diff --git a/modules/v4d/include/opencv2/v4d/detail/framebuffercontext.hpp b/modules/v4d/include/opencv2/v4d/detail/framebuffercontext.hpp
index 3cd83b83d..e3266aa7d 100644
--- a/modules/v4d/include/opencv2/v4d/detail/framebuffercontext.hpp
+++ b/modules/v4d/include/opencv2/v4d/detail/framebuffercontext.hpp
@@ -204,7 +204,7 @@ public:
     bool isClosed();
     bool isShared();
 protected:
-    V4D& getV4D();
+    cv::Ptr<V4D> getV4D();
     int getIndex();
     void setup(const cv::Size& sz);
     void teardown();
diff --git a/modules/v4d/include/opencv2/v4d/detail/imguicontext.hpp b/modules/v4d/include/opencv2/v4d/detail/imguicontext.hpp
index 169baa9a2..e05e9f175 100644
--- a/modules/v4d/include/opencv2/v4d/detail/imguicontext.hpp
+++ b/modules/v4d/include/opencv2/v4d/detail/imguicontext.hpp
@@ -20,6 +20,7 @@ CV_EXPORTS class ImGuiContext {
     FrameBufferContext& mainFbContext_;
     FrameBufferContext glFbContext_;
     std::function<void(const cv::Size&)> renderCallback_;
+    bool firstFrame_ = true;
 public:
     CV_EXPORTS ImGuiContext(FrameBufferContext& fbContext);
     CV_EXPORTS FrameBufferContext& fbCtx();
diff --git a/modules/v4d/include/opencv2/v4d/v4d.hpp b/modules/v4d/include/opencv2/v4d/v4d.hpp
index e787ced62..6485f516c 100644
--- a/modules/v4d/include/opencv2/v4d/v4d.hpp
+++ b/modules/v4d/include/opencv2/v4d/v4d.hpp
@@ -6,9 +6,8 @@
 #ifndef SRC_OPENCV_V4D_V4D_HPP_
 #define SRC_OPENCV_V4D_V4D_HPP_
 #if !defined(OPENCV_V4D_USE_ES3) && !defined(__EMSCRIPTEN__)
-#   define V4D_INIT(w, h, title, offscreen, debug, samples) ({ \
-    cv::Ptr<cv::v4d::V4D> v4d = cv::v4d::V4D::make(cv::Size(w, h), cv::Size(), title, offscreen, debug, samples); \
-    if (!gladLoadGLLoader((GLADloadproc) glfwGetProcAddress))  \
+#   define V4D_INIT_PRIVATE(v4d, install_hooks) ({ \
+        if (!gladLoadGLLoader((GLADloadproc) glfwGetProcAddress))  \
         throw std::runtime_error("Could not initialize GLAD!");  \
     glGetError(); \
     FrameBufferContext::GLScope glScope(v4d->fbCtx(), GL_FRAMEBUFFER); \
@@ -19,8 +18,12 @@
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; \
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad; \
     ImGui::StyleColorsDark(); \
-    ImGui_ImplGlfw_InitForOpenGL(v4d->getGLFWWindow(), true); \
+    ImGui_ImplGlfw_InitForOpenGL(v4d->getGLFWWindow(), install_hooks); \
     ImGui_ImplOpenGL3_Init(); \
+})
+#   define V4D_INIT_MAIN(w, h, title, offscreen, debug, samples) ({ \
+    cv::Ptr<cv::v4d::V4D> v4d = cv::v4d::V4D::make(cv::Size(w, h), cv::Size(), title, offscreen, debug, samples); \
+    V4D_INIT_PRIVATE(v4d, true); \
     v4d; \
     })
 #endif
@@ -43,6 +46,7 @@
 #include <map>
 #include <string>
 
+#include <opencv2/core.hpp>
 #include <opencv2/imgproc.hpp>
 #include <opencv2/videoio.hpp>
 
@@ -373,13 +377,12 @@ private:
     V4D(const cv::Size& size, const cv::Size& fbsize,
             const string& title, bool offscreen, bool debug, int samples);
 
