redisgned v4d-contexts to take variadic arguments instead of lamda-capturing.

modules/v4d/include/opencv2/v4d/detail/framebuffercontext.hpp

@@ -12,10 +12,12 @@
 
 //FIXME
 #include "opencv2/v4d/detail/cl.hpp"
+#include <opencv2/core.hpp>
 #include <opencv2/core/ocl.hpp>
 #include "opencv2/v4d/util.hpp"
 #include <iostream>
 #include <map>
+#include <vector>
 
 struct GLFWwindow;
 typedef unsigned int GLenum;
@@ -24,6 +26,27 @@ typedef unsigned int GLenum;
 namespace cv {
 namespace v4d {
 class V4D;
+
+template <typename ... Args>
+class V4DAndArgsInFunctor : public std::function<void(cv::Ptr<V4D>, Args ...)> {
+public:
+    V4DAndArgsInFunctor(cv::Ptr<V4D> window, Args ... args) : std::function<void(cv::Ptr<V4D>, Args ...)>(window, args...) {
+    }
+};
+template <typename Tfn, typename ... Args>
+class V4DAndFbAndArgsInFunctor : public std::function<void(cv::Ptr<V4D>, cv::UMat&, Args& ...)> {
+public:
+    V4DAndFbAndArgsInFunctor(Tfn fn) : std::function<void(cv::Ptr<V4D>, cv::UMat&, Args& ...)>(fn) {
+    }
+};
+
+template <typename ... Args>
+class V4DAndSizeTAndArgsInFunctor : public std::function<void(cv::Ptr<V4D>, size_t&, Args ...)> {
+public:
+    V4DAndSizeTAndArgsInFunctor(std::function<void(cv::Ptr<V4D>, size_t&, Args ...)> fn) : std::function<void(cv::Ptr<V4D>, size_t&, Args ...)>(fn) {
+    }
+};
+
 namespace detail {
 typedef cv::ocl::OpenCLExecutionContext CLExecContext_t;
 class CLExecScope_t
@@ -217,7 +240,24 @@ public:
       * directly on the framebuffer.
       * @param fn A function object that is passed the framebuffer to be read/manipulated.
       */
-    void execute(std::function<void(cv::UMat&)> fn);
+    template <typename Tfn, typename ... Args>
+    void execute(Tfn fn, Args& ... args) {
+        run_sync_on_main<2>([this, fn, &args...](){
+    #ifndef __EMSCRIPTEN__
+            if(!getCLExecContext().empty()) {
+                CLExecScope_t clExecScope(getCLExecContext());
+                FrameBufferContext::GLScope glScope(*this, GL_FRAMEBUFFER);
+                FrameBufferContext::FrameBufferScope fbScope(*this, framebuffer_);
+                fn(framebuffer_, args...);
+            } else
+    #endif
+            {
+                FrameBufferContext::GLScope glScope(*this, GL_FRAMEBUFFER);
+                FrameBufferContext::FrameBufferScope fbScope(*this, framebuffer_);
+                fn(framebuffer_, args...);
+            }
+        });
+    }
     cv::Vec2f position();
     float pixelRatioX();
     float pixelRatioY();

modules/v4d/include/opencv2/v4d/detail/glcontext.hpp

@@ -19,7 +19,7 @@ namespace detail {
 /*!
  * Used to setup a nanovg context
  */
-class GLContext {
+class CV_EXPORTS GLContext {
     FrameBufferContext& mainFbContext_;
     FrameBufferContext glFbContext_;
 public:
@@ -34,7 +34,7 @@ public:
      * @param fn A function that is passed the size of the framebuffer
      * and performs drawing using opengl
      */
-    void render(std::function<void(const cv::Size&)> fn);
+    void render(std::function<void()> fn);
 
     FrameBufferContext& fbCtx();
 };

modules/v4d/include/opencv2/v4d/detail/nanovgcontext.hpp

@@ -19,7 +19,7 @@ namespace detail {
 /*!
  * Used to setup a nanovg context
  */
-class NanoVGContext {
+class CV_EXPORTS NanoVGContext {
     FrameBufferContext& mainFbContext_;
     FrameBufferContext nvgFbContext_;
     NVGcontext* context_;
@@ -61,7 +61,7 @@ public:
      * @param fn A function that is passed the size of the framebuffer
      * and performs drawing using cv::viz::nvg
      */
-    void render(std::function<void(const cv::Size&)> fn);
+    void render(std::function<void()> fn);
 
     FrameBufferContext& fbCtx();
 private:

modules/v4d/include/opencv2/v4d/detail/timetracker.hpp

@@ -8,6 +8,7 @@
 #include <ostream>
 #include <limits>
 #include <mutex>
+#include <opencv2/core/cvdef.h>
 
 using std::ostream;
 using std::stringstream;
@@ -16,7 +17,7 @@ using std::map;
 using std::chrono::microseconds;
 using std::mutex;
 
