Add LobbySize option to level headers, controls whether the map appears in vote, based on player count

- Prevents a map from appearing on the vote screen if
  there are too many players
- LobbySize
  - Duel - 2 players max
  - Small - 5 players max
  - Medium - 10 players max
  - Large - 16 players max (default if not set)
- Future proofing
  - Doesn't count bot players in gametypes that don't
    support bots

src/d_netcmd.c

@@ -2208,13 +2208,34 @@ void D_SetupVote(INT16 newgametype)
 	WRITEUINT8(p, ((cv_kartencore.value == 1) && (rules & GTR_ENCORE)));
 	WRITEUINT8(p, G_SometimesGetDifferentEncore());
 
+	UINT8 numPlayers = 0;
+
+	for (i = 0; i < MAXPLAYERS; ++i)
+	{
+		if (!playeringame[i] || players[i].spectator)
+		{
+			continue;
+		}
+
+		extern consvar_t cv_forcebots; // debug
+
+		if (!(rules & GTR_BOTS) && players[i].bot && !cv_forcebots.value)
+		{
+			// Gametype doesn't support bots
+			continue;
+		}
+
+		numPlayers++;
+	}
+
 	for (i = 0; i < VOTE_NUM_LEVELS; i++)
 	{
-		UINT16 m = G_RandMap(
+		UINT16 m = G_RandMapPerPlayerCount(
 			G_TOLFlag(newgametype),
 			prevmap, false,
 			(i < VOTE_NUM_LEVELS-1),
-			votebuffer
+			votebuffer,
+			numPlayers
 		);
 		votebuffer[i] = m;
 		WRITEUINT16(p, m);

src/deh_soc.c

@@ -1417,6 +1417,29 @@ void readlevelheader(MYFILE *f, char * name)
 					mapheaderinfo[num]->destroyforchallenge_size = j;
 				}
 			}
+			else if (fastcmp(word, "LOBBYSIZE"))
+			{
+				if (fastcmp(word2, "DUEL"))
+				{
+					mapheaderinfo[num]->playerLimit = 2;
+				}
+				else if (fastcmp(word2, "SMALL"))
+				{
+					mapheaderinfo[num]->playerLimit = 5;
+				}
+				else if (fastcmp(word2, "MEDIUM"))
+				{
+					mapheaderinfo[num]->playerLimit = 10;
+				}
+				else if (fastcmp(word2, "LARGE"))
+				{
+					mapheaderinfo[num]->playerLimit = 16;
+				}
+				else
+				{
+					deh_warning("Level header %d: invalid lobby size '%s'", num, word2);
+				}
+			}
 			else
 				deh_warning("Level header %d: unknown word '%s'", num, word);
 		}

src/doomstat.h

@@ -501,6 +501,7 @@ struct mapheader_t
 
 	UINT8 levelselect;					///< Is this map available in the level select? If so, which map list is it available in?
 	UINT16 menuflags;					///< LF2_flags: options that affect record attack menus
+	UINT8 playerLimit;					///< This map does not appear in multiplayer vote if there are too many players
 
 	// Operational metadata
 	UINT16 levelflags;					///< LF_flags:  merged booleans into one UINT16 for space, see below

src/g_game.c

@@ -3499,7 +3499,7 @@ static UINT16 *g_allowedMaps = NULL;
 static size_t g_randMapStack = 0;
 #endif
 
-UINT16 G_RandMap(UINT32 tolflags, UINT16 pprevmap, boolean ignoreBuffers, boolean callAgainSoon, UINT16 *extBuffer)
+UINT16 G_RandMapPerPlayerCount(UINT32 tolflags, UINT16 pprevmap, boolean ignoreBuffers, boolean callAgainSoon, UINT16 *extBuffer, UINT8 numPlayers)
 {
 	INT32 allowedMapsCount = 0;
 	INT32 extBufferCount = 0;
@@ -3558,6 +3558,12 @@ tryAgain:
 			continue;
 		}
 
+		if (numPlayers > mapheaderinfo[i]->playerLimit)
+		{
+			// Too many players for this map.
+			continue;
+		}
+
 		// Only care about restrictions if the host is a listen server.
 		if (!dedicated)
 		{
@@ -3665,6 +3671,11 @@ tryAgain:
 	return ret;
 }
 
+UINT16 G_RandMap(UINT32 tolflags, UINT16 pprevmap, boolean ignoreBuffers, boolean callAgainSoon, UINT16 *extBuffer)
+{
+	return G_RandMapPerPlayerCount(tolflags, pprevmap, ignoreBuffers, callAgainSoon, extBuffer, 0);
+}
+
 void G_AddMapToBuffer(UINT16 map)
 {
 	if (mapheaderinfo[map]->justPlayed == 0) // Started playing a new map.

src/g_game.h

@@ -277,6 +277,7 @@ FUNCMATH INT32 G_TicsToMilliseconds(tic_t tics);
 UINT32 G_TOLFlag(INT32 pgametype);
 UINT16 G_GetFirstMapOfGametype(UINT16 pgametype);
 
+UINT16 G_RandMapPerPlayerCount(UINT32 tolflags, UINT16 pprevmap, boolean ignoreBuffers, boolean callAgainSoon, UINT16 *extBuffer, UINT8 numPlayers);
 UINT16 G_RandMap(UINT32 tolflags, UINT16 pprevmap, boolean ignoreBuffers, boolean callAgainSoon, UINT16 *extBuffer);
 void G_AddMapToBuffer(UINT16 map);
 

src/p_setup.cpp

@@ -457,6 +457,7 @@ static void P_ClearSingleMapHeaderInfo(INT16 num)
 	mapheaderinfo[num]->levelselect = 0;
 	mapheaderinfo[num]->levelflags = 0;
 	mapheaderinfo[num]->menuflags = 0;
+	mapheaderinfo[num]->playerLimit = MAXPLAYERS;
 	mapheaderinfo[num]->mobj_scale = FRACUNIT;
 	mapheaderinfo[num]->default_waypoint_radius = 0;
 	P_ClearMapHeaderLighting(&mapheaderinfo[num]->lighting);