fix(status): stop burning while standing in water

xsofy/fire.lg

@@ -18,6 +18,26 @@
 (def fire-spread-chance 30)  ;; percent per adjacent flammable per tick
 (def fire-default-ttl 5)
 (def protected-tiles #{13 14})  ;; stairs must survive dragon fire and rune fire
+(def water-tiles #{3 4})        ;; shallow + deep — extinguishes fire, never ignites
+
+(defn water-tile? [tile]
+  (contains? water-tiles tile))
+
+(defn on-water?
+  "True if the entity's current tile is shallow or deep water."
+  [world entity-id]
+  (if-let [[x y] (get-in world [:entities entity-id :pos])]
+    (water-tile? (terrain/tget (:terrain world) (:width world) x y))
+    false))
+
+(defn apply-burning
+  "Apply :burning unless the entity is standing in water (#162).
+   Move-time extinguish already handles walking into water; this closes the
+   standing-still path (e.g. fire-imp shot while already in water)."
+  [world entity-id ttl]
+  (if (on-water? world entity-id)
+    world
+    (status/apply-status world entity-id :burning ttl)))
 
 ;; Fire is light-emitting, so any ignition must invalidate the :lights
 ;; cache — step-fire's own terrain-changed gate only sees fires it spreads
@@ -36,17 +56,20 @@
       world)))
 
 (defn ignite-forced [world x y ttl]
-  "Force fire at a position regardless of terrain."
+  "Force fire at a position regardless of terrain.
+   Water is the exception: it never ignites and never gains fire-ttl (#162)."
   (let [{:keys [terrain width]} world
-        tile (terrain/tget terrain width x y)
-        placed? (and (not= tile 0) (not= tile 8) (not= tile 7)
-                     (not (contains? protected-tiles tile)))]  ;; not void, wall, lava, stairs
-    (when placed?
-      (terrain/tset! terrain width x y fire-tile))
-    (if (contains? protected-tiles tile)
+        tile (terrain/tget terrain width x y)]
+    (if (water-tile? tile)
       world
-      (let [w (assoc-in world [:fire-ttl [x y]] ttl)]
-        (if placed? (assoc w :lights nil) w)))))
+      (let [placed? (and (not= tile 0) (not= tile 8) (not= tile 7)
+                         (not (contains? protected-tiles tile)))]  ;; not void, wall, lava, stairs
+        (when placed?
+          (terrain/tset! terrain width x y fire-tile))
+        (if (contains? protected-tiles tile)
+          world
+          (let [w (assoc-in world [:fire-ttl [x y]] ttl)]
+            (if placed? (assoc w :lights nil) w)))))))
 
 (defn step-fire [world]
   "One tick of fire simulation. Spread, damage, burn out.
@@ -118,7 +141,7 @@
                                               (ent/damage-entity w (:id e) fire-damage))]
                                       ;; only apply burning if still alive
                                       (if (get-in w [:entities (:id e)])
-                                        (status/apply-status w (:id e) :burning 10)
+                                        (apply-burning w (:id e) 10)
                                         w)))
                                   w targets)))
                       w @new-ttl)]

xsofy/spell.lg

@@ -179,7 +179,7 @@
                            pos nil))
            (fn [[world] pos e]
              (let [world (fire/ignite-forced world (first pos) (second pos) ttl)]
-               [(status/apply-status world (:id e) :burning burn-ttl)])))]
+               [(fire/apply-burning world (:id e) burn-ttl)])))]
      (assoc ctx :world w))))
 
 (defn r-ice

xsofy/test/fire_test.lg

@@ -1,7 +1,9 @@
 (ns xsofy.test.fire-test
   (:require [test :refer [deftest is testing]]
             [xsofy.terrain :as terrain]
-            [xsofy.fire :as fire]))
+            [xsofy.status :as status]
+            [xsofy.fire :as fire]
+            [xsofy.spell :as spell]))
 
 (defn- room-world []
   (let [w 12 h 8
@@ -10,7 +12,7 @@
     {:terrain t :width w :height h :fire-ttl {}}))
 
 ;; Regression for the :lights cache gate (perf: only invalidate on real
-;; terrain mutation). step-fire's terrain-changed gate only sees fires it
+;; terrain mutation). step-fire's own terrain-changed gate only sees fires it
 ;; spreads or burns out — ignitions from burning-entities-ignite / dragon /
 ;; rune fire run in separate phases, so the ignite helpers must invalidate
 ;; :lights themselves or a new fire emits no light until it spreads.
@@ -35,3 +37,44 @@
         _ (terrain/tset! (:terrain w) (:width w) 3 3 8)]  ;; wall — not flammable
     (let [w' (fire/ignite w 3 3)]
       (is (= [] (:lights w'))))))
+
+;; --- #162: water prevents burning / forced ignition ---
+
+(deftest ignite-forced-skips-water
+  (testing "shallow and deep water never become fire"
+    (doseq [tile [3 4]]
+      (let [w (assoc (room-world) :lights [])
+            _ (terrain/tset! (:terrain w) (:width w) 3 3 tile)
+            w' (fire/ignite-forced w 3 3 5)]
+        (is (= tile (terrain/tget (:terrain w') (:width w') 3 3)))
+        (is (nil? (get-in w' [:fire-ttl [3 3]])))
+        (is (= [] (:lights w')))))))
+
+(deftest apply-burning-skipped-on-water
+  (testing "entity standing in water does not catch fire"
+    (doseq [tile [3 4]]
+      (let [w (-> (room-world)
+                  (assoc :entities {:e {:id :e :pos [3 3] :body {:hp 10}}}))
+            _ (terrain/tset! (:terrain w) (:width w) 3 3 tile)
+            w' (fire/apply-burning w :e 12)]
+        (is (not (status/has-status? w' :e :burning))))))
+  (testing "entity on floor still burns"
+    (let [w (-> (room-world)
+                (assoc :entities {:e {:id :e :pos [3 3] :body {:hp 10}}}))
+          w' (fire/apply-burning w :e 12)]
+      (is (status/has-status? w' :e :burning)))))
+
+(deftest fire-imp-spell-on-water-does-not-burn
+  (testing "an imp's fire rune leaves a player in water unburned"
+    (doseq [tile [3 4]]
+      (let [w (-> (room-world)
+                  (assoc :entities {:player {:id :player :pos [3 3]
+                                             :body {:hp 20 :max-hp 20}}
+                                    :imp {:id :imp :pos [2 3]
+                                          :body {:hp 8 :max-hp 8}}}))
+            _ (terrain/tset! (:terrain w) (:width w) 3 3 tile)
+            result (spell/eval-spell w :imp [3 3] [:fire])
+            w' (:world result)]
+        (is (= tile (terrain/tget (:terrain w') (:width w') 3 3)))
+        (is (nil? (get-in w' [:fire-ttl [3 3]])))
+        (is (not (status/has-status? w' :player :burning)))))))

xsofy/world.lg

@@ -712,7 +712,7 @@
                 (opctx/with-context {:source :lava :reason :hazard}
                   (ent/damage-entity world entity-id 8))
                 (#(if (get-in % [:entities entity-id])
-                    (status/apply-status % entity-id :burning 12)
+                    (fire/apply-burning % entity-id 12)
                     %))))
         ;; chasm: 10 fall damage
         6 (opctx/with-context {:source :chasm :reason :hazard}