-    cv::Ptr<V4D> self();
-
-
     cv::Point2f getMousePosition();
     void setMousePosition(const cv::Point2f& pt);
 
     void swapContextBuffers();
+protected:
+    cv::Ptr<V4D> self();
 };
 }
 } /* namespace kb */
diff --git a/modules/v4d/samples/beauty-demo.cpp b/modules/v4d/samples/beauty-demo.cpp
index a6e15def6..488adf27e 100644
--- a/modules/v4d/samples/beauty-demo.cpp
+++ b/modules/v4d/samples/beauty-demo.cpp
@@ -379,7 +379,7 @@ int main(int argc, char **argv) {
 int main() {
 #endif
     using namespace cv::v4d;
-    cv::Ptr<V4D> window = V4D::make(cv::Size(WIDTH, HEIGHT), cv::Size(), "Beauty Demo", OFFSCREEN);
+    cv::Ptr<V4D> window = V4D_INIT_MAIN(WIDTH, HEIGHT, "Beautification Demo", false, false, 0);
     facemark->loadModel("assets/lbfmodel.yaml");
 
     window->setScaling(scale);
diff --git a/modules/v4d/samples/cube-demo.cpp b/modules/v4d/samples/cube-demo.cpp
index ff7dbb8f8..793a05536 100644
--- a/modules/v4d/samples/cube-demo.cpp
+++ b/modules/v4d/samples/cube-demo.cpp
@@ -245,7 +245,7 @@ int main(int argc, char** argv) {
 #else
 int main() {
 #endif
-    cv::Ptr<V4D> window = V4D_INIT(WIDTH, HEIGHT, "Cube Demo", false, false, 0);
+    cv::Ptr<V4D> window = V4D_INIT_MAIN(WIDTH, HEIGHT, "Cube Demo", false, false, 0);
 
     window->printSystemInfo();
 
diff --git a/modules/v4d/samples/custom_source_and_sink.cpp b/modules/v4d/samples/custom_source_and_sink.cpp
index f115e135d..e1e53a635 100644
--- a/modules/v4d/samples/custom_source_and_sink.cpp
+++ b/modules/v4d/samples/custom_source_and_sink.cpp
@@ -7,7 +7,7 @@ using namespace cv;
 using namespace cv::v4d;
 
 int main() {
-    Ptr<V4D> window = V4D::make(Size(960, 960), cv::Size(), "Custom Source/Sink");
+    Ptr<V4D> window = V4D_INIT_MAIN(960, 960, "Custom Source/Sink", false, false, 0);
 
     string hr = "Hello Rainbow!";
 	//Make a source that generates rainbow frames.
diff --git a/modules/v4d/samples/display_image.cpp b/modules/v4d/samples/display_image.cpp
index 9fe7539ca..b384241bf 100644
--- a/modules/v4d/samples/display_image.cpp
+++ b/modules/v4d/samples/display_image.cpp
@@ -8,7 +8,7 @@ int main() {
     //Creates a V4D window for on screen rendering with a window size of 720p and a framebuffer of the same size.
 	//Please note that while the window size may change the framebuffer size may not. If you need multiple framebuffer
 	//sizes you need multiple V4D objects
-    Ptr<V4D> window = V4D::make(Size(960, 960), cv::Size(), "Display image");
+    cv::Ptr<V4D> window = V4D_INIT_MAIN(960, 960, "Display Image", false, false, 0);
 
     //Loads an image as a UMat (just in case we have hardware acceleration available)
 #ifdef __EMSCRIPTEN__
diff --git a/modules/v4d/samples/display_image_fb.cpp b/modules/v4d/samples/display_image_fb.cpp
index e8154198f..73a51a2e2 100644
--- a/modules/v4d/samples/display_image_fb.cpp
+++ b/modules/v4d/samples/display_image_fb.cpp
@@ -6,7 +6,7 @@ using namespace cv::v4d;
 
 int main() {
     //Creates a V4D object
-    Ptr<V4D> window = V4D::make(Size(960, 960), cv::Size(), "Display image and FB");
+    Ptr<V4D> window = V4D_INIT_MAIN(960, 960, "Display Image and FB", false, false, 0);
 
