Book acquirement again:

* Weigh magic skills stronger to bias against manuals.
* Fall through to randart (theme) books if all spells are known.
* Allow spell school combinations (Conj/Fire) in naming randarts after
  hell lords and others.


git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@9122 c06c8d41-db1a-0410-9941-cceddc491573

5 files changed, 215 insertions, 83 deletions

diff --git a/crawl-ref/source/dat/database/randbook.txt b/crawl-ref/source/dat/database/randbook.txt
index acbef6af85..0bc397000c 100644
--- a/crawl-ref/source/dat/database/randbook.txt
+++ b/crawl-ref/source/dat/database/randbook.txt
@@ -27,6 +27,18 @@
 # a keyword that is used as a prefix for "level book".
 # @level@ is parsed to the word describing the spell level.
 #
+# Books also may get previous "owners" (or authors) that may be the gifting
+# god (if gifted), a name depending on school(s) as defined in this file,
+# a random name, or an appropriate god (if not a god gift).
+# The school dependant names consist of uniques or spell names that have a
+# strong connection to one or more schools. Pandemonium or hell lords' names
+# may only get used if a book is "highlevel", i.e. contains at least one
+# spell of level 6 or higher.
+# If the first and second school are different the two names are tested in
+# combination, in alphabetical order. If this is not the case or nothing is
+# found (or "__NONE" == the empty string was returned) and all spells match
+# the primary school try again with only that one.
+#
 # See the explanation in the main file, randname.txt, for more general
 # information on randart naming.
 ######################################################
@@ -693,27 +705,97 @@ Gliding
 %%%%
 # potential previous owners of books
 # __NONE is parsed to the empty string
-Conjuration owner
+# First, combinations.
+highlevel Conjuration Earth owner
+
+Dispater
+
+@Conjuration Earth owner@
+%%%%
+Conjuration Earth owner
 
 Lee
 
 Lehudib
+%%%%
+highlevel Conjuration Fire owner
 
-Iskenderun
+Asmodeus
 
-Erolcha
+Cerebov
 
-Louise
+w:5
+@Conjuration Fire owner@
+%%%%
+Conjuration Fire owner
+
+Azrael
+
+Margery
+
+__NONE
+%%%%
+highlevel Conjuration Necromancy owner
+
+Ereshkigal
+
+@Conjuration Necromancy owner@
+%%%%
+Conjuration Necromancy owner
 
 Boris
 
 Nergalle
 
-Josephine
+__NONE
+%%%%
+highlevel Conjuration Summoning owner
 
-Frederick
+Asmodeus
+
+Dispater
+
+w:5
+__NONE
 %%%%
-high-level Conjuration owner
+highlevel Conjuration Translocation owner
+
+Lom Lobon
+
+__NONE
+%%%%
+Earth Transmutation owner
+
+Roxanne
+
+__NONE
+%%%%
+highlevel Earth Summoning owner
+
+Dispater
+
+__NONE
+%%%%
+highlevel Fire Summoning owner
+
+Asmodeus
+
+__NONE
+%%%%
+highlevel Necromancy Poison owner
+
+Gloorx Vloq
+
+__NONE
+%%%%
+Necromancy Transmutation owner
+
+Cigotuvi
+
+__NONE
+%%%%
+# Single spell schools.
+highlevel Conjuration owner
 
 Asmodeus
 
@@ -728,6 +810,26 @@ Lom Lobon
 w:30
 @Conjuration owner@
 %%%%
+Conjuration owner
+
+Lee
+
+Lehudib
+
+Iskenderun
+
+Erolcha
+
+Louise
+
+Boris
+
+Nergalle
+
+Josephine
+
+Frederick
+%%%%
 Enchantment owner
 
 Ilsuiw
@@ -738,11 +840,7 @@ Norris
 
 __NONE
 %%%%
-Summoning owner
-
-__NONE
-%%%%
-high-level Summoning owner
+highlevel Summoning owner
 
 Asmodeus
 
@@ -752,15 +850,11 @@ Mnoleg
 
 @Summoning owner@
 %%%%
-Fire owner
-
-Azrael
-
-Margery
+Summoning owner
 
 __NONE
 %%%%
-high-level Fire owner
+highlevel Fire owner
 
 Asmodeus
 
@@ -769,6 +863,14 @@ Cerebov
 w:20
 @Fire owner@
 %%%%
+Fire owner
+
+Azrael
+
+Margery
+
+__NONE
+%%%%
 Ice owner
 
 w:5
@@ -784,6 +886,15 @@ Roxanne
 
 __NONE
 %%%%
+highlevel Necromancy owner
+
+Ereshkigal
+
+Gloorx Vloq
+
+w:40
+@Necromancy owner@
+%%%%
 Necromancy owner
 
