diff --git a/toonz/sources/common/tvrender/qtofflinegl.cpp b/toonz/sources/common/tvrender/qtofflinegl.cpp
index 4c8eca57..4c4c4ff5 100644
--- a/toonz/sources/common/tvrender/qtofflinegl.cpp
+++ b/toonz/sources/common/tvrender/qtofflinegl.cpp
@@ -98,7 +98,6 @@ QtOfflineGL::QtOfflineGL(TDimension rasterSize, std::shared_ptr<TOfflineGL::Imp>
 
 QtOfflineGL::~QtOfflineGL()
 {
-	delete m_context;
 }
 
 //-----------------------------------------------------------------------------
@@ -107,22 +106,22 @@ void QtOfflineGL::createContext(TDimension rasterSize, std::shared_ptr<TOfflineG
 {
 	// Imposto il formato dei Pixel (pixelFormat)
 	/*
-	 32,                    // 32-bit color depth 
-	 0, 0, 0, 0, 0, 0,      // color bits ignored 
-	 8,                     // no alpha buffer 
-	 0,                     // shift bit ignored 
-	 0,                     // no accumulation buffer 
-	 0, 0, 0, 0,            // accum bits ignored 
-	 32,                    // 32-bit z-buffer 
-	 32,                    // max stencil buffer 
-	 0,                     // no auxiliary buffer 
-	 PFD_MAIN_PLANE,        // main layer 
-	 0,                     // reserved 
-	 0, 0, 0                // layer masks ignored 
+	 32,                    // 32-bit color depth
+	 0, 0, 0, 0, 0, 0,      // color bits ignored
+	 8,                     // no alpha buffer
+	 0,                     // shift bit ignored
+	 0,                     // no accumulation buffer
+	 0, 0, 0, 0,            // accum bits ignored
+	 32,                    // 32-bit z-buffer
+	 32,                    // max stencil buffer
+	 0,                     // no auxiliary buffer
+	 PFD_MAIN_PLANE,        // main layer
+	 0,                     // reserved
+	 0, 0, 0                // layer masks ignored
 
 	 ATTENZIONE !! SU MAC IL FORMATO E' DIVERSO (casomai possiamo mettere un ifdef)
 
-	 SPECIFICHE  MAC = depth_size 24, stencil_size 8, alpha_size 1 
+	 SPECIFICHE  MAC = depth_size 24, stencil_size 8, alpha_size 1
 
   */
 
@@ -155,36 +154,36 @@ void QtOfflineGL::createContext(TDimension rasterSize, std::shared_ptr<TOfflineG
   fmt.setDirectRendering(false);
 #endif
 #endif
-	/* FIXME: ここでいう QPixmap は Level Strip のセルに相当する. 
-	 QPixmap に GLContext を生成して bind できれば描画したベクタのラスタ画像がそこに反映されるはずだが
-	 QLContext の生成ができないためにうまくいかない.
-   */
-	printf("QPixmap(%d, %d)\n", rasterSize.lx, rasterSize.ly);
-	//QPixmap *m_pixmap = new QPixmap(rasterSize.lx, rasterSize.ly);
 
-	// Inizializzo un contesto openGL utilizzando una QPixmap
+	QSurfaceFormat format;
+	format.setProfile(QSurfaceFormat::CompatibilityProfile);
 
-	m_context = new QOpenGLContext();
-	//m_context = new QGLContext(fmt);
-
-	m_surface = new QOffscreenSurface();
-	m_surface->setFormat(m_context->format());
-	//QSurfaceFormat sfmt = QGuiApplication::focusWindow()->format();
+	m_surface = std::make_shared<QOffscreenSurface>();
+	m_surface->setFormat(format);
 	m_surface->create();
 
-	printf("create context:%p [thread:0x%x]\n", m_context, QThread::currentThreadId());
-	//m_context->setFormat(sfmt);
+	m_context = std::make_shared<QOpenGLContext>();
+	m_context->setFormat(format);
+	m_context->create();
+	m_context->makeCurrent(m_surface.get());
+
+	QOpenGLFramebufferObjectFormat fbo_format;
+	m_fbo = std::make_shared<QOpenGLFramebufferObject>(rasterSize.lx, rasterSize.ly, fbo_format);
+	m_fbo->bind();
+
+	printf("create context:%p [thread:0x%x]\n", m_context.get(), QThread::currentThreadId());
 
 	// Creo il contesto OpenGL - assicurandomi che sia effettivamente creato
 	// NOTA: Se il contesto non viene creato, di solito basta ritentare qualche volta.
-	bool ret = m_context->create();
+
 }
 //-----------------------------------------------------------------------------
 
 void QtOfflineGL::makeCurrent()
 {
 	if (m_context) {
-		m_context->makeCurrent(m_surface);
+	        m_context->moveToThread(QThread::currentThread());
+		m_context->makeCurrent(m_surface.get());
 	}
 	// else
 	//  m_oldContext = 0;
@@ -225,15 +224,7 @@ void QtOfflineGL::getRaster(TRaster32P raster)
 	int ly = raster->getLy();
 
 	raster->lock();
-	glReadPixels(0, 0, lx, ly,
-				 GL_RGBA /*GL_BGRA_EXT*/, GL_UNSIGNED_BYTE,
-				 raster->getRawData());
-
-#ifdef WIN32
-	swapRedBlueChannels(raster->getRawData(), lx * ly);
-#elif MACOSX
-	rightRotateBits(raster->getRawData(), lx * ly);
-#endif
+	raster->copy( TRaster32P(lx, ly, m_fbo->width(), (TPixelRGBM32 *)m_fbo->toImage(false).bits(), false) );
 	raster->unlock();
 }
 
