From 2ae6fda70edb6fbfcd64ad56f77ba4bf8bbf7949 Mon Sep 17 00:00:00 2001
From: Infendro <infendro@noreply.infendro.com>
Date: Fri, 30 Jan 2026 15:16:48 +0100
Subject: [PATCH] implement xoshiro256++ and xoshiro256**

---
 .../com/infendro/random/prng/Xoshiro256pp.kt  | 28 +++++++++++++++++++
 .../com/infendro/random/prng/Xoshiro256ss.kt  | 28 +++++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 src/commonMain/kotlin/com/infendro/random/prng/Xoshiro256pp.kt
 create mode 100644 src/commonMain/kotlin/com/infendro/random/prng/Xoshiro256ss.kt

diff --git a/src/commonMain/kotlin/com/infendro/random/prng/Xoshiro256pp.kt b/src/commonMain/kotlin/com/infendro/random/prng/Xoshiro256pp.kt
new file mode 100644
index 0000000..ff60ce8
--- /dev/null
+++ b/src/commonMain/kotlin/com/infendro/random/prng/Xoshiro256pp.kt
@@ -0,0 +1,28 @@
+package com.infendro.random.prng
+
+import com.infendro.bytes.bytearray.toLongArray
+import com.infendro.hash.sha2.`SHA-256`
+import com.infendro.random.PRNG
+import kotlin.properties.Delegates.notNull
+
+class Xoshiro256pp : PRNG() {
+    private var s: LongArray by notNull()
+
+    override fun seed(seed: ByteArray) {
+        s = `SHA-256`.hash(seed).toLongArray()
+    }
+
+    override fun generate(): Int {
+        val result = (s[0] + s[3]).rotateLeft(23) + s[0]
+
+        val t = s[1] shl 17
+        s[2] = s[2] xor s[0]
+        s[3] = s[3] xor s[1]
+        s[1] = s[1] xor s[2]
+        s[0] = s[0] xor s[3]
+        s[2] = s[2] xor t
+        s[3] = s[3].rotateLeft(45)
+
+        return (result ushr 32).toInt()
+    }
+}
diff --git a/src/commonMain/kotlin/com/infendro/random/prng/Xoshiro256ss.kt b/src/commonMain/kotlin/com/infendro/random/prng/Xoshiro256ss.kt
new file mode 100644
index 0000000..6fbfb1a
--- /dev/null
+++ b/src/commonMain/kotlin/com/infendro/random/prng/Xoshiro256ss.kt
@@ -0,0 +1,28 @@
+package com.infendro.random.prng
+
+import com.infendro.bytes.bytearray.toLongArray
+import com.infendro.hash.sha2.`SHA-256`
+import com.infendro.random.PRNG
+import kotlin.properties.Delegates.notNull
+
+class Xoshiro256ss : PRNG() {
+    private var s: LongArray by notNull()
+
+    override fun seed(seed: ByteArray) {
+        s = `SHA-256`.hash(seed).toLongArray()
+    }
+
+    override fun generate(): Int {
+        val result = (s[1] * 5).rotateLeft(7) * 9
+
+        val t = s[1] shl 17
+        s[2] = s[2] xor s[0]
+        s[3] = s[3] xor s[1]
+        s[1] = s[1] xor s[2]
+        s[0] = s[0] xor s[3]
+        s[2] = s[2] xor t
+        s[3] = s[3].rotateLeft(45)
+
+        return (result ushr 32).toInt()
+    }
+}