New terrain type - grass.

Finally got around to adding grass to EvilHack. I pulled the majority of
the code from xNetHack's implementation (too many commits to reference
them all here), and then made my own modifications to it.

Grass is a new terrain type that you can walk on. It appears as a bright
green dot, same shape and orientation as a regular room/floor tile.
Monsters that can hide (M1_CONCEAL flag) under things can also hide in
the grass (and due to this behavior, can now hide under other bits of
furniture, like thrones, ladders [not stairs], altars, sinks, and
graves). Grass can also be burned away by fire. If a grass tile is
unseen/unlit, it'll darken just like a regular floor tile does.

The only thing I've really added grass to so far, is Aphroditie's level,
and garden rooms. While here, I also made some improvements to
Aphroditie's level - all of the rooms are technically gardens now.
Because garden rooms spawn their own nymphs, fountains, and trees, I've
made some tweaks to the level to compensate (read: not have the level be
completely full of nymphs). Because of these changes, I increased the
minimum level Aphroditie's level can spawn from five to eight.

I'll include grass in some existing levels in future commits. It'll also
be a part of the Druid quest levels once those are created.

dat/Druid.des

@@ -11,12 +11,12 @@ MAZE: "Dru-strt",' '
 FLAGS: noteleport,hardfloor
 GEOMETRY:center,center
 MAP
-........................
-........................
-........................
-........................
-........................
-........................
+gggggggggggggggggggggggg
+gggggggggggggggggggggggg
+gggggggggggggggggggggggg
+gggggggggggggggggggggggg
+gggggggggggggggggggggggg
+gggggggggggggggggggggggg
 ENDMAP
 
 # Dungeon Description
@@ -91,8 +91,8 @@ OBJECT:('[',"runed bracers"),(02,02),blessed,0,name:"Bracers of the First Circle
 #	and goal levels.
 #
 
-MAZE: "Dru-fila" , 'P'
-INIT_MAP: mines, '.' , 'P' , false , true , lit , false
+MAZE: "Dru-fila" , 't'
+INIT_MAP: mines, '.' , 't' , false , true , lit , false
 NOMAP
 #
 STAIR: random, up
@@ -127,8 +127,8 @@ TRAP: random, random
 TRAP: random, random
 TRAP: random, random
 
-MAZE: "Dru-filb" , 'P'
-INIT_MAP: mines, '.' , 'P' , false , true , lit , false
+MAZE: "Dru-filb" , 't'
+INIT_MAP: mines, '.' , 't' , false , true , lit , false
 NOMAP
 #
 STAIR: random, up

dat/dungeon.def

@@ -26,7 +26,7 @@ CHAINBRANCH:	"Sokoban" "oracle" + (1, 0) up
 RNDLEVEL:	"bigrm" "B" @ (10, 3) 40 10
 CHAINBRANCH:	"The Quest" "oracle" + (6, 2) portal
 BRANCH:		"Fort Ludios" @ (18, 4) portal
-LEVEL:		"nymph" "N" @ (5, 15) 45
+LEVEL:		"nymph" "N" @ (8, 15) 45
 RNDLEVEL:	"medusa" "none" @ (-5, 4) 4
 LEVALIGN:	chaotic
 CHAINBRANCH:	"The Ice Queen's Realm" "medusa" + (-1, 0) portal

dat/nymph.des

@@ -1,19 +1,17 @@
 # NetHack 3.6  nymph.des  $NHDT-Date: 1595116228 2020/07/18 23:50:28 $  $NHDT-Branch: master $:$NHDT-Revision: 1.9 $
 #
 # Nymph level (from UnNetHack, which came from Slash'EM)
-# Level is slightly modified from the original
+# Level is modified from the original
 #
 
