Node World Space Positioning (#1743)

* node set world position

* Adapt tests

core/2d/Node.cpp

@@ -1935,6 +1935,18 @@ Vec2 Node::getWorldPosition() const
     return convertToWorldSpace(Vec2(_anchorPoint.x * _contentSize.width, _anchorPoint.y * _contentSize.height));
 }
 
+void Node::setWorldPosition(const Vec2& position)
+{
+    auto p = getParent();
+    if (p)
+    {
+        auto m = p->getNodeToWorldTransform();
+        auto v = m.getInversed() * (Vec3(-m.m[12], -m.m[13], 0) + Vec3(position.x, position.y, 0));
+        setPosition(Vec2(v.x, v.y));
+    }
+    else setPosition(position);
+}
+
 void Node::updateTransform()
 {
     // Recursively iterate over children

core/2d/Node.h

@@ -1609,12 +1609,19 @@ class AX_DLL Node : public Ref
     Vec2 convertTouchToNodeSpaceAR(Touch* touch) const;
 
     /**
-     * Gets position of widget in world space.
+     * Gets position of node in world space.
      *
-     * @return Position of widget in world space.
+     * @return Position of node in world space.
      */
     Vec2 getWorldPosition() const;
 
+    /**
+     * Sets position of node in world space.
+     *
+     * @param position Position of node in world space.
+     */
+    void setWorldPosition(const Vec2& position);
+
     /**
      *  Sets an additional transform matrix to the node.
      *

tests/cpp-tests/Source/NodeTest/NodeTest.cpp

@@ -72,6 +72,7 @@ CocosNodeTests::CocosNodeTests()
     ADD_TEST_CASE(NodeNameTest);
     ADD_TEST_CASE(Issue16100Test);
     ADD_TEST_CASE(Issue16735Test);
+    ADD_TEST_CASE(NodeWorldSpace);
 }
 
 TestCocosNodeDemo::TestCocosNodeDemo(void) {}
@@ -1520,3 +1521,50 @@ std::string Issue16735Test::subtitle() const
 {
     return "Sprite should appear on the center of screen";
 }
+
+//------------------------------------------------------------------
+//
+// NodeWorldSpace
+//
+//------------------------------------------------------------------
+void NodeWorldSpace::onEnter()
+{
+    TestCocosNodeDemo::onEnter();
+
+    scheduleUpdate();
+
+    parent = Sprite::create("Images/grossini.png");
+    addChild(parent);
+
+    child = Sprite::create("Images/grossini.png");
+    child->setScale(0.5);
+    parent->addChild(child);
+}
+
+void NodeWorldSpace::onExit()
+{
+    TestCocosNodeDemo::onExit();
+}
+
+void NodeWorldSpace::update(float dt)
+{
+    elapsedTime += dt;
+
+    auto visibleSize = Director::getInstance()->getVisibleSize();
+    auto origin      = Director::getInstance()->getVisibleOrigin();
+
+    parent->setPosition(Vec2(visibleSize.x / 2 + sin(elapsedTime * 2) * 100, 50));
+    parent->setRotation(elapsedTime * 180);
+
+    child->setWorldPosition(visibleSize / 2);
+}
+
+std::string NodeWorldSpace::title() const
+{
+    return "World Space Position";
+}
+
+std::string NodeWorldSpace::subtitle() const
+{
+    return "Child sprite (small one) should always stay at the center of screen\nthe child sprite is a child of the moving parent sprite";
+}

tests/cpp-tests/Source/NodeTest/NodeTest.h

@@ -352,4 +352,21 @@ class Issue16735Test : public TestCocosNodeDemo
     virtual void onExit() override;
 };
 
+class NodeWorldSpace : public TestCocosNodeDemo
+{
+public:
+    CREATE_FUNC(NodeWorldSpace);
+    void update(float dt) override;
+    virtual std::string title() const override;
+    virtual std::string subtitle() const override;
+
+    float elapsedTime;
+
+    ax::Sprite* parent;
+    ax::Sprite* child;
+
+    virtual void onEnter() override;
+    virtual void onExit() override;
+};
+
 #endif