Fix issue with fixed framerate in nanogui

testbed/nanogui/src/common.cpp

@@ -55,7 +55,7 @@ void mainloop() {
        view roughly every 50 ms; this is to support animations
        such as progress bars while keeping the system load
        reasonably low */
-    std::thread refresh_thread = std::thread(
+    /*std::thread refresh_thread = std::thread(
         [&]() {
             std::chrono::milliseconds time(50);
             while (__mainloop_active) {
@@ -63,7 +63,7 @@ void mainloop() {
                 glfwPostEmptyEvent();
             }
         }
-    );
+    );*/
 
     try {
         while (__mainloop_active) {
@@ -87,14 +87,15 @@ void mainloop() {
             }
 
             /* Wait for mouse/keyboard or empty refresh events */
-            glfwWaitEvents();
+            //glfwWaitEvents();
+            glfwPollEvents();
         }
     } catch (const std::exception &e) {
         std::cerr << "Caught exception in main loop: " << e.what() << std::endl;
         abort();
     }
 
-    refresh_thread.join();
+    //refresh_thread.join();
 }
 
 void leave() {

testbed/src/Gui.cpp

@@ -64,14 +64,6 @@ void Gui::init() {
 
     mApp->setVisible(true);
     mApp->performLayout();
-    //window->center();
-
-
-    // Init UI
-    /*if (!imguiRenderGLInit("DroidSans.ttf")) {
-        fprintf(stderr, "Could not init GUI renderer.\n");
-        exit(EXIT_FAILURE);
-    }*/
 
     mTimeSinceLastProfilingDisplay = glfwGetTime();
 }
@@ -91,11 +83,10 @@ void Gui::update() {
     mFPSLabel->setCaption(std::string("FPS : ") + floatToString(mCachedFPS, 0));
 
     // Frame time
-    mFrameTimeLabel->setCaption(std::string("Frame time (ms) : ") + floatToString(mCachedUpdateTime * 1000.0, 1));
+    mFrameTimeLabel->setCaption(std::string("Frame time : ") + floatToString(mCachedUpdateTime * 1000.0, 1) + std::string(" ms"));
 
     // Physics time
-    mPhysicsTimeLabel->setCaption("Physics time (ms) : " + floatToString(mCachedPhysicsUpdateTime * 1000.0, 1));
-
+    mPhysicsTimeLabel->setCaption(std::string("Physics time : ") + floatToString(mCachedPhysicsUpdateTime * 1000.0, 1) + std::string(" ms"));
 }
 
 void Gui::createSimulationPanel() {
@@ -426,10 +417,10 @@ void Gui::createProfilingPanel() {
     mFPSLabel = new Label(profilingPanel, std::string("FPS : ") + floatToString(mCachedFPS, 0),"sans-bold");
 
     // Update time
-    mFrameTimeLabel = new Label(profilingPanel, std::string("Frame time (ms) : ") + floatToString(mCachedUpdateTime * 1000.0, 1),"sans-bold");
+    mFrameTimeLabel = new Label(profilingPanel, std::string("Frame time : ") + floatToString(mCachedUpdateTime * 1000.0, 1) + std::string(" ms"),"sans-bold");
 
     // Update time
-    mPhysicsTimeLabel = new Label(profilingPanel, "Physics time (ms) : " + floatToString(mCachedPhysicsUpdateTime * 1000.0, 1),"sans-bold");
+    mPhysicsTimeLabel = new Label(profilingPanel, std::string("Physics time : ") + floatToString(mCachedPhysicsUpdateTime * 1000.0, 1) + std::string(" ms"),"sans-bold");
 
     profilingPanel->setVisible(true);
 }

testbed/src/TestbedApplication.cpp

@@ -213,11 +213,12 @@ void TestbedApplication::drawContents() {
     // Render the scene
     mCurrentScene->render();
 
-    mGui.update();
-
     // Check the OpenGL errors
     checkOpenGLErrors();
 
+
+    mGui.update();
+
     // Compute the current framerate
     computeFPS();
 }
@@ -291,6 +292,12 @@ void TestbedApplication::checkOpenGLErrorsInternal(const char* file, int line) {
 // Compute the FPS
 void TestbedApplication::computeFPS() {
 
+    // Note : By default the nanogui library is using glfwWaitEvents() to process
+    //        events and sleep to target a framerate of 50 ms (using a thread
+    //        sleeping). However, for games we prefer to use glfwPollEvents()
+    //        instead and remove the update. Therefore the file common.cpp of the
+    //        nanogui library has been modified to have a faster framerate
+
     mNbFrames++;
 
     //  Get the number of seconds since start
@@ -386,6 +393,16 @@ bool TestbedApplication::scrollEvent(const Vector2i &p, const Vector2f &rel) {
     return mCurrentScene->scrollingEvent(rel[0], rel[1], SCROLL_SENSITIVITY);
 }
 
+void TestbedApplication::drawAll() {
+    glClearColor(mBackground[0], mBackground[1], mBackground[2], 1.0f);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+
+    drawContents();
+    drawWidgets();
+
+    glfwSwapBuffers(mGLFWWindow);
+}
+
 // Callback method to receive scrolling events
 void TestbedApplication::scroll(GLFWwindow* window, double xAxis, double yAxis) {
 

testbed/src/TestbedApplication.h

@@ -190,6 +190,7 @@ class TestbedApplication : public Screen {
         /// Destructor
         virtual ~TestbedApplication();
 
+        virtual void drawAll();
         virtual void drawContents();
 
         /// Window resize event handler
@@ -275,13 +276,13 @@ inline void TestbedApplication::displayContactPoints(bool display) {
 
 // Enable/Disable Vertical synchronization
 inline void TestbedApplication::enableVSync(bool enable) {
-    /*mIsVSyncEnabled = enable;
+    mIsVSyncEnabled = enable;
     if (mIsVSyncEnabled) {
         glfwSwapInterval(1);
     }
     else {
         glfwSwapInterval(0);
-    }*/
+    }
 }
 
 #endif