API flush static cairo pattern cache

(should probably be cleaned regularly
e.g. meterbridge resize)

gtk2_ardour/ardour_ui.cc

@@ -577,6 +577,7 @@ ARDOUR_UI::~ARDOUR_UI ()
 		delete secondary_clock;
 		delete _process_thread;
 		delete gui_object_state;
+		FastMeter::flush_pattern_cache ();
 	}
 }
 

libs/gtkmm2ext/fastmeter.cc

@@ -133,6 +133,24 @@ FastMeter::~FastMeter ()
 {
 }
 
+void
+FastMeter::flush_pattern_cache () {
+	Pattern10Map::iterator i1;
+	PatternBgMap::iterator ib;
+	for (ib = hb_pattern_cache.begin(); ib !=  hb_pattern_cache.end(); ++ib) {
+		hb_pattern_cache.erase(ib);
+	}
+	for (i1 = hm_pattern_cache.begin(); i1 !=  hm_pattern_cache.end(); ++i1) {
+		hm_pattern_cache.erase(i1);
+	}
+	for (ib = vb_pattern_cache.begin(); ib !=  vb_pattern_cache.end(); ++ib) {
+		vb_pattern_cache.erase(ib);
+	}
+	for (i1 = vm_pattern_cache.begin(); i1 !=  vm_pattern_cache.end(); ++i1) {
+		vm_pattern_cache.erase(i1);
+	}
+}
+
 Cairo::RefPtr<Cairo::Pattern>
 FastMeter::generate_meter_pattern (
 		int width, int height, int *clr, float *stp, int styleflags, bool horiz)

libs/gtkmm2ext/gtkmm2ext/fastmeter.h

@@ -52,6 +52,7 @@ class LIBGTKMM2EXT_API FastMeter : public CairoWidget {
 			int styleflags = 3
 			);
 	virtual ~FastMeter ();
+	static void flush_pattern_cache();
 
 	void set (float level, float peak = -1);
 	void clear ();