-struct TimeInfo {
+struct CV_EXPORTS TimeInfo {
     long totalCnt_ = 0;
     long totalTime_ = 0;
     long iterCnt_ = 0;
@@ -60,7 +61,7 @@ inline std::ostream& operator<<(ostream &os, TimeInfo &ti) {
     return os;
 }
 
-class TimeTracker {
+class CV_EXPORTS TimeTracker {
 private:
     static TimeTracker *instance_;
     mutex mapMtx_;

modules/v4d/include/opencv2/v4d/util.hpp

@@ -78,14 +78,22 @@ make_function(T *t)
 static thread_local bool sync_run = false;
 template<std::size_t Tid>
 void run_sync_on_main(std::function<void()> fn) {
+    CV_Assert(fn);
+
     if(sync_run)
         throw std::runtime_error("Encountered nested run_sync_on_main");
     sync_run = true;
+
 #ifdef __EMSCRIPTEN__
-    emscripten_sync_run_in_main_runtime_thread(EM_FUNC_SIG_V, cv::v4d::detail::get_fn_ptr<Tid>(fn));
+    typedef void* function_t( void* ) ;
+    function_t* ptr_fun = fn.target<function_t>() ;
+    //Check that the function object wrapped something callable
+    CV_Assert( ptr_fun != nullptr );
+    emscripten_sync_run_in_main_runtime_thread(EM_FUNC_SIG_V, ptr_fun);
 #else
     fn();
 #endif
+
     sync_run = false;
 }
 

modules/v4d/include/opencv2/v4d/v4d.hpp

@@ -18,7 +18,11 @@
 #include "detail/threadpool.hpp"
 #include "opencv2/v4d/detail/gl.hpp"
 #include "opencv2/v4d/detail/framebuffercontext.hpp"
+#include "opencv2/v4d/detail/nanovgcontext.hpp"
 #include "opencv2/v4d/detail/imguicontext.hpp"
+#include "opencv2/v4d/detail/timetracker.hpp"
+#include "opencv2/v4d/detail/glcontext.hpp"
+
 
 #include <iostream>
 #include <future>
@@ -26,6 +30,8 @@
 #include <map>
 #include <string>
 #include <memory>
+#include <vector>
+#include <type_traits>
 
 #include <opencv2/core.hpp>
 #include <opencv2/imgproc.hpp>
@@ -38,6 +44,7 @@ using std::string;
 
 struct GLFWwindow;
 
+
 /*!
  * OpenCV namespace
  */
@@ -57,6 +64,24 @@ enum AllocateFlags {
  * Private namespace
  */
 namespace detail {
+
+//https://stackoverflow.com/questions/19961873/test-if-a-lambda-is-stateless#:~:text=As%20per%20the%20Standard%2C%20if,lambda%20is%20stateless%20or%20not.
+template <typename T, typename U>
+struct helper : helper<T, decltype(&U::operator())>
+{};
+
+template <typename T, typename C, typename R, typename... A>
+struct helper<T, R(C::*)(A...) const>
+{
+    static const bool value = std::is_convertible<T, R(*)(A...)>::value;
+};
+
+template<typename T>
+struct is_stateless
+{
+    static const bool value = helper<T,T>::value;
+};
+
 class FrameBufferContext;
 class CLVAContext;
 class NanoVGContext;
@@ -71,8 +96,8 @@ template<typename T> std::string int_to_hex( T i )
   return stream.str();
 }
 
-template<typename T, typename... U> std::string func_id(std::function<T (U ...)> f) {
+template<typename Tfn> std::string func_id(Tfn& fn) {
-    return int_to_hex((size_t) &f);
+    return int_to_hex((size_t) &fn);
 }
 }
 
