don't call endFrame() unless beginFrame() was called

only use condition_variable on non-emscripten builds

thermion_dart/native/include/Log.hpp

@@ -32,7 +32,7 @@ static void Log(const char *fmt, ...) {
 #endif   
     va_end(args);
 }
-#endif
+#endif // ifdef __EMSCRIPTEN__
 
 #if defined(_WIN32) || defined(_WIN64)
 #define __FILENAME__ (strrchr(__FILE__, '\\') ? strrchr(__FILE__, '\\') + 1 : __FILE__)

thermion_dart/native/include/rendering/RenderThread.hpp

@@ -75,10 +75,8 @@ public:
     #endif
 
     bool mRendered = false;
-
-private:
-
     bool mRender = false;
+private:
     std::mutex _taskMutex;
     std::condition_variable _cv;
     std::deque<std::function<void()>> _tasks;
@@ -106,8 +104,9 @@ auto RenderThread::add_task(std::packaged_task<Rt()>& pt) -> std::future<Rt> {
     _tasks.push_back([pt = std::make_shared<std::packaged_task<Rt()>>(
                          std::move(pt))]
                     { (*pt)(); });
-    
+    #ifndef __EMSCRIPTEN__
     _cv.notify_one();
+    #endif
     
     
     return ret;

thermion_dart/native/src/RenderTicker.cpp

@@ -65,16 +65,19 @@ namespace thermion
   bool RenderTicker::render(uint64_t frameTimeInNanos)
   {
     auto startTime = std::chrono::high_resolution_clock::now();
-    bool rendered = false;
+    
     std::lock_guard lock(mMutex);
 
     for (auto animationManager : mAnimationManagers) {
       animationManager->update(frameTimeInNanos);
-      TRACE("Updated AnimationManager");
     }
+
+    auto durationNs = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::high_resolution_clock::now() - mLastRender).count() / 1e6f;
+    TRACE("Updated animations in %.3f ms", durationNs);
+    
+    int numRendered = 0;
     
     #ifdef ENABLE_TRACING
-    int numRendered = 0;
     TRACE("%d swapchains", mRenderable.size());
     #endif
     
@@ -87,22 +90,21 @@ namespace thermion
         bool beginFrame = mRenderer->beginFrame(swapChain, frameTimeInNanos);
         if (beginFrame)
         {
-          rendered = true;
+          numRendered++;        
-          auto durationNs = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::high_resolution_clock::now() - mLastRender).count() / 1e6f;
+          durationNs = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::high_resolution_clock::now() - mLastRender).count() / 1e6f;
           TRACE("Beginning frame (%.3f ms since last endFrame())", durationNs);
           for (auto view : views)
           {
             mRenderer->render(view);
           }
-          mLastRender = std::chrono::high_resolution_clock::now();
+          mLastRender = std::chrono::high_resolution_clock::now();          
+          mRenderer->endFrame();
         } else {
-          auto durationNs = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::high_resolution_clock::now() - mLastRender).count() / 1e6f;
+          durationNs = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::high_resolution_clock::now() - mLastRender).count() / 1e6f;
           TRACE("Skipping frame (%.3f ms since last endFrame())", durationNs);
         }
-        mRenderer->endFrame();
+
-        
     #ifdef ENABLE_TRACING
-        numRendered++;
       } else {
         TRACE("No views for swapchain");
       }
@@ -115,11 +117,11 @@ namespace thermion
     mEngine->execute();
     #endif
     auto endTime = std::chrono::high_resolution_clock::now();
-    auto durationNs = std::chrono::duration_cast<std::chrono::nanoseconds>(endTime - startTime).count();
+    durationNs = std::chrono::duration_cast<std::chrono::nanoseconds>(endTime - startTime).count();
     float durationMs = durationNs / 1e6f;
 
