From 53481fb9a300aa7ac56330a2fd8379db5f6dbb8c Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Tue, 13 Oct 2020 20:36:57 +0200
Subject: [PATCH] - Blood: simplified  management of XSectors and XWalls.

This does not need a free list - they get statically allocated per level, so a simple counter is enough.
---
 source/blood/src/db.cpp       | 21 +++++++++------------
 source/blood/src/db.h         |  3 +--
 source/blood/src/loadsave.cpp |  8 ++++----
 3 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/source/blood/src/db.cpp b/source/blood/src/db.cpp
index 4ca95c4f7..786a09aea 100644
--- a/source/blood/src/db.cpp
+++ b/source/blood/src/db.cpp
@@ -50,6 +50,10 @@ SPRITEHIT gSpriteHit[kMaxXSprites];
 
 int xvel[kMaxSprites], yvel[kMaxSprites], zvel[kMaxSprites];
 
+unsigned short nextXSprite[kMaxXSprites];
+int XWallsUsed, XSectorsUsed;
+
+
 
 char qsector_filler[kMaxSectors];
 
@@ -257,10 +261,6 @@ int qchangespritestat(short nSprite, short nStatus)
     return ChangeSpriteStat(nSprite, nStatus);
 }
 
-unsigned short nextXSprite[kMaxXSprites];
-unsigned short nextXWall[kMaxXWalls];
-unsigned short nextXSector[kMaxXSectors];
-
 void InitFreeList(unsigned short *pList, int nCount)
 {
     for (int i = 1; i < nCount; i++)
@@ -302,9 +302,8 @@ void dbDeleteXSprite(int nXSprite)
 
 unsigned short dbInsertXWall(int nWall)
 {
-    int nXWall = nextXWall[0];
-    nextXWall[0] = nextXWall[nXWall];
-    if (nXWall == 0)
+    int nXWall = XWallsUsed++;
+    if (nXWall >= kMaxXWalls)
     {
         I_Error("Out of free XWalls");
     }
@@ -316,9 +315,8 @@ unsigned short dbInsertXWall(int nWall)
 
 unsigned short dbInsertXSector(int nSector)
 {
-    int nXSector = nextXSector[0];
-    nextXSector[0] = nextXSector[nXSector];
-    if (nXSector == 0)
+    int nXSector = XSectorsUsed++;
+    if (nXSector >= kMaxXSectors)
     {
         I_Error("Out of free XSectors");
     }
@@ -335,12 +333,11 @@ void dbInit(void)
     {
         xsprite[i].reference = -1;
     }
-    InitFreeList(nextXWall, kMaxXWalls);
+    XWallsUsed = XSectorsUsed = 0;
     for (int i = 1; i < kMaxXWalls; i++)
     {
         xwall[i].reference = -1;
     }
-    InitFreeList(nextXSector, kMaxXSectors);
     for (int i = 1; i < kMaxXSectors; i++)
     {
         xsector[i].reference = -1;
diff --git a/source/blood/src/db.h b/source/blood/src/db.h
index b780afdd0..6c8ec4c68 100644
--- a/source/blood/src/db.h
+++ b/source/blood/src/db.h
@@ -306,8 +306,7 @@ extern const char *gAmmoText[];
 extern const char *gWeaponText[];
 
 extern unsigned short nextXSprite[kMaxXSprites];
-extern unsigned short nextXWall[kMaxXWalls];
-extern unsigned short nextXSector[kMaxXSectors];
+extern int XWallsUsed, XSectorsUsed;
 
 static inline int GetWallType(int nWall)
 {
diff --git a/source/blood/src/loadsave.cpp b/source/blood/src/loadsave.cpp
index dba177efb..e0708dba7 100644
--- a/source/blood/src/loadsave.cpp
+++ b/source/blood/src/loadsave.cpp
@@ -602,8 +602,8 @@ void MyLoadSave::Load(void)
     Read(&byte_19AE44, sizeof(byte_19AE44));
     Read(gStatCount, sizeof(gStatCount));
     Read(nextXSprite, sizeof(nextXSprite));
-    Read(nextXWall, sizeof(nextXWall));
-    Read(nextXSector, sizeof(nextXSector));
+    Read(&XWallsUsed, sizeof(XWallsUsed));
+    Read(&XSectorsUsed, sizeof(XSectorsUsed));
     memset(xsprite, 0, sizeof(xsprite));
     for (int nSprite = 0; nSprite < kMaxSprites; nSprite++)
     {
@@ -687,8 +687,8 @@ void MyLoadSave::Save(void)
     Write(&byte_19AE44, sizeof(byte_19AE44));
     Write(gStatCount, sizeof(gStatCount));
     Write(nextXSprite, sizeof(nextXSprite));
-    Write(nextXWall, sizeof(nextXWall));
-    Write(nextXSector, sizeof(nextXSector));
+    Write(&XWallsUsed, sizeof(XWallsUsed));
+    Write(&XSectorsUsed, sizeof(XSectorsUsed));
     for (int nSprite = 0; nSprite < kMaxSprites; nSprite++)
     {
         if (sprite[nSprite].statnum < kMaxStatus)