Fix ui::Layout scissor clipping (#20352)

* Added RenderTexture::saveToFileAsNonPMA() to save images without PMA.
Set the PMA parameter to true when calling initWithRawData() inside RenderTexture::newImage(), since textures are PMA.
Renamed Image::premultipliedAlpha() to Image::premultiplyAlpha() to better reflect it's action, and made it public.
Added Image::reversePremultipliedAlpha() to allow the reversing of the PMA.
Updated CCImage-ios.mm to set the correct bitmapInfo for PMA and non-PMA images before saving a file.
Updated RenderTextureTest::RenderTextureSave() to cater for non-PMA file saving.

* [CCImage-ios.mm] Fixed indentation.

* [UILayout.cpp] Fix for incorrect SCISSOR clipping rectangle calculation.
[UILayoutTest.cpp] Test added to reproduce issue with SCISSOR clipping.

* Get reference to clipping rectangle instead of a copy.

Author: rh101

cocos/ui/UILayout.cpp

@@ -463,11 +463,10 @@ const Rect& Layout::getClippingRect()
 {
     if (_clippingRectDirty)
     {
-        Vec2 worldPos = convertToWorldSpace(Vec2::ZERO);
-        AffineTransform t = getNodeToWorldAffineTransform();
-        float scissorWidth = _contentSize.width*t.a;
-        float scissorHeight = _contentSize.height*t.d;
-        Rect parentClippingRect;
+        const Vec2 worldPos = convertToWorldSpace(Vec2::ZERO);
+        const AffineTransform t = getNodeToWorldAffineTransform();
+        const float scissorWidth = _contentSize.width * t.a;
+        const float scissorHeight = _contentSize.height * t.d;
         Layout* parent = this;
 
         while (parent)
@@ -485,29 +484,29 @@ const Rect& Layout::getClippingRect()
 
         if (_clippingParent)
         {
-            parentClippingRect = _clippingParent->getClippingRect();
-            float finalX = worldPos.x - (scissorWidth * _anchorPoint.x);
-            float finalY = worldPos.y - (scissorHeight * _anchorPoint.y);
+            const Rect& parentClippingRect = _clippingParent->getClippingRect();
+            float finalX = worldPos.x;
+            float finalY = worldPos.y;
             float finalWidth = scissorWidth;
             float finalHeight = scissorHeight;
 
-            float leftOffset = worldPos.x - parentClippingRect.origin.x;
+            const float leftOffset = worldPos.x - parentClippingRect.origin.x;
             if (leftOffset < 0.0f)
             {
                 finalX = parentClippingRect.origin.x;
                 finalWidth += leftOffset;
             }
-            float rightOffset = (worldPos.x + scissorWidth) - (parentClippingRect.origin.x + parentClippingRect.size.width);
+            const float rightOffset = (worldPos.x + scissorWidth) - (parentClippingRect.origin.x + parentClippingRect.size.width);
             if (rightOffset > 0.0f)
             {
                 finalWidth -= rightOffset;
             }
-            float topOffset = (worldPos.y + scissorHeight) - (parentClippingRect.origin.y + parentClippingRect.size.height);
+            const float topOffset = (worldPos.y + scissorHeight) - (parentClippingRect.origin.y + parentClippingRect.size.height);
             if (topOffset > 0.0f)
             {
                 finalHeight -= topOffset;
             }
-            float bottomOffset = worldPos.y - parentClippingRect.origin.y;
+            const float bottomOffset = worldPos.y - parentClippingRect.origin.y;
             if (bottomOffset < 0.0f)
             {
                 finalY = parentClippingRect.origin.y;
@@ -528,8 +527,8 @@ const Rect& Layout::getClippingRect()
         }
         else
         {
-            _clippingRect.origin.x = worldPos.x - (scissorWidth * _anchorPoint.x);
-            _clippingRect.origin.y = worldPos.y - (scissorHeight * _anchorPoint.y);
+            _clippingRect.origin.x = worldPos.x;
+            _clippingRect.origin.y = worldPos.y;
             _clippingRect.size.width = scissorWidth;
             _clippingRect.size.height = scissorHeight;
         }

tests/cpp-tests/Classes/UITest/CocoStudioGUITest/UILayoutTest/UILayoutTest.cpp

@@ -42,6 +42,7 @@ UILayoutTests::UILayoutTests()
     ADD_TEST_CASE(UILayoutComponentTest);
     ADD_TEST_CASE(UILayoutComponent_Berth_Test);
     ADD_TEST_CASE(UILayoutComponent_Berth_Stretch_Test);
+    ADD_TEST_CASE(UILayoutTest_Issue19890);
 }
 
