From 02c1d9eb4144d23b1cebc9b6be628ee904c135ce Mon Sep 17 00:00:00 2001
From: Charles <charles@localhost>
Date: Wed, 11 Apr 2001 14:52:28 +0000
Subject: [PATCH]

---
 source/enemy/npc.cpp   | 12 ++++++---
 source/enemy/npc.h     |  2 ++
 source/enemy/nworm.cpp | 61 ++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 70 insertions(+), 5 deletions(-)

diff --git a/source/enemy/npc.cpp b/source/enemy/npc.cpp
index f2e01e8a5..2b3269554 100644
--- a/source/enemy/npc.cpp
+++ b/source/enemy/npc.cpp
@@ -511,7 +511,7 @@ void CNpcEnemy::postInit()
 
 			m_npcPath.setPathType( CNpcPath::PONG_PATH );
 
-			// create head of list
+			// create start of list
 			CNpcPositionHistory *newPosition;
 			newPosition = new ("position history") CNpcPositionHistory;
 			newPosition->pos = Pos;
@@ -521,17 +521,23 @@ void CNpcEnemy::postInit()
 
 			// create rest of list
 
-			for ( int histLength = 1 ; histLength < ( 10 * NPC_PARASITIC_WORM_SPACING ) ; histLength++ )
+			for ( int histLength = 1 ; histLength < ( NPC_PARASITIC_WORM_LENGTH * NPC_PARASITIC_WORM_SPACING ) ; histLength++ )
 			{
 				newPosition = new ("position history") CNpcPositionHistory;
 				newPosition->pos = Pos;
 				newPosition->next = NULL;
+				newPosition->prev = currentPosition;
 
 				currentPosition->next = newPosition;
 				currentPosition = newPosition;
 			}
 
-			for ( int segCount = 0 ; segCount < 10 ; segCount++ )
+			// link ends together for circular list
+
+			currentPosition->next = m_positionHistory;
+			m_positionHistory->prev = currentPosition;
+
+			for ( int segCount = 0 ; segCount < NPC_PARASITIC_WORM_LENGTH ; segCount++ )
 			{
 				CNpcEnemy *segment;
 				segment = new ("segment") CNpcEnemy;
diff --git a/source/enemy/npc.h b/source/enemy/npc.h
index 684fb1971..20c849902 100644
--- a/source/enemy/npc.h
+++ b/source/enemy/npc.h
@@ -391,6 +391,7 @@ protected:
 		NPC_BOOGER_MONSTER_MAX_EXTENSION = 20,
 		NPC_SUB_SHARK_HIGH_SPEED = 6,
 		NPC_PARASITIC_WORM_SPACING = 6,
+		NPC_PARASITIC_WORM_LENGTH = 10,
 		EXTEND_UP = true,
 		EXTEND_DOWN = false,
 		EXTEND_RIGHT = true,
@@ -611,6 +612,7 @@ protected:
 	public:
 		DVECTOR						pos;
 		CNpcPositionHistory			*next;
+		CNpcPositionHistory			*prev;
 	};
 
 	CNpcPositionHistory		*m_positionHistory;
diff --git a/source/enemy/nworm.cpp b/source/enemy/nworm.cpp
index 10be16906..a125bf5ab 100644
--- a/source/enemy/nworm.cpp
+++ b/source/enemy/nworm.cpp
@@ -39,7 +39,64 @@ void CNpcEnemy::processParasiticWormMovement( int _frames )
 	m_extension += 256;
 	m_extension &= 4095;
 
-	// add new (old) position onto list head
+	m_positionHistory = m_positionHistory->prev;
+	m_positionHistory->pos = oldPos;
+
+	CNpcPositionHistory *newPos;
+	newPos = m_positionHistory;
+	for ( skipCounter = 1 ; skipCounter < NPC_PARASITIC_WORM_SPACING ; skipCounter++ )
+	{
+		newPos = newPos->next;
+	}
+
+	CThing	*List=Next;
+
+	oldPos = Pos;
+
+	s32 extension = m_extension;
+	u8 downShift = 2;
+
+	while( List )
+	{
+		CNpcEnemy *segment = (CNpcEnemy *) List;
+
+		s32 xDist = oldPos.vx - newPos->pos.vx;
+		s32 yDist = oldPos.vy - newPos->pos.vy;
+
+		s16 headingToTarget = ratan2( yDist, xDist );
+
+		segment->setHeading( headingToTarget );
+
+		DVECTOR sinPos;
+
+		sinPos = newPos->pos;
+		s32 diff = ( ( 10 >> downShift ) * rsin( extension ) ) >> 12;
+		sinPos.vx += ( diff * rcos( headingToTarget + 1024 ) ) >> 12;
+		sinPos.vy += ( diff * rsin( headingToTarget + 1024 ) ) >> 12;
+
+		List->setPos( sinPos );
+		oldPos = newPos->pos;
+
+		List = List->getNext();
+
+		if ( List )
+		{
+			for ( skipCounter = 0 ; skipCounter < NPC_PARASITIC_WORM_SPACING ; skipCounter++ )
+			{
+				newPos = newPos->next;
+			}
+		}
+
+		extension += 1024;
+		extension &= 4095;
+
+		if ( downShift > 0 )
+		{
+			downShift--;
+		}
+	}
+
+	/*// add new (old) position onto list head
 	CNpcPositionHistory *newPos;
 	newPos = new ("position history") CNpcPositionHistory;
 	newPos->pos = oldPos;
@@ -111,5 +168,5 @@ void CNpcEnemy::processParasiticWormMovement( int _frames )
 		{
 			downShift--;
 		}
-	}
+	}*/
 }
\ No newline at end of file