@@ -181,15 +206,24 @@ public:
      */
     CV_EXPORTS cv::ogl::Texture2D& texture();
     CV_EXPORTS std::string title();
-    CV_EXPORTS void gl(std::function<void()> fn);
+    template <typename Tfn, typename ... Args>
-    CV_EXPORTS void gl(std::function<void(const cv::Size&)> fn);
+    void gl(Tfn fn, Args&& ... args) {
-    /*!
+        TimeTracker::getInstance()->execute("gl(" + detail::func_id(fn) + ")/" + std::to_string(-1), [this, fn, &args...](){
-     * Execute function object fn inside an opengl context.
+            glCtx(-1).render([=]() {
-     * This is how all OpenGL operations should be executed.
+                fn(args...);
-     * @param fn A function object that is passed the size of the framebuffer
+            });
-     */
+        });
-    CV_EXPORTS void gl(std::function<void(const cv::Size&)> fn, const uint32_t& idx);
+    }
-    CV_EXPORTS void gl(std::function<void()> fn, const uint32_t& idx);
+
+    template <typename Tfn, typename ... Args>
+    void gl(const size_t& idx, Tfn fn, Args&& ... args) {
+        TimeTracker::getInstance()->execute("gl(" + detail::func_id(fn) + ")/" + std::to_string(-1), [this, fn, idx, &args...](){
+            glCtx(idx).render([=]() {
+                fn(args...);
+            });
+        });
+    }
+
     /*!
      * Execute function object fn inside a framebuffer context.
      * The context acquires the framebuffer from OpenGL (either by up-/download or by cl-gl sharing)
@@ -197,7 +231,13 @@ public:
      * directly on the framebuffer.
      * @param fn A function object that is passed the framebuffer to be read/manipulated.
      */
-    CV_EXPORTS void fb(std::function<void(cv::UMat&)> fn);
+    template <typename Tfn, typename ... Args>
+    void fb(Tfn fn, Args& ... args) {
+        CV_Assert(detail::is_stateless<decltype(fn)>::value);
+        TimeTracker::getInstance()->execute("fb(" + detail::func_id(fn) + ")", [this, fn, &args...]{
+            fbCtx().execute(fn, args...);
+        });
+    }
     /*!
      * Execute function object fn inside a nanovg context.
      * The context takes care of setting up opengl and nanovg states.
@@ -205,8 +245,15 @@ public:
      * @param fn A function that is passed the size of the framebuffer
      * and performs drawing using cv::viz::nvg
      */
-    CV_EXPORTS void nvg(std::function<void(const cv::Size&)> fn);
+    template <typename Tfn, typename ... Args>
-    CV_EXPORTS void nvg(std::function<void()> fn);
+    void nvg(Tfn fn, Args&& ... args) {
+        TimeTracker::getInstance()->execute("nvg(" + detail::func_id(fn) + ")", [this, fn, &args...](){
+            nvgCtx().render([this, fn, &args...]() {
+                fn(args...);
+            });
+        });
+    }
+
     CV_EXPORTS void imgui(std::function<void(ImGuiContext* ctx)> fn);
 
     /*!
@@ -316,7 +363,7 @@ public:
      * Get the current size of the window.
      * @return The window size.
      */
-    CV_EXPORTS cv::Size framebufferSize();
+    CV_EXPORTS cv::Size fbSize();
     /*!
      * Set the window size
      * @param sz The future size of the window.

modules/v4d/samples/beauty-demo.cpp

@@ -249,25 +249,25 @@ static bool iteration(cv::Ptr<V4D> window) {
         if (!faceRect.empty() && facemark->fit(down, faceRects, shapes)) {
             FaceFeatures features(faceRect, shapes[0], float(down.size().width) / WIDTH);
 
-            window->nvg([&features]() {
+            window->nvg([](FaceFeatures& f) {
                 //Draw the face oval of the first face
-                draw_face_oval_mask(features);
+                draw_face_oval_mask(f);
-            });
+            }, features);
 
             window->fb([](cv::UMat &frameBuffer) {
                 //Convert/Copy the mask
                 cvtColor(frameBuffer, faceOval, cv::COLOR_BGRA2GRAY);
             });
 
-            window->nvg([&features]() {
+            window->nvg([](FaceFeatures& f) {
                 //Draw eyes eyes and lips areas of the first face
-                draw_face_eyes_and_lips_mask(features);
+                draw_face_eyes_and_lips_mask(f);
-            });
+            }, features);
 
-            window->fb([](cv::UMat &frameBuffer) {
+            window->fb([](cv::UMat &frameBuffer, cv::UMat& e) {
                 //Convert/Copy the mask
-                cvtColor(frameBuffer, eyesAndLipsMaskGrey, cv::COLOR_BGRA2GRAY);
+                cvtColor(frameBuffer, e, cv::COLOR_BGRA2GRAY);
-            });
+            }, eyesAndLipsMaskGrey);
 
             //Create the skin mask
             cv::subtract(faceOval, eyesAndLipsMaskGrey, faceSkinMaskGrey);
@@ -316,9 +316,9 @@ static bool iteration(cv::Ptr<V4D> window) {
         }
 
         //write the result to the framebuffer
-        window->fb([](cv::UMat &frameBuffer) {
+        window->fb([](cv::UMat &frameBuffer, cv::UMat& f) {
-            cvtColor(frameOut, frameBuffer, cv::COLOR_BGR2BGRA);
+            cvtColor(f, frameBuffer, cv::COLOR_BGR2BGRA);
-        });
+        }, frameOut);
 
         window->write();
 

modules/v4d/samples/cube-demo.cpp

@@ -224,7 +224,7 @@ static void glow_effect(const cv::UMat& src, cv::UMat& dst, const int ksize) {
 
 using namespace cv::v4d;
 static bool iteration(cv::Ptr<V4D> window) {
-    window->once([=](){ window->gl(init_scene);});
+    window->once([=](){ window->gl(init_scene, window->fbSize());});
 