 Borgnjor
@@ -800,28 +911,25 @@ Murray
 
 Nergalle
 %%%%
-high-level Necromancy owner
-
-Ereshkigal
-
-Gloorx Vloq
-
-w:40
-@Necromancy owner@
-%%%%
 Divination owner
 
 __NONE
 %%%%
+highlevel Translocation owner
+
+Lom Lobon
+
+@Translocation owner@
+%%%%
 Translocation owner
 
 __NONE
 %%%%
-high-level Translocation owner
+highlevel Poison owner
 
-Lom Lobon
+Gloorx Vloq
 
-@Translocation owner@
+@Poison owner@
 %%%%
 Poison owner
 
@@ -831,11 +939,12 @@ Alistair
 
 __NONE
 %%%%
-high-level Poison owner
+highlevel Earth owner
 
-Gloorx Vloq
+Dispater
 
-@Poison owner@
+w:30
+@Earth owner@
 %%%%
 Earth owner
 
@@ -847,13 +956,6 @@ Roxanne
 
 __NONE
 %%%%
-high-level Earth owner
-
-Dispater
-
-w:30
-@Earth owner@
-%%%%
 Air owner
 
 __NONE
diff --git a/crawl-ref/source/effects.cc b/crawl-ref/source/effects.cc
index 9161e0f80e..c5acfe2441 100644
--- a/crawl-ref/source/effects.cc
+++ b/crawl-ref/source/effects.cc
@@ -1322,13 +1322,13 @@ static int _spell_weight(spell_type spell)
             int skill = you.skills[spell_type2skill(disc)]
                         * 100 / species_skills(i, you.species);
 
-            weight += skill;
+            weight += skill + 1;
             count++;
         }
     }
     ASSERT(count > 0);
 
-    int level = spell_difficulty(spell);
+    int level = spell_difficulty(spell) - 1;
 
     return std::max(0, weight/count - 2*level);
 }
@@ -1396,25 +1396,26 @@ static void _do_book_acquirement(item_def &book, int agent)
     // Manuals are too useful for Xom, and useless when gifted from Sif Muna.
     if (agent != GOD_XOM && agent != GOD_SIF_MUNA)
     {
-        int weights[NUM_SKILLS];
         int magic_weights = 0;
         int other_weights = 0;
 
         for (int i = 0; i < NUM_SKILLS; i++)
         {
             if (i > SK_UNARMED_COMBAT && i < SK_SPELLCASTING)
-            {
-                weights[i] = 0;
                 continue;
-            }
 
-            weights[i] = you.skills[i]
-                         * 100 / species_skills(i, you.species);
+            int weight = you.skills[i] * 100 / species_skills(i, you.species);
 
+            // Anyone can get Spellcasting 1. Doesn't prove anything.
+            if (i == SK_SPELLCASTING && weight >= 1)
+                weight--;
+
+            // Count magic skills double to bias against manuals
+            // for magic users.
             if (i >= SK_SPELLCASTING && i <= SK_POISON_MAGIC)
-                magic_weights += weights[i];
+                magic_weights += 2*weight;
             else
-                other_weights += weights[i];
+                other_weights += weight;
         }
 
         if (x_chance_in_y(other_weights, magic_weights + other_weights))
@@ -1445,6 +1446,26 @@ static void _do_book_acquirement(item_def &book, int agent)
 
     switch (choice)
     {
+    default:
+    {
+        int total_weights = 0;
+
+        // Pick a random spellbook according to unknown spells contained.
+        int weights[MAX_NORMAL_BOOK+1];
+        for (int bk = 0; bk <= MAX_NORMAL_BOOK; bk++)
+        {
+            weights[bk]    = _book_weight(bk);
+            total_weights += weights[bk];
+        }
+
+        if (total_weights > 0)
+        {
+            book.sub_type = choose_random_weighted(weights,
+                                                   weights + ARRAYSZ(weights));
+            break;
+        }
+        // else intentional fall-through
+    }
     case BOOK_RANDART_THEME:
         book.sub_type = choice;
         make_book_theme_randart(book, 0, 0, 7, 22, SPELL_NO_SPELL, owner);
@@ -1479,10 +1500,7 @@ static void _do_book_acquirement(item_def &book, int agent)
                         * 100 / species_skills(i, you.species);
 
             int w = (skill < 12) ? skill + 3
-                                 : 25 - skill;
-
-            if (w < 0)
-                w = 0;
+                                 : std::max(0, 25 - skill);
 
             // If we don't know any magic skills, make non-magic skills
             // more likely.
@@ -1500,25 +1518,12 @@ static void _do_book_acquirement(item_def &book, int agent)
             return;
         }
 
