TeslaRel410/restoration/source410/BT/MECHWEAP.CPP

//===========================================================================//
// File:	mechweap.cpp                                                        //
// Project: BattleTech           Brick: Mech weapons                          //
// Contents: MechWeapon -- the base weapon subsystem                         //
//---------------------------------------------------------------------------//
// Copyright (C) 1995, Virtual World Entertainment, Inc.                     //
// All Rights reserved worldwide                                             //
// This unpublished sourcecode is PROPRIETARY and CONFIDENTIAL               //
//===========================================================================//

#include <bt.hpp>
#pragma hdrstop

#if !defined(MECHWEAP_HPP)
#	include <mechweap.hpp>
#endif

#if !defined(MECH_HPP)
#	include <mech.hpp>
#endif

#if !defined(SEGMENT_HPP)
#	include <segment.hpp>
#endif

#include <string.h>
#include <stdlib.h>

#if !defined(RANDOM_HPP)
#	include <random.hpp>
#endif

Derivation
	MechWeapon::ClassDerivations(
		PoweredSubsystem::ClassDerivations,
		"MechWeapon"
	);

//
//#############################################################################
// Message handlers.  MechWeapon publishes no handlers of its own yet (the
// weapon fire/damage handler wave), but the set MUST be a real defined object:
// the surviving CODE PPC.CPP binds the inherited name (`PPC::MessageHandlers`)
// into PPC::DefaultData, and a declared-but-undefined static links as a
// zero-filled common block -- the same silent-NULL trap as the
// Emitter::AttributeIndex crash (see MECHWEAP.NOTES.md).
//#############################################################################
//
MechWeapon::MessageHandlerSet
	MechWeapon::MessageHandlers(
		0,
		NULL,
		Subsystem::MessageHandlers
	);

//
//#############################################################################
// Attribute Support -- the 1995 binary table (@0x511890), IDs pinned so the
// streamed per-mech control mappings resolve: TriggerState (0x13) is what the
// authored fire buttons bind (the controls push then writes the trigger state
// straight into fireImpulse each frame).  The pads bridge our chain gap
// 2..0x11 (parents publish nothing yet) -- REQUIRED, because Build leaves
// uncovered gap slots uninitialized; they target rechargeLevel, harmless if a
// stray mapping ever binds one (BT411 shipped the same).  Pip*/WeaponRange
// pads-to-rechargeLevel where the member isn't reconstructed yet are noted.
//#############################################################################
//
#define MECHWEAP_PAD(n, name) \
	{ (int)MechWeapon::MechWeaponPadFirstAttributeID + n, name, \
		(Simulation::AttributePointer)&MechWeapon::rechargeLevel }

const MechWeapon::IndexEntry
	MechWeapon::AttributePointers[]=
{
	MECHWEAP_PAD( 0, "MechWeaponPad02"),
	MECHWEAP_PAD( 1, "MechWeaponPad03"),
	MECHWEAP_PAD( 2, "MechWeaponPad04"),
	MECHWEAP_PAD( 3, "MechWeaponPad05"),
	MECHWEAP_PAD( 4, "MechWeaponPad06"),
	MECHWEAP_PAD( 5, "MechWeaponPad07"),
	MECHWEAP_PAD( 6, "MechWeaponPad08"),
	MECHWEAP_PAD( 7, "MechWeaponPad09"),
	MECHWEAP_PAD( 8, "MechWeaponPad0A"),
	MECHWEAP_PAD( 9, "MechWeaponPad0B"),
	MECHWEAP_PAD(10, "MechWeaponPad0C"),
	MECHWEAP_PAD(11, "MechWeaponPad0D"),
	MECHWEAP_PAD(12, "MechWeaponPad0E"),
	MECHWEAP_PAD(13, "MechWeaponPad0F"),
	MECHWEAP_PAD(14, "MechWeaponPad10"),
	MECHWEAP_PAD(15, "MechWeaponPad11"),
	ATTRIBUTE_ENTRY(MechWeapon, PercentDone,		rechargeLevel),		// 0x12
	ATTRIBUTE_ENTRY(MechWeapon, TriggerState,		fireImpulse),		// 0x13
	ATTRIBUTE_ENTRY(MechWeapon, DistanceToTarget,	rangeToTarget),		// 0x14
	ATTRIBUTE_ENTRY(MechWeapon, TargetWithinRange,	targetWithinRange),	// 0x15
	ATTRIBUTE_ENTRY(MechWeapon, WeaponRange,		effectiveRange),	// 0x16
	{ (int)MechWeapon::PipPositionAttributeID,		"PipPosition",		// 0x17 (pip
		(Simulation::AttributePointer)&MechWeapon::rechargeLevel },		//  members
	{ (int)MechWeapon::PipColorAttributeID,			"PipColor",			// 0x18  not yet
		(Simulation::AttributePointer)&MechWeapon::rechargeLevel },		//  recon-
	{ (int)MechWeapon::PipExtendedRangeAttributeID,	"PipExtendedRange",	// 0x19  structed)
		(Simulation::AttributePointer)&MechWeapon::rechargeLevel },
	ATTRIBUTE_ENTRY(MechWeapon, EstimatedReadyTime,	estimatedReadyTime),// 0x1A
	ATTRIBUTE_ENTRY(MechWeapon, RearFiring,			rearFiring),		// 0x1B
	ATTRIBUTE_ENTRY(MechWeapon, WeaponState,		weaponAlarm)		// 0x1C
};

