From 406499dd53c1c552c0c6e6efa07dddb3570080d0 Mon Sep 17 00:00:00 2001
From: Matt Woodrow <mwoodrow@mozilla.com>
Date: Fri, 22 Jun 2018 11:35:49 +1200
Subject: [PATCH] Bug 1372458 - Fold opacity into filter drawing rather than
 using a temporary surface. r=mstange

MozReview-Commit-ID: 6ByhxshY3uO

--HG--
extra : rebase_source : 7c0add57b0de49ede96ddb46f5dfd0b9f2cadb3c
---
 layout/svg/nsFilterInstance.cpp      |  9 +++++----
 layout/svg/nsFilterInstance.h        |  5 +++--
 layout/svg/nsSVGIntegrationUtils.cpp | 11 +----------
 3 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/layout/svg/nsFilterInstance.cpp b/layout/svg/nsFilterInstance.cpp
index 51202c689be4..daf816e929bf 100644
--- a/layout/svg/nsFilterInstance.cpp
+++ b/layout/svg/nsFilterInstance.cpp
@@ -65,7 +65,8 @@ nsFilterInstance::PaintFilteredFrame(nsIFrame *aFilteredFrame,
                                      gfxContext* aCtx,
                                      nsSVGFilterPaintCallback *aPaintCallback,
                                      const nsRegion *aDirtyArea,
-                                     imgDrawingParams& aImgParams)
+                                     imgDrawingParams& aImgParams,
+                                     float aOpacity)
 {
   auto& filterChain = aFilteredFrame->StyleEffects()->mFilters;
   UniquePtr<UserSpaceMetrics> metrics = UserSpaceMetricsForFrame(aFilteredFrame);
@@ -97,7 +98,7 @@ nsFilterInstance::PaintFilteredFrame(nsIFrame *aFilteredFrame,
                             aPaintCallback, scaleMatrixInDevUnits,
                             aDirtyArea, nullptr, nullptr, nullptr);
   if (instance.IsInitialized()) {
-    instance.Render(aCtx, aImgParams);
+    instance.Render(aCtx, aImgParams, aOpacity);
   }
 }
 
@@ -493,7 +494,7 @@ nsFilterInstance::BuildSourceImage(DrawTarget *aDest, imgDrawingParams& aImgPara
 }
 
 void
-nsFilterInstance::Render(gfxContext* aCtx, imgDrawingParams& aImgParams)
+nsFilterInstance::Render(gfxContext* aCtx, imgDrawingParams& aImgParams, float aOpacity)
 {
   MOZ_ASSERT(mTargetFrame, "Need a frame for rendering");
 
@@ -521,7 +522,7 @@ nsFilterInstance::Render(gfxContext* aCtx, imgDrawingParams& aImgParams)
     mSourceGraphic.mSourceSurface, mSourceGraphic.mSurfaceRect,
     mFillPaint.mSourceSurface, mFillPaint.mSurfaceRect,
     mStrokePaint.mSourceSurface, mStrokePaint.mSurfaceRect,
-    mInputImages, Point(0, 0));
+    mInputImages, Point(0, 0), DrawOptions(aOpacity));
 }
 
 nsRegion
diff --git a/layout/svg/nsFilterInstance.h b/layout/svg/nsFilterInstance.h
index b38e7a334e12..3a26dd7988e0 100644
--- a/layout/svg/nsFilterInstance.h
+++ b/layout/svg/nsFilterInstance.h
@@ -88,7 +88,8 @@ public:
                                  gfxContext* aCtx,
                                  nsSVGFilterPaintCallback *aPaintCallback,
                                  const nsRegion* aDirtyArea,
-                                 imgDrawingParams& aImgParams);
+                                 imgDrawingParams& aImgParams,
+                                 float aOpacity = 1.0f);
 
   /**
    * Returns the post-filter area that could be dirtied when the given
@@ -168,7 +169,7 @@ private:
    * by passing it as the aPostFilterDirtyRegion argument to the
    * nsFilterInstance constructor.
    */
-  void Render(gfxContext* aCtx, imgDrawingParams& aImgParams);
+  void Render(gfxContext* aCtx, imgDrawingParams& aImgParams, float aOpacity = 1.0f);
 
   const FilterDescription& ExtractDescriptionAndAdditionalImages(nsTArray<RefPtr<SourceSurface>>& aOutAdditionalImages)
   {
diff --git a/layout/svg/nsSVGIntegrationUtils.cpp b/layout/svg/nsSVGIntegrationUtils.cpp
index d2168eeec7f9..c3337b5d6190 100644
--- a/layout/svg/nsSVGIntegrationUtils.cpp
+++ b/layout/svg/nsSVGIntegrationUtils.cpp
@@ -1084,22 +1084,13 @@ nsSVGIntegrationUtils::PaintFilter(const PaintFramesParams& aParams)
   gfxContextAutoSaveRestore autoSR(&context);
   EffectOffsets offsets = MoveContextOriginToUserSpace(firstFrame, aParams);
 
-  if (opacity != 1.0f) {
-    context.PushGroupForBlendBack(gfxContentType::COLOR_ALPHA, opacity,
-                                  nullptr, Matrix());
-  }
-
   /* Paint the child and apply filters */
   RegularFramePaintCallback callback(aParams.builder, aParams.layerManager,
                                      offsets.offsetToUserSpaceInDevPx);
   nsRegion dirtyRegion = aParams.dirtyRect - offsets.offsetToBoundingBox;
 
   nsFilterInstance::PaintFilteredFrame(frame, &context, &callback,
-                                       &dirtyRegion, aParams.imgParams);
-
-  if (opacity != 1.0f) {
-    context.PopGroupAndBlend();
-  }
+                                       &dirtyRegion, aParams.imgParams, opacity);
 }
 
 class PaintFrameCallback : public gfxDrawingCallback {