Merge pull request #90 from kralverde/surface_generation

start work on noise for chunk generation

pumpkin-core/src/random/gaussian.rs

@@ -1,18 +1,14 @@
-use super::Random;
+use super::RandomImpl;
 
-pub trait GaussianGenerator: Random {
-    fn has_next_gaussian(&self) -> bool;
+pub trait GaussianGenerator: RandomImpl {
+    fn stored_next_gaussian(&self) -> Option<f64>;
 
-    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 set_stored_next_gaussian(&mut self, value: Option<f64>);
 
     fn calculate_gaussian(&mut self) -> f64 {
-        if self.has_next_gaussian() {
-            self.set_has_next_gaussian(false);
-            self.stored_next_gaussian()
+        if let Some(gaussian) = self.stored_next_gaussian() {
+            self.set_stored_next_gaussian(None);
+            gaussian
         } else {
             loop {
                 let d = 2f64 * self.next_f64() - 1f64;
@@ -21,8 +17,7 @@ pub trait GaussianGenerator: Random {
 
                 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);
+                    self.set_stored_next_gaussian(Some(e * g));
                     return d * g;
                 }
             }

pumpkin-core/src/random/legacy_rand.rs

@@ -1,11 +1,10 @@
 use super::{
-    gaussian::GaussianGenerator, hash_block_pos, java_string_hash, Random, RandomSplitter,
+    gaussian::GaussianGenerator, hash_block_pos, java_string_hash, RandomDeriverImpl, RandomImpl,
 };
 
-struct LegacyRand {
+pub struct LegacyRand {
     seed: u64,
-    internal_next_gaussian: f64,
-    internal_has_next_gaussian: bool,
+    internal_next_gaussian: Option<f64>,
 }
 
 impl LegacyRand {
@@ -18,29 +17,20 @@ impl LegacyRand {
 }
 
 impl GaussianGenerator for LegacyRand {
-    fn has_next_gaussian(&self) -> bool {
-        self.internal_has_next_gaussian
-    }
-
-    fn stored_next_gaussian(&self) -> f64 {
+    fn stored_next_gaussian(&self) -> Option<f64> {
         self.internal_next_gaussian
     }
 
-    fn set_has_next_gaussian(&mut self, value: bool) {
-        self.internal_has_next_gaussian = value;
-    }
-
-    fn set_stored_next_gaussian(&mut self, value: f64) {
+    fn set_stored_next_gaussian(&mut self, value: Option<f64>) {
         self.internal_next_gaussian = value;
     }
 }
 
-impl Random for LegacyRand {
+impl RandomImpl for LegacyRand {
     fn from_seed(seed: u64) -> Self {
         LegacyRand {
             seed: (seed ^ 0x5DEECE66D) & 0xFFFFFFFFFFFF,
-            internal_has_next_gaussian: false,
-            internal_next_gaussian: 0f64,
+            internal_next_gaussian: None,
         }
     }
 
@@ -77,7 +67,8 @@ impl Random for LegacyRand {
         self.next(1) != 0
     }
 
-    fn next_splitter(&mut self) -> impl RandomSplitter {
+    #[allow(refining_impl_trait)]
+    fn next_splitter(&mut self) -> LegacySplitter {
         LegacySplitter::new(self.next_i64() as u64)
     }
 
@@ -86,21 +77,21 @@ impl Random for LegacyRand {
     }
 
     fn next_bounded_i32(&mut self, bound: i32) -> i32 {
-        if bound & (bound - 1) == 0 {
-            (bound as u64).wrapping_mul(self.next(31) >> 31) as i32
+        if (bound & bound.wrapping_sub(1)) == 0 {
+            ((bound as u64).wrapping_mul(self.next(31)) >> 31) as i32
         } else {
             loop {
                 let i = self.next(31) as i32;
                 let j = i % bound;
-                if (i - j + (bound - 1)) > 0 {
+                if (i.wrapping_sub(j).wrapping_add(bound.wrapping_sub(1))) >= 0 {
                     return j;
                 }
             }
         }
     }
 }
 
