From 00a35b6a3c27751e8eea390003b15dcf0928ff80 Mon Sep 17 00:00:00 2001 From: Jonathan Watt Date: Thu, 16 Jun 2011 12:06:05 +0100 Subject: [PATCH] Bug 664130 - Document what GetOpaqueRegion is useful for. r=roc. --HG-- extra : rebase_source : abde1fd28975506a58068725e5cbb660620760f8 --- layout/base/nsDisplayList.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/layout/base/nsDisplayList.h b/layout/base/nsDisplayList.h index 5b75bbdc0566..3b8238e18cc1 100644 --- a/layout/base/nsDisplayList.h +++ b/layout/base/nsDisplayList.h @@ -647,7 +647,9 @@ public: } /** * @return a region of the item that is opaque --- every pixel painted - * with an opaque color. + * with an opaque color. This is useful for determining when one piece + * of content completely obscures another so that we can do occlusion + * culling. */ virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, PRBool* aForceTransparentSurface = nsnull)