     //Render using OpenGL
     window->gl(render_scene);

modules/v4d/samples/custom_source_and_sink.cpp

@@ -44,15 +44,15 @@ int main() {
 			return false;
 
 		//Render "Hello Rainbow!" over the video
-		win->nvg([hr](const Size& sz) {
+		win->nvg([](const Size& sz, const string& str) {
 			using namespace cv::v4d::nvg;
 
 			fontSize(40.0f);
 			fontFace("sans-bold");
 			fillColor(Scalar(255, 0, 0, 255));
 			textAlign(NVG_ALIGN_CENTER | NVG_ALIGN_TOP);
-			text(sz.width / 2.0, sz.height / 2.0, hr.c_str(), hr.c_str() + hr.size());
+			text(sz.width / 2.0, sz.height / 2.0, str.c_str(), str.c_str() + str.size());
-		});
+		}, win->fbSize(), hr);
 
 		win->write();
 

modules/v4d/samples/display_image_fb.cpp

@@ -17,16 +17,16 @@ int main() {
     //We have to manually resize and color convert the image when using direct frambuffer access.
     UMat resized;
     UMat converted;
-    resize(image, resized, window->framebufferSize());
+    resize(image, resized, window->fbSize());
     cvtColor(resized, converted, COLOR_RGB2BGRA);
 
     window->run([converted](Ptr<V4D> win){
 		//Create a fb context and copy the prepared image to the framebuffer. The fb context
 		//takes care of retrieving and storing the data on the graphics card (using CL-GL
 		//interop if available), ready for other contexts to use
-		win->fb([&](UMat& framebuffer){
+		win->fb([](UMat& framebuffer, const cv::UMat& c){
-	        converted.copyTo(framebuffer);
+	        c.copyTo(framebuffer);
-	    });
+	    }, converted);
 		return win->display();
 	});
 }

modules/v4d/samples/display_image_nvg.cpp

@@ -26,33 +26,33 @@ int main() {
 	    //Execute only once
 	    win->once([win, &image]() {
 	        //Creates a NanoVG context. The wrapped C-functions of NanoVG are available in the namespace cv::v4d::nvg;
-	        win->nvg([&image](const cv::Size sz) {
+	        win->nvg([](Image_t& img) {
 	            using namespace cv::v4d::nvg;
 	            //Create the image and receive a handle.
-	            int handle = createImage(image.filename_.c_str(), NVG_IMAGE_NEAREST);
+	            int handle = createImage(img.filename_.c_str(), NVG_IMAGE_NEAREST);
 	            //Make sure it was created successfully
 	            CV_Assert(handle > 0);
 	            //Query the image size
-	            imageSize(handle, &image.w_, &image.h_);
+	            imageSize(handle, &img.w_, &img.h_);
 	            //Create a simple image pattern with the image dimensions
-	            image.paint_ = imagePattern(0, 0, image.w_, image.h_, 0.0f/180.0f*NVG_PI, handle, 1.0);
+	            img.paint_ = imagePattern(0, 0, img.w_, img.h_, 0.0f/180.0f*NVG_PI, handle, 1.0);
-	        });
+	        }, image);
 	    });
 
 	    //Creates a NanoVG context to draw the loaded image over again to the screen.
-	    win->nvg([&image](const cv::Size sz) {
+	    win->nvg([](const Image_t& img, const cv::Size& sz) {
 	        using namespace cv::v4d::nvg;
 	        beginPath();
 	        //Scale all further calls to window size
-	        scale(double(sz.width)/image.w_, double(sz.height)/image.h_);
+	        scale(double(sz.width)/img.w_, double(sz.height)/img.h_);
 	        //Create a rounded rectangle with the images dimensions.
 	        //Note that actually this rectangle will have the size of the window
 	        //because of the previous scale call.
-	        roundedRect(0,0, image.w_, image.h_, 50);
+	        roundedRect(0,0, img.w_, img.h_, 50);
 	        //Fill the rounded rectangle with our picture
-	        fillPaint(image.paint_);
+	        fillPaint(img.paint_);
 	        fill();
-	    });
+	    }, image, win->fbSize());
 	    //Displays the framebuffer in the window. Returns false if the windows has been closed.
 	    return win->display();
     });

modules/v4d/samples/font-demo.cpp

@@ -110,11 +110,11 @@ static bool iteration(cv::Ptr<V4D> window) {
                 circle(rng.uniform(0, sz.width) , rng.uniform(0, sz.height), size / 2.0);
                 stroke();
             }
-        });
+        }, window->fbSize());
 
-        window->fb([](cv::UMat& frameBuffer){
+        window->fb([](cv::UMat& frameBuffer, cv::UMat& f){
-            frameBuffer.copyTo(stars);
+            frameBuffer.copyTo(f);
-        });
+        }, stars);
         update_stars = false;
     }
 