     //Loads an image as a UMat (just in case we have hardware acceleration available)
 #ifdef __EMSCRIPTEN__
diff --git a/modules/v4d/samples/font-demo.cpp b/modules/v4d/samples/font-demo.cpp
index e325545fd..6f647282c 100644
--- a/modules/v4d/samples/font-demo.cpp
+++ b/modules/v4d/samples/font-demo.cpp
@@ -204,7 +204,7 @@ static bool iteration(cv::Ptr<V4D> window) {
 
 int main() {
     try {
-        cv::Ptr<V4D> window = V4D::make(cv::Size(WIDTH, HEIGHT), cv::Size(), "Font Demo", OFFSCREEN);
+        cv::Ptr<V4D> window = V4D_INIT_MAIN(WIDTH, HEIGHT, "Font Demo", false, false, 0);
 //        if(!OFFSCREEN) {
 //            setup_gui(window);
 //        }
diff --git a/modules/v4d/samples/font_rendering.cpp b/modules/v4d/samples/font_rendering.cpp
index c7e64e623..c602b30e9 100644
--- a/modules/v4d/samples/font_rendering.cpp
+++ b/modules/v4d/samples/font_rendering.cpp
@@ -4,7 +4,7 @@ using namespace cv;
 using namespace cv::v4d;
 
 int main() {
-    Ptr<V4D> window = V4D::make(Size(960, 960), cv::Size(), "Font Rendering");
+    cv::Ptr<V4D> window = V4D_INIT_MAIN(960, 960, "Font Rendering", false, false, 0);
 
     //The text to render
 	string hw = "Hello World";
diff --git a/modules/v4d/samples/font_with_gui.cpp b/modules/v4d/samples/font_with_gui.cpp
index 176ecf184..ac3a9db20 100644
--- a/modules/v4d/samples/font_with_gui.cpp
+++ b/modules/v4d/samples/font_with_gui.cpp
@@ -4,7 +4,7 @@ using namespace cv;
 using namespace cv::v4d;
 
 int main() {
-    Ptr<V4D> window = V4D::make(Size(960, 960), cv::Size(), "Font Rendering with GUI");
+    Ptr<V4D> window = V4D_INIT_MAIN(960, 960, "Font Rendering with GUI", false, false, 0);
 
     //The text color. NanoGUI uses rgba with floating point
 //	nanogui::Color textColor = {0.0f, 0.0f, 1.0f, 1.0f};
diff --git a/modules/v4d/samples/many_cubes-demo.cpp b/modules/v4d/samples/many_cubes-demo.cpp
index 43a32b43d..25781aa6d 100644
--- a/modules/v4d/samples/many_cubes-demo.cpp
+++ b/modules/v4d/samples/many_cubes-demo.cpp
@@ -258,7 +258,7 @@ int main(int argc, char** argv) {
 #else
 int main() {
 #endif
-    cv::Ptr<V4D> window = V4D_INIT(WIDTH, HEIGHT, "Many Cubes Demo", false, false, 0);
+    cv::Ptr<V4D> window = V4D_INIT_MAIN(WIDTH, HEIGHT, "Many Cubes Demo", false, false, 0);
     window->printSystemInfo();
 
 #ifndef __EMSCRIPTEN__
diff --git a/modules/v4d/samples/nanovg-demo.cpp b/modules/v4d/samples/nanovg-demo.cpp
index ebe3a3ec3..e9e95df60 100644
--- a/modules/v4d/samples/nanovg-demo.cpp
+++ b/modules/v4d/samples/nanovg-demo.cpp
@@ -184,7 +184,7 @@ int main(int argc, char **argv) {
 #else
 int main() {
 #endif
-    cv::Ptr<V4D> window = V4D::make(cv::Size(WIDTH, HEIGHT), cv::Size(), "NanoVG Demo", OFFSCREEN);
+    cv::Ptr<V4D> window = V4D_INIT_MAIN(WIDTH, HEIGHT, "Mandelbrot Shader Demo", false, false, 0);
     window->printSystemInfo();
 
 #ifndef __EMSCRIPTEN__
diff --git a/modules/v4d/samples/optflow-demo.cpp b/modules/v4d/samples/optflow-demo.cpp
index 784b12bee..9c7ce6263 100644
--- a/modules/v4d/samples/optflow-demo.cpp
+++ b/modules/v4d/samples/optflow-demo.cpp
@@ -506,7 +506,7 @@ int main() {
 #endif
     try {
         using namespace cv::v4d;
-        cv::Ptr<V4D> window = V4D_INIT(WIDTH, HEIGHT, "Sparse Optical Flow Demo", false, false, 0);
+        cv::Ptr<V4D> window = V4D_INIT_MAIN(WIDTH, HEIGHT, "Sparse Optical Flow Demo", false, false, 0);
 
