Fix permanent-MP abilities being usable when only temporary MP (e.g.

from a ring of magical power) is available. [2664906]
This does not apply to HP costs because there's no way to abuse that.
In theory it might still be possible to get negative real MP with the
high/low magic mutations.


git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@9347 c06c8d41-db1a-0410-9941-cceddc491573

5 files changed, 84 insertions, 177 deletions

diff --git a/crawl-ref/source/abl-show.cc b/crawl-ref/source/abl-show.cc
index 0c1ada0d03..2e5bbab3d5 100644
--- a/crawl-ref/source/abl-show.cc
+++ b/crawl-ref/source/abl-show.cc
@@ -988,7 +988,10 @@ static bool _activate_talent(const talent& tal)
     const ability_def& abil = get_ability_def(tal.which);
 
     // Check that we can afford to pay the costs.
-    if (!enough_mp( abil.mp_cost, false ))
+    // Note that mutation shenanigans might leave us with negative MP,
+    // so don't fail in that case if there's no MP cost.
+    if (abil.mp_cost > 0
+        && !enough_mp(abil.mp_cost, false, !(abil.flags & ABFLAG_PERMANENT_MP)))
     {
         crawl_state.zero_turns_taken();
         return (false);
diff --git a/crawl-ref/source/player.cc b/crawl-ref/source/player.cc
index e86bc5a5cb..5ff67c0139 100644
--- a/crawl-ref/source/player.cc
+++ b/crawl-ref/source/player.cc
@@ -3493,25 +3493,20 @@ void level_change(bool skip_attribute_increase)
         inc_max_hp( hp_adjust );
         inc_max_mp( mp_adjust );
 
-        deflate_hp( you.hp_max, false );
+        deflate_hp(you.hp_max, false);
 
         you.magic_points = std::max(0, you.magic_points);
 
-        {
-            unwind_var<int> hpmax(you.hp_max);
-            unwind_var<int> hp(you.hp);
-            unwind_var<int> mpmax(you.max_magic_points);
-            unwind_var<int> mp(you.magic_points);
-            // calculate "real" values for note-taking, i.e. ignore Berserk,
-            // transformations or equipped items
-            calc_hp(true);
-            calc_mp(true);
-
-            char buf[200];
-            sprintf(buf, "HP: %d/%d MP: %d/%d",
-                    you.hp, you.hp_max, you.magic_points, you.max_magic_points);
-            take_note(Note(NOTE_XP_LEVEL_CHANGE, you.experience_level, 0, buf));
-        }
+        // Get "real" values for note-taking, i.e. ignore Berserk,
+        // transformations or equipped items.
+        const int note_maxhp = get_real_hp(false, false);
+        const int note_maxmp = get_real_mp(false);
+
+        char buf[200];
+        sprintf(buf, "HP: %d/%d MP: %d/%d",
+                std::min(you.hp, note_maxhp), note_maxhp,
+                std::min(you.magic_points, note_maxmp), note_maxmp);
+        take_note(Note(NOTE_XP_LEVEL_CHANGE, you.experience_level, 0, buf));
 
         // recalculate for game
         calc_hp();
@@ -4780,21 +4775,32 @@ bool enough_hp(int minimum, bool suppress_msg)
     return (true);
 }
 
-bool enough_mp(int minimum, bool suppress_msg)
+bool enough_mp(int minimum, bool suppress_msg, bool include_items)
 {
     ASSERT(!crawl_state.arena);
 
-    if (you.magic_points < minimum)
+    bool rc = false;
+
+    if (get_real_mp(include_items) < minimum)
+    {
+        if (!suppress_msg)
+            mpr("You haven't enough magic capacity.");        
+    }
+    else if (you.magic_points < minimum)
     {
         if (!suppress_msg)
             mpr("You haven't enough magic at the moment.");
+    }
+    else
+        rc = true;
 
+    if (!rc)
+    {
         crawl_state.cancel_cmd_again();
         crawl_state.cancel_cmd_repeat();
-        return (false);
     }
 
-    return (true);
+    return (rc);
 }
 
 // Note that "max_too" refers to the base potential, the actual
@@ -5033,6 +5039,42 @@ int get_real_hp(bool trans, bool rotted)
     return (hitp);
 }
 
