From 287f3fb2e3317bb6bd6d8608f1aa051c601aeca4 Mon Sep 17 00:00:00 2001
From: EvidenceB <49488517+EvidenceBKidscode@users.noreply.github.com>
Date: Sun, 23 Aug 2020 22:50:14 +0200
Subject: [PATCH] Avoid drawing clipped out formspec elements (#10095)

---
 src/gui/guiFormSpecMenu.cpp    | 10 +++++++---
 src/gui/guiScrollContainer.cpp | 12 ++++++++++++
 src/gui/guiScrollContainer.h   |  2 ++
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/gui/guiFormSpecMenu.cpp b/src/gui/guiFormSpecMenu.cpp
index 76441c645..7e3ad3b15 100644
--- a/src/gui/guiFormSpecMenu.cpp
+++ b/src/gui/guiFormSpecMenu.cpp
@@ -3483,10 +3483,14 @@ void GUIFormSpecMenu::drawMenu()
 		e->setVisible(true);
 
 	/*
-		Call base class
-		(This is where all the drawing happens.)
+		This is where all the drawing happens.
 	*/
-	gui::IGUIElement::draw();
+	core::list<IGUIElement*>::Iterator it = Children.begin();
+	for (; it != Children.end(); ++it)
+		if ((*it)->isNotClipped() ||
+				AbsoluteClippingRect.isRectCollided(
+						(*it)->getAbsolutePosition()))
+			(*it)->draw();
 
 	for (gui::IGUIElement *e : m_clickthrough_elements)
 		e->setVisible(false);
diff --git a/src/gui/guiScrollContainer.cpp b/src/gui/guiScrollContainer.cpp
index 88cdc7057..0fe4c41bd 100644
--- a/src/gui/guiScrollContainer.cpp
+++ b/src/gui/guiScrollContainer.cpp
@@ -56,6 +56,18 @@ bool GUIScrollContainer::OnEvent(const SEvent &event)
 	return IGUIElement::OnEvent(event);
 }
 
+void GUIScrollContainer::draw()
+{
+	if (isVisible()) {
+		core::list<IGUIElement *>::Iterator it = Children.begin();
+		for (; it != Children.end(); ++it)
+			if ((*it)->isNotClipped() ||
+					AbsoluteClippingRect.isRectCollided(
+							(*it)->getAbsolutePosition()))
+				(*it)->draw();
+	}
+}
+
 void GUIScrollContainer::updateScrolling()
 {
 	s32 pos = m_scrollbar->getPos();
diff --git a/src/gui/guiScrollContainer.h b/src/gui/guiScrollContainer.h
index a0306291e..9e3ec6e93 100644
--- a/src/gui/guiScrollContainer.h
+++ b/src/gui/guiScrollContainer.h
@@ -32,6 +32,8 @@ public:
 
 	virtual bool OnEvent(const SEvent &event) override;
 
+	virtual void draw() override;
+
 	inline void onScrollEvent(gui::IGUIElement *caller)
 	{
 		if (caller == m_scrollbar)