improve caching of metric and tick patters

* selectively clear cache (meterbridge, mixer)
* free memory of patterns on clear

5 files changed, 32 insertions, 8 deletions

diff --git a/gtk2_ardour/gain_meter.cc b/gtk2_ardour/gain_meter.cc
index ae6f03f210..36ed5e918e 100644
--- a/gtk2_ardour/gain_meter.cc
+++ b/gtk2_ardour/gain_meter.cc
@@ -1086,7 +1086,7 @@ GainMeter::meter_configuration_changed (ChanCount c)
 			set_meter_strip_name ("AudioMidiTrackMetricsInactive");
 		}
 	}
-	meter_clear_pattern_cache(); // XXX only once
+	meter_clear_pattern_cache(4);
 }
 
 void
diff --git a/gtk2_ardour/meter_patterns.cc b/gtk2_ardour/meter_patterns.cc
index 9de01146b0..f749927e9a 100644
--- a/gtk2_ardour/meter_patterns.cc
+++ b/gtk2_ardour/meter_patterns.cc
@@ -485,9 +485,34 @@ gint meter_expose_metrics (GdkEventExpose *ev, std::vector<ARDOUR::DataType> typ
 	return true;
 }
 
-void meter_clear_pattern_cache() {
-	// TODO allow to clear meterbridge "*Left|Right" patterns independenly
-	metric_patterns.clear();
-	ticks_patterns.clear();
+void meter_clear_pattern_cache(int which) {
+	MetricPatterns::iterator i = metric_patterns.begin();
+	TickPatterns::iterator j = ticks_patterns.begin();
+
+	while (i != metric_patterns.end()) {
+		int m = 4;
+		std::string n = i->first;
+		if (n.substr(n.length() - 4) == "Left")  { m = 1; }
+		if (n.substr(n.length() - 5) == "Right") { m = 2; }
+		if (which & m) {
+			cairo_pattern_destroy(i->second);
+			metric_patterns.erase(i++);
+		} else {
+			++i;
+		}
+	}
+
+	while (j != ticks_patterns.end()) {
+		int m = 4;
+		std::string n = j->first;
+		if (n.substr(n.length() - 4) == "Left")  { m = 1; }
+		if (n.substr(n.length() - 5) == "Right") { m = 2; }
+		if (which & m) {
+			cairo_pattern_destroy(j->second);
+			ticks_patterns.erase(j++);
+		} else {
+			++j;
+		}
+	}
 	RedrawMetrics();
 }
diff --git a/gtk2_ardour/meter_patterns.h b/gtk2_ardour/meter_patterns.h
index df755f7ace..a664f478f2 100644
--- a/gtk2_ardour/meter_patterns.h
+++ b/gtk2_ardour/meter_patterns.h
@@ -40,7 +40,7 @@ cairo_pattern_t* meter_render_metrics (Gtk::Widget& w, std::vector<ARDOUR::DataT
 gint meter_expose_ticks (GdkEventExpose *ev, std::vector<ARDOUR::DataType> types, Gtk::DrawingArea *mta);
 gint meter_expose_metrics (GdkEventExpose *ev, std::vector<ARDOUR::DataType> types, Gtk::DrawingArea *mma);
 
-void meter_clear_pattern_cache();
+void meter_clear_pattern_cache(int which=7);
 
 #endif
 
diff --git a/gtk2_ardour/meter_strip.cc b/gtk2_ardour/meter_strip.cc
index a4cc56d61c..88a946585a 100644
--- a/gtk2_ardour/meter_strip.cc
+++ b/gtk2_ardour/meter_strip.cc
@@ -372,14 +372,12 @@ MeterStrip::meter_configuration_changed (ChanCount c)
 void
 MeterStrip::on_size_request (Gtk::Requisition* r)
 {
-	meter_clear_pattern_cache();
 	VBox::on_size_request(r);
 }
 
 void
 MeterStrip::on_size_allocate (Gtk::Allocation& a)
 {
-	meter_clear_pattern_cache();
 	const int wh = a.get_height();
 	int nh = ceilf(wh * .11f);
 	if (nh < 52) nh = 52;
diff --git a/gtk2_ardour/meterbridge.cc b/gtk2_ardour/meterbridge.cc
index 227f533a18..24b21656d1 100644
--- a/gtk2_ardour/meterbridge.cc
+++ b/gtk2_ardour/meterbridge.cc
@@ -327,6 +327,7 @@ Meterbridge::scroll_right ()
 void
 Meterbridge::on_size_request (Gtk::Requisition* r)
 {
+	meter_clear_pattern_cache(3);
 	Gtk::Window::on_size_request(r);
 
 	Gdk::Geometry geom;