@@ -129,7 +129,7 @@ static bool iteration(cv::Ptr<V4D> window) {
         update_perspective = false;
     }
 
-    window->nvg([translateY](const cv::Size& sz) {
+    window->nvg([](const cv::Size& sz, const int32_t& ty) {
         using namespace cv::v4d::nvg;
         clear();
         fontSize(font_size);
@@ -138,22 +138,22 @@ static bool iteration(cv::Ptr<V4D> window) {
         textAlign(NVG_ALIGN_CENTER | NVG_ALIGN_TOP);
 
         /** only draw lines that are visible **/
-        translate(0, translateY);
+        translate(0, ty);
 
         for (size_t i = 0; i < lines.size(); ++i) {
             y = (i * font_size);
-            if (y + translateY < textHeight && y + translateY + font_size > 0) {
+            if (y + ty < textHeight && y + ty + font_size > 0) {
                 text(sz.width / 2.0, y, lines[i].c_str(), lines[i].c_str() + lines[i].size());
             }
         }
-    });
+    }, window->fbSize(), translateY);
 
-    window->fb([](cv::UMat& framebuffer) {
+    window->fb([](cv::UMat& framebuffer, cv::UMat& w, cv::UMat& s, cv::Mat& t) {
         //Pseudo 3D text effect.
-        cv::warpPerspective(framebuffer, warped, tm, framebuffer.size(), cv::INTER_LINEAR, cv::BORDER_CONSTANT, cv::Scalar());
+        cv::warpPerspective(framebuffer, w, t, framebuffer.size(), cv::INTER_LINEAR, cv::BORDER_CONSTANT, cv::Scalar());
         //Combine layers
-        cv::add(stars, warped, framebuffer);
+        cv::add(s, w, framebuffer);
-    });
+    }, warped, stars, tm);
 
     if(-translateY > textHeight) {
         //reset the scroll once the text is out of the picture

modules/v4d/samples/font_rendering.cpp

@@ -11,15 +11,15 @@ int main() {
 
     window->run([hw](Ptr<V4D> win){
         //Render the text at the center of the screen. Note that you can load you own fonts.
-        win->nvg([hw](const Size& sz) {
+        win->nvg([](const Size& sz, const string& str) {
             using namespace cv::v4d::nvg;
             clear();
             fontSize(40.0f);
             fontFace("sans-bold");
             fillColor(Scalar(255, 0, 0, 255));
             textAlign(NVG_ALIGN_CENTER | NVG_ALIGN_TOP);
-            text(sz.width / 2.0, sz.height / 2.0, hw.c_str(), hw.c_str() + hw.size());
+            text(sz.width / 2.0, sz.height / 2.0, str.c_str(), str.c_str() + str.size());
-        });
+        }, win->fbSize(), hw);
 
 		return win->display();
 	});

modules/v4d/samples/font_with_gui.cpp

@@ -24,15 +24,15 @@ int main() {
 
 	window->run([&](Ptr<V4D> win) {
 		//Render the text at the center of the screen using parameters from the GUI.
-		win->nvg([&](const Size& sz) {
+		win->nvg([](const Size& sz, const string& str, float s, float c[3]) {
 			using namespace cv::v4d::nvg;
 			clear();
-			fontSize(size);
+			fontSize(s);
 			fontFace("sans-bold");
-			fillColor(Scalar(color[2] * 255, color[1] * 255, color[0] * 255, 255));
+			fillColor(Scalar(c[2] * 255, c[1] * 255, c[0] * 255, 255));
 			textAlign(NVG_ALIGN_CENTER | NVG_ALIGN_TOP);
-			text(sz.width / 2.0, sz.height / 2.0, hw.c_str(), hw.c_str() + hw.size());
+			text(sz.width / 2.0, sz.height / 2.0, str.c_str(), str.c_str() + str.size());
-		});
+		}, win->fbSize(), hw, size, color);
 
 		return win->display();
 	});

modules/v4d/samples/many_cubes-demo.cpp

@@ -230,7 +230,7 @@ using namespace cv::v4d;
 static bool iteration(cv::Ptr<V4D> window) {
     window->once([=](){
         for(size_t i = 0; i < NUMBER_OF_CUBES; ++i)
-            window->gl([=](const cv::Size sz){ init_scene(sz, i); }, i);
+            window->gl(i, [](const cv::Size& sz, const size_t& idx){ init_scene(sz, idx); }, window->fbSize(), i);
     });
 
     window->gl([](){
@@ -241,10 +241,10 @@ static bool iteration(cv::Ptr<V4D> window) {
 