+int get_real_mp(bool include_items)
+{
+    // base_magic_points2 accounts for species
+    int enp = (you.base_magic_points2 - 5000);
+
+    int spell_extra = (you.experience_level * you.skills[SK_SPELLCASTING]) / 4;
+    int invoc_extra = (you.experience_level * you.skills[SK_INVOCATIONS]) / 6;
+
+    enp += std::max(spell_extra, invoc_extra);
+    enp = stepdown_value(enp, 9, 18, 45, 100);
+
+    // this is our "rotted" base (applied after scaling):
+    enp += (you.base_magic_points - 5000);
+
+    // Yes, we really do want this duplication... this is so the stepdown
+    // doesn't truncate before we apply the rotted base.  We're doing this
+    // the nice way. -- bwr
+    enp = std::min(enp, 50);
+
+    // Now applied after scaling so that power items are more useful -- bwr
+    if (include_items)
+        enp += player_magical_power();
+
+    // Analogous to ROBUST/FRAIL
+    enp *= (10 + player_mutation_level(MUT_HIGH_MAGIC)
+               - player_mutation_level(MUT_LOW_MAGIC));
+    enp /= 10;
+
+    if (enp > 50)
+        enp = 50 + ((enp - 50) / 2);
+
+    enp = std::max(enp, 0);
+
+    return enp;
+}
+
 static int _get_contamination_level()
 {
     const int glow = you.magic_contamination;
diff --git a/crawl-ref/source/player.h b/crawl-ref/source/player.h
index bdc557bc09..bc214b322a 100644
--- a/crawl-ref/source/player.h
+++ b/crawl-ref/source/player.h
@@ -348,45 +348,18 @@ bool player_wearing_slot( int eq );
 bool you_tran_can_wear(const item_def &item);
 bool you_tran_can_wear( int eq, bool check_mutation = false );
 
-/* ***********************************************************************
- * called from: ability - effects - fight - it_use3 - ouch - spell -
- *              spells - spells2 - spells3 - spells4
- * *********************************************************************** */
-void dec_hp(int hp_loss, bool fatal, const char *aux = NULL);
-
-
-/* ***********************************************************************
- * called from: ability - it_use3 - spell - spells3
- * *********************************************************************** */
-bool enough_hp (int minimum, bool suppress_msg);
-
+bool enough_hp(int minimum, bool suppress_msg);
+bool enough_mp(int minimum, bool suppress_msg, bool include_items = true);
 
-/* ***********************************************************************
- * called from: ability - it_use3
- * *********************************************************************** */
-bool enough_mp (int minimum, bool suppress_msg);
-
-
-/* ***********************************************************************
- * called from: ability - fight - it_use3 - monstuff - ouch - spell
- * *********************************************************************** */
+void dec_hp(int hp_loss, bool fatal, const char *aux = NULL);
 void dec_mp(int mp_loss);
 
-
-/* ***********************************************************************
- * called from: ability - acr - fight - it_use2 - it_use3 - spells3
- * *********************************************************************** */
 void inc_mp(int mp_gain, bool max_too);
-
-
-/* ***********************************************************************
- * called from: acr - fight - food - spells1 - spells2
- * *********************************************************************** */
 void inc_hp(int hp_gain, bool max_too);
 
 void rot_hp( int hp_loss );
 void unrot_hp( int hp_recovered );
-int player_rotted( void );
+int player_rotted();
 void rot_mp( int mp_loss );
 
 void inc_max_hp( int hp_gain );
@@ -395,28 +368,14 @@ void dec_max_hp( int hp_loss );
 void inc_max_mp( int mp_gain );
 void dec_max_mp( int mp_loss );
 
-/* ***********************************************************************
- * called from: acr - misc - religion - skills2 - spells1 - transfor
- * *********************************************************************** */
 void deflate_hp(int new_level, bool floor);
-
-
-/* ***********************************************************************
- * called from: acr - it_use2 - newgame - ouch - religion - spell - spells1
- * *********************************************************************** */
 void set_hp(int new_amount, bool max_too);
 
 int get_real_hp(bool trans, bool rotted = false);
+int get_real_mp(bool include_items);
 
-/* ***********************************************************************
- * called from: it_use3 - newgame
- * *********************************************************************** */
 void set_mp(int new_amount, bool max_too);
 
-// last updated 19apr2001 {gdl}
-/* ***********************************************************************
- * called from:
- * *********************************************************************** */
 void contaminate_player(int change, bool controlled = false,
                         bool status_only = false);
 
diff --git a/crawl-ref/source/skills2.cc b/crawl-ref/source/skills2.cc
index aacb6c817a..dc2fa7680e 100644
--- a/crawl-ref/source/skills2.cc
+++ b/crawl-ref/source/skills2.cc
@@ -2108,65 +2108,18 @@ void init_skill_order( void )
     }
 }
 
-int calc_hp(bool real_hp)
+void calc_hp()
 {
-    int hitp = get_real_hp(!real_hp, false);
-
-    you.hp_max = hitp;
-
-    deflate_hp( you.hp_max, false );
-
-    return (hitp);
-}                               // end calc_hp()
+    you.hp_max = get_real_hp(true, false);
+    deflate_hp(you.hp_max, false);
+}
 