-        int skill = choose_random_weighted(weights,
-                                           weights + ARRAYSZ(weights));
         book.sub_type = BOOK_MANUAL;
-        book.plus = skill;
+        book.plus     = choose_random_weighted(weights, weights + NUM_SKILLS);
         // Set number of reads possible before it "crumbles to dust".
-        book.plus2 = 3 + random2(15);
+        book.plus2    = 3 + random2(15);
         break;
     }
-
-    default:
-    {
-        // Pick a random spellbook according to unknown spells contained.
-        int weights[MAX_NORMAL_BOOK+1];
-        for (int bk = 0; bk <= MAX_NORMAL_BOOK; bk++)
-            weights[bk] = _book_weight(bk);
-
-        book.sub_type = choose_random_weighted(weights,
-                                               weights + ARRAYSZ(weights));
-    }
     }
 }
 
diff --git a/crawl-ref/source/spl-book.cc b/crawl-ref/source/spl-book.cc
index e771b0ce31..a70637fb47 100644
--- a/crawl-ref/source/spl-book.cc
+++ b/crawl-ref/source/spl-book.cc
@@ -2446,8 +2446,9 @@ bool make_book_theme_randart(item_def &book, int disc1, int disc2,
     for (int i = 0; i < SPELLBOOK_SIZE; i++)
     {
         spell_vec[i] = (long) chosen_spells[i];
-        if (spell_difficulty(chosen_spells[i]) > highest_level)
-            highest_level = spell_difficulty(chosen_spells[i]);
+        int diff = spell_difficulty(chosen_spells[i]);
+        if (diff > highest_level)
+            highest_level = diff;
 
         if (all_spells_disc1 && is_valid_spell(chosen_spells[i])
             && !spell_typematch( chosen_spells[i], disc1 ))
@@ -2471,18 +2472,40 @@ bool make_book_theme_randart(item_def &book, int disc1, int disc2,
         const bool god_gift = (god != GOD_NO_GOD);
         if (god_gift && !one_chance_in(4))
             owner = god_name(god, false);
-        else if (all_spells_disc1
-                 && (god_gift && one_chance_in(3) || one_chance_in(5)))
+        else if (god_gift && one_chance_in(3) || one_chance_in(5))
         {
-            std::string lookup = spelltype_long_name(disc1);
-            if (highest_level >= 6 + random2(3))
-                owner = getRandNameString("high-level " + lookup + " owner");
+            bool highlevel = (highest_level >= 6 + random2(3));
 
-            if (owner.empty() || owner == "__NONE")
-                owner = getRandNameString(lookup + " owner");
+            if (disc1 != disc2)
+            {
+                std::string schools[2];
+                schools[0] = spelltype_long_name(disc1);
+                schools[1] = spelltype_long_name(disc2);
+                std::sort(schools, schools + 2);
+                std::string lookup = schools[0] + " " + schools[1];
+
+                if (highlevel)
+                    owner = getRandNameString("highlevel " + lookup + " owner");
+
+                if (owner.empty() || owner == "__NONE")
+                    owner = getRandNameString(lookup + " owner");
+
+                if (owner == "__NONE")
+                    owner = "";
+            }
 
-            if (owner == "__NONE")
-                owner = "";
+            if (owner.empty() && all_spells_disc1)
+            {
+                std::string lookup = spelltype_long_name(disc1);
+                if (highlevel && disc1 == disc2)
+                    owner = getRandNameString("highlevel " + lookup + " owner");
+
+                if (owner.empty() || owner == "__NONE")
+                    owner = getRandNameString(lookup + " owner");
+
+                if (owner == "__NONE")
+                    owner = "";
+            }
         }
 
         if (owner.empty())
diff --git a/crawl-ref/source/stuff.h b/crawl-ref/source/stuff.h
index 2a63276b7a..464fb1794d 100644
--- a/crawl-ref/source/stuff.h
+++ b/crawl-ref/source/stuff.h
@@ -233,10 +233,10 @@ int choose_random_weighted(Iterator beg, const Iterator end)
 
     int totalweight = 0;
     int count = 0, result = 0;
-    while ( beg != end )
+    while (beg != end)
     {
         totalweight += *beg;
-        if ( random2(totalweight) < *beg )
+        if (random2(totalweight) < *beg)
         {
             result = count;
 #if DEBUG
@@ -246,7 +246,9 @@ int choose_random_weighted(Iterator beg, const Iterator end)
         ++count;
         ++beg;
     }
+#if DEBUG
     ASSERT(times_set > 0);
+#endif
     return result;
 }
 
diff --git a/crawl-ref/source/tutorial.cc b/crawl-ref/source/tutorial.cc
index 18326f1689..fb131a5d56 100644
--- a/crawl-ref/source/tutorial.cc
+++ b/crawl-ref/source/tutorial.cc
@@ -1634,7 +1634,7 @@ void learned_something_new(tutorial_event_type seen_what, coord_def gc)
 #endif
                 ". You can eat it by typing <w>e</w>"
 #ifdef USE_TILE
-                " or by clicking on it with your <w>left mouse button</w> "
+                " or by clicking on it with your <w>left mouse button</w>"
 #endif
                 ".";
         break;