From 574cc6049ff0e005b67319294b1cbd68336470bd Mon Sep 17 00:00:00 2001
From: toaster <rollerorbital@gmail.com>
Date: Wed, 21 Sep 2022 23:01:58 +0100
Subject: [PATCH] NUMMAPS is dead

Dynamically allocated mapheaderinfo. 1035 reserved slots in a google doc is a thing of the past
---
 src/deh_soc.c  |  5 -----
 src/doomdata.h |  2 --
 src/doomstat.h |  4 ++--
 src/g_game.c   |  4 ++--
 src/p_setup.c  | 34 ++++++++++++++++++++++++++++++++++
 5 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/src/deh_soc.c b/src/deh_soc.c
index 3e9855256..030b7f644 100644
--- a/src/deh_soc.c
+++ b/src/deh_soc.c
@@ -1095,11 +1095,6 @@ void readlevelheader(MYFILE *f, char * name)
 
 	const INT32 num = G_MapNumber(name);
 
-	if (num >= NUMMAPS)
-	{
-		I_Error("Too many maps!");
-	}
-
 	if (f->wad > mainwads && num < nummapheaders)
 	{
 		// only mark as a major mod if it replaces an already-existing mapheaderinfo
diff --git a/src/doomdata.h b/src/doomdata.h
index b891bc8a4..dbe7c1f84 100644
--- a/src/doomdata.h
+++ b/src/doomdata.h
@@ -218,8 +218,6 @@ typedef struct
 
 #define ZSHIFT 4
 
-#define NUMMAPS 1035
-
 /* slope thing types */
 enum
 {
diff --git a/src/doomstat.h b/src/doomstat.h
index a9d82419b..807aec2d6 100644
--- a/src/doomstat.h
+++ b/src/doomstat.h
@@ -440,8 +440,8 @@ typedef struct
 #define LF2_NOTIMEATTACK  (1<<2) ///< Hide this map in Time Attack modes
 #define LF2_VISITNEEDED   (1<<3) ///< Not available in Time Attack modes until you visit the level
 
-extern mapheader_t* mapheaderinfo[NUMMAPS];
-extern INT32 nummapheaders;
+extern mapheader_t** mapheaderinfo;
+extern INT32 nummapheaders, mapallocsize;
 
 // This could support more, but is that a good idea?
 // Keep in mind that it may encourage people making overly long cups just because they "can", and would be a waste of memory.
diff --git a/src/g_game.c b/src/g_game.c
index 7a3e90676..21e30df41 100644
--- a/src/g_game.c
+++ b/src/g_game.c
@@ -192,8 +192,8 @@ mapthing_t *bflagpoint;
 struct quake quake;
 
 // Map Header Information
-mapheader_t* mapheaderinfo[NUMMAPS] = {NULL};
-INT32 nummapheaders;
+mapheader_t** mapheaderinfo = {NULL};
+INT32 nummapheaders, mapallocsize = 0;
 
 // Kart cup definitions
 cupheader_t *kartcupheaders = NULL;
diff --git a/src/p_setup.c b/src/p_setup.c
index a74d9c137..ae3ca64b2 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -422,9 +422,43 @@ static void P_ClearSingleMapHeaderInfo(INT16 i)
   */
 void P_AllocMapHeader(INT16 i)
 {
+	if (i > nummapheaders)
+		I_Error("P_AllocMapHeader: Called on %d, should be %d", i, nummapheaders);
+
+	if (i >= NEXTMAP_SPECIAL)
+	{
+		I_Error("P_AllocMapHeader: Too many maps!");
+	}
+
+	if (i >= mapallocsize)
+	{
+		if (!mapallocsize)
+		{
+			mapallocsize = 16;
+		}
+		else
+		{
+			mapallocsize *= 2;
+		}
+
+		mapheaderinfo = Z_ReallocAlign(
+			(void*) mapheaderinfo,
+			sizeof(mapheader_t*) * mapallocsize,
+			PU_STATIC,
+			NULL,
+			sizeof(mapheader_t*) * 8
+		);
+
+		if (!mapheaderinfo)
+			I_Error("P_AllocMapHeader: Not enough memory to realloc mapheaderinfo (size %d)", mapallocsize);
+	}
+
 	if (!mapheaderinfo[i])
 	{
 		mapheaderinfo[i] = Z_Malloc(sizeof(mapheader_t), PU_STATIC, NULL);
+		if (!mapheaderinfo[i])
+			I_Error("P_AllocMapHeader: Not enough memory to allocate new mapheader");
+
 		mapheaderinfo[i]->lumpnum = LUMPERROR;
 		mapheaderinfo[i]->lumpname = NULL;
 		mapheaderinfo[i]->thumbnailPic = NULL;