 #ifndef __EMSCRIPTEN__
         menuWindow = V4D::make(cv::Size(240, 360), cv::Size(), "Display Settings", OFFSCREEN);
diff --git a/modules/v4d/samples/pedestrian-demo.cpp b/modules/v4d/samples/pedestrian-demo.cpp
index cc02abc56..4397be4f6 100644
--- a/modules/v4d/samples/pedestrian-demo.cpp
+++ b/modules/v4d/samples/pedestrian-demo.cpp
@@ -235,7 +235,7 @@ int main(int argc, char **argv) {
 int main() {
 #endif
     using namespace cv::v4d;
-    cv::Ptr<V4D> window = V4D::make(cv::Size(WIDTH, HEIGHT), cv::Size(), "Pedestrian Demo", OFFSCREEN);
+    cv::Ptr<V4D> window = V4D_INIT_MAIN(WIDTH, HEIGHT, "Pedestrian Demo", false, false, 0);
     hog.setSVMDetector(cv::HOGDescriptor::getDefaultPeopleDetector());
 
     window->printSystemInfo();
diff --git a/modules/v4d/samples/render_opengl.cpp b/modules/v4d/samples/render_opengl.cpp
index 0bdb2721b..372a8006f 100644
--- a/modules/v4d/samples/render_opengl.cpp
+++ b/modules/v4d/samples/render_opengl.cpp
@@ -5,7 +5,7 @@ using namespace cv;
 using namespace cv::v4d;
 
 int main() {
-    Ptr<V4D> window = V4D_INIT(960, 960, "GL Blue Screen", false, false, 0);
+    Ptr<V4D> window = V4D_INIT_MAIN(960, 960, "GL Blue Screen", false, false, 0);
 
     window->run([=](Ptr<V4D> window) {
         window->gl([]() {
diff --git a/modules/v4d/samples/shader-demo.cpp b/modules/v4d/samples/shader-demo.cpp
index 5811a14e5..34f232885 100644
--- a/modules/v4d/samples/shader-demo.cpp
+++ b/modules/v4d/samples/shader-demo.cpp
@@ -339,7 +339,7 @@ int main(int argc, char** argv) {
 int main() {
 #endif
     try {
-        cv::Ptr<V4D> window = V4D::make(cv::Size(WIDTH, HEIGHT), cv::Size(), "Shader Demo", OFFSCREEN);
+        cv::Ptr<V4D> window = V4D_INIT_MAIN(WIDTH, HEIGHT, "Mandelbrot Shader Demo", false, false, 0);
 
 //        if (!OFFSCREEN) {
 //            setup_gui(window);
diff --git a/modules/v4d/samples/vector_graphics.cpp b/modules/v4d/samples/vector_graphics.cpp
index 682d6a4ba..bb527b5a1 100644
--- a/modules/v4d/samples/vector_graphics.cpp
+++ b/modules/v4d/samples/vector_graphics.cpp
@@ -4,7 +4,7 @@ using namespace cv;
 using namespace cv::v4d;
 
 int main() {
-    Ptr<V4D> window = V4D::make(Size(960, 960), cv::Size(), "Vector Graphics");
+    Ptr<V4D> window = V4D_INIT_MAIN(960, 960, "Vector Graphics", false, false, 0);
 
     window->run([=](Ptr<V4D> window) {
         //Creates a NanoVG context and draws googly eyes that occasionally blink.
diff --git a/modules/v4d/samples/vector_graphics_and_fb.cpp b/modules/v4d/samples/vector_graphics_and_fb.cpp
index ef1698578..9ba972293 100644
--- a/modules/v4d/samples/vector_graphics_and_fb.cpp
+++ b/modules/v4d/samples/vector_graphics_and_fb.cpp
@@ -5,7 +5,7 @@ using namespace cv;
 using namespace cv::v4d;
 
