From 6dc2e7c80f8621cad024b3381cd4b83d7adc115c Mon Sep 17 00:00:00 2001
From: cjo <cjo@ulyco.com>
Date: Mon, 22 Apr 2013 12:15:27 -0700
Subject: [PATCH] Mana Shield mutation, revised.

---
 crawl-ref/source/enum.h          |  3 +++
 crawl-ref/source/main.cc         | 21 +++++++++++++++++++--
 crawl-ref/source/mon-abil.cc     |  4 +++-
 crawl-ref/source/mutation-data.h | 30 ++++++++++++++++++++++++++++++
 crawl-ref/source/mutation.cc     |  5 +++++
 crawl-ref/source/ouch.cc         | 16 ++++++++++++++++
 6 files changed, 76 insertions(+), 3 deletions(-)

diff --git a/crawl-ref/source/enum.h b/crawl-ref/source/enum.h
index 02e476c..453df1f 100644
--- a/crawl-ref/source/enum.h
+++ b/crawl-ref/source/enum.h
@@ -2773,6 +2773,9 @@ enum mutation_type
     MUT_TENDRILS,
     MUT_JELLY_GROWTH,
     MUT_JELLY_MISSILE,
+    MUT_MANA_SHIELD, // added new values here, is that correct? -cjo
+    MUT_MANA_REGENERATION,
+    MUT_MANA_LINK,
     NUM_MUTATIONS,
 
     RANDOM_MUTATION,
diff --git a/crawl-ref/source/main.cc b/crawl-ref/source/main.cc
index 3252ea1..492f9b2 100644
--- a/crawl-ref/source/main.cc
+++ b/crawl-ref/source/main.cc
@@ -2923,6 +2923,11 @@ static void _check_sanctuary()
     decrease_sanctuary_radius();
 }
 
+// cjo: Handles player hp and mp regeneration. If the counter you.hit_points_regeneration
+// is over 100, a loop restores 1 hp and decreased the counter by 100 (so you can regen
+// more than 1hp per turn). If the counter is below 100, it is increased by a variable
+// calculated from delay, BASELINE_DELAY, and your regeneration rate. MP regeneration happens
+// similarly, but the countup depends on delay, BASELINE_DELAY, and you.max_magic_points
 static void _regenerate_hp_and_mp(int delay)
 {
     if (crawl_state.disables[DIS_PLAYER_REGEN])
@@ -2940,7 +2945,15 @@ static void _regenerate_hp_and_mp(int delay)
 
     while (tmp >= 100)
     {
-        inc_hp(1);
+        if (you.mutation[MUT_MANA_LINK] // at low mp, "mana link" restores mp in place of hp
+           && you.magic_points < you.max_magic_points * 2 / 3)
+        {
+            inc_mp(1);
+        }
+        else // standard hp regeneration
+        {
+            inc_hp(1);
+        }
         tmp -= 100;
     }
 
@@ -2959,7 +2972,11 @@ static void _regenerate_hp_and_mp(int delay)
     if (you.magic_points < you.max_magic_points)
     {
         const int base_val = 7 + you.max_magic_points / 2;
-        tmp += div_rand_round(base_val * delay, BASELINE_DELAY);
+        int mp_regen_countup = div_rand_round(base_val * delay, BASELINE_DELAY);
+        if (you.mutation[MUT_MANA_REGENERATION])
+            mp_regen_countup *= 2;
+
+        tmp += mp_regen_countup;
     }
 
     while (tmp >= 100)
diff --git a/crawl-ref/source/mon-abil.cc b/crawl-ref/source/mon-abil.cc
index 958e032..12b8415 100644
--- a/crawl-ref/source/mon-abil.cc
+++ b/crawl-ref/source/mon-abil.cc
@@ -3573,8 +3573,10 @@ void mon_nearby_ability(monster* mons)
             interrupt_activity(AI_MONSTER_ATTACKS, mons);
 
             int mp = min(5 + random2avg(13, 3), you.magic_points);
-            dec_mp(mp);
+            if (you.mutation[MUT_MANA_LINK]) // this mutation cuts mp loss in half
+                mp = div_rand_round(mp, 2);
 
