Themerooms: Engraving hints the location of buried treasure

Add two new themeroom functions that are called when generating
the level: pre_themerooms_generate and post_themerooms_generate,
calles before and after themerooms_generate.

Allow the buried treasure -themeroom to put down an engraving
anywhere on the level, hinting at the location of the treasure.

des.object contents function now gets the generated object passed
to it as a parameter.

dat/nhlib.lua

@@ -50,3 +50,8 @@ function monkfoodshop()
    end
    return "food shop";
 end
+
+-- pline with variable number of arguments
+function pline(fmt, ...)
+   nh.pline(string.format(fmt, table.unpack({...})));
+end

dat/themerms.lua

@@ -14,8 +14,15 @@
 --     the room only gets what you define in here.
 --   - use type = "themed" to force a room that's never converted
 --     to a special room, such as a shop or a temple.
--- core calls themerooms_generate() multiple times per level
+--
--- to generate a single themed room.
+-- for each level, the core first calls pre_themerooms_generate(),
+-- then it calls themerooms_generate() multiple times until it decides
+-- enough rooms have been generated, and then it calls
+-- post_themerooms_generate().  The lua state is persistent through
+-- the gameplay, but not across saves, so remember to reset any variables.
+
+
+local buried_treasure = { };
 
 themeroom_fills = {
 
@@ -74,7 +81,12 @@ themeroom_fills = {
 
    -- Buried treasure
    function(rm)
-      des.object({ id = "chest", buried = true, contents = function()
+      des.object({ id = "chest", buried = true, contents = function(otmp)
+                      local xobj = otmp:totable();
+                      -- keep track of the last buried treasure
+                      if (xobj.NO_OBJ == nil) then
+                         buried_treasure = { x = xobj.ox, y = xobj.oy };
+                      end
                       for i = 1, d(3,4) do
                          des.object();
                       end
@@ -649,6 +661,7 @@ function is_eligible(room, mkrm)
    return true
 end
 
+-- called repeatedly until the core decides there are enough rooms
 function themerooms_generate()
    local pick = 1;
    local total_frequency = 0;
@@ -678,6 +691,34 @@ function themerooms_generate()
    end
 end
 
+-- called before any rooms are generated
+function pre_themerooms_generate()
+   -- reset the buried treasure location
+   buried_treasure = { };
+end
+
+-- called after all rooms have been generated
+function post_themerooms_generate()
+   if (buried_treasure.x ~= nil) then
+      local floors = selection.negate():filter_mapchar(".");
+      local pos = floors:rndcoord(0);
+      local tx = buried_treasure.x - pos.x - 1;
+      local ty = buried_treasure.y - pos.y;
+      local dig = "";
+      if (tx == 0 and ty == 0) then
+         dig = " here";
+      else
+         if (tx < 0 or tx > 0) then
+            dig = string.format(" %i %s", math.abs(tx), (tx > 0) and "east" or "west");
+         end
+         if (ty < 0 or ty > 0) then
+            dig = dig .. string.format(" %i %s", math.abs(ty), (ty > 0) and "south" or "north");
+         end
+      end
+      des.engraving({ coord = pos, type = "burn", text = "Dig" .. dig });
+   end
+end
+
 function themeroom_fill(rm)
    local pick = 1;
    local total_frequency = 0;
@@ -706,3 +747,4 @@ function themeroom_fill(rm)
       themeroom_fills[pick](rm);
    end
 end
+

doc/lua.adoc

@@ -651,6 +651,7 @@ Example:
  des.non_passwall(selection);
  des.non_passwall();
 
+
 === object
 
 Create an object. The table parameter accepts the following:
@@ -682,7 +683,7 @@ Create an object. The table parameter accepts the following:
 | male        | boolean  | Is statue male?
 | female      | boolean  | Is statue female?
 | laid_by_you | boolean  | Is an egg laid by you?
-| contents    | function | Container contents
+| contents    | function | Container contents. The container object is given as a parameter. See <<Obj>> class.
 |===
 
