Avoid huge cost of restoring previously bound framebuffer

Change-Id: I2dbf01ea4ec330268198af6f9404f736812cf4c2
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/src/quick3d/imports/scene3d/scene3drenderer.cpp b/src/quick3d/imports/scene3d/scene3drenderer.cpp
index feb194a0b..690822280 100644
--- a/src/quick3d/imports/scene3d/scene3drenderer.cpp
+++ b/src/quick3d/imports/scene3d/scene3drenderer.cpp
@@ -257,7 +257,14 @@ void Scene3DRenderer::render()
             saver.context()->makeCurrent(saver.surface());
 
         // Blit multisampled FBO with non multisampled FBO with texture attachment
-        QOpenGLFramebufferObject::blitFramebuffer(m_finalFBO.data(), m_multisampledFBO.data());
+        const QRect dstRect(QPoint(0, 0), m_finalFBO->size());
+        const QRect srcRect(QPoint(0, 0), m_multisampledFBO->size());
+        QOpenGLFramebufferObject::blitFramebuffer(m_finalFBO.data(), dstRect,
+                                                  m_multisampledFBO.data(), srcRect,
+                                                  GL_COLOR_BUFFER_BIT,
+                                                  GL_NEAREST,
+                                                  0, 0,
+                                                  QOpenGLFramebufferObject::DontRestoreFramebufferBinding);
 
         // Restore QtQuick FBO
         m_multisampledFBO->bindDefault();