Fix for CCRenderTexture on Android sleep/resume

When an android app goes into the background, all gl context is lost, including any frame buffer objects that are required for rendering to a texture. When the android app returns to focus, a new FBO is generated for each render texture allowing rendering to the texture to continue.

cocos2dx/misc_nodes/CCRenderTexture.cpp

@@ -59,12 +59,19 @@ CCRenderTexture::CCRenderTexture()
 , m_nClearStencil(0)
 , m_bAutoDraw(false)
 {
+#if CC_ENABLE_CACHE_TEXTURE_DATA
     // Listen this event to save render texture before come to background.
     // Then it can be restored after coming to foreground on Android.
     CCNotificationCenter::sharedNotificationCenter()->addObserver(this,
                                                                   callfuncO_selector(CCRenderTexture::listenToBackground),
                                                                   EVENT_COME_TO_BACKGROUND,
                                                                   NULL);
+    
+    CCNotificationCenter::sharedNotificationCenter()->addObserver(this,
+                                                                  callfuncO_selector(CCRenderTexture::listenToForeground),
+                                                                  EVNET_COME_TO_FOREGROUND, // this is misspelt
+                                                                  NULL);
+#endif
 }
 
 CCRenderTexture::~CCRenderTexture()
@@ -79,28 +86,58 @@ CCRenderTexture::~CCRenderTexture()
     }
     CC_SAFE_DELETE(m_pUITextureImage);
 
+#if CC_ENABLE_CACHE_TEXTURE_DATA
     CCNotificationCenter::sharedNotificationCenter()->removeObserver(this, EVENT_COME_TO_BACKGROUND);
+    CCNotificationCenter::sharedNotificationCenter()->removeObserver(this, EVNET_COME_TO_FOREGROUND);
+#endif
 }
 
 void CCRenderTexture::listenToBackground(cocos2d::CCObject *obj)
 {
 #if CC_ENABLE_CACHE_TEXTURE_DATA
-    
     CC_SAFE_DELETE(m_pUITextureImage);
     
     // to get the rendered texture data
-    m_pUITextureImage = newCCImage();
-
+    m_pUITextureImage = newCCImage(false);
 
     if (m_pUITextureImage)
     {
         const CCSize& s = m_pTexture->getContentSizeInPixels();
         VolatileTexture::addDataTexture(m_pTexture, m_pUITextureImage->getData(), kTexture2DPixelFormat_RGBA8888, s);
+        
+        if ( m_pTextureCopy )
+        {
+            VolatileTexture::addDataTexture(m_pTextureCopy, m_pUITextureImage->getData(), kTexture2DPixelFormat_RGBA8888, s);
+        }
     }
     else
     {
         CCLOG("Cache rendertexture failed!");
     }
+    
+    glDeleteFramebuffers(1, &m_uFBO);
+    m_uFBO = 0;
+#endif
+}
+
+void CCRenderTexture::listenToForeground(cocos2d::CCObject *obj)
+{
+#if CC_ENABLE_CACHE_TEXTURE_DATA
+    // -- regenerate frame buffer object and attach the texture
+    glGetIntegerv(GL_FRAMEBUFFER_BINDING, &m_nOldFBO);
+    
+    glGenFramebuffers(1, &m_uFBO);
+    glBindFramebuffer(GL_FRAMEBUFFER, m_uFBO);
+    
+    m_pTexture->setAliasTexParameters();
+    
+    if ( m_pTextureCopy )
+    {
+        m_pTextureCopy->setAliasTexParameters();
+    }
+    
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_pTexture->getName(), 0);
+    glBindFramebuffer(GL_FRAMEBUFFER, m_nOldFBO);
 #endif
 }
 
@@ -590,7 +627,7 @@ bool CCRenderTexture::saveToFile(const char *szFilePath)
 {
     bool bRet = false;
 
-    CCImage *pImage = newCCImage();
+    CCImage *pImage = newCCImage(true);
     if (pImage)
     {
         bRet = pImage->saveToFile(szFilePath, kCCImageFormatJPEG);
@@ -605,7 +642,7 @@ bool CCRenderTexture::saveToFile(const char *fileName, tCCImageFormat format)
     CCAssert(format == kCCImageFormatJPEG || format == kCCImageFormatPNG,
              "the image can only be saved as JPG or PNG format");
 
-    CCImage *pImage = newCCImage();
+    CCImage *pImage = newCCImage(true);
     if (pImage)
     {
         std::string fullpath = CCFileUtils::sharedFileUtils()->getWriteablePath() + fileName;
@@ -619,7 +656,7 @@ bool CCRenderTexture::saveToFile(const char *fileName, tCCImageFormat format)
 }
 
 /* get buffer as CCImage */
-CCImage* CCRenderTexture::newCCImage()
+CCImage* CCRenderTexture::newCCImage(bool flipImage)
 {
     CCAssert(m_ePixelFormat == kCCTexture2DPixelFormat_RGBA8888, "only RGBA8888 can be saved as image");
 
@@ -656,6 +693,8 @@ CCImage* CCRenderTexture::newCCImage()
         glReadPixels(0,0,nSavedBufferWidth, nSavedBufferHeight,GL_RGBA,GL_UNSIGNED_BYTE, pTempData);
         this->end();
 
+        if ( flipImage ) // -- flip is only required when saving image to file
+        {
             // to get the actual texture data
             // #640 the image read from rendertexture is dirty
             for (int i = 0; i < nSavedBufferHeight; ++i)
@@ -666,6 +705,12 @@ CCImage* CCRenderTexture::newCCImage()
             }
 
             pImage->initWithImageData(pBuffer, nSavedBufferWidth * nSavedBufferHeight * 4, CCImage::kFmtRawData, nSavedBufferWidth, nSavedBufferHeight, 8);
+        }
+        else
+        {
+            pImage->initWithImageData(pTempData, nSavedBufferWidth * nSavedBufferHeight * 4, CCImage::kFmtRawData, nSavedBufferWidth, nSavedBufferHeight, 8);
+        }
+        
     } while (0);
 
     CC_SAFE_DELETE_ARRAY(pBuffer);

cocos2dx/misc_nodes/CCRenderTexture.h

@@ -128,7 +128,7 @@ public:
     /* creates a new CCImage from with the texture's data.
        Caller is responsible for releasing it by calling delete.
      */
-    CCImage* newCCImage();
+    CCImage* newCCImage(bool flipImage = true);
 
     /** saves the texture into a file using JPEG format. The file will be saved in the Documents folder.
         Returns YES if the operation is successful.
@@ -145,6 +145,11 @@ public:
      */
     void listenToBackground(CCObject *obj);
     
+    /** Listen "come to foreground" message and restore the frame buffer object
+     It only has effect on Android.
+     */
+    void listenToForeground(CCObject *obj);
+    
     /** Valid flags: GL_COLOR_BUFFER_BIT, GL_DEPTH_BUFFER_BIT, GL_STENCIL_BUFFER_BIT. They can be OR'ed. Valid when "autoDraw is YES. */
     unsigned int getClearFlags() const;
     void setClearFlags(unsigned int uClearFlags);