Implement "Passive Freeze" mutation (DS)

4 files changed, 63 insertions, 1 deletions

diff --git a/crawl-ref/source/cloud.cc b/crawl-ref/source/cloud.cc
index 523d7cd8f3..1916914ed1 100644
--- a/crawl-ref/source/cloud.cc
+++ b/crawl-ref/source/cloud.cc
@@ -530,6 +530,8 @@ int max_cloud_damage(cloud_type cl_type, int power)
 
         // Intentional fall-throuigh
     case CLOUD_COLD:
+        if (you.mutation[MUT_PASSIVE_FREEZE])
+            return (0);
         if (cl_type == CLOUD_COLD)
             resist = player_res_cold();
 
@@ -665,6 +667,9 @@ void in_a_cloud()
         break;
 
     case CLOUD_COLD:
+        if (you.mutation[MUT_PASSIVE_FREEZE])
+            break;
+
         mpr("You are engulfed in freezing vapours!");
 
         resist = player_res_cold();
@@ -791,8 +796,9 @@ bool is_damaging_cloud(cloud_type type, bool temp)
         if (temp && you.duration[DUR_FIRE_SHIELD])
             return (false);
     case CLOUD_CHAOS:
-    case CLOUD_COLD:
         return (true);
+    case CLOUD_COLD:
+        return (!you.mutation[MUT_PASSIVE_FREEZE]);
 
     // Only harmful if the player doesn't have the necessary resistances.
     // Takes into account what the player can *know* and what s/he can
diff --git a/crawl-ref/source/enum.h b/crawl-ref/source/enum.h
index 069a081841..9967fbd948 100644
--- a/crawl-ref/source/enum.h
+++ b/crawl-ref/source/enum.h
@@ -2424,6 +2424,7 @@ enum mutation_type
     MUT_ICEMAIL,
     MUT_CONSERVE_SCROLLS,
     MUT_CONSERVE_POTIONS,
+    MUT_PASSIVE_FREEZE,
     NUM_MUTATIONS,
 
     RANDOM_MUTATION = 100,
diff --git a/crawl-ref/source/mutation.cc b/crawl-ref/source/mutation.cc
index 69362b8a6d..1c7594290b 100644
--- a/crawl-ref/source/mutation.cc
+++ b/crawl-ref/source/mutation.cc
@@ -1217,6 +1217,13 @@ mutation_def mutation_defs[] = {
       {"", "", ""},
       "conserve potions",
     },
+
+    { MUT_PASSIVE_FREEZE,             0,  1, false, false,
+      {"A frigid envelope surrounds you and freezes all who hurt you.", "", ""},
+      {"Your skin feels very cold...", "", ""},
+      {"", "", ""},
+      "passive freeze",
+    },
 };
 
 const mutation_def& get_mutation_def(mutation_type mut)
diff --git a/crawl-ref/source/ouch.cc b/crawl-ref/source/ouch.cc
index 96f806bbfc..e5ae609ed7 100644
--- a/crawl-ref/source/ouch.cc
+++ b/crawl-ref/source/ouch.cc
@@ -34,6 +34,7 @@
 #include "externs.h"
 
 #include "artefact.h"
+#include "beam.h"
 #include "chardump.h"
 #include "delay.h"
 #include "effects.h"
@@ -857,6 +858,52 @@ static void _yred_mirrors_injury(int dam, int death_source)
     }
 }
 
+static void _passive_freeze(kill_method_type death_type, int death_source)
+{
+    if (you.mutation[MUT_PASSIVE_FREEZE] && death_type == KILLED_BY_MONSTER)
+    {
+        if (invalid_monster_index(death_source))
+            return;
+
+        monsters *mon = &menv[death_source];
+
+        if (!mon->alive())
+            return;
+
+        bolt beam;
+        beam.flavour = BEAM_COLD;
+        beam.thrower = KILL_YOU;
+
+        const int orig_hurted = roll_dice(1, 11);
+        int hurted = mons_adjust_flavoured(mon, beam, orig_hurted);
+
+        if (!hurted)
+            return;
+
+        simple_monster_message(mon, " is very cold.");
+
+#ifndef USE_TILE
+        flash_monster_colour(mon, LIGHTBLUE, 200);
+#endif
+
+        mon->hurt(&you, hurted);
+
+        if (mon->alive())
+        {
+            mon->expose_to_element(BEAM_COLD, orig_hurted);
+            print_wounds(mon);
+
+            const int cold_res = mon->res_cold();
+
+            if (cold_res <= 0)
+            {
+                const int stun = (1 - cold_res) * random2(7);
+                mon->speed_increment -= stun;
+            }
+        }
+    }
+}
+
 static void _maybe_spawn_jellies(int dam, const char* aux,
                                   kill_method_type death_type, int death_source)
 {
@@ -1029,6 +1076,7 @@ void ouch(int dam, int death_source, kill_method_type death_type,
                       Note(NOTE_HP_CHANGE, you.hp, you.hp_max, damage_desc.c_str()) );
 
             _yred_mirrors_injury(dam, death_source);
+            _passive_freeze(death_type, death_source);
             _maybe_spawn_jellies(dam, aux, death_type, death_source);
 
             return;