@@ -260,7 +251,6 @@ QtOfflineGLPBuffer::QtOfflineGLPBuffer(TDimension rasterSize)
 
 QtOfflineGLPBuffer::~QtOfflineGLPBuffer()
 {
-	delete m_context;
 }
 
 //-----------------------------------------------------------------------------
@@ -269,22 +259,22 @@ void QtOfflineGLPBuffer::createContext(TDimension rasterSize)
 {
 	// Imposto il formato dei Pixel (pixelFormat)
 	/*
-      32,                    // 32-bit color depth 
-      0, 0, 0, 0, 0, 0,      // color bits ignored 
-      8,                     // no alpha buffer 
-      0,                     // shift bit ignored 
-      0,                     // no accumulation buffer 
-      0, 0, 0, 0,            // accum bits ignored 
-      32,                    // 32-bit z-buffer 
-      32,                    // max stencil buffer 
-      0,                     // no auxiliary buffer 
-      PFD_MAIN_PLANE,        // main layer 
-      0,                     // reserved 
-      0, 0, 0                // layer masks ignored 
-      
+      32,                    // 32-bit color depth
+      0, 0, 0, 0, 0, 0,      // color bits ignored
+      8,                     // no alpha buffer
+      0,                     // shift bit ignored
+      0,                     // no accumulation buffer
+      0, 0, 0, 0,            // accum bits ignored
+      32,                    // 32-bit z-buffer
+      32,                    // max stencil buffer
+      0,                     // no auxiliary buffer
+      PFD_MAIN_PLANE,        // main layer
+      0,                     // reserved
+      0, 0, 0                // layer masks ignored
+
       ATTENZIONE !! SU MAC IL FORMATO E' DIVERSO (casomai possiamo mettere un ifdef)
 
-      SPECIFICHE  MAC = depth_size 24, stencil_size 8, alpha_size 1 
+      SPECIFICHE  MAC = depth_size 24, stencil_size 8, alpha_size 1
 
     */
 
@@ -321,15 +311,16 @@ void QtOfflineGLPBuffer::createContext(TDimension rasterSize)
 	while (pBufferSize < sizeMax)
 		pBufferSize *= 2;
 
-	m_context = new QGLPixelBuffer(QSize(pBufferSize, pBufferSize), fmt);
+	m_context = std::make_shared<QGLPixelBuffer>(QSize(pBufferSize, pBufferSize), fmt);
 }
 
 //-----------------------------------------------------------------------------
 
 void QtOfflineGLPBuffer::makeCurrent()
 {
-	if (m_context)
+        if (m_context){
 		m_context->makeCurrent();
+	}
 }
 
 //-----------------------------------------------------------------------------
diff --git a/toonz/sources/include/qtofflinegl.h b/toonz/sources/include/qtofflinegl.h
index f0e6022c..7eacaddd 100644
--- a/toonz/sources/include/qtofflinegl.h
+++ b/toonz/sources/include/qtofflinegl.h
@@ -7,17 +7,19 @@
 #include <QGLFormat>
 #include <QGLContext>
 #include <QGLPixelBuffer>
+#include <QOpenGLFramebufferObject>
 
 #include "tofflinegl.h"
 
 class QtOfflineGL : public TOfflineGL::Imp
 {
 public:
-	QOpenGLContext *m_context;
-	QOpenGLContext *m_oldContext;
-	QOffscreenSurface *m_surface;
+        std::shared_ptr<QOpenGLContext> m_context;
+        std::shared_ptr<QOpenGLContext> m_oldContext;
+        std::shared_ptr<QOffscreenSurface> m_surface;
+        std::shared_ptr<QOpenGLFramebufferObject> m_fbo;
 
-	QtOfflineGL(TDimension rasterSize, std::shared_ptr<TOfflineGL::Imp> shared);
+        QtOfflineGL(TDimension rasterSize, std::shared_ptr<TOfflineGL::Imp> shared);
 	~QtOfflineGL();
 
 	void createContext(TDimension rasterSize, std::shared_ptr<TOfflineGL::Imp> shared);
@@ -35,7 +37,7 @@ public:
 class QtOfflineGLPBuffer : public TOfflineGL::Imp
 {
 public:
-	QGLPixelBuffer *m_context;
+        std::shared_ptr<QGLPixelBuffer> m_context;
 
 	QtOfflineGLPBuffer(TDimension rasterSize);
 	~QtOfflineGLPBuffer();