Even better spread out hashCode for 2d vectors

gradle.properties

@@ -4,7 +4,7 @@ kotlin.code.style=official
 specifyKotlinAsDependency=false
 
 projectGroup=ru.dbotthepony.kommons
-projectVersion=2.13.0
+projectVersion=2.13.1
 
 guavaDepVersion=33.0.0
 gsonDepVersion=2.8.9

linear-algebra/src/main/kotlin/ru/dbotthepony/kommons/vector/Vector2d.kt

@@ -116,7 +116,14 @@ data class Vector2d(
 	}
 
 	override fun hashCode(): Int {
-		return x.hashCode().rotateLeft(16) xor y.hashCode()
+		var x = x.hashCode().rotateLeft(16) xor y.hashCode()
+		// avalanche bits using murmur3 hash
+		x = x xor (x ushr 16)
+		x *= -0x7a143595
+		x = x xor (x ushr 13)
+		x *= -0x3d4d51cb
+		x = x xor (x ushr 16)
+		return x
 	}
 
 	override fun toString(): String {

linear-algebra/src/main/kotlin/ru/dbotthepony/kommons/vector/Vector2f.kt

@@ -116,7 +116,14 @@ data class Vector2f(
 	}
 
 	override fun hashCode(): Int {
-		return x.hashCode().rotateLeft(16) xor y.hashCode()
+		var x = x.hashCode().rotateLeft(16) xor y.hashCode()
+		// avalanche bits using murmur3 hash
+		x = x xor (x ushr 16)
+		x *= -0x7a143595
+		x = x xor (x ushr 13)
+		x *= -0x3d4d51cb
+		x = x xor (x ushr 16)
+		return x
 	}
 
 	override fun toString(): String {

linear-algebra/src/main/kotlin/ru/dbotthepony/kommons/vector/Vector2i.kt

@@ -93,7 +93,14 @@ data class Vector2i(
 	}
 
 	override fun hashCode(): Int {
-		return x.rotateLeft(16) xor y
+		var x = x.rotateLeft(16) xor y
+		// avalanche bits using murmur3 hash
+		x = x xor (x ushr 16)
+		x *= -0x7a143595
+		x = x xor (x ushr 13)
+		x *= -0x3d4d51cb
+		x = x xor (x ushr 16)
+		return x
 	}
 
 	override fun toString(): String {