Merge pull request #29 from goostengine/rng-singleton

Add `Random` singleton

core/math/random.cpp

@@ -0,0 +1,7 @@
+#include "random.h"
+
+Random *Random::singleton = nullptr;
+
+void Random::_bind_methods() {
+ ClassDB::bind_method(D_METHOD("new_instance"), &Random::new_instance);
+}

core/math/random.h

@@ -0,0 +1,27 @@
+#ifndef GOOST_RANDOM_H
+#define GOOST_RANDOM_H
+
+#include "core/math/random_number_generator.h"
+
+class Random : public RandomNumberGenerator {
+ GDCLASS(Random, RandomNumberGenerator);
+
+private:
+ static Random *singleton;
+
+protected:
+ static void _bind_methods();
+
+public:
+ static Random* get_singleton() { return singleton; }
+
+ Ref<Random> new_instance() const { return memnew(Random); }
+
+ Random() {
+ if (!singleton) {
+ singleton = this;
+ }
+ }
+};
+
+#endif // GOOST_RANDOM_H

core/math/register_math_types.cpp

@@ -4,12 +4,19 @@
 
 #include "2d/geometry/goost_geometry_2d.h"
 #include "2d/geometry/goost_geometry_2d_bind.h"
+#include "random.h"
 
+static Ref<Random> _random;
 static _GoostGeometry2D *_goost_geometry_2d = nullptr;
 
 namespace goost {
 
 void register_math_types() {
+ _random.instance();
+ ClassDB::register_class<Random>();
+ Object *random = Object::cast_to<Object>(Random::get_singleton());
+ Engine::get_singleton()->add_singleton(Engine::Singleton("Random", random));
+
  _goost_geometry_2d = memnew(_GoostGeometry2D);
  GoostGeometry2D::initialize();
 
@@ -24,6 +31,7 @@ void register_math_types() {
 }
 
 void unregister_math_types() {
+ _random.unref();
  memdelete(_goost_geometry_2d);
  GoostGeometry2D::finalize();
 }

doc/Random.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="Random" inherits="RandomNumberGenerator" version="3.2">
+ <brief_description>
+ An instance of [RandomNumberGenerator] available at [@GlobalScope].
+ </brief_description>
+ <description>
+ This is a singleton which allows to use [RandomNumberGenerator] methods without instantiating a dedicated object. This means that [Random] can be used via script with methods such as [method @GDScript.randi]:
+ [codeblock]
+ Random.randomize() # Time-based.
+ Random.seed = hash("Goost") # Manual.
+ var i = Random.randi() % 100
+ var f = Random.randf_range(-1.0, 1.0)
+ [/codeblock]
+ The class may implement other methods other than what [RandomNumberGenerator] already provides out of the box.
+ It's not possible to instantiate a new [Random] instance with [code]Random.new()[/code] in GDScript. If you'd like to instantiate a local instance of [Random], use [method new_instance] instead, or [code]ClassDB.instance("Random")[/code], see [method ClassDB.instance].
+ </description>
+ <tutorials>
+ </tutorials>
+ <methods>
+ <method name="new_instance" qualifiers="const">
+ <return type="Random">
+ </return>
+ <description>
+ Instantiates a new local [Random] instance based on [RandomNumberGenerator]. Does not override the [Random] instance accessible at [@GlobalScope].
+ </description>
+ </method>
+ </methods>
+ <constants>
+ </constants>
+</class>

goost.py

@@ -57,6 +57,7 @@ def get_child_components(parent):
  "PolyDecompParameters2D",
  "PolyOffsetParameters2D",
  "PolyNode2D",
+ "Random",
  "ShapeCast2D",
  "VisualShape2D",
 ]

tests/project/goost/core/math/test_random.gd

@@ -0,0 +1,23 @@
+extends "res://addons/gut/test.gd"
+
+
+func test_create_local_instance():
+ var rng = Random.new_instance()
+ Random.seed = hash("Goost")
+ rng.seed = 37
+ assert_ne(rng, Random, "The new local instance should not override the global one")
+ assert_ne(rng.seed, Random.seed)
+ assert_lt(rng.randf(), 1.0)
+
+
+func test_singleton():
+ Random.randomize()
+ Random.seed = 37
+ for x in 100:
+ var f = Random.randf()
+ assert_lt(f, 1.0)
+ assert_gt(f, 0.0)
+ for x in 100:
+ var i = Random.randi() % 100
+ assert_lt(i, 99)
+ assert_gt(i, 0)