Fix globules' sprites flickering to white and back.

libgag/include/EventListener.h

@@ -41,10 +41,11 @@ class EventListener {
 	static std::condition_variable startedCond;
 	static std::mutex doneMutex;
 	static std::condition_variable doneCond;
-	static std::mutex renderMutex;
+	static std::recursive_mutex renderMutex;
 	void setPainter(std::function<void()> f);
 	void addPainter(const std::string& name, std::function<void()> f);
 	void removePainter(const std::string& name);
+	static void ensureContext();
 	void paint();
 private:
 	std::function<void()> painter;

libgag/src/EventListener.cpp

@@ -26,21 +26,24 @@ std::mutex EventListener::startMutex;
 std::condition_variable EventListener::startedCond;
 std::mutex EventListener::doneMutex;
 std::condition_variable EventListener::doneCond;
-std::mutex EventListener::renderMutex;
+std::recursive_mutex EventListener::renderMutex;
 
 #define SIZE_MOVE_TIMER_ID 1
 #if defined(_WIN32) || defined(__MINGW32__) || defined(__MINGW64__)
 #define WINDOWS_OR_MINGW 1
 #endif
 
+// The depth variable is used to return early when indirect recursion happens
 EventListener::EventListener(GraphicContext* gfx)
 : painter(nullptr), depth(0)
 {
+	assert(gfx);
 	this->gfx = gfx;
 	el = this;
 	done = false;
 	quit = true;
 }
+
 void EventListener::stop()
 {
 	quit = true;
@@ -49,25 +52,38 @@ void EventListener::stop()
 		doneCond.wait(lock);
 	}
 }
+
 EventListener::~EventListener()
 {
 }
+
+// Create an OpenGL context or set existing context as current on this thread.
+void EventListener::ensureContext()
+{
+	instance()->gfx->createGLContext();
+}
+
+// deprecated; use addPainter/removePainter instead.
 void EventListener::setPainter(std::function<void()> f)
 {
-	std::unique_lock<std::mutex> lock(renderMutex);
+	std::unique_lock<std::recursive_mutex> lock(renderMutex);
 	painter = f;
 }
 
+/* name should be the class name that the function is called on
+ * f is the function to call to draw the screen.
+ */
 void EventListener::addPainter(const std::string& name, std::function<void()> f)
 {
-	std::unique_lock<std::mutex> lock(renderMutex);
+	std::unique_lock<std::recursive_mutex> lock(renderMutex);
 	painters.insert(std::pair<const std::string, std::function<void()> >(name, f));
 }
+// Erase the latest painter added with the name `name` from the multimap
 void EventListener::removePainter(const std::string& name)
 {
 	if (painters.empty())
 		assert("Tried to remove a painter when painters map is empty.");
-	std::unique_lock<std::mutex> lock(renderMutex);
+	std::unique_lock<std::recursive_mutex> lock(renderMutex);
 	for (std::multimap<const std::string, std::function<void()> >::reverse_iterator it = painters.rbegin(); it != painters.rend(); ++it)
 	{
 		if (it->first == name)
@@ -79,14 +95,15 @@ void EventListener::removePainter(const std::string& name)
 		}
 	}
 }
+// Draw all the registered painters in order
 void EventListener::paint()
 {
 	depth++;
 	if (depth > 1)
 		return;
 	if (painters.size())
 	{
-		std::unique_lock<std::mutex> lock(renderMutex);
+		std::unique_lock<std::recursive_mutex> lock(renderMutex);
 		gfx->createGLContext();
 		for (std::multimap<const std::string, std::function<void()> >::iterator it = painters.begin(); it != painters.end(); ++it)
 		{

libgag/src/GUIBase.cpp

@@ -530,10 +530,7 @@ namespace GAGGUI
 				dispatchEvents(&windowEvent);
 
 			// draw
-			{
-				std::unique_lock<std::mutex> lock(EventListener::instance()->renderMutex);
-				dispatchPaint();
-			}
+			dispatchPaint();
 