+            dec_mp(mp);
             mons->heal(mp, true); // heh heh {dlb}
         }
         break;
diff --git a/crawl-ref/source/mutation-data.h b/crawl-ref/source/mutation-data.h
index 5c596dc..cbabf27 100644
--- a/crawl-ref/source/mutation-data.h
+++ b/crawl-ref/source/mutation-data.h
@@ -1098,6 +1098,36 @@
   "augmentation"
 },
 
+{ MUT_MANA_SHIELD,                    0,  1, false, false, false,
+  "mana shield",
+
+  {"When hurt, damage is shared between your health and your mana reserves.", "", ""},
+  {"You feel your magical essence form a protective shroud around your flesh.", "", ""},
+  {"", "", ""},
+
+  "mana shield"
+},
+
+{ MUT_MANA_REGENERATION,              0,  1, false, false, false,
+  "mana regeneration",
+
+  {"You regenerate mana rapidly.", "", ""},
+  {"You feel your mana shroud grow more resiliant.", "", ""},
+  {"", "", ""},
+
+  "mana regeneration"
+},
+
+{ MUT_MANA_LINK,                      0,  1, false, false, false,
+  "mana link",
+
+  {"When low on mana, you restore mana in place of health. and you resist mana draining attacks.", "", ""},
+  {"You feel your life force and your magical essence meld.", "", ""},
+  {"", "", ""},
+
+  "mana link"
+},
+
 // Jiyva only mutations
 { MUT_GELATINOUS_BODY,                0,  3, false,  true,  true,
   NULL,
diff --git a/crawl-ref/source/mutation.cc b/crawl-ref/source/mutation.cc
index d3a14b0..46500e5 100644
--- a/crawl-ref/source/mutation.cc
+++ b/crawl-ref/source/mutation.cc
@@ -803,6 +803,9 @@ static int _calc_mutation_amusement_value(mutation_type which_mutation)
     case MUT_MUTATION_RESISTANCE:
     case MUT_ROBUST:
     case MUT_HIGH_MAGIC:
+    case MUT_MANA_SHIELD:
+    case MUT_MANA_REGENERATION:
+    case MUT_MANA_LINK:
         amusement /= 2;  // not funny
         break;
 
@@ -1928,6 +1931,8 @@ static const facet_def _demon_facets[] =
       { -33, 0, 0 } },
     { 2, { MUT_SAPROVOROUS, MUT_FOUL_STENCH, MUT_FOUL_STENCH },
       { -33, 0, 0 } },
+    { 2, { MUT_MANA_SHIELD, MUT_MANA_REGENERATION, MUT_MANA_LINK },
+      { -33, 0, 0 } },
     // Tier 3 facets
     { 3, { MUT_CONSERVE_SCROLLS, MUT_HEAT_RESISTANCE, MUT_HURL_HELLFIRE },
       { 50, 50, 50 } },
diff --git a/crawl-ref/source/ouch.cc b/crawl-ref/source/ouch.cc
index f15fd34..9935290 100644
--- a/crawl-ref/source/ouch.cc
+++ b/crawl-ref/source/ouch.cc
@@ -1139,6 +1139,22 @@ void ouch(int dam, int death_source, kill_method_type death_type,
                 return;
         }
 
+        // Currently the effect from MUT_MANA_SHIELD is the same as "spirit shield"
+        if (you.mutation[MUT_MANA_SHIELD] && death_type != KILLED_BY_POISON)
+        {
+            // round off fairly (important for taking 1 damage at a time)
+            int mp = div_rand_round(dam * you.magic_points,
+                                    you.hp + you.magic_points);
+            // but don't kill the player with round-off errors
+            mp = max(mp, dam + 1 - you.hp);
+            mp = min(mp, you.magic_points);
+
+            dam -= mp;
+            dec_mp(mp);
+            if (dam <= 0)
+                return;
+        }
+
         if (dam >= you.hp && you.hp_max > 0 && god_protects_from_harm())
         {
             simple_god_message(" protects you from harm!");
-- 
1.8.1.2