     //Render using multiple OpenGL contexts
     for(size_t i = 0; i < NUMBER_OF_CUBES; ++i) {
-        window->gl([i](){
+        window->gl(i, [](const size_t idx){
-            double pos = (((double(i) / NUMBER_OF_CUBES) * 2.0) - 1) + (1.0 / NUMBER_OF_CUBES);
+            double pos = (((double(idx) / NUMBER_OF_CUBES) * 2.0) - 1) + (1.0 / NUMBER_OF_CUBES);
-            double angle = sin((double(i) / NUMBER_OF_CUBES) * 2 * M_PI);
+            double angle = sin((double(idx) / NUMBER_OF_CUBES) * 2 * M_PI);
-            render_scene(pos, pos, angle, i);
+            render_scene(pos, pos, angle, idx);
         }, i);
     }
     //To slow for WASM

modules/v4d/samples/nanovg-demo.cpp

@@ -164,9 +164,9 @@ static bool iteration(cv::Ptr<V4D> window) {
     });
 
     //Render using nanovg
-    window->nvg([hue](const cv::Size &sz) {
+    window->nvg([](const cv::Size &sz, const double& h) {
-        draw_color_wheel(sz.width - 300, sz.height - 300, 250.0f, 250.0f, hue);
+        draw_color_wheel(sz.width - 300, sz.height - 300, 250.0f, 250.0f, h);
-    });
+    }, window->fbSize(), hue);
 
     window->write();
 

modules/v4d/samples/optflow-demo.cpp

@@ -406,7 +406,7 @@ static bool iteration(cv::Ptr<V4D> window) {
     if(!window->capture())
         return false;
 
-    static thread_local cv::Size fbSz = window->framebufferSize();
+    static thread_local cv::Size fbSz = window->fbSize();
     //BGRA
     static thread_local cv::UMat background, down;
     static thread_local cv::UMat foreground(fbSz, CV_8UC4, cv::Scalar::all(0));

modules/v4d/samples/pedestrian-demo.cpp

@@ -212,12 +212,12 @@ static bool iteration(cv::Ptr<V4D> window) {
         float cy = tracked.y * HEIGHT_SCALE + (height / 2.0f);
         ellipse(cx, cy, width / 2.0f, height / 2.0f);
         stroke();
-    });
+    }, window->fbSize());
 
     //Put it all together
-    window->fb([](cv::UMat& frameBuffer){
+    window->fb([](cv::UMat& frameBuffer, cv::UMat& bg){
-        composite_layers(background, frameBuffer, frameBuffer, BLUR_KERNEL_SIZE);
+        composite_layers(bg, frameBuffer, frameBuffer, BLUR_KERNEL_SIZE);
-    });
+    }, background);
 
     window->write();
 

modules/v4d/samples/shader-demo.cpp

@@ -268,12 +268,12 @@ static void setup_gui(cv::Ptr<V4D> window) {
 }
 
 static bool iteration(cv::Ptr<V4D> window) {
-    window->once([=](){ window->gl(init_scene);});
+    window->once([=](){ window->gl(init_scene, window->fbSize());});
 
     if(!window->capture())
         return false;
 
-    window->gl(render_scene);
+    window->gl(render_scene, window->fbSize());
 
 #ifndef __EMSCRIPTEN__
     window->fb([](cv::UMat& frameBuffer) {

modules/v4d/samples/vector_graphics.cpp

@@ -91,7 +91,7 @@ int main() {
             ellipse(rx, ry, ex, ey);
             fillPaint(gloss);
             fill();
-        });
+        }, win->fbSize());
 
         return win->display();
     });

modules/v4d/samples/vector_graphics_and_fb.cpp

@@ -90,7 +90,7 @@ int main() {
             ellipse(rx, ry, ex, ey);
             fillPaint(gloss);
             fill();
-        });
+        }, win->fbSize());
 
         //Provides the framebuffer as left-off by the nvg context.
         win->fb([](UMat& framebuffer) {

modules/v4d/samples/video_editing.cpp

@@ -34,15 +34,15 @@ int main(int argc, char** argv) {
 			return false; //end of input video
 
 		//Render on top of the video
-		win->nvg([hv](const Size& sz) {
+		win->nvg([](const Size& sz, const string& str) {
 			using namespace cv::v4d::nvg;
 
 			fontSize(40.0f);
 			fontFace("sans-bold");
 			fillColor(Scalar(255, 0, 0, 255));
 			textAlign(NVG_ALIGN_CENTER | NVG_ALIGN_TOP);
-			text(sz.width / 2.0, sz.height / 2.0, hv.c_str(), hv.c_str() + hv.size());
+			text(sz.width / 2.0, sz.height / 2.0, str.c_str(), str.c_str() + str.size());
-		});
+		}, win->fbSize(), hv);
 
