improved perlin basic blockgen

Sources/Voxelotl/Random/RandomCollectionExtensions.swift

@@ -0,0 +1,19 @@
+public extension MutableCollection {
+  mutating func shuffle<T: RandomProvider>(using provider: inout T) {
+    guard self.count > 1 else {
+      return
+    }
+    for (first, remaining) in zip(self.indices, stride(from: 0x100, to: 1, by: -1)) {
+      let i = self.index(first, offsetBy: provider.next(in: remaining))
+      self.swapAt(first, i)
+    }
+  }
+}
+
+public extension Sequence {
+  func shuffled<T: RandomProvider>(using provider: inout T) -> [Self.Element] {
+    var copy = Array(self)
+    copy.shuffle(using: &provider)
+    return copy
+  }
+}