-struct LegacySplitter {
+pub struct LegacySplitter {
     seed: u64,
 }
 
@@ -110,25 +101,26 @@ impl LegacySplitter {
     }
 }
 
-impl RandomSplitter for LegacySplitter {
-    fn split_u64(&self, seed: u64) -> impl Random {
+#[allow(refining_impl_trait)]
+impl RandomDeriverImpl for LegacySplitter {
+    fn split_u64(&self, seed: u64) -> LegacyRand {
         LegacyRand::from_seed(seed)
     }
 
-    fn split_string(&self, seed: &str) -> impl Random {
+    fn split_string(&self, seed: &str) -> LegacyRand {
         let string_hash = java_string_hash(seed);
         LegacyRand::from_seed((string_hash as u64) ^ self.seed)
     }
 
-    fn split_pos(&self, x: i32, y: i32, z: i32) -> impl Random {
+    fn split_pos(&self, x: i32, y: i32, z: i32) -> LegacyRand {
         let pos_hash = hash_block_pos(x, y, z);
         LegacyRand::from_seed((pos_hash as u64) ^ self.seed)
     }
 }
 
 #[cfg(test)]
 mod test {
-    use crate::random::{Random, RandomSplitter};
+    use crate::random::{RandomDeriverImpl, RandomImpl};
 
     use super::LegacyRand;
 
@@ -163,6 +155,17 @@ mod test {
         for value in values {
             assert_eq!(rand.next_bounded_i32(0xf), value);
         }
+
+        let mut rand = LegacyRand::from_seed(0);
+        for _ in 0..10 {
+            assert_eq!(rand.next_bounded_i32(1), 0);
+        }
+
+        let mut rand = LegacyRand::from_seed(0);
+        let values = [1, 1, 0, 1, 1, 0, 1, 0, 1, 1];
+        for value in values {
+            assert_eq!(rand.next_bounded_i32(2), value);
+        }
     }
 
     #[test]

pumpkin-core/src/random/mod.rs

@@ -1,13 +1,156 @@
+use legacy_rand::{LegacyRand, LegacySplitter};
+use xoroshiro128::{Xoroshiro, XoroshiroSplitter};
+
 mod gaussian;
 pub mod legacy_rand;
 pub mod xoroshiro128;
 
