Illuminate weapon/armour glow code

Simplified it to a simple plus threshold per armour class (body,
shield, etc), rather than a weird mix of random chance and poorly-
specified thresholds. Likewise set a threshold for weapons.

1 files changed, 26 insertions, 9 deletions

diff --git a/crawl-ref/source/makeitem.cc b/crawl-ref/source/makeitem.cc
index 0322f8e5a2..c2b65ee900 100644
--- a/crawl-ref/source/makeitem.cc
+++ b/crawl-ref/source/makeitem.cc
@@ -2947,7 +2947,7 @@ static bool _weapon_is_visibly_special(const item_def &item)
     if (visibly_branded || is_artefact(item))
         return true;
 
-    if (x_chance_in_y(item.plus - 2, 3))
+    if (item.plus >= 3)
         return true;
 
     if (item.flags & ISFLAG_CURSED && one_chance_in(3))
@@ -2956,6 +2956,30 @@ static bool _weapon_is_visibly_special(const item_def &item)
     return false;
 }
 
+/**
+ * Return the number of plusses required for a type of armour to glow.
+ * (From plus alone.)
+ *
+ * @param armour_type   The type of armour being considered.
+ * @return              The armour plus value required to be interesting.
+ */
+static int _armour_plus_threshold(equipment_type armour_type)
+{
+    switch (armour_type)
+    {
+        // body armour is very common; squelch most of it
+        case EQ_BODY_ARMOUR:
+            return 3;
+        // cloaks & shields are fairly common
+        case EQ_CLOAK:
+        case EQ_SHIELD:
+            return 2;
+        // aux armour is relatively uncommon
+        default:
+            return 1;
+    }
+}
+
 static bool _armour_is_visibly_special(const item_def &item)
 {
     const int brand = get_armour_ego_type(item);
@@ -2970,15 +2994,8 @@ static bool _armour_is_visibly_special(const item_def &item)
     if (item.is_mundane())
         return false;
 
-    // body armour with +3 or more can be interesting; any aux armour with any
-    // plus is interesting, except for cloaks, because zot. (they need +2.)
-    if (x_chance_in_y(item.plus - 2, 3)
-        || item.plus > 0 && get_armour_slot(item) != EQ_BODY_ARMOUR
-                         && (get_armour_slot(item) != EQ_CLOAK
-                             || item.plus > 1))
-    {
+    if (item.plus >= _armour_plus_threshold(get_armour_slot(item)))
         return true;
-    }
 
     if (item.flags & ISFLAG_CURSED && one_chance_in(3))
         return true;