     TRACE("Total render() time: %.3f ms", durationMs);
-    return rendered;
+    return numRendered > 0;
   }
 
   void RenderTicker::addAnimationManager(AnimationManager* animationManager) {

thermion_dart/native/src/rendering/RenderThread.cpp

@@ -27,20 +27,23 @@ static void mainLoop(void* arg) {
     auto startTime = std::chrono::high_resolution_clock::now();
 
     auto timeSinceLastLoopStart = std::chrono::duration_cast<std::chrono::milliseconds>(startTime - loopStart).count();
-    if(timeSinceLastLoopStart > 20) {
+    // if(timeSinceLastLoopStart > 20) {
-        Log("%dms elapsed since last loop", timeSinceLastLoopStart);
+    //     Log("%dms elapsed since last loop", timeSinceLastLoopStart);
-    }
+    // }
+
     loopStart = startTime;
     rt->mRendered = false;
     long long elapsed = 0;
     int numIters = 0;
-    while (!rt->_stop && elapsed < 10) {
+    while (!rt->_stop && elapsed < 12) {
         rt->iter();
         numIters++;
         auto now = std::chrono::high_resolution_clock::now();
         elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(now - startTime).count();
     } 
-    // Log("Spent %lldms processing, %d iters", elapsed, numIters);
+    // if(!rt->mRendered) {
+    //     Log("Spent %lldms processing, %d iters, rendered %s, render requested %s, context lost %s", elapsed, numIters, rt->mRendered ? "true" : "false", rt->mRender ? "true" : "false", emscripten_is_webgl_context_lost(Thermion_getGLContext()) ? "yes" : "no");
+    // }
     if(rt->_stop) {
         Log("RenderThread stopped")
         emscripten_set_main_loop_arg(nullptr, nullptr, 0, true);
@@ -109,7 +112,9 @@ void RenderThread::requestFrame()
         TRACE("Warning - frame requested before previous frame has completed rendering");
     }
     mRender = true;
+    #ifndef __EMSCRIPTEN__
     _cv.notify_one();
+    #endif
 }
 
 void RenderThread::iter()

thermion_dart/native/web/include/ThermionWebApi.h

@@ -8,6 +8,7 @@ extern "C" {
 
 void Thermion_resizeCanvas(int width, int height);
 EMSCRIPTEN_WEBGL_CONTEXT_HANDLE Thermion_createGLContext();
+EMSCRIPTEN_WEBGL_CONTEXT_HANDLE Thermion_getGLContext();
 
 
 #ifdef __cplusplus

thermion_dart/native/web/src/cpp/ThermionWebApi.cpp

@@ -24,7 +24,13 @@ extern "C"
   EMSCRIPTEN_KEEPALIVE void Thermion_resizeCanvas(int width, int height) {
     emscripten_set_canvas_element_size("#thermion_canvas", width, height);
   }
-  
+
+  static EMSCRIPTEN_WEBGL_CONTEXT_HANDLE _context;
+
+  EMSCRIPTEN_WEBGL_CONTEXT_HANDLE EMSCRIPTEN_KEEPALIVE Thermion_getGLContext() {
+    return _context;
+  }
+
   EMSCRIPTEN_WEBGL_CONTEXT_HANDLE EMSCRIPTEN_KEEPALIVE Thermion_createGLContext() {
     
     std::cout << "Creating WebGL context." << std::endl;
@@ -43,16 +49,16 @@ extern "C"
     attr.renderViaOffscreenBackBuffer = EM_FALSE;
     attr.majorVersion = 2;
     
-    auto context = emscripten_webgl_create_context("#thermion_canvas", &attr);
+    _context = emscripten_webgl_create_context("#thermion_canvas", &attr);
 
-    if(!context) {
+    if(!_context) {
       std::cout << "Failed to create WebGL context" << std::endl;  
-      return context;
+      return _context;
     }
     
     std::cout << "Created WebGL context " << attr.majorVersion << "." << attr.minorVersion << std::endl;
 
-    auto success = emscripten_webgl_make_context_current((EMSCRIPTEN_WEBGL_CONTEXT_HANDLE)context);
+    auto success = emscripten_webgl_make_context_current(_context);
     if(success != EMSCRIPTEN_RESULT_SUCCESS) {
       std::cout << "Failed to make WebGL context current"<< std::endl;
     } else { 
@@ -65,7 +71,7 @@ extern "C"
       glClear(GL_COLOR_BUFFER_BIT);
     }
     std::cout << "Returning context" << std::endl;
-    return context;
+    return _context;
   }
 
   emscripten::val emscripten_make_uint8_buffer(int ptr, int length) {