From 5c59c9aa715882d31c92e4d10c8a9b3e35f0ae78 Mon Sep 17 00:00:00 2001
From: Mira Grudzinska <veleveta@gmail.com>
Date: Sun, 1 Jan 2023 20:05:18 +0100
Subject: [PATCH] scene: fixing nested masking

For any type of masking composition may be required.

@Issue: https://github.com/Samsung/thorvg/issues/1295
---
 src/lib/tvgScene.cpp   |  2 +-
 src/lib/tvgSceneImpl.h | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/lib/tvgScene.cpp b/src/lib/tvgScene.cpp
index 0beec47b..9ed7d45d 100644
--- a/src/lib/tvgScene.cpp
+++ b/src/lib/tvgScene.cpp
@@ -25,7 +25,7 @@
 /* External Class Implementation                                        */
 /************************************************************************/
 
-Scene::Scene() : pImpl(new Impl())
+Scene::Scene() : pImpl(new Impl(this))
 {
     Paint::pImpl->id = TVG_CLASS_ID_SCENE;
     Paint::pImpl->method(new PaintMethod<Scene::Impl>(pImpl));
diff --git a/src/lib/tvgSceneImpl.h b/src/lib/tvgSceneImpl.h
index 6a7614c6..b6c68262 100644
--- a/src/lib/tvgSceneImpl.h
+++ b/src/lib/tvgSceneImpl.h
@@ -60,6 +60,11 @@ struct Scene::Impl
     Array<Paint*> paints;
     uint8_t opacity;                     //for composition
     RenderMethod* renderer = nullptr;    //keep it for explicit clear
+    Scene* scene = nullptr;
+
+    Impl(Scene* s) : scene(s)
+    {
+    }
 
     ~Impl()
     {
@@ -81,8 +86,14 @@ struct Scene::Impl
 
     bool needComposition(uint32_t opacity)
     {
+        if (opacity == 0 || paints.count == 0) return false;
+
+        //Masking may require composition (even if opacity == 255)
+        auto compMethod = scene->composite(nullptr);
+        if (compMethod != CompositeMethod::None && compMethod != CompositeMethod::ClipPath) return true;
+
         //Half translucent requires intermediate composition.
-        if (opacity == 255 || opacity == 0) return false;
+        if (opacity == 255) return false;
 
         //If scene has several children or only scene, it may require composition.
         if (paints.count > 1) return true;