Halve displayed SH values (crate)

So that shield enchantments are back to giving 1 (displayed)
SH, and SH generally is somewhat more in line with AC/EV;
1 SH should be very roughly as good as 1 EV, against things
they affect.

This also tweaks the 'bone plates' mutation slightly, for
rounding reasons; the first level is buffed very slightly,
and the third is very slightly nerfed.

6 files changed, 29 insertions, 10 deletions

diff --git a/crawl-ref/source/hiscores.cc b/crawl-ref/source/hiscores.cc
index 7c57c4f646..9009efb3ae 100644
--- a/crawl-ref/source/hiscores.cc
+++ b/crawl-ref/source/hiscores.cc
@@ -1555,7 +1555,7 @@ void scorefile_entry::init(time_t dt)
 
     ac    = you.armour_class();
     ev    = player_evasion();
-    sh    = player_shield_class();
+    sh    = player_displayed_shield_class();
 
     god = you.religion;
     if (!you_worship(GOD_NO_GOD))
diff --git a/crawl-ref/source/mutation-data.h b/crawl-ref/source/mutation-data.h
index 03c1e3067a..8d4303ca5c 100644
--- a/crawl-ref/source/mutation-data.h
+++ b/crawl-ref/source/mutation-data.h
@@ -1403,9 +1403,9 @@ static const mutation_def mut_data[] =
 { MUT_LARGE_BONE_PLATES,              2,  3, false, true,
   "large bone plates",
 
-  {"You are partially covered in large bone plates (AC +2, SH +3).",
-   "You are mostly covered in large bone plates (AC +3, SH +6).",
-   "You are completely covered in large bone plates (AC +4, SH +9)."},
+  {"You are partially covered in large bone plates (AC +2, SH +2).",
+   "You are mostly covered in large bone plates (AC +3, SH +3).",
+   "You are completely covered in large bone plates (AC +4, SH +4)."},
 
   {"Large bone plates grow over parts of your arms.",
    "Large bone plates spread over more of your arms.",
diff --git a/crawl-ref/source/output.cc b/crawl-ref/source/output.cc
index a69ceeed15..0250d57ed2 100644
--- a/crawl-ref/source/output.cc
+++ b/crawl-ref/source/output.cc
@@ -804,7 +804,7 @@ static void _print_stats_ac(int x, int y)
     }
     else
         textcolor(HUD_VALUE_COLOUR);
-    CPRINTF("%2d ", player_shield_class());
+    CPRINTF("%2d ", player_displayed_shield_class());
 }
 
 static void _print_stats_ev(int x, int y)
@@ -2130,10 +2130,10 @@ static vector<formatted_string> _get_overview_stats()
     if (boosted_sh)
     {
         snprintf(buf, sizeof buf, "SH <lightblue>%2d</lightblue>",
-                 player_shield_class());
+                 player_displayed_shield_class());
     }
     else
-        snprintf(buf, sizeof buf, "SH %2d", player_shield_class());
+        snprintf(buf, sizeof buf, "SH %2d", player_displayed_shield_class());
     cols1.add_formatted(1, buf, false);
 
     const char* str_col = colour_to_str(_get_stat_colour(STAT_STR)).c_str();
diff --git a/crawl-ref/source/player.cc b/crawl-ref/source/player.cc
index e052c6df1a..5ba1691b51 100644
--- a/crawl-ref/source/player.cc
+++ b/crawl-ref/source/player.cc
@@ -2627,6 +2627,12 @@ int player_wizardry()
            + you.wearing(EQ_STAFF, STAFF_WIZARDRY);
 }
 
+/**
+ * Calculate the SH value used internally.
+ *
+ * Exactly twice the value displayed to players, for legacy reasons.
+ * @return      The player's current SH value.
+ */
 int player_shield_class()
 {
     int shield = 0;
@@ -2685,9 +2691,9 @@ int player_shield_class()
     }
 
     // mutations
-    // +3, +6, +9
+    // +2, +4, +6 (displayed)
     shield += (player_mutation_level(MUT_LARGE_BONE_PLATES) > 0
-               ? player_mutation_level(MUT_LARGE_BONE_PLATES) * 300
+               ? player_mutation_level(MUT_LARGE_BONE_PLATES) * 200 + 200
                : 0);
 
     stat += qazlal_sh_boost() * 100;
@@ -2695,6 +2701,17 @@ int player_shield_class()
     return (shield + stat + 50) / 100;
 }
 
+/**
+ * Calculate the SH value that should be displayed to players.
+ *
+ * Exactly half the internal value, for legacy reasons.
+ * @return      The SH value to be displayed.
+ */
+int player_displayed_shield_class()
+{
+    return player_shield_class() / 2;
+}
+
 bool player_sust_abil(bool calc_unid)
 {
     return you.wearing(EQ_RINGS, RING_SUSTAIN_ABILITIES, calc_unid)
diff --git a/crawl-ref/source/player.h b/crawl-ref/source/player.h
index e82a1b5dad..3bf40c5a89 100644
--- a/crawl-ref/source/player.h
+++ b/crawl-ref/source/player.h
@@ -892,6 +892,7 @@ int player_res_magic(bool calc_unid = true, bool temp = true);
 bool player_control_teleport(bool temp = true);
 
 int player_shield_class();
+int player_displayed_shield_class();
 
 int player_spec_air();
 int player_spec_cold();
diff --git a/crawl-ref/source/tileweb.cc b/crawl-ref/source/tileweb.cc
index 06d75d7589..a0d005d3d7 100644
--- a/crawl-ref/source/tileweb.cc
+++ b/crawl-ref/source/tileweb.cc
@@ -748,7 +748,8 @@ void TilesFramework::_send_player(bool force_full)
 
     _update_int(force_full, c.armour_class, you.armour_class(), "ac");
     _update_int(force_full, c.evasion, player_evasion(), "ev");
-    _update_int(force_full, c.shield_class, player_shield_class(), "sh");
+    _update_int(force_full, c.shield_class, player_displayed_shield_class(),
+                "sh");
 
     _update_int(force_full, c.strength, (int8_t) you.strength(false), "str");
     _update_int(force_full, c.strength_max, (int8_t) you.max_strength(), "str_max");