 		//Write video to the sink (do nothing in case of WebAssembly)
 		win->write();

modules/v4d/src/detail/framebuffercontext.cpp

@@ -5,8 +5,6 @@
 #include "opencv2/v4d/v4d.hpp"
 #include "opencv2/v4d/detail/framebuffercontext.hpp"
 #include "opencv2/v4d/util.hpp"
-#include "glcontext.hpp"
-#include "nanovgcontext.hpp"
 #include "opencv2/core/ocl.hpp"
 #include "opencv2/core/opengl.hpp"
 #include <exception>
@@ -631,24 +629,6 @@ void FrameBufferContext::copyFrom(const cv::UMat& src) {
     });
 }
 
-void FrameBufferContext::execute(std::function<void(cv::UMat&)> fn) {
-    run_sync_on_main<2>([&,this](){
-#ifndef __EMSCRIPTEN__
-        if(!getCLExecContext().empty()) {
-            CLExecScope_t clExecScope(getCLExecContext());
-            FrameBufferContext::GLScope glScope(*this, GL_FRAMEBUFFER);
-            FrameBufferContext::FrameBufferScope fbScope(*this, framebuffer_);
-            fn(framebuffer_);
-        } else
-#endif
-        {
-            FrameBufferContext::GLScope glScope(*this, GL_FRAMEBUFFER);
-            FrameBufferContext::FrameBufferScope fbScope(*this, framebuffer_);
-            fn(framebuffer_);
-        }
-    });
-}
-
 cv::ogl::Texture2D& FrameBufferContext::getTexture2D() {
     return *texture_;
 }

modules/v4d/src/detail/glcontext.cpp

@@ -3,7 +3,7 @@
 // of this distribution and at http://opencv.org/license.html.
 // Copyright Amir Hassan (kallaballa) <amir@viel-zu.org>
 
-#include "glcontext.hpp"
+#include "opencv2/v4d/detail/glcontext.hpp"
 #include "opencv2/v4d/detail/gl.hpp"
 
 namespace cv {
@@ -18,8 +18,8 @@ GLContext::GLContext(FrameBufferContext& fbContext) :
 #endif
 }
 
-void GLContext::render(std::function<void(const cv::Size&)> fn) {
+void GLContext::render(std::function<void()> fn) {
-    run_sync_on_main<15>([&,this](){
+    run_sync_on_main<15>([this, fn](){
 #ifndef __EMSCRIPTEN__
         if(!fbCtx().isShared()) {
             UMat tmp;
@@ -38,7 +38,7 @@ void GLContext::render(std::function<void(const cv::Size&)> fn) {
             GL_CHECK(glClear(GL_COLOR_BUFFER_BIT));
             GL_CHECK(glClearColor(cColor[0], cColor[1], cColor[2], cColor[3]));
 #endif
-            fn(fbCtx().size());
+            fn();
         }
         if(!fbCtx().isShared()) {
 #ifdef __EMSCRIPTEN__

modules/v4d/src/detail/nanovgcontext.cpp

@@ -3,7 +3,7 @@
 // of this distribution and at http://opencv.org/license.html.
 // Copyright Amir Hassan (kallaballa) <amir@viel-zu.org>
 
-#include "nanovgcontext.hpp"
+#include "opencv2/v4d/detail/nanovgcontext.hpp"
 #include "opencv2/v4d/nvg.hpp"
 #include "opencv2/v4d/detail/gl.hpp"
 #include "nanovg_gl.h"
@@ -41,7 +41,7 @@ NanoVGContext::NanoVGContext(FrameBufferContext& fbContext) :
     });
 }
 
-void NanoVGContext::render(std::function<void(const cv::Size&)> fn) {
+void NanoVGContext::render(std::function<void()> fn) {
     run_sync_on_main<14>([this, fn]() {
 #ifndef __EMSCRIPTEN__
         if (!fbCtx().isShared()) {
@@ -59,7 +59,7 @@ void NanoVGContext::render(std::function<void(const cv::Size&)> fn) {
 #endif
             NanoVGContext::Scope nvgScope(*this);
             cv::v4d::nvg::detail::NVG::initializeContext(context_);
-            fn(fbCtx().size());
+            fn();
         }
         if (!fbCtx().isShared()) {
 #ifdef __EMSCRIPTEN__

modules/v4d/src/detail/timetracker.cpp

@@ -5,7 +5,7 @@
  *      Author: elchaschab
  */
 
-#include "timetracker.hpp"
+#include "opencv2/v4d/detail/timetracker.hpp"
 
 TimeTracker* TimeTracker::instance_;
 

modules/v4d/src/v4d.cpp

@@ -6,11 +6,10 @@
 #include "opencv2/v4d/v4d.hpp"
 #include "opencv2/v4d/detail/framebuffercontext.hpp"
 #include "detail/clvacontext.hpp"
-#include "detail/nanovgcontext.hpp"
-#include "detail/glcontext.hpp"
-#include "detail/timetracker.hpp"
 #include <sstream>
 #include <algorithm>
+#include <opencv2/core.hpp>
+#include <vector>
 
 namespace cv {
 namespace v4d {
@@ -156,59 +155,6 @@ size_t V4D::numGlCtx() {
     return std::max(off_t(0), off_t(glContexts_.size()) - 1);
 }
 