 LEVEL: "nymph"
-ROOM: "ordinary", unlit, random, random, (12,7)
+ROOM: "garden", unlit, random, random, (12,07)
 {
-TERRAIN: random, 'T'
-TERRAIN: random, 'T'
-[30%]: TERRAIN: random, 'T'
-[30%]: TERRAIN: random, 'T'
-[30%]: TERRAIN: random, 'T'
-[30%]: TERRAIN: random, 'T'
-FOUNTAIN: random
+[30%]:TERRAIN: random, 'T'
+[30%]:TERRAIN: random, 'T'
+[30%]:TERRAIN: random, 'T'
+[30%]:TERRAIN: random, 'T'
+FOUNTAIN:random
 TRAP:"board",random
 TRAP:"board",random
 OBJECT:('(',"chest"),random
@@ -33,60 +31,79 @@ OBJECT:random, random
 OBJECT:random, random
 OBJECT:random, random
 OBJECT:random, random
-MONSTER: 'n', random, hostile
-MONSTER: 'n', random, hostile
-MONSTER: 'n', random, hostile
-MONSTER: 'n', random, hostile
-MONSTER: 'n', random, hostile
+MONSTER:'n', random, hostile
+MONSTER:'n', random, hostile
+MONSTER:'n', random, hostile
+IF [75%] {
+  IF [75%] {
+    MONSTER:('s',"centipede"), random, hostile
+  } ELSE {
+    MONSTER:('s',"scorpion"), random, hostile
+  }
+}
+# nymph queen
 MONSTER:('n',"Aphrodite"), random, hostile
 }
 
-ROOM: "ordinary", random, random, random, random
+# stairs up room
+ROOM: "garden", random, random, random, random
 {
-TERRAIN: random, 'T'
+STAIR:random, up
 TRAP:"board",random
-STAIR: random, up
 OBJECT:random,random
-MONSTER: 'n', random, hostile
 }
 
-ROOM: "ordinary", random, random, random, random
+# stairs down room
+ROOM: "garden", random, random, random, random
 {
-[30%]: TERRAIN: random, 'T'
-[30%]: TERRAIN: random, 'T'
+STAIR:random, down
 TRAP:"board",random
-TRAP: random, random
-STAIR: random, down
+TRAP:random, random
 OBJECT:random, random
-MONSTER: 'n', random, hostile
 }
 
-ROOM: "ordinary", random, random, random, random
+ROOM: "garden", random, random, random, random
 {
-[40%]: TERRAIN: random, 'T'
-[30%]: TERRAIN: random, 'T'
 TRAP:"board",random
 OBJECT:random, random
 OBJECT:random, random
-MONSTER: 'n', random, hostile
+IF [50%] {
+  IF [75%] {
+    MONSTER:('s',"centipede"), random, hostile
+  } ELSE {
+    MONSTER:('S',"snake"), random, hostile
+  }
+}
 }
 
-ROOM: "ordinary", random, random, random, random
+ROOM: "garden", random, random, random, random
 {
-[30%]: TERRAIN: random, 't'
-[30%]: TERRAIN: random, 'T'
 TRAP:"board",random
-TRAP: random, random
+TRAP:random, random
 OBJECT:random, random
-MONSTER: 'n', random, hostile
+IF [50%] {
+  IF [75%] {
+    MONSTER:('s',"centipede"), random, hostile
+  } ELSE {
+    MONSTER:('S',"pit viper"), random, hostile
+  }
+}
+
 }
 
-ROOM: "ordinary", random, random, random, random
+ROOM: "garden", random, random, random, random
 {
 TRAP:"board",random
+TRAP:random, random
 OBJECT:random, random
-TRAP: random, random
-MONSTER: 'n', random, hostile
+IF [50%] {
+  IF [75%] {
+    MONSTER:('s',"centipede"), random, hostile
+  } ELSE {
+    MONSTER:('s',"scorpion"), random, hostile
+  }
+}
+
 }
 
