Merge pull request #697 from wesnoth/flickerfix

Hacky fix for the flickering when a screen is fully redrawn.

src/display.cpp

@@ -2720,6 +2720,7 @@ void display::draw(bool update,bool force) {
 	}
 
 	if (dirty_) {
+		flip_locker flip_lock(screen_);
 		dirty_ = false;
 		redraw_everything();
 		return;

src/events.cpp

@@ -471,6 +471,7 @@ void pump()
 			}
 			case DRAW_ALL_EVENT:
 			{
+				flip_locker flip_lock(CVideo::get_singleton());
 				/* iterate backwards as the most recent things will be at the top */
 				for( std::deque<context>::iterator i = event_contexts.begin() ; i != event_contexts.end(); ++i) {
 					const std::vector<sdl_handler*>& event_handlers = (*i).handlers;

src/video.cpp

@@ -220,7 +220,8 @@ CVideo::CVideo(FAKE_TYPES type) :
 	mode_changed_(false),
 	fake_screen_(false),
 	help_string_(0),
-	updatesLocked_(0)
+	updatesLocked_(0),
+	flip_locked_(0)
 {
 	assert(!singleton_);
 	singleton_ = this;
@@ -495,7 +496,7 @@ void CVideo::delay(unsigned int milliseconds)
 
 void CVideo::flip()
 {
-	if(fake_screen_)
+	if(fake_screen_ || flip_locked_ > 0)
 		return;
 #ifdef SDL_GPU
 	assert(render_target_);
@@ -716,3 +717,11 @@ void CVideo::set_resolution(const unsigned width, const unsigned height)
 	preferences::_set_resolution(std::make_pair(width, height));
 	preferences::_set_maximized(false);
 }
+
+void CVideo::lock_flips(bool lock) {
+	if (lock) {
+		++flip_locked_;
+	} else {
+		--flip_locked_;
+	}
+}

src/video.hpp

@@ -209,6 +209,8 @@ public:
 	 */
 	std::vector<std::pair<int, int> > get_available_resolutions(const bool include_current = false);
 
+	void lock_flips(bool);
+
 private:
 	static CVideo* singleton_;
 
@@ -242,6 +244,7 @@ private:
 	int help_string_;
 
 	int updatesLocked_;
+	int flip_locked_;
 };
 
 //an object which will lock the display for the duration of its lifetime.
@@ -269,6 +272,21 @@ private:
 	bool unlock;
 };
 
+class flip_locker
+{
+public:
+	flip_locker(CVideo &video) : video_(video) {
+		video_.lock_flips(true);
+	}
+	~flip_locker() {
+		video_.lock_flips(false);
+	}
+
+private:
+	CVideo& video_;
+};
+
+
 namespace video2 {
 class draw_layering: public events::sdl_handler {
 protected: