Ensure that a continuous rise in drop rate boosts results in a continuous rise in actual drop rate.

3 files changed, 18 insertions, 5 deletions

diff --git a/src/generic/random.cpp b/src/generic/random.cpp
index e37a3d1..d29c984 100644
--- a/src/generic/random.cpp
+++ b/src/generic/random.cpp
@@ -25,6 +25,8 @@ namespace tmwa
 {
 namespace random_
 {
-    std::mt19937 generate{std::random_device()()};
+    std::random_device seed_class;
+    std::mt19937 generate{seed_class()};//std::random_device()()};
+    std::mt19937_64 generate64{ ((uint64_t)seed_class() << 32) + seed_class()};
 } // namespace random_
 } // namespace tmwa
diff --git a/src/generic/random.hpp b/src/generic/random.hpp
index 897ad43..7310e21 100644
--- a/src/generic/random.hpp
+++ b/src/generic/random.hpp
@@ -33,8 +33,10 @@ namespace random_
 {
     /// Get a random number from 0 .. 2**32 - 1
     extern std::mt19937 generate;
+    extern std::mt19937_64 generate64;
 
     /// Get a random number from 0 .. bound - 1
+    // TODO: Deduplicate this.
     inline
     int to(int bound)
     {
@@ -42,6 +44,13 @@ namespace random_
         return dist(generate);
     }
 
+    inline
+    int64_t to(int64_t bound)
+    {
+        std::uniform_int_distribution<int64_t> dist(0, bound - 1);
+        return dist(generate64);
+    }
+
     /// Get a random number from low .. high (inclusive!)
     inline
     int in(int low, int high)
@@ -58,8 +67,9 @@ namespace random_
         return dist(generate);
     }
 
+    template<typename T = int>
     inline
-    bool chance(Fraction f)
+    bool chance(Fraction<T> f)
     {
         if (f.num <= 0)
             return false;
@@ -75,7 +85,7 @@ namespace random_
     template<class C>
     auto choice(C&& c) -> decltype(*c.begin())
     {
-        return *(c.begin() + random_::to(c.size()));
+        return *(c.begin() + random_::to((int64_t)c.size()));
     }
 
     // allow bare braces
diff --git a/src/generic/random.t.hpp b/src/generic/random.t.hpp
index b4c4764..985ba3b 100644
--- a/src/generic/random.t.hpp
+++ b/src/generic/random.t.hpp
@@ -25,9 +25,10 @@ namespace tmwa
 {
 namespace random_
 {
+    template<class T = int>
     struct Fraction
     {
-        int num, den;
+        T num, den;
     };
 
     template<class T, T den>
@@ -35,7 +36,7 @@ namespace random_
     {
         T num;
 
-        operator Fraction()
+        operator Fraction<T>()
         {
             return {num, den};
         }