 int main() {
-    Ptr<V4D> window = V4D::make(Size(960, 960), cv::Size(), "Vector Graphics and Framebuffer");
+    Ptr<V4D> window = V4D_INIT_MAIN(960, 960, "Vector Graphics and Framebuffer", false, false, 0);
 
     window->run([=](Ptr<V4D> window) {
         //Again creates a NanoVG context and draws googly eyes
diff --git a/modules/v4d/samples/video-demo.cpp b/modules/v4d/samples/video-demo.cpp
index b0ce80f1d..ac47949e9 100644
--- a/modules/v4d/samples/video-demo.cpp
+++ b/modules/v4d/samples/video-demo.cpp
@@ -218,7 +218,7 @@ int main(int argc, char** argv) {
 int main() {
 #endif
     using namespace cv::v4d;
-    cv::Ptr<V4D> window = V4D::make(cv::Size(WIDTH, HEIGHT), cv::Size(), "Video Demo", OFFSCREEN, false);
+    cv::Ptr<V4D> window = V4D_INIT_MAIN(WIDTH, HEIGHT, "Video Demo", false, false, 0);
     window->printSystemInfo();
 
 #ifndef __EMSCRIPTEN__
diff --git a/modules/v4d/samples/video_editing.cpp b/modules/v4d/samples/video_editing.cpp
index 8d0fc590a..cf5c563b9 100644
--- a/modules/v4d/samples/video_editing.cpp
+++ b/modules/v4d/samples/video_editing.cpp
@@ -4,7 +4,7 @@ using namespace cv;
 using namespace cv::v4d;
 
 int main(int argc, char** argv) {
-    Ptr<V4D> window = V4D::make(cv::Size(960, 960), cv::Size(), "Video Editing");
+    Ptr<V4D> window = V4D_INIT_MAIN(960, 960, "Video Editing", false, false, 0);
 
     //In case of WebAssembly
     CV_UNUSED(argc);
diff --git a/modules/v4d/src/detail/framebuffercontext.cpp b/modules/v4d/src/detail/framebuffercontext.cpp
index 41d3507f3..6bef80c36 100644
--- a/modules/v4d/src/detail/framebuffercontext.cpp
+++ b/modules/v4d/src/detail/framebuffercontext.cpp
@@ -271,7 +271,7 @@ void FrameBufferContext::init() {
     }
     this->makeCurrent();
 #ifndef __EMSCRIPTEN__
-    glfwSwapInterval(1);
+    glfwSwapInterval(0);
 #endif
 #if !defined(OPENCV_V4D_USE_ES3) && !defined(__EMSCRIPTEN__)
     if (!gladLoadGLLoader((GLADloadproc) glfwGetProcAddress))
@@ -367,8 +367,8 @@ void FrameBufferContext::init() {
 //            });
 }
 
-V4D& FrameBufferContext::getV4D() {
-   return *v4d_;
+cv::Ptr<V4D> FrameBufferContext::getV4D() {
+   return v4d_->self();
 }
 
 int FrameBufferContext::getIndex() {
diff --git a/modules/v4d/src/detail/glcontext.cpp b/modules/v4d/src/detail/glcontext.cpp
index 81fad96c8..cdaddad26 100644
--- a/modules/v4d/src/detail/glcontext.cpp
+++ b/modules/v4d/src/detail/glcontext.cpp
@@ -9,7 +9,7 @@ namespace cv {
 namespace v4d {
 namespace detail {
 GLContext::GLContext(FrameBufferContext& fbContext) :
-        mainFbContext_(fbContext), glFbContext_(fbContext.getV4D(), "OpenGL", fbContext) {
+        mainFbContext_(fbContext), glFbContext_(*fbContext.getV4D(), "OpenGL", fbContext) {
 #ifdef __EMSCRIPTEN__
     run_sync_on_main<19>([&,this](){
         mainFbContext_.initWebGLCopy(fbCtx().getIndex());
diff --git a/modules/v4d/src/detail/imguicontext.cpp b/modules/v4d/src/detail/imguicontext.cpp
index 82fac61a1..5dd1f79c3 100644
--- a/modules/v4d/src/detail/imguicontext.cpp
+++ b/modules/v4d/src/detail/imguicontext.cpp
@@ -19,7 +19,8 @@ namespace cv {
 namespace v4d {
 namespace detail {
 ImGuiContext::ImGuiContext(FrameBufferContext& fbContext) :
-        mainFbContext_(fbContext), glFbContext_(fbContext.getV4D(), "ImGUI", fbContext) {
+        mainFbContext_(fbContext), glFbContext_(*fbContext.getV4D(), "ImGUI", fbContext) {
+    V4D_INIT_PRIVATE(mainFbContext_.getV4D(), false);
 #ifdef __EMSCRIPTEN__
     run_sync_on_main<24>([&,this](){
         mainFbContext_.initWebGLCopy(fbCtx().getIndex());
@@ -27,12 +28,12 @@ ImGuiContext::ImGuiContext(FrameBufferContext& fbContext) :
 #endif
 }
 
