From eb5b297fefbdf181a79d63735ae50bbfadcaf341 Mon Sep 17 00:00:00 2001
From: Nonunknown <nonunknown777@gmail.com>
Date: Sat, 15 Oct 2022 09:43:16 -0300
Subject: [PATCH] add ability to pick random value from array

(cherry picked from commit 9f4dbf415da6d150788915cb35a9c3dc7f04c547)

Co-authored-by: BleedingXiko <66162192+BleedingXiko@users.noreply.github.com>
---
 core/array.cpp        |  5 +++++
 core/array.h          |  1 +
 core/variant_call.cpp |  2 ++
 doc/classes/Array.xml | 10 ++++++++++
 4 files changed, 18 insertions(+)

diff --git a/core/array.cpp b/core/array.cpp
index 056ee332f10..08cdec7323a 100644
--- a/core/array.cpp
+++ b/core/array.cpp
@@ -31,6 +31,7 @@
 #include "array.h"
 
 #include "core/hashfuncs.h"
+#include "core/math/math_funcs.h"
 #include "core/object.h"
 #include "core/variant.h"
 #include "core/vector.h"
@@ -407,6 +408,10 @@ Variant Array::pop_front() {
 	}
 	return Variant();
 }
+Variant Array::pick_random() const {
+	ERR_FAIL_COND_V_MSG(_p->array.size() == 0, Variant(), "Can't take value from empty array.");
+	return operator[](Math::rand() % _p->array.size());
+}
 
 Variant Array::pop_at(int p_pos) {
 	if (_p->array.empty()) {
diff --git a/core/array.h b/core/array.h
index 09aed83981d..2fcfc4ba813 100644
--- a/core/array.h
+++ b/core/array.h
@@ -72,6 +72,7 @@ public:
 	void fill(const Variant &p_value);
 
 	Variant front() const;
+	Variant pick_random() const;
 	Variant back() const;
 
 	Array &sort();
diff --git a/core/variant_call.cpp b/core/variant_call.cpp
index e57e6bde059..db2a4671425 100644
--- a/core/variant_call.cpp
+++ b/core/variant_call.cpp
@@ -578,6 +578,7 @@ struct _VariantCall {
 	VCALL_LOCALMEM2(Array, insert);
 	VCALL_LOCALMEM1(Array, remove);
 	VCALL_LOCALMEM0R(Array, front);
+	VCALL_LOCALMEM0R(Array, pick_random)
 	VCALL_LOCALMEM0R(Array, back);
 	VCALL_LOCALMEM2R(Array, find);
 	VCALL_LOCALMEM2R(Array, rfind);
@@ -1960,6 +1961,7 @@ void register_variant_methods() {
 	ADDFUNC1NC(ARRAY, NIL, Array, remove, INT, "position", varray());
 	ADDFUNC1NC(ARRAY, NIL, Array, erase, NIL, "value", varray());
 	ADDFUNC0R(ARRAY, NIL, Array, front, varray());
+	ADDFUNC0R(ARRAY, NIL, Array, pick_random, varray())
 	ADDFUNC0R(ARRAY, NIL, Array, back, varray());
 	ADDFUNC2R(ARRAY, INT, Array, find, NIL, "what", INT, "from", varray(0));
 	ADDFUNC2R(ARRAY, INT, Array, rfind, NIL, "what", INT, "from", varray(-1));
diff --git a/doc/classes/Array.xml b/doc/classes/Array.xml
index 8ca08eae8a3..5e9f692dadb 100644
--- a/doc/classes/Array.xml
+++ b/doc/classes/Array.xml
@@ -263,6 +263,16 @@
 				Returns the minimum value contained in the array if all elements are of comparable types. If the elements can't be compared, [code]null[/code] is returned.
 			</description>
 		</method>
+		<method name="pick_random">
+			<return type="Variant" />
+			<description>
+				Returns a random value from the target array.
+				[codeblock]
+				var array: Array[int] = [1, 2, 3, 4]
+				print(array.pick_random())  # Prints either of the four numbers.
+				[/codeblock]
+			</description>
+		</method>
 		<method name="pop_at">
 			<return type="Variant" />
 			<argument index="0" name="position" type="int" />