Implement TSO's halo. It applies backlight to the player and all

monsters within the (circular) halo, and then keeps the duration of that 
backlight from running out.  You currently lose it if you go under 
penance.  Also, there are no visual effects yet, other than the usual 
backlight effects.


git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@3669 c06c8d41-db1a-0410-9941-cceddc491573

7 files changed, 129 insertions, 32 deletions

diff --git a/crawl-ref/source/acr.cc b/crawl-ref/source/acr.cc
index d5b40a209c..11512ecb80 100644
--- a/crawl-ref/source/acr.cc
+++ b/crawl-ref/source/acr.cc
@@ -2693,8 +2693,12 @@ static void decrement_durations()
         Options.tutorial_events[TUT_YOU_ENCHANTED] = tut_slow;
     }
 
-    if (you.duration[DUR_BACKLIGHT] > 0 && !--you.duration[DUR_BACKLIGHT] && !you.backlit())
+    // players inside a halo don't lose backlight
+    if (you.duration[DUR_BACKLIGHT] > 0 && !halo_radius()
+        && !--you.duration[DUR_BACKLIGHT] && !you.backlit())
+    {
         mpr("You are no longer glowing.", MSGCH_DURATION);
+    }
 
     // Leak piety from the piety pool into actual piety.
     // Note that changes of religious status without corresponding actions
@@ -2884,6 +2888,8 @@ static void world_reacts()
 
     check_sanctuary();
 
+    manage_halo();
+
     run_environment_effects();
 
     if ( !you.cannot_act() && !you.mutation[MUT_BLURRY_VISION] &&
diff --git a/crawl-ref/source/misc.cc b/crawl-ref/source/misc.cc
index 80636c4bdb..856f91ded9 100644
--- a/crawl-ref/source/misc.cc
+++ b/crawl-ref/source/misc.cc
@@ -2108,3 +2108,21 @@ void reveal_secret_door(int x, int y)
     grd[x][y] = grid_is_opaque(door) ?
         DNGN_CLOSED_DOOR : DNGN_OPEN_DOOR;
 }
+
+// Is there a monster in a circle with the given radius, centered on the
+// player's position?  If so, return the distance to it.  Otherwise,
+// return -1.
+int mons_inside_circle(int posx, int posy, int radius)
+{
+    if (!inside_level_bounds(posx, posy))
+        return -1;
+
+    int dist = distance(posx, posy, you.x_pos, you.y_pos);
+    if (dist > radius*radius)
+        return -1;
+
+    if (mgrd[posx][posy] != NON_MONSTER)
+        return dist;
+
+    return -1;
+}
diff --git a/crawl-ref/source/misc.h b/crawl-ref/source/misc.h
index b967684ac4..aaf4b86f16 100644
--- a/crawl-ref/source/misc.h
+++ b/crawl-ref/source/misc.h
@@ -125,9 +125,11 @@ int speed_to_duration(int speed);
 
 bool scramble(void);
 
-bool interrupt_cmd_repeat( activity_interrupt_type ai, 
+bool interrupt_cmd_repeat( activity_interrupt_type ai,
                            const activity_interrupt_data &at );
 
 void reveal_secret_door(int x, int y);
 
+int mons_inside_circle(int posx, int posy, int radius);
+
 #endif
diff --git a/crawl-ref/source/mon-util.cc b/crawl-ref/source/mon-util.cc
index ef3e325ce2..958f6bcd8d 100644
--- a/crawl-ref/source/mon-util.cc
+++ b/crawl-ref/source/mon-util.cc
@@ -49,6 +49,7 @@
 #include "player.h"
 #include "randart.h"
 #include "religion.h"
+#include "spells3.h"
 #include "spl-util.h"
 #include "stuff.h"
 #include "terrain.h"
@@ -4093,6 +4094,10 @@ bool monsters::del_ench(enchant_type ench, bool quiet)
     if (i == enchantments.end())
         return (false);
 
