From 9752377a15e14f76ffc4c3324784b43cfca63dbf Mon Sep 17 00:00:00 2001
From: Gwilym Kuiper <gw@ilym.me>
Date: Wed, 23 Mar 2022 21:46:59 +0000
Subject: [PATCH] Move the random number generator to a crate level thing

---
 agb/src/hash_map.rs | 31 +------------------------------
 agb/src/lib.rs      |  2 ++
 2 files changed, 3 insertions(+), 30 deletions(-)

diff --git a/agb/src/hash_map.rs b/agb/src/hash_map.rs
index 3a53868e..fe9ee3a6 100644
--- a/agb/src/hash_map.rs
+++ b/agb/src/hash_map.rs
@@ -918,35 +918,6 @@ mod test {
         }
     }
 
-    struct RandomNumberGenerator {
-        state: [u32; 4],
-    }
-
-    impl RandomNumberGenerator {
-        const fn new() -> Self {
-            Self {
-                state: [1014776995, 476057059, 3301633994, 706340607],
-            }
-        }
-
-        fn next(&mut self) -> i32 {
-            let result = (self.state[0].wrapping_add(self.state[3]))
-                .rotate_left(7)
-                .wrapping_mul(9);
-            let t = self.state[1].wrapping_shr(9);
-
-            self.state[2] ^= self.state[0];
-            self.state[3] ^= self.state[1];
-            self.state[1] ^= self.state[2];
-            self.state[0] ^= self.state[3];
-
-            self.state[2] ^= t;
-            self.state[3] = self.state[3].rotate_left(11);
-
-            result as i32
-        }
-    }
-
     struct NoisyDrop {
         i: i32,
         dropped: bool,
@@ -985,7 +956,7 @@ mod test {
     #[test_case]
     fn extreme_case(_gba: &mut Gba) {
         let mut map = HashMap::new();
-        let mut rng = RandomNumberGenerator::new();
+        let mut rng = crate::rng::RandomNumberGenerator::new();
 
         let mut answers: [Option<i32>; 128] = [None; 128];
 
diff --git a/agb/src/lib.rs b/agb/src/lib.rs
index 245bc690..66d8c2b8 100644
--- a/agb/src/lib.rs
+++ b/agb/src/lib.rs
@@ -153,6 +153,8 @@ pub mod mgba;
 pub use agb_fixnum as fixnum;
 /// Contains an implementation of a hashmap which suits the gameboy advance's hardware.
 pub mod hash_map;
+/// Simple random number generator
+pub mod rng;
 mod single;
 /// Implements sound output.
 pub mod sound;