 // UILayoutTest
@@ -956,3 +957,62 @@ bool UILayoutComponent_Berth_Stretch_Test::init()
     }
     return false;
 }
+
+bool UILayoutTest_Issue19890::init()
+{
+    if (!UIScene::init())
+    {
+        return false;
+    }
+
+    const Size widgetSize = _widget->getContentSize();
+
+    auto label = Text::create("Issue 19890", "fonts/Marker Felt.ttf", 32);
+    label->setAnchorPoint(Vec2(0.5f, -1.0f));
+    label->setPosition(Vec2(widgetSize.width / 2.0f,
+        widgetSize.height / 2.0f + label->getContentSize().height * 1.5f));
+    _uiLayer->addChild(label);
+
+    Text* alert = Text::create("3 panels should be completely visible", "fonts/Marker Felt.ttf", 20);
+    alert->setColor(Color3B(159, 168, 176));
+    alert->setPosition(Vec2(widgetSize.width / 2.0f,
+        widgetSize.height / 2.0f - alert->getContentSize().height * 3.075f));
+    _uiLayer->addChild(alert);
+
+    Layout* root = static_cast<Layout*>(_uiLayer->getChildByTag(81));
+
+    Layout* background = dynamic_cast<Layout*>(root->getChildByName("background_Panel"));
+    const Size backgroundSize = background->getContentSize();
+
+    auto panel = ui::Layout::create();
+    panel->setBackGroundColor(Color3B::RED);
+    panel->setBackGroundColorType(ui::Layout::BackGroundColorType::SOLID);
+    panel->setClippingType(ui::Layout::ClippingType::SCISSOR);
+    panel->setPosition(backgroundSize / 2);
+    panel->setAnchorPoint(Vec2::ANCHOR_MIDDLE);
+    panel->setClippingEnabled(true);
+    panel->setContentSize(backgroundSize); // from the left to the screen end
+    background->addChild(panel);
+
+    auto panel2 = ui::Layout::create();
+    panel2->setBackGroundColor(Color3B::BLUE);
+    panel2->setBackGroundColorType(ui::Layout::BackGroundColorType::SOLID);
+    panel2->setClippingType(ui::Layout::ClippingType::SCISSOR);
+    panel2->setPosition(panel->getContentSize() / 2);
+    panel2->setAnchorPoint(Vec2::ANCHOR_MIDDLE);
+    panel2->setClippingEnabled(true);
+    panel2->setContentSize(panel->getContentSize() / 2); // from the left to the screen end
+    panel->addChild(panel2);
+
+    auto panel3 = ui::Layout::create();
+    panel3->setBackGroundColor(Color3B::GREEN);
+    panel3->setBackGroundColorType(ui::Layout::BackGroundColorType::SOLID);
+    panel3->setClippingType(ui::Layout::ClippingType::SCISSOR);
+    panel3->setPosition(panel2->getContentSize() / 2);
+    panel3->setAnchorPoint(Vec2::ANCHOR_MIDDLE);
+    panel3->setClippingEnabled(true);
+    panel3->setContentSize(panel2->getContentSize() / 2); // from the left to the screen end
+    panel2->addChild(panel3);
+
+    return true;
+}

tests/cpp-tests/Classes/UITest/CocoStudioGUITest/UILayoutTest/UILayoutTest.h

@@ -162,4 +162,12 @@ class UILayoutComponent_Berth_Stretch_Test : public UILayoutComponentTest
     CREATE_FUNC(UILayoutComponent_Berth_Stretch_Test);
 };
 
+class UILayoutTest_Issue19890 : public UIScene
+{
+public:
+    virtual bool init() override;
+
+    CREATE_FUNC(UILayoutTest_Issue19890);
+};
+
 #endif /* defined(__TestCpp__UILayoutTest__) */