-int calc_mp(bool real_mp)
+void calc_mp()
 {
-    int enp;
-
-    // base_magic_points2 accounts for species and magic potions
-    enp = (you.base_magic_points2 - 5000);
-
-    int spell_extra = (you.experience_level * you.skills[SK_SPELLCASTING]) / 4;
-    int invoc_extra = (you.experience_level * you.skills[SK_INVOCATIONS]) / 6;
-
-    if (spell_extra > invoc_extra)
-        enp += spell_extra;
-    else
-        enp += invoc_extra;
-
-    you.max_magic_points = stepdown_value( enp, 9, 18, 45, 100 );
-
-    // this is our "rotted" base (applied after scaling):
-    you.max_magic_points += (you.base_magic_points - 5000);
-
-    // Yes, we really do want this duplication... this is so the stepdown
-    // doesn't truncate before we apply the rotted base.  We're doing this
-    // the nice way. -- bwr
-    if (you.max_magic_points > 50)
-        you.max_magic_points = 50;
-
-    // now applied after scaling so that power items are more useful -- bwr
-    if (!real_mp)
-        you.max_magic_points += player_magical_power();
-
-    // analogous to ROBUST/FRAIL
-    you.max_magic_points *= (10 + player_mutation_level(MUT_HIGH_MAGIC)
-                                - player_mutation_level(MUT_LOW_MAGIC));
-    you.max_magic_points /= 10;
-
-    if (you.max_magic_points > 50)
-        you.max_magic_points = 50 + ((you.max_magic_points - 50) / 2);
-
-    if (you.max_magic_points < 0)
-        you.max_magic_points = 0;
-
-    if (you.magic_points > you.max_magic_points)
-        you.magic_points = you.max_magic_points;
-
+    you.max_magic_points = get_real_mp(true);
+    you.magic_points = std::min(you.magic_points, you.max_magic_points);
     you.redraw_magic_points = true;
-
-    return (you.max_magic_points);
-}                               // end calc_mp()
+}
 
 unsigned int skill_exp_needed(int lev)
 {
diff --git a/crawl-ref/source/skills2.h b/crawl-ref/source/skills2.h
index 97ac2d92a1..93e3464ec7 100644
--- a/crawl-ref/source/skills2.h
+++ b/crawl-ref/source/skills2.h
@@ -10,80 +10,30 @@
 #ifndef SKILLS2_H
 #define SKILLS2_H
 
-#define MAX_SKILL_ORDER         100
+const int MAX_SKILL_ORDER = 100;
 
 #include "enum.h"
 
-// last_updated 24may2000 {dlb}
-/* ***********************************************************************
- * called from: chardump - it_use3 - itemname - skills
- * *********************************************************************** */
 const char *skill_name(int which_skill);
 int str_to_skill(const std::string &skill);
 
-// last_updated 24may2000 {dlb}
-/* ***********************************************************************
- * called from: describe
- * *********************************************************************** */
 std::string skill_title(
     unsigned char best_skill, unsigned char skill_lev,
     // these used for ghosts and hiscores:
     int species = -1, int str = -1, int dex = -1, int god = -1 );
 
-// last_updated Sept 20 -- bwr
-/* ***********************************************************************
- * called from: acr - chardump - player - skills - stuff
- * *********************************************************************** */
-std::string player_title( void );
-
+std::string player_title();
 
 skill_type best_skill(int min_skill, int max_skill, int excl_skill = -1);
+void init_skill_order();
 
-void init_skill_order( void );
-
-
-// last_updated 24may2000 {dlb}
-/* ***********************************************************************
- * called from: acr - it_use2 - item_use - newgame - ouch - player - skills
- * *********************************************************************** */
-int calc_mp(bool real_mp = false);
-
+void calc_mp();
+void calc_hp();
 
-// last_updated 24may2000 {dlb}
-/* ***********************************************************************
- * called from: ability - acr - food - it_use2 - misc - mutation -
- *              newgame - ouch - player - skills - spells1 - transfor
- * *********************************************************************** */
-int calc_hp(bool real_hp = false);
-
-
-// last_updated 24may2000 {dlb}
-/* ***********************************************************************
- * called from: newgame - skills - skills2
- * *********************************************************************** */
 int species_skills(int skill, species_type species);
-
-
-// last_updated 24may2000 {dlb}
-/* ***********************************************************************
- * called from: newgame - skills - skills2
- * *********************************************************************** */
 unsigned int skill_exp_needed(int lev);
-
-
-// last_updated 24may2000 {dlb}
-/* ***********************************************************************
- * called from: acr
- * *********************************************************************** */
 void show_skills();
-
-
-// last_updated 14jan2001 {gdl}
-/* ***********************************************************************
- * called from: item_use
- * *********************************************************************** */
 void wield_warning(bool newWeapon = true);
-
 bool is_invalid_skill(int skill);
 
 #endif