gs: introspect gs state directly

pcsx2/GS/GS.h

@@ -1965,3 +1965,5 @@ struct GSErrorGlVertexArrayTooSmall : GSError
 };
 
 extern GSApp theApp;
+
+extern bool gsopen_done;

pcsx2/gui/AppMain.cpp

@@ -868,7 +868,7 @@ void Pcsx2App::OpenGsPanel()
 		gsFrame->SetSize( oldsize );
 	}
 
-	//TODO: MAKE SURE GS IS CLOSED HERE
+    pxAssertDev( !gsopen_done, "GS Plugin must be closed prior to opening a new Gs Panel!" );
 
 #ifdef __WXGTK__
 	// The x window/display are actually very deeper in the widget. You need both display and window

pcsx2/gui/FrameForGS.cpp

@@ -688,7 +688,7 @@ void GSFrame::AppStatusEvent_OnSettingsApplied()
 
 	if( g_Conf->GSWindow.CloseOnEsc )
 	{
-		if (IsShown() /*&& TODO: CHECK IS GS IS CLOSED */)
+		if (IsShown() && !gsopen_done)
 			Show( false );
 	}
 }

pcsx2/gui/GlobalCommands.cpp

@@ -400,12 +400,11 @@ namespace Implementations
 			return;
 		if (renderswitch_delay == 0)
 		{
-			/* TODO: reimplement this:
-			 * ScopedCoreThreadPause paused_core(new SysExecEvent_SaveSinglePlugin(PluginId_GS));
-			 * renderswitch = !renderswitch;
-			 * paused_core.AllowResume();
-			 * renderswitch_delay = -1;
-			 */
+			 ScopedCoreThreadPause paused_core();
+             GSfreeze();
+			 renderswitch = !renderswitch;
+			 paused_core.AllowResume();
+			 renderswitch_delay = -1;
 		}
 	}