-void V4D::gl(std::function<void()> fn) {
-    TimeTracker::getInstance()->execute("gl(" + detail::func_id(fn) + ")/" + std::to_string(-1), [this, fn](){
-        glCtx(-1).render([=](const cv::Size& sz) {
-            CV_UNUSED(sz);
-            fn();
-        });
-    });
-}
-
-
-void V4D::gl(std::function<void(const cv::Size&)> fn) {
-    TimeTracker::getInstance()->execute("gl(" + detail::func_id(fn) + ")/" + std::to_string(-1), [this, fn](){
-        glCtx(-1).render(fn);
-    });
-}
-
-void V4D::gl(std::function<void()> fn, const uint32_t& idx) {
-    TimeTracker::getInstance()->execute("gl(" + detail::func_id(fn) + ")/" + std::to_string(idx), [this, fn, idx](){
-        glCtx(idx).render([=](const cv::Size& sz) {
-            CV_UNUSED(sz);
-            fn();
-        });
-    });
-}
-
-
-void V4D::gl(std::function<void(const cv::Size&)> fn, const uint32_t& idx) {
-    TimeTracker::getInstance()->execute("gl(" + detail::func_id(fn) + ")/" + std::to_string(idx), [this, fn, idx](){
-        glCtx(idx).render(fn);
-    });
-}
-
-
-void V4D::fb(std::function<void(cv::UMat&)> fn) {
-    TimeTracker::getInstance()->execute("fb(" + detail::func_id(fn) + ")", [this, fn](){
-        fbCtx().execute(fn);
-    });
-}
-
-void V4D::nvg(std::function<void()> fn) {
-    TimeTracker::getInstance()->execute("nvg(" + detail::func_id(fn) + ")", [this, fn](){
-        nvgCtx().render([fn](const cv::Size& sz) {
-            CV_UNUSED(sz);
-            fn();
-        });
-    });
-}
-
-void V4D::nvg(std::function<void(const cv::Size&)> fn) {
-    TimeTracker::getInstance()->execute("nvg(" + detail::func_id(fn) + ")", [this, fn](){
-        nvgCtx().render(fn);
-    });
-}
 
 void V4D::imgui(std::function<void(ImGuiContext* ctx)> fn) {
     TimeTracker::getInstance()->execute("imgui(" + detail::func_id(fn) + ")", [this, fn](){
@@ -355,18 +301,19 @@ void V4D::feed(cv::InputArray in) {
             in.copyTo(videoFrame);
         }, frame);
 
-        fb([&frame](cv::UMat& framebuffer){
+        //V4DAndFbAndArgsInFunctor<cv::UMat&> fn();
-            frame.copyTo(framebuffer);
+        fb([](cv::UMat& fb, cv::UMat& f) {
-        });
+            f.copyTo(fb);
+        }, frame);
     });
 }
 
 cv::_InputArray V4D::fetch() {
     cv::UMat frame;
     TimeTracker::getInstance()->execute("copyTo", [this, &frame](){
-        fb([frame](cv::UMat& framebuffer){
+        fb([](cv::UMat& fb, cv::UMat& f) {
-            framebuffer.copyTo(frame);
+            fb.copyTo(f);
-        });
+        }, frame);
     });
     return frame;
 }
@@ -426,9 +373,9 @@ bool V4D::capture(std::function<void(cv::UMat&)> fn) {
                 return v->clvaCtx().capture(func, frame);
             }, this, fn, nextReaderFrame_);
 
-        fb([this](cv::UMat& frameBuffer){
+        fb([](cv::UMat& fb, cv::UMat& f){
-            currentReaderFrame_.copyTo(frameBuffer);
+            f.copyTo(fb);
-        });
+        }, this->currentReaderFrame_);
     });
     return res;
 }
@@ -465,9 +412,9 @@ void V4D::write(std::function<void(const cv::UMat&)> fn) {
         if (futureWriter_.valid())
             futureWriter_.get();
 
-        fb([this](cv::UMat& frameBuffer){
+        fb([](cv::UMat& fb, cv::UMat& f){
-            frameBuffer.copyTo(currentWriterFrame_);
+            fb.copyTo(f);
-        });
+        }, currentWriterFrame_);
 
         futureWriter_ = thread_pool_.enqueue([](V4D* v, std::function<void(const UMat&)> func, cv::UMat& frame) {
             v->clvaCtx().write(func, frame);
@@ -495,7 +442,7 @@ float V4D::pixelRatioY() {
     return fbCtx().pixelRatioY();
 }
 
-cv::Size V4D::framebufferSize() {
+cv::Size V4D::fbSize() {
     return fbCtx().size();
 }