Merge pull request #66 from kralverde/xoroshiro

implement xoroshiro128 RNG

pumpkin-core/Cargo.toml

@@ -7,4 +7,5 @@ edition.workspace = true
 serde = { version = "1.0", features = ["derive"] }
 fastnbt = { git = "https://github.com/owengage/fastnbt.git" }
 uuid.workspace = true
-colored = "2"
+colored = "2"
+md5 = "0.7.0"

pumpkin-core/src/lib.rs

@@ -1 +1,2 @@
+pub mod random;
 pub mod text;

pumpkin-core/src/random/gaussian.rs

@@ -0,0 +1,31 @@
+use super::Random;
+
+pub trait GaussianGenerator: Random {
+    fn has_next_gaussian(&self) -> bool;
+
+    fn set_has_next_gaussian(&mut self, value: bool);
+
+    fn stored_next_gaussian(&self) -> f64;
+
+    fn set_stored_next_gaussian(&mut self, value: f64);
+
+    fn calculate_gaussian(&mut self) -> f64 {
+        if self.has_next_gaussian() {
+            self.set_has_next_gaussian(false);
+            self.stored_next_gaussian()
+        } else {
+            loop {
+                let d = 2f64 * self.next_f64() - 1f64;
+                let e = 2f64 * self.next_f64() - 1f64;
+                let f = d * d + e * e;
+
+                if f < 1f64 && f != 0f64 {
+                    let g = (-2f64 * f.ln() / f).sqrt();
+                    self.set_stored_next_gaussian(e * g);
+                    self.set_has_next_gaussian(true);
+                    return d * g;
+                }
+            }
+        }
+    }
+}

pumpkin-core/src/random/mod.rs

@@ -0,0 +1,53 @@
+pub mod xoroshiro128;
+
+mod gaussian;
+
+pub trait Random {
+    fn from_seed(seed: u64) -> Self;
+
+    fn split(&mut self) -> Self;
+
+    fn next_splitter(&mut self) -> impl RandomSplitter;
+
+    fn next(&mut self, bits: u64) -> u64;
+
+    fn next_i32(&mut self) -> i32;
+
+    fn next_bounded_i32(&mut self, bound: i32) -> i32;
+
+    fn next_inbetween_i32(&mut self, min: i32, max: i32) -> i32 {
+        self.next_bounded_i32(max - min + 1) + min
+    }
+
+    fn next_i64(&mut self) -> i64;
+
+    fn next_bool(&mut self) -> bool;
+
+    fn next_f32(&mut self) -> f32;
+
+    fn next_f64(&mut self) -> f64;
+
+    fn next_gaussian(&mut self) -> f64;
+
+    fn next_triangular(&mut self, mode: f64, deviation: f64) -> f64 {
+        mode + deviation * (self.next_f64() - self.next_f64())
+    }
+
+    fn skip(&mut self, count: i32) {
+        for _ in 0..count {
+            self.next_i32();
+        }
+    }
+
+    fn next_inbetween_i32_exclusive(&mut self, min: i32, max: i32) -> i32 {
+        min + self.next_bounded_i32(max - min)
+    }
+}
+
+pub trait RandomSplitter {
+    fn split_string(&self, seed: &str) -> impl Random;
+
+    fn split_u64(&self, seed: u64) -> impl Random;
+
+    fn split_pos(&self, x: i32, y: i32, z: i32) -> impl Random;
+}