIVER.cpp), so every other
+// inherited message still routes to its base handler.  (Previously this was a
+// bare copy of Entity's set -- base TakeDamage dropped unaimed/-1 zone hits.)
+const Receiver::HandlerEntry
+	Mech::MessageHandlerEntries[] =
+	{
+		MESSAGE_ENTRY(Mech, TakeDamage),
+	};
+
 Receiver::MessageHandlerSet
-	Mech::MessageHandlers(Entity::GetMessageHandlers());
+	Mech::MessageHandlers(
+		ELEMENTS(Mech::MessageHandlerEntries),
+		Mech::MessageHandlerEntries,
+		Entity::GetMessageHandlers());
+
+//#############################################################################
+// STEP 6 -- cylinder hit-location support (consumed by dmgtable.cpp)
+//#############################################################################
+//
+// World -> mech-local point transform (binary FUN_00408bf8 reading owner+0xd0).
+// Uses the inherited Entity::localToWorld (the render/collision object matrix);
+// MultiplyByInverse gives the world->local change of coordinates.
+//
+Point3D
+	Mech::WorldToLocal(const Point3D &world)
+{
+	Point3D local;
+	local.MultiplyByInverse(world, localToWorld);
+	return local;
+}
+
+//
+// The roster torso (sinkSourceSubsystem @0x438, ClassID 0xBC5) -- parity with
+// the binary's *(mech+0x438).
+//
+void *
+	Mech::TorsoOrientationSource()
+{
+	return GetTorsoSubsystem();
+}
+
+//
+// Live torso twist (yaw) in radians -- binary torso+0x1d8.  Reached via the
+// torso.cpp bridge (Torso is a complete type there; including torso.hpp here
+// would collide with mech.cpp's local subsystem stubs).  0 for no/fixed torso.
+//
+Scalar
+	Mech::TorsoHeading()
+{
+	return BTGetTorsoTwist(GetTorsoSubsystem());
+}
+
+//
+// Height reference the cylinder table normalises impact height against -- the
+// binary's *(mech+0x2ec)+0xc, a stance height written from mech+0x518 (standing)
+// / +0x51c (ducked).  standingTemplateMaxY is that value (collisionTemplate->maxY
+// captured at ctor); fall back to the live template if the ground model was off
+// when the ctor ran (standingTemplateMaxY left 0).
+//
+Scalar
+	Mech::CylinderReferenceHeight()
+{
+	if (standingTemplateMaxY > 0.0f)
+	{
+		return standingTemplateMaxY;
+	}
+	BoxedSolid *tmpl = GetCollisionTemplate();
+	return tmpl ? tmpl->maxY : 0.0f;					// ResolveHit guards <= 0
+}
+
+//
+// Mech override of Entity::TakeDamageMessageHandler (binary @0x4a037a, the two
+// call sites into the glue @0x49ed0c).  An unaimed hit arrives with
+// invalidDamageZone set (damageZone < 0); resolve its zone from the cylinder
+// hit-location table (mech[0x111]) using the impact point, clear the flag, then
+// hand off to the base handler which routes damageZones[zone]->TakeDamage.  Aimed
+// (reticle) hits carry a valid zone and pass straight through.
+//
+void
+	Mech::TakeDamageMessageHandler(TakeDamageMessage *message)
+{
+	Check(message);
+	DamageLookupTable *table = (DamageLookupTable *)Wword(0x111);
+	if (message->invalidDamageZone && table != 0)
+	{
+		int zone = table->ResolveHit(message->damageData.impactPoint);
+		message->damageZone        = zone;
+		message->invalidDamageZone = False;
+		if (BTEnvOn("BT_CYL_LOG", 0))
+		{
+			DEBUG_STREAM << "[cyl] unaimed hit -> zone " << zone
+				<< " (impact " << message->damageData.impactPoint.x << ","
+				<< message->damageData.impactPoint.y << ","
+				<< message->damageData.impactPoint.z << ")\n" << std::flush;
+		}
+	}
+	Entity::TakeDamageMessageHandler(message);			// base: damageZones[zone]->TakeDamage
+}

 //
 // Mech attribute table.  DENSE PREFIX 0x15..0x21 (JointedMover::NextAttributeID
@@ -1208,17 +1308,42 @@ Mech::Mech(
 	}

 	//
-	// Cylinder damage-zone table (resource type 0x1d, by name) -- the per-impact zone
-	// resolver consumed by Mech::TakeDamageMessageHandler for unaimed/-1 hits.  STILL A
-	// STUB here (StandingAnimation placeholder); the real CylinderDamageZoneTable is
-	// STEP 6a of the damage reconstruction.  Left as-was so the rest builds; the empty
-	// name makes the lookup a no-op until then.
+	// Cylinder hit-location table (resource type 0x1d = DamageLookupTableStream) --
+	// the per-impact zone resolver consumed by Mech::TakeDamageMessageHandler for
+	// unaimed/-1 hits (STEP 6).  Faithful to the ctor @part_012.c:10411-10425: the
+	// table is found by the mech's DamageZoneStream (type-0x14) NAME -- the offline
+	// builder writes BOTH the 0x14 and 0x1d resources under the model name (see
+	// CreateDamageZoneStream ~line 1930), so they share it -- then streamed and
+	// cached at mech[0x111] (byte 0x444).  (Was an empty-name StandingAnimation
+	// stub -> 0 rows; the real class is dmgtable.cpp.)
 	//
-	char shadowName[32];
-	shadowName[0] = '\0';
-	int animSeg = ResourceFindByName(shadowName, 0x1d);	// FUN_00406ff8 (TODO STEP 6a: cylinder table)
-	MemStreamX animMem(animSeg);
-	Wword(0x111) = (int)new (Memory::Allocate(0x2c)) StandingAnimation(this, &animMem);	// FUN_0049ea48
+	Wword(0x111) = 0;
+	ResourceDescription *dzForName =
+		MechFindResource(creation_message->resourceID,
+			ResourceDescription::DamageZoneStreamResourceType);		// type 0x14 (for its name)
+	ResourceDescription *cylRes = (dzForName != 0)
+		? application->GetResourceFile()->FindResourceDescription(
+			dzForName->resourceName,
+			ResourceDescription::DamageLookupTableStreamResourceType)	// FUN_00406ff8, type 0x1d
+		: 0;
+	if (cylRes != 0)
+	{
+		cylRes->Lock();
+		{
+			DynamicMemoryStream cylStream(							// FUN_004032dc, offset 0
+				cylRes->resourceAddress, cylRes->resourceSize, 0);
+			DamageLookupTable *table = new DamageLookupTable(this, &cylStream);	// FUN_0049ea48
+			Wword(0x111) = (int)table;
+			DEBUG_STREAM << "[cyl] table '" << dzForName->resourceName
+				<< "' layers=" << table->LayerCount() << "\n" << std::flush;
+		}
+		cylRes->Unlock();
+	}
+	else
+	{
+		DEBUG_STREAM << "[cyl] no DamageLookupTable (type 0x1d) for '"
+			<< (dzForName ? dzForName->resourceName : "?") << "'\n" << std::flush;
+	}

 	//
 	// Bind the three creation-name strings from the MakeMessage.
@@ -1276,9 +1401,9 @@ Mech::~Mech()
 			<< "\n" << std::flush;
 	}

-	if (Wword(0x111) != 0)								// standing animation
+	if (Wword(0x111) != 0)								// cylinder hit-location table (STEP 6)
 	{
-		((Releasable *)Wword(0x111))->Release();
+		delete (DamageLookupTable *)Wword(0x111);		// frees layers/slices/entries
 	}

 	//