MechWeapon::AttributeIndexSet
	MechWeapon::AttributeIndex(
		ELEMENTS(MechWeapon::AttributePointers),
		MechWeapon::AttributePointers,
		Subsystem::AttributeIndex
	);

MechWeapon::SharedData
	MechWeapon::DefaultData(
		MechWeapon::ClassDerivations,
		MechWeapon::MessageHandlers,
		MechWeapon::AttributeIndex,
		Subsystem::StateCount
	);

MechWeapon::MechWeapon(
	Mech				*owner,
	int					subsystem_ID,
	SubsystemResource	*subsystem_resource,
	SharedData			&shared_data
):
	PoweredSubsystem(owner, subsystem_ID, subsystem_resource, shared_data)
{
	Check(owner);
	Check_Pointer(subsystem_resource);

	rechargeRate			= subsystem_resource->rechargeRate;
	weaponRange				= subsystem_resource->weaponRange;
	damageAmount			= subsystem_resource->damageAmount;
	damageType				= subsystem_resource->damageType;
	heatCostToFire			= subsystem_resource->heatCostToFire;
	explosionResourceID		= subsystem_resource->explosionModelFile;
	targetWithinRange		= False;

	damageData.damageType	= damageType;
	damageData.damageAmount	= damageAmount;

	//
	// Fire-machine state: spawn fully charged and Loaded (ready to fire).
	//
	fireImpulse				= 0.0f;
	previousFireImpulse		= 0.0f;
	rechargeLevel			= 1.0f;
	rangeToTarget			= 0.0f;
	effectiveRange			= weaponRange;
	estimatedReadyTime		= 0;
	recoil					= 0.0f;
	weaponAlarm.Initialize(WeaponStateCount);
	weaponAlarm.SetLevel(LoadedState);

	//
	// REAR-FIRING resolve (the binary ctor tail @004b99a8): a weapon is
	// rear-mounted when its MOUNT SEGMENT's site name carries the 'b' (back)
	// marker -- the back gun ports (sitelbgunport / siterbgunport) are the only
	// port names containing it.  Rear-mounted weapons fire only into the
	// LOOK-BACK view; everything else fires forward.  The look-state commit
	// (Mech::CommitLookState) re-arms viewFireEnable on every view change; a
	// weapon spawns armed for the forward view.
	//
	rearFiring = False;
	{
		EntitySegment *mount = owner->GetSegment(GetSegmentIndex());
		if (mount != NULL)
		{
			const char *mount_name = mount->GetName();
			if (mount_name != NULL && strstr(mount_name, "b") != NULL)
			{
				rearFiring = True;
			}
		}
	}
	viewFireEnable = (rearFiring == False);

	if (getenv("BT_MECH_LOG"))
	{
		EntitySegment *mount = owner->GetSegment(GetSegmentIndex());
		DEBUG_STREAM << "[weap] '" << GetName()
			<< "' seg=" << GetSegmentIndex() << " mount=";
		if (mount != NULL)
		{
			DEBUG_STREAM << mount->GetName();
		}
		else
		{
			DEBUG_STREAM << "<none>";
		}
		DEBUG_STREAM << " rear=" << (int)rearFiring << endl << flush;
	}

	Check_Fpu();
}

MechWeapon::~MechWeapon()
{
}

Logical
	MechWeapon::TestClass(Mech &)
{
	return True;
}

//
//#############################################################################
// CheckFireEdge -- the rising-edge detector on fireImpulse (binary @004b9608).
// TriggerState (attr 0x13) carries the raw ControlsButton INT bit-copied by the
// streamed direct mapping (+(button+1) press / -(button+1) release), so the
// release value reads as a negative NaN in float terms; the binary's x87
// compare effectively treated it as "released".  Comparing the BIT PATTERNS as
// signed ints is sign-correct for the button ints AND for genuine float values
// (0.0f = 0x0, positives > 0, negatives/NaNs < 0), reproducing the binary's
// behavior exactly.
//#############################################################################
//
Logical
	MechWeapon::CheckFireEdge()
{
	Check(this);

	int current  = *(int *)&fireImpulse;
	int previous = *(int *)&previousFireImpulse;
	Logical edge = (current > 0 && previous <= 0) ? True : False;
	previousFireImpulse = fireImpulse;
	return edge;
}

