# HG changeset patch
# User MJP
# Date 1392302191 -3600
#      Thu Feb 13 15:36:31 2014 +0100
# Node ID 51b04aaa85e08c2b656c5ee63306587d03db06e6
# Parent  32b2308512d03fc964bcb3b894c13c5a27cb4307
Update linkgraph only if needed

diff -r 32b2308512d0 -r 51b04aaa85e0 src/main_gui.cpp
--- a/src/main_gui.cpp	Tue Feb 11 21:17:43 2014 +0000
+++ b/src/main_gui.cpp	Thu Feb 13 15:36:31 2014 +0100
@@ -254,8 +254,10 @@
 	virtual void OnTick()
 	{
 		if (--refresh == 0) {
-			this->viewport->overlay->RebuildCache();
-			this->GetWidget<NWidgetBase>(WID_M_VIEWPORT)->SetDirty(this);
+			if (this->viewport->overlay->GetCargoMask()) {
+				this->viewport->overlay->RebuildCache();
+				this->GetWidget<NWidgetBase>(WID_M_VIEWPORT)->SetDirty(this);
+			}
 			this->refresh = LINKGRAPH_REFRESH_PERIOD;
 		}
 	}
diff -r 32b2308512d0 -r 51b04aaa85e0 src/viewport.cpp
--- a/src/viewport.cpp	Tue Feb 11 21:17:43 2014 +0000
+++ b/src/viewport.cpp	Thu Feb 13 15:36:31 2014 +0100
@@ -1477,13 +1477,14 @@
 	dp.height = UnScaleByZoom(dp.height, zoom);
 	_cur_dpi = &dp;
 
-	/* translate to window coordinates */
-	dp.left = x;
-	dp.top = y;
-
-	if (vp->overlay != NULL) vp->overlay->Draw(&dp);
-
-	/* translate back to world coordinates */
+	if (vp->overlay != NULL && vp->overlay->GetCargoMask() != 0) {
+		/* Translate to window coordinates. */
+		dp.left = x;
+		dp.top = y;
+		vp->overlay->Draw(&dp);
+	}
+
+	/* Translate back to world coordinates. */
 	dp.left = UnScaleByZoom(_vd.dpi.left, zoom);
 	dp.top = UnScaleByZoom(_vd.dpi.top, zoom);