 			// wait timer
 			frameWaitTime=SDL_GetTicks()-frameStartTime;
@@ -680,6 +677,8 @@ namespace GAGGUI
 	void Screen::dispatchPaint(void)
 	{
 		assert(gfx);
+		std::unique_lock<std::recursive_mutex> lock(EventListener::renderMutex);
+		EventListener::ensureContext();
 		gfx->setClipRect();
 		paint();
 		for (std::set<Widget *>::iterator it=widgets.begin(); it!=widgets.end(); ++it)

libgag/src/GraphicContext.cpp

@@ -349,6 +349,8 @@ namespace GAGCore
 		#ifdef HAVE_OPENGL
 		if (_gc->optionFlags & GraphicContext::USEGPU)
 		{
+			std::unique_lock<std::recursive_mutex> lock(EventListener::renderMutex);
+			EventListener::ensureContext();
 			glState.setTexture(texture);
 
 			void *pixelsPtr;
@@ -2061,7 +2063,7 @@ namespace GAGCore
 	}
 
 	SDL_Surface* GraphicContext::getOrCreateSurface(int w, int h, Uint32 flags) {
-		std::unique_lock<std::mutex> lock(EventListener::instance()->renderMutex);
+		std::unique_lock<std::recursive_mutex> lock(EventListener::renderMutex);
 		if (flags & USEGPU)
 		{
 			if (sdlsurface)

src/Engine.cpp

@@ -507,13 +507,13 @@ int Engine::run(void)
 				if (nextGuiStep == 0)
 				{
 					// we draw
-					static bool isPainterSet = false;
-					if (!isPainterSet)
+					if (!gui.isRegistered)
 					{
+						std::unique_lock<std::recursive_mutex> lock(EventListener::renderMutex);
 						EventListener::instance()->addPainter("GameGUI", std::bind(&GameGUI::drawAll, &gui, gui.localTeamNo));
-						isPainterSet = true;
+						gui.isRegistered = true;
 					}
-					std::unique_lock<std::mutex> lock(EventListener::instance()->renderMutex);
+					std::unique_lock<std::recursive_mutex> lock(EventListener::renderMutex);
 					globalContainer->gfx->createGLContext();
 					gui.drawAll(gui.localTeamNo);
 					globalContainer->gfx->nextFrame();

src/GameGUI.cpp

@@ -184,7 +184,7 @@ GameGUI::GameGUI()
 	         128, // width
 	         128, //height
 	         Minimap::ShowFOW), // minimap mode
-
+	  isRegistered(false),
 	  ghostManager(game)
 {
 }
@@ -4385,6 +4385,8 @@ void GameGUI::drawInGameScrollableText(void)
 
 void GameGUI::drawAll(int team)
 {
+	std::unique_lock<std::recursive_mutex> lock(EventListener::renderMutex);
+	EventListener::ensureContext();
 	// draw the map
 	Uint32 drawOptions =	(drawHealthFoodBar ? Game::DRAW_HEALTH_FOOD_BAR : 0) |
 								(drawPathLines ?  Game::DRAW_PATH_LINE : 0) |

src/GameGUI.h

@@ -201,6 +201,10 @@ class GameGUI
 	bool hardPause;
 	bool isRunning;
 	bool notmenu;
+
+	// isRegistered tracks whether this instance of GameGUI has been registered with EventListener.
+	bool isRegistered;
+
 	//! true if user close the glob2 window.
 	bool exitGlobCompletely;
 	//! true if the game needs to flush all outgoing orders and exit

src/MapEdit.cpp

@@ -1210,6 +1210,8 @@ bool MapEdit::save(const std::string filename, const std::string name)
 
 void MapEdit::draw(void)
 {
+	std::unique_lock<std::recursive_mutex> lock(EventListener::renderMutex);
+	EventListener::ensureContext();
 	drawMap(0, 0, globalContainer->gfx->getW() - 0, globalContainer->gfx->getH(), true, true);
 
 	drawMenu();