//
//#############################################################################
// ComputeOutputVoltage -- the recharge-dial writer (binary @004b9c9c, vtable
// slot the Emitter overrides with its own voltage form):
//     rechargeLevel = (rechargeRate - recoil) / rechargeRate
// The Loading tick decays recoil from rechargeRate toward 0, so the dial rises
// 0 -> 1 over the authored RechargeRate seconds.
//#############################################################################
//
void
	MechWeapon::ComputeOutputVoltage()
{
	Check(this);

	rechargeLevel = (rechargeRate - recoil) / rechargeRate;
}

Logical
	MechWeapon::TestInstance() const
{
	return IsDerivedFrom(ClassDerivations);
}

//
//#############################################################################
// FireWeapon  Abstract -- each concrete weapon (Emitter/PPC, ProjectileWeapon/
// Gauss/MissileLauncher) overrides this.  Reaching the base is a bug.
//#############################################################################
//
void
	MechWeapon::FireWeapon()
{
	Fail("MechWeapon::FireWeapon -- should not be here (abstract)");
}

//
//#############################################################################
// HasActiveTarget -- the owner mech's target slot (binary owner+0x388).
//#############################################################################
//
Logical
	MechWeapon::HasActiveTarget()
{
	Check(this);
	return (owner != NULL && owner->GetTargetEntity() != NULL)
		? True : False;
}

//
//#############################################################################
// UpdateTargeting -- refresh the range to the current target and the
// within-range flag (binary @004b9bdc).  effectiveRange is the (heat-degraded,
// later) weapon range.
//#############################################################################
//
Logical
	MechWeapon::UpdateTargeting()
{
	Check(this);

	Entity *target = (owner != NULL) ? owner->GetTargetEntity() : NULL;
	if (target == NULL)
	{
		targetWithinRange = False;
		return False;
	}

	Vector3D span;
	span.Subtract(
		target->localOrigin.linearPosition,
		owner->localOrigin.linearPosition
	);
	rangeToTarget = span.Length();
	targetWithinRange = (rangeToTarget <= effectiveRange) ? True : False;
	return targetWithinRange;
}

//
//#############################################################################
// SendDamage  Deliver this weapon's damage to the struck entity: build the
// engine TakeDamageMessage (inflictor = our mech) and dispatch it AT the
// target, whose handler routes damageZones[zone]->TakeDamage with the
// authored per-type scales.  INTERIM zone pick: a uniform roll over the
// target's hull zones -- the authentic resolver is the reticle hit (aimed) or
// the cylinder hit-location table (unaimed), both in the render/mech3 wave.
//#############################################################################
//
void
	MechWeapon::SendDamage(Entity *target, Damage &damage)
{
	Check(this);
	Check(target);

	int zone = -1;
	if (target->damageZoneCount > 0)
	{
		zone = Random(target->damageZoneCount);

		//
		// DEV hook BT_FORCE_ZONE=n: pin every hit to zone n (concentrated
		// fire -- exercises the zone-death cascade headlessly).
		//
		{
			const char *force_zone = getenv("BT_FORCE_ZONE");
			if (force_zone != NULL)
			{
				int forced = atoi(force_zone);
				if (forced >= 0 && forced < target->damageZoneCount)
				{
					zone = forced;
				}
			}
		}
	}

	Entity::TakeDamageMessage
		hit(
			Entity::TakeDamageMessageID,
			sizeof(Entity::TakeDamageMessage),
			(owner != NULL) ? owner->GetEntityID() : EntityID::Null,
			zone,
			damage
		);
	target->Dispatch(&hit);

	if (getenv("BT_MECH_LOG"))
	{
		DEBUG_STREAM << "[dmg] '" << GetName()
			<< "' hit zone " << zone
			<< " amount=" << damage.damageAmount
			<< " type=" << damage.damageType;
		if (zone >= 0 && zone < target->damageZoneCount
			&& target->damageZones != NULL
			&& target->damageZones[zone] != NULL)
		{
			DEBUG_STREAM << " -> zoneLevel="
				<< target->damageZones[zone]->damageLevel;
		}
		DEBUG_STREAM << endl << flush;
	}
}

//
//#############################################################################
// CreateStreamedSubsystem  Model-load-time construction.  Not yet reconstructed.
//#############################################################################
//
int
	MechWeapon::CreateStreamedSubsystem(
		ResourceFile				*,
		NotationFile				*,
		const char					*,
		const char					*,
		SubsystemResource			*,
		NotationFile				*,
		const ResourceDirectories	*,
		int
	)
{
	Fail("MechWeapon::CreateStreamedSubsystem -- mechweap.cpp not yet reconstructed");
	return 0;
}