 Example:
@@ -694,7 +695,8 @@ Example:
  des.object("scimitar", {6, 7});
  des.object({ class = "%" });
  des.object({ id = "boulder", x = 03, y = 12});
- des.object({ id = "chest", coord = {03, 12}, locked = true, contents = function() des.object("rock"); end });
+ des.object({ id = "chest", coord = {03, 12}, locked = true, contents = function(obj) des.object("rock"); end });
+
 
 === random_corridors
 

src/mklev.c

@@ -289,6 +289,13 @@ makerooms(void)
 
     if (themes) {
         create_des_coder();
+        iflags.in_lua = g.in_mk_themerooms = TRUE;
+        g.themeroom_failed = FALSE;
+        lua_getglobal(themes, "pre_themerooms_generate");
+        if ( nhl_pcall(themes, 0, 0)){
+            impossible("Lua error: %s", lua_tostring(themes, -1));
+        }
+        iflags.in_lua = g.in_mk_themerooms = FALSE;
     }
 
     /* make rooms until satisfied */
@@ -321,6 +328,15 @@ makerooms(void)
         }
     }
     if (themes) {
+        reset_xystart_size();
+        iflags.in_lua = g.in_mk_themerooms = TRUE;
+        g.themeroom_failed = FALSE;
+        lua_getglobal(themes, "post_themerooms_generate");
+        if ( nhl_pcall(themes, 0, 0)){
+            impossible("Lua error: %s", lua_tostring(themes, -1));
+        }
+        iflags.in_lua = g.in_mk_themerooms = FALSE;
+
         wallification(1, 0, COLNO - 1, ROWNO - 1);
         free(g.coder);
         g.coder = NULL;

src/sp_lev.c

@@ -55,7 +55,7 @@ static boolean m_bad_boulder_spot(coordxy, coordxy);
 static int pm_to_humidity(struct permonst *);
 static unsigned int sp_amask_to_amask(unsigned int sp_amask);
 static void create_monster(monster *, struct mkroom *);
-static void create_object(object *, struct mkroom *);
+static struct obj *create_object(object *, struct mkroom *);
 static void create_altar(altar *, struct mkroom *);
 static boolean search_door(struct mkroom *, coordxy *, coordxy *, xint16, int);
 static void create_corridor(corridor *);
@@ -2125,7 +2125,7 @@ create_monster(monster* m, struct mkroom* croom)
 /*
  * Create an object in a room.
  */
-static void
+static struct obj *
 create_object(object* o, struct mkroom* croom)
 {
     struct obj *otmp;
@@ -2267,7 +2267,7 @@ create_object(object* o, struct mkroom* croom)
                     artifact_exists(otmp, safe_oname(otmp), FALSE,
                                     ONAME_NO_FLAGS); /* flags don't matter */
                 obfree(otmp, NULL);
-                return;
+                return NULL;
             }
         }
     }
@@ -2359,11 +2359,14 @@ create_object(object* o, struct mkroom* croom)
             boolean dealloced;
 
             (void) bury_an_obj(otmp, &dealloced);
-            if (dealloced && container_idx) {
+            if (dealloced) {
-                container_obj[container_idx - 1] = NULL;
+                if (container_idx)
+                    container_obj[container_idx - 1] = NULL;
+                otmp = NULL;
             }
         }
     }
+    return otmp;
 }
 
 /*
@@ -3461,6 +3464,7 @@ lspo_object(lua_State *L)
     lua_Integer ox = -1, oy = -1;
     int argc = lua_gettop(L);
     int maybe_contents = 0;
+    struct obj *otmp = NULL;
 
     create_des_coder();
 
@@ -3601,14 +3605,15 @@ lspo_object(lua_State *L)
     }
 
     do {
-        create_object(&tmpobj, g.coder->croom);
+        otmp = create_object(&tmpobj, g.coder->croom);
         quancnt--;
     } while ((quancnt > 0) && ((tmpobj.id > STRANGE_OBJECT)
                                && !objects[tmpobj.id].oc_merge));
 
     if (lua_type(L, -1) == LUA_TFUNCTION) {
         lua_remove(L, -2);
-        if (nhl_pcall(L, 0, 0)){
+        nhl_push_obj(L, otmp);
+        if (nhl_pcall(L, 1, 0)){
             impossible("Lua error: %s", lua_tostring(L, -1));
         }
     } else