+    // monsters inside a halo don't lose backlight
+    if (ench == ENCH_BACKLIGHT && mons_inside_halo(x, y))
+        return (false);
+
     const mon_enchant me = i->second;
     const enchant_type et = i->first;
     enchantments.erase(et);
diff --git a/crawl-ref/source/religion.cc b/crawl-ref/source/religion.cc
index 9ecb27ed13..e0ac11ea98 100644
--- a/crawl-ref/source/religion.cc
+++ b/crawl-ref/source/religion.cc
@@ -412,14 +412,21 @@ void dec_penance(god_type god, int val)
             take_note(Note(NOTE_MOLLIFY_GOD, god));
             you.penance[god] = 0;
 
-            // When you've worked through all your penance, you get
-            // another chance to make hostile holy beings neutral.
-            if (is_good_god(you.religion))
-                moral_beings_attitude_change();
+            // the halo is once more available
+            if (god == GOD_SHINING_ONE && you.religion == GOD_SHINING_ONE
+                && you.piety >= piety_breakpoint(0))
+            {
+                mpr("Your divine halo starts to return!");
+            }
 
             // bonuses now once more effective
             if (god == GOD_BEOGH && you.religion == GOD_BEOGH)
                  you.redraw_armour_class = true;
+
+            // When you've worked through all your penance, you get
+            // another chance to make hostile holy beings neutral.
+            if (is_good_god(you.religion))
+                moral_beings_attitude_change();
         }
         else
             you.penance[god] -= val;
@@ -455,10 +462,13 @@ void inc_penance(god_type god, int val)
         // orcish bonuses don't apply under penance
         if (god == GOD_BEOGH)
             you.redraw_armour_class = true;
+        // nor does TSO's halo or divine shield
         else if (god == GOD_SHINING_ONE)
         {
+            mpr("Your divine halo starts to fade.");
+
             if (you.duration[DUR_DIVINE_SHIELD])
-            {   // nor does TSO's divine shield
+            {
                 mpr("Your divine shield disappears!");
                 you.duration[DUR_DIVINE_SHIELD] = 0;
                 you.attribute[ATTR_DIVINE_SHIELD] = 0;
@@ -1824,6 +1834,12 @@ mprf(MSGCH_DIAGNOSTICS, "Piety increasing by %d (and %d taken from hysteresis)",
                 learned_something_new(TUT_NEW_ABILITY);
             }
 
+            if (you.religion == GOD_SHINING_ONE)
+            {
+                if (i == 0)
+                    mpr("A divine halo surrounds you!");
+            }
+
             // When you gain a piety level, you get another chance to
             // make hostile holy beings neutral.
             if (is_good_god(you.religion))
@@ -1839,16 +1855,16 @@ mprf(MSGCH_DIAGNOSTICS, "Piety increasing by %d (and %d taken from hysteresis)",
 
     if (you.piety > 160 && old_piety <= 160)
     {
-        // When you gain piety of more than 160, you get another chance
-        // to make hostile holy beings neutral.
-        if (is_good_god(you.religion))
-            moral_beings_attitude_change();
-
         if ((you.religion == GOD_SHINING_ONE || you.religion == GOD_LUGONU)
             && you.num_gifts[you.religion] == 0)
         {
             simple_god_message( " will now bless your weapon at an altar...once.");
         }
+
+        // When you gain piety of more than 160, you get another chance
+        // to make hostile holy beings neutral.
+        if (is_good_god(you.religion))
+            moral_beings_attitude_change();
     }
 
     do_god_gift(false);
@@ -2139,21 +2155,26 @@ void lose_piety(int pgn)
                     }
                 }
 
-                if ( need_water_walking() && !beogh_water_walk() )
+                if (you.religion == GOD_SHINING_ONE)
                 {
-                    fall_into_a_pool( you.x_pos, you.y_pos, true,
-                                      grd[you.x_pos][you.y_pos] );
+                    if (i == 0)
+                        mpr("Your divine halo starts to fade.");
                 }
 