-pub trait Random {
+pub enum RandomGenerator {
+    Xoroshiro(Xoroshiro),
+    Legacy(LegacyRand),
+}
+
+impl RandomGenerator {
+    #[inline]
+    pub fn split(&mut self) -> Self {
+        match self {
+            Self::Xoroshiro(rand) => Self::Xoroshiro(rand.split()),
+            Self::Legacy(rand) => Self::Legacy(rand.split()),
+        }
+    }
+
+    #[inline]
+    pub fn next_splitter(&mut self) -> RandomDeriver {
+        match self {
+            Self::Xoroshiro(rand) => RandomDeriver::Xoroshiro(rand.next_splitter()),
+            Self::Legacy(rand) => RandomDeriver::Legacy(rand.next_splitter()),
+        }
+    }
+
+    #[inline]
+    pub fn next(&mut self, bits: u64) -> u64 {
+        match self {
+            Self::Xoroshiro(rand) => rand.next(bits),
+            Self::Legacy(rand) => rand.next(bits),
+        }
+    }
+
+    #[inline]
+    pub fn next_i32(&mut self) -> i32 {
+        match self {
+            Self::Xoroshiro(rand) => rand.next_i32(),
+            Self::Legacy(rand) => rand.next_i32(),
+        }
+    }
+
+    #[inline]
+    pub fn next_bounded_i32(&mut self, bound: i32) -> i32 {
+        match self {
+            Self::Xoroshiro(rand) => rand.next_bounded_i32(bound),
+            Self::Legacy(rand) => rand.next_bounded_i32(bound),
+        }
+    }
+
+    #[inline]
+    pub fn next_inbetween_i32(&mut self, min: i32, max: i32) -> i32 {
+        self.next_bounded_i32(max - min + 1) + min
+    }
+
+    #[inline]
+    pub fn next_i64(&mut self) -> i64 {
+        match self {
+            Self::Xoroshiro(rand) => rand.next_i64(),
+            Self::Legacy(rand) => rand.next_i64(),
+        }
+    }
+
+    #[inline]
+    pub fn next_bool(&mut self) -> bool {
+        match self {
+            Self::Xoroshiro(rand) => rand.next_bool(),
+            Self::Legacy(rand) => rand.next_bool(),
+        }
+    }
+
+    #[inline]
+    pub fn next_f32(&mut self) -> f32 {
+        match self {
+            Self::Xoroshiro(rand) => rand.next_f32(),
+            Self::Legacy(rand) => rand.next_f32(),
+        }
+    }
+
+    #[inline]
+    pub fn next_f64(&mut self) -> f64 {
+        match self {
+            Self::Xoroshiro(rand) => rand.next_f64(),
+            Self::Legacy(rand) => rand.next_f64(),
+        }
+    }
+
+    #[inline]
+    pub fn next_gaussian(&mut self) -> f64 {
+        match self {
+            Self::Xoroshiro(rand) => rand.next_gaussian(),
+            Self::Legacy(rand) => rand.next_gaussian(),
+        }
+    }
+
+    #[inline]
+    pub fn next_triangular(&mut self, mode: f64, deviation: f64) -> f64 {
+        mode + deviation * (self.next_f64() - self.next_f64())
+    }
+
+    #[inline]
+    pub fn skip(&mut self, count: i32) {
+        for _ in 0..count {
+            self.next_i64();
+        }
+    }
+
+    #[inline]
+    pub fn next_inbetween_i32_exclusive(&mut self, min: i32, max: i32) -> i32 {
+        min + self.next_bounded_i32(max - min)
+    }
+}
+
+pub enum RandomDeriver {
+    Xoroshiro(XoroshiroSplitter),
+    Legacy(LegacySplitter),
+}
+
+impl RandomDeriver {
+    #[inline]
+    pub fn split_string(&self, seed: &str) -> RandomGenerator {
+        match self {
+            Self::Xoroshiro(deriver) => RandomGenerator::Xoroshiro(deriver.split_string(seed)),
+            Self::Legacy(deriver) => RandomGenerator::Legacy(deriver.split_string(seed)),
+        }
+    }
+
+    #[inline]
+    pub fn split_u64(&self, seed: u64) -> RandomGenerator {
+        match self {
+            Self::Xoroshiro(deriver) => RandomGenerator::Xoroshiro(deriver.split_u64(seed)),
+            Self::Legacy(deriver) => RandomGenerator::Legacy(deriver.split_u64(seed)),
+        }
+    }
+
+    #[inline]
+    pub fn split_pos(&self, x: i32, y: i32, z: i32) -> RandomGenerator {
+        match self {
+            Self::Xoroshiro(deriver) => RandomGenerator::Xoroshiro(deriver.split_pos(x, y, z)),
+            Self::Legacy(deriver) => RandomGenerator::Legacy(deriver.split_pos(x, y, z)),
+        }
+    }
+}
+
+pub trait RandomImpl {
     fn from_seed(seed: u64) -> Self;
 
     fn split(&mut self) -> Self;
 
-    fn next_splitter(&mut self) -> impl RandomSplitter;
+    fn next_splitter(&mut self) -> impl RandomDeriverImpl;
 
     fn next(&mut self, bits: u64) -> u64;
 
@@ -44,12 +187,12 @@ pub trait Random {
     }
 }
 
-pub trait RandomSplitter {
-    fn split_string(&self, seed: &str) -> impl Random;
+pub trait RandomDeriverImpl {
+    fn split_string(&self, seed: &str) -> impl RandomImpl;
 
-    fn split_u64(&self, seed: u64) -> impl Random;
+    fn split_u64(&self, seed: u64) -> impl RandomImpl;
 
-    fn split_pos(&self, x: i32, y: i32, z: i32) -> impl Random;
+    fn split_pos(&self, x: i32, y: i32, z: i32) -> impl RandomImpl;
 }
 
 fn hash_block_pos(x: i32, y: i32, z: i32) -> i64 {