From 75d69fb4ecfe3bc925bd27700782d884e88369cc Mon Sep 17 00:00:00 2001
From: poke1024 <poke1024@gmx.de>
Date: Wed, 10 Jan 2018 19:36:53 +0100
Subject: [PATCH] Add shuffle() method to Array

---
 core/array.cpp        | 14 ++++++++++++++
 core/array.h          |  1 +
 core/variant_call.cpp |  2 ++
 doc/classes/Array.xml |  5 +++++
 4 files changed, 22 insertions(+)

diff --git a/core/array.cpp b/core/array.cpp
index c53fea1f280..0ddac1662c8 100644
--- a/core/array.cpp
+++ b/core/array.cpp
@@ -266,6 +266,20 @@ Array &Array::sort_custom(Object *p_obj, const StringName &p_function) {
 	return *this;
 }
 
+void Array::shuffle() {
+
+	const int n = _p->array.size();
+	if (n < 2)
+		return;
+	Variant *data = _p->array.ptrw();
+	for (int i = n - 1; i >= 1; i--) {
+		const int j = Math::rand() % (i + 1);
+		const Variant tmp = data[j];
+		data[j] = data[i];
+		data[i] = tmp;
+	}
+}
+
 template <typename Less>
 _FORCE_INLINE_ int bisect(const Vector<Variant> &p_array, const Variant &p_value, bool p_before, const Less &p_less) {
 
diff --git a/core/array.h b/core/array.h
index 7c6fc590484..684a8e265db 100644
--- a/core/array.h
+++ b/core/array.h
@@ -71,6 +71,7 @@ public:
 
 	Array &sort();
 	Array &sort_custom(Object *p_obj, const StringName &p_function);
+	void shuffle();
 	int bsearch(const Variant &p_value, bool p_before = true);
 	int bsearch_custom(const Variant &p_value, Object *p_obj, const StringName &p_function, bool p_before = true);
 	Array &invert();
diff --git a/core/variant_call.cpp b/core/variant_call.cpp
index e9f7af3f633..5ee7f48dda0 100644
--- a/core/variant_call.cpp
+++ b/core/variant_call.cpp
@@ -490,6 +490,7 @@ struct _VariantCall {
 	VCALL_LOCALMEM1(Array, erase);
 	VCALL_LOCALMEM0(Array, sort);
 	VCALL_LOCALMEM2(Array, sort_custom);
+	VCALL_LOCALMEM0(Array, shuffle);
 	VCALL_LOCALMEM2R(Array, bsearch);
 	VCALL_LOCALMEM4R(Array, bsearch_custom);
 	VCALL_LOCALMEM0R(Array, duplicate);
@@ -1634,6 +1635,7 @@ void register_variant_methods() {
 	ADDFUNC0RNC(ARRAY, NIL, Array, pop_front, varray());
 	ADDFUNC0NC(ARRAY, NIL, Array, sort, varray());
 	ADDFUNC2NC(ARRAY, NIL, Array, sort_custom, OBJECT, "obj", STRING, "func", varray());
+	ADDFUNC0NC(ARRAY, NIL, Array, shuffle, varray());
 	ADDFUNC2R(ARRAY, INT, Array, bsearch, NIL, "value", BOOL, "before", varray(true));
 	ADDFUNC4R(ARRAY, INT, Array, bsearch_custom, NIL, "value", OBJECT, "obj", STRING, "func", BOOL, "before", varray(true));
 	ADDFUNC0NC(ARRAY, NIL, Array, invert, varray());
diff --git a/doc/classes/Array.xml b/doc/classes/Array.xml
index 9445a1732ef..f767f8b337b 100644
--- a/doc/classes/Array.xml
+++ b/doc/classes/Array.xml
@@ -296,6 +296,11 @@
 				[/codeblock]
 			</description>
 		</method>
+		<method name="shuffle">
+			<description>
+				Shuffle the array such that the items will have a random order.
+			</description>
+		</method>
 	</methods>
 	<constants>
 	</constants>