From f1f31deb987db188bc27cf222da23931da2294db Mon Sep 17 00:00:00 2001
From: sjchao <jingchaoshi@qq.com>
Date: Fri, 29 Mar 2013 16:05:28 +0800
Subject: [PATCH] Fix the display bug when a scrollView nested in another
 scrollView

---
 extensions/GUI/CCScrollView/CCScrollView.cpp | 30 ++++++++++++++++----
 extensions/GUI/CCScrollView/CCScrollView.h   |  5 ++++
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/extensions/GUI/CCScrollView/CCScrollView.cpp b/extensions/GUI/CCScrollView/CCScrollView.cpp
index e90ec50fd4..dbce3012d2 100644
--- a/extensions/GUI/CCScrollView/CCScrollView.cpp
+++ b/extensions/GUI/CCScrollView/CCScrollView.cpp
@@ -492,11 +492,24 @@ void CCScrollView::beforeDraw()
 {
     if (m_bClippingToBounds)
     {
-		CCRect frame = getViewRect();
-        
-        glEnable(GL_SCISSOR_TEST);
-        
-        CCEGLView::sharedOpenGLView()->setScissorInPoints(frame.origin.x, frame.origin.y, frame.size.width, frame.size.height);
+		m_bScissorRestored = false;
+        CCRect frame = getViewRect();
+        if (CCEGLView::sharedOpenGLView()->isScissorEnable()) {
+            m_bScissorRestored = true;
+            m_tParentScissorRect = CCEGLView::sharedOpenGLView()->getScissorRect();
+            //set the intersection of m_tParentScissorRect and frame as the new scissor rect
+            if (frame.intersectsRect(m_tParentScissorRect)) {
+                float x = MAX(frame.origin.x, m_tParentScissorRect.origin.x);
+                float y = MAX(frame.origin.y, m_tParentScissorRect.origin.y);
+                float xx = MIN(frame.origin.x+frame.size.width, m_tParentScissorRect.origin.x+m_tParentScissorRect.size.width);
+                float yy = MIN(frame.origin.y+frame.size.height, m_tParentScissorRect.origin.y+m_tParentScissorRect.size.height);
+                CCEGLView::sharedOpenGLView()->setScissorInPoints(x, y, xx-x, yy-y);
+            }
+        }
+        else {
+            glEnable(GL_SCISSOR_TEST);
+            CCEGLView::sharedOpenGLView()->setScissorInPoints(frame.origin.x, frame.origin.y, frame.size.width, frame.size.height);
+        }
     }
 }
 
@@ -508,7 +521,12 @@ void CCScrollView::afterDraw()
 {
     if (m_bClippingToBounds)
     {
-        glDisable(GL_SCISSOR_TEST);
+        if (m_bScissorRestored) {//restore the parent's scissor rect
+            CCEGLView::sharedOpenGLView()->setScissorInPoints(m_tParentScissorRect.origin.x, m_tParentScissorRect.origin.y, m_tParentScissorRect.size.width, m_tParentScissorRect.size.height);
+        }
+        else {
+            glDisable(GL_SCISSOR_TEST);
+        }
     }
 }
 
diff --git a/extensions/GUI/CCScrollView/CCScrollView.h b/extensions/GUI/CCScrollView/CCScrollView.h
index 9c9955a3f9..00602374ac 100644
--- a/extensions/GUI/CCScrollView/CCScrollView.h
+++ b/extensions/GUI/CCScrollView/CCScrollView.h
@@ -317,6 +317,11 @@ protected:
      * max and min scale
      */
     float m_fMinScale, m_fMaxScale;
+    /**
+     * scissor rect for parent, just for restoring GL_SCISSOR_BOX
+     */
+    CCRect m_tParentScissorRect;
+    bool m_bScissorRestored;
 };
 
 // end of GUI group