 RANDOM_CORRIDORS

dat/symbols

@@ -80,6 +80,7 @@ start: NHAccess
 	S_sewage: \042 
 	S_pool: \042
 	S_ice: \042
+	S_grass: \035
 	S_lava: \035
 	S_vodbridge: \035
 	S_hodbridge: \032
@@ -194,7 +195,6 @@ start: Blank
         S_falling_rock_trap: \032
         S_feline: \032
         S_fire_trap: \032
-        S_ice_trap: \032
         S_flashbeam: \032
         S_food: \032
         S_forge: \032
@@ -205,6 +205,7 @@ start: Blank
         S_giant: \032
         S_gnome: \032
         S_golem: \032
+        S_grass: \032
         S_grave: \032
         S_gremlin: \032
         S_hbeam: \032
@@ -217,6 +218,7 @@ start: Blank
         S_humanoid: \032
         S_hwall: \032
         S_ice: \032
+        S_ice_trap: \032
         S_imp: \032
         S_invisible: \032
         S_jabberwock: \032
@@ -357,7 +359,8 @@ start: IBMgraphics
 	S_puddle: \xf7			# meta-w, approx. equals
 	S_sewage: \xf7			# meta-w, approx. equals
 	S_pool: \xf7			# meta-w, approx. equals
-	S_ice: \xfa				# meta-z, centered dot
+	S_ice: \xfa			# meta-z, centered dot
+	S_grass: \xfa			# meta-z, centered dot
 	S_lava: \xf7			# meta-w, approx. equals
 	S_vodbridge: \xfa		# meta-z, centered dot
 	S_hodbridge: \xfa		# meta-z, centered dot
@@ -571,11 +574,12 @@ start: curses
 	S_ndoor: \xfe			# meta-z, centered dot
 	S_bars: \xfc			# meta-|, not-equals sign (was '#')
 	S_tree: \xe7			# meta-g, plus or minus sign
-        S_deadtree: \xe7                # meta-g, plus or minus sign
+	S_deadtree: \xe7                # meta-g, plus or minus sign
 	S_room: \xfe			# meta-z, centered dot
 	S_corr: \xe1			# meta-a, solid block
 	S_litcorr: \xe1			# meta-a, solid block
 	S_ice: \xfe			# meta-z, centered dot
+	S_grass: \xfe                   # meta-z, centered dot
 	S_vodbridge: \xfe		# meta-z, centered dot
 	S_hodbridge: \xfe		# meta-z, centered dot
 	S_vbeam: \xf8			# meta-3, vertical rule
@@ -614,7 +618,8 @@ start: DECgraphics
 	S_puddle: \xe0			# meta-\, diamond
 	S_sewage: \xe0			# meta-\, diamond
 	S_pool: \xe0			# meta-\, diamond
-	S_ice: \xfe				# meta-~, centered dot
+	S_ice: \xfe			# meta-~, centered dot
+	S_grass: \xfe                   # meta-~, centered dot
 	S_lava: \xe0			# meta-\, diamond
 	S_vodbridge: \xfe		# meta-~, centered dot
 	S_hodbridge: \xfe		# meta-~, centered dot

doc/Guidebook.mn

@@ -4578,6 +4578,7 @@ F	S_fungus	(fungus or mold)
 H	S_giant	(giant humanoid)
 G	S_gnome	(gnome)
 \'	S_golem	(golem)
+\.	S_grass (grass)
 |	S_grave	(grave)
 g	S_gremlin	(gremlin)
 \-	S_hbeam	(horizontal beam [zap animation])

doc/evilhack-changelog.md

@@ -3637,4 +3637,5 @@ The following changes to date are:
 - Initial Druid quest text
 - Finish up Druid quest text, fix formatting
 - All demons/devils are now unaligned (evil)
+- New terrain type - grass
 

include/display.h

@@ -242,6 +242,10 @@
                                     /* else U_AP_TYPE == M_AP_MONSTER */    \
                                     : monnum_to_glyph(youmonst.mappearance)))
 
+/* Get a string describing the terrain at (x, y) */
+#define explain_terrain(x, y) \
+    (defsyms[back_to_defsym((x), (y))].explanation)
+
 /*
  * A glyph is an abstraction that represents a _unique_ monster, object,
  * dungeon part, or effect.  The uniqueness is important.  For example,

include/extern.h

@@ -413,6 +413,7 @@ E void FDECL(row_refresh, (int, int, int));
 E void NDECL(cls);
 E void FDECL(flush_screen, (int));
 E int FDECL(back_to_glyph, (XCHAR_P, XCHAR_P));
+E int FDECL(back_to_defsym, (XCHAR_P, XCHAR_P));
 E int FDECL(zapdir_to_glyph, (int, int, int));
 E int FDECL(glyph_at, (XCHAR_P, XCHAR_P));
 E void NDECL(set_wall_state);
@@ -1685,6 +1686,7 @@ E int FDECL(dochug, (struct monst *));
 E boolean FDECL(m_digweapon_check, (struct monst *, XCHAR_P, XCHAR_P));
 E int FDECL(m_move, (struct monst *, int));
 E int FDECL(m_move_aggress, (struct monst *, XCHAR_P, XCHAR_P));
+E int FDECL(concealed_spot, (int, int));
 E void FDECL(dissolve_bars, (int, int));
 E boolean FDECL(closed_door, (int, int));
 E boolean FDECL(accessible, (int, int));