-                if ( you.religion == GOD_BEOGH )
+                if ( need_water_walking() && !beogh_water_walk() )
                 {
-                    // every piety level change also affects AC from
-                    // orcish gear
-                    you.redraw_armour_class = true;
+                    fall_into_a_pool( you.x_pos, you.y_pos, true,
+                                      grd[you.x_pos][you.y_pos] );
                 }
             }
         }
     }
+
+    if ( you.religion == GOD_BEOGH )
+    {
+        // every piety level change also affects AC from orcish gear
+        you.redraw_armour_class = true;
+    }
 }
 
 static bool tso_retribution()
@@ -3456,6 +3477,8 @@ void excommunication(god_type new_god)
         break;
 
     case GOD_SHINING_ONE:
+        mpr("Your divine halo starts to fade.");
+
         if (you.duration[DUR_DIVINE_SHIELD])
         {
             mpr("Your divine shield disappears!");
diff --git a/crawl-ref/source/spells3.cc b/crawl-ref/source/spells3.cc
index 588795ee8d..670b435169 100644
--- a/crawl-ref/source/spells3.cc
+++ b/crawl-ref/source/spells3.cc
@@ -927,26 +927,20 @@ bool cast_sanctuary(const int power)
     const int pattern = random2(4);
     int count = 0;
     int monster = -1;
-    
+
     for (int x=-radius; x<=radius; x++)
          for (int y=-radius; y<=radius; y++)
          {
               int posx = you.x_pos + x;
               int posy = you.y_pos + y;
-
-              if (!inside_level_bounds(posx, posy))
-                  continue;
-
-              int dist = distance(posx, posy, you.x_pos, you.y_pos);
-              if (dist > radius*radius)
-                  continue;
+              int dist = mons_inside_circle(posx, posy, radius);
 
               // scare all hostile monsters inside sanctuary
-              if (mgrd[posx][posy] != NON_MONSTER)
+              if (dist != -1)
               {
                   monster = mgrd[posx][posy];
                   monsters *mon = &menv[monster];
-                  
+
                   if (!mons_friendly(mon)
                       && mon->add_ench(mon_enchant(ENCH_FEAR, 0, KC_YOU)))
                   {
@@ -954,7 +948,7 @@ bool cast_sanctuary(const int power)
                       count++;
                   }
               }
-                  
+
               // forming patterns
               if (pattern == 0    // outward rays
                     && (x == 0 || y == 0 || x == y || x == -y)
@@ -976,10 +970,56 @@ bool cast_sanctuary(const int power)
              simple_monster_message(&menv[monster], " turns to flee the light!");
          else if (count > 0)
              mpr("The monsters scatter in all directions!");
-         
+
     return (true);
 }
 
+int halo_radius()
+{
+    if (you.religion == GOD_SHINING_ONE && you.piety >= piety_breakpoint(0)
+        && !you.penance[GOD_SHINING_ONE])
+    {
+        return you.piety / 20;
+    }
+    else
+        return 0;
+}
+
+void manage_halo()
+{
+    int radius = halo_radius();
+
+    if (radius == 0)
+        return;
+
+    int monster = -1;
+
+    if (!you.duration[DUR_BACKLIGHT])
+        you.duration[DUR_BACKLIGHT] = 1;
+
+    for (int x=-radius; x<=radius; x++)
+         for (int y=-radius; y<=radius; y++)
+         {
+              int posx = you.x_pos + x;
+              int posy = you.y_pos + y;
+
+              // affect all monsters inside the halo
+              if (mons_inside_halo(posx, posy))
+              {
+                  monster = mgrd[posx][posy];
+                  monsters *mon = &menv[monster];
+
+                  if (!mon->has_ench(ENCH_BACKLIGHT))
+                      mon->add_ench(ENCH_BACKLIGHT);
+              }
+         }
+}
+
+bool mons_inside_halo(int posx, int posy)
+{
+    return (mons_inside_circle(posx, posy, halo_radius()) != -1);
+}
+
 void cast_poison_ammo(void)
 {
     const int ammo = you.equip[EQ_WEAPON];
diff --git a/crawl-ref/source/spells3.h b/crawl-ref/source/spells3.h
index 8972658739..508993da42 100644
--- a/crawl-ref/source/spells3.h
+++ b/crawl-ref/source/spells3.h
@@ -67,7 +67,10 @@ bool cast_selective_amnesia(bool force);
 int cast_smiting(int power, dist &);
 bool remove_sanctuary(bool did_attack = false);
 void decrease_sanctuary_radius(void);
-bool cast_sanctuary(int power);
+bool cast_sanctuary(const int power);
+int halo_radius(void);
+void manage_halo(void);
+bool mons_inside_halo(int posx, int posy);
 
 // updated 24may2000 {dlb}
 /* ***********************************************************************