-bool show_demo_window = true;
 
 void ImGuiContext::build(std::function<void(const cv::Size&)> fn) {
     renderCallback_ = fn;
 }
 
+bool show_demo_window = true;
 void ImGuiContext::render() {
     run_sync_on_main<25>([&,this](){
 #ifndef __EMSCRIPTEN__
@@ -43,24 +44,19 @@ void ImGuiContext::render() {
         }
 #endif
         {
-            fbCtx().getV4D().makeCurrent();
+            fbCtx().getV4D()->makeCurrent();
             GL_CHECK(glBindFramebuffer(GL_FRAMEBUFFER, 0));
             GL_CHECK(glDrawBuffer(GL_BACK));
-            GL_CHECK(glViewport(0, 0, fbCtx().getV4D().size().width, fbCtx().getV4D().size().height));
-
-//            GL_CHECK(glClear(GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT));
-//#ifdef __EMSCRIPTEN__
-//            //Preserve the clear color state though it is a bit costly. We don't want to interfere.
-//            GLfloat cColor[4];
-//            GL_CHECK(glGetFloatv(GL_COLOR_CLEAR_VALUE, cColor));
-//            GL_CHECK(glClearColor(0,0,0,0));
-//            GL_CHECK(glClear(GL_COLOR_BUFFER_BIT));
-//            GL_CHECK(glClearColor(cColor[0], cColor[1], cColor[2], cColor[3]));
-//#endif
+            GL_CHECK(glViewport(0, 0, fbCtx().getV4D()->size().width, fbCtx().getV4D()->size().height));
             ImGui_ImplOpenGL3_NewFrame();
             ImGui_ImplGlfw_NewFrame();
             ImGui::NewFrame();
-            renderCallback_(fbCtx().getV4D().size());
+            ImGui::Begin("Display"); \
+            ImGuiIO& io = ImGui::GetIO(); \
+            ImGui::Text("%.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate); \
+            ImGui::End();
+            if(renderCallback_)
+                renderCallback_(fbCtx().getV4D()->size());
             ImGui::Render();
             ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
         }
diff --git a/modules/v4d/src/detail/nanovgcontext.cpp b/modules/v4d/src/detail/nanovgcontext.cpp
index 3f8427795..553337ae3 100644
--- a/modules/v4d/src/detail/nanovgcontext.cpp
+++ b/modules/v4d/src/detail/nanovgcontext.cpp
@@ -12,7 +12,7 @@ namespace v4d {
 namespace detail {
 
