From 4799fc937a514072649ff5acef9fe2c8005ee5da Mon Sep 17 00:00:00 2001
From: Pasi Kallinen <paxed@alt.org>
Date: Fri, 17 Mar 2023 19:35:57 +0200
Subject: [PATCH] Add level flag for plane of fire fumaroles

Also reduce the size of the gas clouds.

Breaks saves and bones.
---
 dat/fire.lua         |  2 +-
 doc/lua.adoc         |  1 +
 include/patchlevel.h |  2 +-
 include/rm.h         |  1 +
 src/allmain.c        |  2 +-
 src/do.c             |  2 +-
 src/mkmaze.c         | 16 +++++++++++++---
 src/sp_lev.c         |  2 ++
 8 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/dat/fire.lua b/dat/fire.lua
index 3a6ff7272..c97973c02 100644
--- a/dat/fire.lua
+++ b/dat/fire.lua
@@ -6,7 +6,7 @@
 --
 des.level_init({ style = "solidfill", fg = " " });
 
-des.level_flags("mazelevel", "noteleport", "hardfloor", "shortsighted", "hot")
+des.level_flags("mazelevel", "noteleport", "hardfloor", "shortsighted", "hot", "fumaroles")
 -- The player lands, upon arrival, in the
 -- lower-right.  The location of the
 -- portal to the next level is randomly chosen.
diff --git a/doc/lua.adoc b/doc/lua.adoc
index fa8be9f35..6de9a16c9 100644
--- a/doc/lua.adoc
+++ b/doc/lua.adoc
@@ -614,6 +614,7 @@ Set flags for this level.
 | temperate     | Level is neither hot nor cold.
 | nomongen      | Prevents random monster generation.
 | nodeathdrops  | Prevents killed monsters from dropping corpses or random death drops.
+| fumaroles     | Lava emits poison gas clouds at random.
 |===
 
 Example:
diff --git a/include/patchlevel.h b/include/patchlevel.h
index 5c59ef223..b67307b1f 100644
--- a/include/patchlevel.h
+++ b/include/patchlevel.h
@@ -17,7 +17,7 @@
  * Incrementing EDITLEVEL can be used to force invalidation of old bones
  * and save files.
  */
-#define EDITLEVEL 78
+#define EDITLEVEL 79
 
 /*
  * Development status possibilities.
diff --git a/include/rm.h b/include/rm.h
index 4f9982492..2b74524d5 100644
--- a/include/rm.h
+++ b/include/rm.h
@@ -392,6 +392,7 @@ struct levelflags {
     Bitfield(rndmongen, 1);    /* random monster generation allowed? */
     Bitfield(deathdrops, 1);   /* monsters may drop corpses/death drops */
     Bitfield(noautosearch, 1); /* automatic searching disabled */
+    Bitfield(fumaroles, 1);    /* lava emits poison gas at random */
 
     schar temperature;         /* +1 == hot, -1 == cold */
 };
diff --git a/src/allmain.c b/src/allmain.c
index 4793ce376..c71cfbaf9 100644
--- a/src/allmain.c
+++ b/src/allmain.c
@@ -333,7 +333,7 @@ moveloop_core(void)
                 /* vision will be updated as bubbles move */
                 if (Is_waterlevel(&u.uz) || Is_airlevel(&u.uz))
                     movebubbles();
-                else if (Is_firelevel(&u.uz))
+                else if (gl.level.flags.fumaroles)
                     fumaroles();
 
                 /* when immobile, count is in turns */
diff --git a/src/do.c b/src/do.c
index 12062af71..f41e45db9 100644
--- a/src/do.c
+++ b/src/do.c
@@ -1730,7 +1730,7 @@ goto_level(
     /* initial movement of bubbles just before vision_recalc */
     if (Is_waterlevel(&u.uz) || Is_airlevel(&u.uz))
         movebubbles();
-    else if (Is_firelevel(&u.uz))
+    else if (gl.level.flags.fumaroles)
         fumaroles();
 
     /* Reset the screen. */
diff --git a/src/mkmaze.c b/src/mkmaze.c
index 5cff6f854..3d74edd2d 100644
--- a/src/mkmaze.c
+++ b/src/mkmaze.c
@@ -1390,15 +1390,25 @@ mkportal(coordxy x, coordxy y, xint16 todnum, xint16 todlevel)
 void
 fumaroles(void)
 {
-    xint16 n;
+    xint16 n, nmax = rn2(3);
+    int sizemin = 5;
     boolean snd = FALSE, loud = FALSE;
 
-    for (n = rn2(3) + 2; n; n--) {
+    if (Is_firelevel(&u.uz)) {
+        nmax++;
+        sizemin += 5;
+    }
+    if (gl.level.flags.temperature > 0) {
+        nmax++;
+        sizemin += 5;
+    }
+
+    for (n = nmax; n; n--) {
         coordxy x = rn1(COLNO - 4, 3);
         coordxy y = rn1(ROWNO - 4, 3);
 
         if (levl[x][y].typ == LAVAPOOL) {
-            NhRegion *r = create_gas_cloud(x, y, rn1(30, 20), rn1(10, 5));
+            NhRegion *r = create_gas_cloud(x, y, rn1(10, sizemin), rn1(10, 5));
 
             clear_heros_fault(r);
             snd = TRUE;
diff --git a/src/sp_lev.c b/src/sp_lev.c
index 605364b0b..29117f925 100644
--- a/src/sp_lev.c
+++ b/src/sp_lev.c
@@ -3747,6 +3747,8 @@ lspo_level_flags(lua_State *L)
             gl.level.flags.deathdrops = 0;
         else if (!strcmpi(s, "noautosearch"))
             gl.level.flags.noautosearch = 1;
+        else if (!strcmpi(s, "fumaroles"))
+            gl.level.flags.fumaroles = 1;
         else {
             char buf[BUFSZ];
             Sprintf(buf, "Unknown level flag %s", s);