Merge lp:~hikiko/unity/unity.panel-draw-optimisation into lp:unity

[Eleni Maria Stea]

PanelView: Don't draw it if the geo doesn't intersect the monitor geo (as in ezoom)

added check to see if the panel geometry intersects the geometry of the monitor the panel belongs to. If there's no intersection there's no need to draw it (return). If there is intersection we should only draw the intersection area (clip the non visible parts).

Optimisation in PanelView::Draw:
added check to see if the panel geometry intersects the geometry of the monitor the panel belongs to. If there's no intersection there's no need to draw it (return). If there is intersection we should only draw the intersection area (clip the non visible parts).

[Marco Trevisan (Treviño) (3v1n0)]

+1

review: Approve

=== modified file 'panel/PanelView.cpp'
--- panel/PanelView.cpp	2016-03-31 05:57:11 +0000
+++ panel/PanelView.cpp	2016-05-19 10:31:21 +0000
@@ -300,10 +300,16 @@
 PanelView::Draw(nux::GraphicsEngine& GfxContext, bool force_draw)
 {
   nux::Geometry const& geo = GetGeometry();
+  nux::Geometry const& mgeo = UScreen::GetDefault()->GetMonitorGeometry(monitor_);
+  nux::Geometry isect = mgeo.Intersect(geo);
+
+  if(!isect.width || !isect.height)
+      return;
+
   UpdateBackground();
 
   bool overlay_mode = InOverlayMode();
-  GfxContext.PushClippingRectangle(geo);
+  GfxContext.PushClippingRectangle(isect);
 
   if (IsTransparent())
   {
@@ -331,7 +337,7 @@
       rop.SrcBlend = GL_ONE;
       rop.DstBlend = GL_ONE_MINUS_SRC_ALPHA;
 
-      GfxContext.PushClippingRectangle(geo);
+      GfxContext.PushClippingRectangle(isect);
 
 #ifndef NUX_OPENGLES_20
       if (GfxContext.UsingGLSLCodePath())