 NanoVGContext::NanoVGContext(FrameBufferContext& fbContext) :
-        mainFbContext_(fbContext), nvgFbContext_(fbContext.getV4D(), "NanoVG", fbContext), context_(
+        mainFbContext_(fbContext), nvgFbContext_(*fbContext.getV4D(), "NanoVG", fbContext), context_(
                 nullptr) {
     run_sync_on_main<13>([this]() {
         {
diff --git a/modules/v4d/src/v4d.cpp b/modules/v4d/src/v4d.cpp
index b035daea7..8c676d7ef 100644
--- a/modules/v4d/src/v4d.cpp
+++ b/modules/v4d/src/v4d.cpp
@@ -25,15 +25,15 @@ V4D::V4D(const cv::Size& size, const cv::Size& fbsize, const string& title, bool
 #ifdef __EMSCRIPTEN__
     printf(""); //makes sure we have FS as a dependency
 #endif
-        mainFbContext_ = new detail::FrameBufferContext(*this, fbsize.empty() ? size : fbsize, offscreen, title_, 3,
+    self_ = cv::Ptr<V4D>(this);
+    mainFbContext_ = new detail::FrameBufferContext(*this, fbsize.empty() ? size : fbsize, offscreen, title_, 3,
                 2, samples_, debug_, nullptr, nullptr);
 #ifndef __EMSCRIPTEN__
-        CLExecScope_t scope(mainFbContext_->getCLExecContext());
+    CLExecScope_t scope(mainFbContext_->getCLExecContext());
 #endif
-        nvgContext_ = new detail::NanoVGContext(*mainFbContext_);
-        clvaContext_ = new detail::CLVAContext(*mainFbContext_);
-        imguiContext_ = new detail::ImGuiContext(*mainFbContext_);
-        self_ = cv::Ptr<V4D>(this);
+    nvgContext_ = new detail::NanoVGContext(*mainFbContext_);
+    clvaContext_ = new detail::CLVAContext(*mainFbContext_);
+    imguiContext_ = new detail::ImGuiContext(*mainFbContext_);
 }
 
 V4D::~V4D() {
@@ -447,6 +447,7 @@ void V4D::swapContextBuffers() {
             FrameBufferContext::GLScope glScope(glCtx(i).fbCtx(), GL_READ_FRAMEBUFFER);
             glCtx(i).fbCtx().blitFrameBufferToScreen(viewport(), glCtx(i).fbCtx().getWindowSize(), isScaling());
 //            GL_CHECK(glFinish());
+            glfwSwapInterval(0);
 #ifndef __EMSCRIPTEN__
             glfwSwapBuffers(glCtx(i).fbCtx().getGLFWWindow());
 #else
@@ -459,6 +460,7 @@ void V4D::swapContextBuffers() {
         FrameBufferContext::GLScope glScope(nvgCtx().fbCtx(), GL_READ_FRAMEBUFFER);
         nvgCtx().fbCtx().blitFrameBufferToScreen(viewport(), nvgCtx().fbCtx().getWindowSize(), isScaling());
 //        GL_CHECK(glFinish());
+        glfwSwapInterval(0);
 #ifndef __EMSCRIPTEN__
         glfwSwapBuffers(nvgCtx().fbCtx().getGLFWWindow());
 #else
@@ -469,6 +471,7 @@ void V4D::swapContextBuffers() {
         FrameBufferContext::GLScope glScope(imguiCtx().fbCtx(), GL_READ_FRAMEBUFFER);
         imguiCtx().fbCtx().blitFrameBufferToScreen(viewport(), imguiCtx().fbCtx().getWindowSize(), isScaling());
 //        GL_CHECK(glFinish());
+        glfwSwapInterval(0);
 #ifndef __EMSCRIPTEN__
         glfwSwapBuffers(imguiCtx().fbCtx().getGLFWWindow());
 #else
@@ -484,15 +487,13 @@ bool V4D::display() {
 #else
     if (true) {
 #endif
-
-        run_sync_on_main<6>([&, this](){
+        run_sync_on_main<6>([&, this]() {
             {
-               FrameBufferContext::GLScope glScope(fbCtx(), GL_READ_FRAMEBUFFER);
-               fbCtx().blitFrameBufferToScreen(viewport(), fbCtx().getWindowSize(), isScaling());
+                FrameBufferContext::GLScope glScope(fbCtx(), GL_READ_FRAMEBUFFER);
+                fbCtx().blitFrameBufferToScreen(viewport(), fbCtx().getWindowSize(), isScaling());
             }
             imguiCtx().render();
-//            if(debug_)
-                swapContextBuffers();
+            swapContextBuffers();
             fbCtx().makeCurrent();
 #ifndef __EMSCRIPTEN__
             glfwSwapBuffers(fbCtx().getGLFWWindow());
@@ -503,7 +504,7 @@ bool V4D::display() {
             result = !glfwWindowShouldClose(getGLFWWindow());
         });
     }
-    if(frameCnt_ == (std::numeric_limits<uint64_t>().max() - 1))
+    if (frameCnt_ == (std::numeric_limits<uint64_t>().max() - 1))
         frameCnt_ = 0;
     else
         ++frameCnt_;