The Tor Browser: gfx/layers/client/ClientTiledThebesLayer.cpp@b8a032363ba2 (annotated)

gfx/layers/client/ClientTiledThebesLayer.cpp@b8a032363ba2 (annotated)

gfx/layers/client/ClientTiledThebesLayer.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "ClientTiledThebesLayer.h"
 #include "FrameMetrics.h"               // for FrameMetrics
 #include "Units.h"                      // for ScreenIntRect, CSSPoint, etc
 #include "UnitTransforms.h"             // for TransformTo
 #include "ClientLayerManager.h"         // for ClientLayerManager, etc
 #include "gfx3DMatrix.h"                // for gfx3DMatrix
 #include "gfxPlatform.h"                // for gfxPlatform
 #include "gfxPrefs.h"                   // for gfxPrefs
 #include "gfxRect.h"                    // for gfxRect
 #include "mozilla/Assertions.h"         // for MOZ_ASSERT, etc
 #include "mozilla/gfx/BaseSize.h"       // for BaseSize
 #include "mozilla/gfx/Rect.h"           // for Rect, RectTyped
 #include "mozilla/layers/LayersMessages.h"
 #include "mozilla/mozalloc.h"           // for operator delete, etc
 #include "nsISupportsImpl.h"            // for MOZ_COUNT_CTOR, etc
 #include "nsRect.h"                     // for nsIntRect
 namespace mozilla {
 namespace layers {
 ClientTiledThebesLayer::ClientTiledThebesLayer(ClientLayerManager* const aManager)
   : ThebesLayer(aManager,
                 static_cast<ClientLayer*>(MOZ_THIS_IN_INITIALIZER_LIST()))
   , mContentClient()
 {
   MOZ_COUNT_CTOR(ClientTiledThebesLayer);
   mPaintData.mLastScrollOffset = ParentLayerPoint(0, 0);
   mPaintData.mFirstPaint = true;
 }
 ClientTiledThebesLayer::~ClientTiledThebesLayer()
 {
   MOZ_COUNT_DTOR(ClientTiledThebesLayer);
 }
 void
 ClientTiledThebesLayer::ClearCachedResources()
 {
   if (mContentClient) {
     mContentClient->ClearCachedResources();
   }
 }
 void
 ClientTiledThebesLayer::FillSpecificAttributes(SpecificLayerAttributes& aAttrs)
 {
   aAttrs = ThebesLayerAttributes(GetValidRegion());
 }
 static LayoutDeviceRect
 ApplyParentLayerToLayoutTransform(const gfx3DMatrix& aTransform, const ParentLayerRect& aParentLayerRect)
 {
   return TransformTo<LayoutDevicePixel>(aTransform, aParentLayerRect);
 }
 void
 ClientTiledThebesLayer::BeginPaint()
 {
   if (ClientManager()->IsRepeatTransaction()) {
     return;
   }
   mPaintData.mLowPrecisionPaintCount = 0;
   mPaintData.mPaintFinished = false;
   mPaintData.mCompositionBounds.SetEmpty();
   mPaintData.mCriticalDisplayPort.SetEmpty();
   if (!GetBaseTransform().Is2DIntegerTranslation()) {
     // Give up if the layer is transformed. The code below assumes that there
     // is no transform set, and not making that assumption would cause huge
     // complication to handle a quite rare case.
     //
     // FIXME The intention is to bail out of this function when there's a CSS
     //       transform set on the layer, but unfortunately there's no way to
     //       distinguish transforms due to scrolling from transforms due to
     //       CSS transforms.
     //
     //       Because of this, there may be unintended behaviour when setting
     //       2d CSS translations on the children of scrollable displayport
     //       layers.
     return;
   }
 #ifdef MOZ_WIDGET_ANDROID
   // Subframes on Fennec are not async scrollable because they have no displayport.
   // However, the code in RenderLayer() picks up a displayport from the nearest
   // scrollable ancestor container layer anyway, which is incorrect for Fennec. This
   // behaviour results in the subframe getting clipped improperly and perma-blank areas
   // while scrolling the subframe. To work around this, we detect if this layer is
   // the primary scrollable layer and disable the tiling behaviour if it is not.
   bool isPrimaryScrollableThebesLayer = false;
   if (Layer* scrollable = ClientManager()->GetPrimaryScrollableLayer()) {
     if (GetParent() == scrollable) {
       for (Layer* child = scrollable->GetFirstChild(); child; child = child->GetNextSibling()) {
         if (child->GetType() == Layer::TYPE_THEBES) {
           if (child == this) {
             // |this| is the first thebes layer child of the GetPrimaryScrollableLayer()
             isPrimaryScrollableThebesLayer = true;
           }
           break;
         }
       }
     }
   }
   if (!isPrimaryScrollableThebesLayer) {
     return;
   }
 #endif
   // Get the metrics of the nearest scrollable layer and the nearest layer
   // with a displayport.
   ContainerLayer* displayPortParent = nullptr;
   ContainerLayer* scrollParent = nullptr;
   for (ContainerLayer* parent = GetParent(); parent; parent = parent->GetParent()) {
     const FrameMetrics& metrics = parent->GetFrameMetrics();
     if (!scrollParent && metrics.GetScrollId() != FrameMetrics::NULL_SCROLL_ID) {
       scrollParent = parent;
     }
     if (!metrics.mDisplayPort.IsEmpty()) {
       displayPortParent = parent;
       // Any layer that has a displayport must be scrollable, so we can break
       // here.
       break;
     }
   }
   if (!displayPortParent || !scrollParent) {
     // No displayport or scroll parent, so we can't do progressive rendering.
     // Just set the composition bounds to empty and return.
 #if defined(MOZ_WIDGET_ANDROID) || defined(MOZ_B2G)
     // Both Android and b2g are guaranteed to have a displayport set, so this
     // should never happen.
     NS_WARNING("Tiled Thebes layer with no scrollable container parent");
 #endif
     return;
   }
   // Note, not handling transformed layers lets us assume that LayoutDevice
   // space of the scroll parent layer is the same as LayoutDevice space of
   // this layer.
   const FrameMetrics& scrollMetrics = scrollParent->GetFrameMetrics();
   const FrameMetrics& displayportMetrics = displayPortParent->GetFrameMetrics();
   // Calculate the transform required to convert ParentLayer space of our
   // display port parent to LayoutDevice space of this layer.
   gfx::Matrix4x4 transform = scrollParent->GetTransform();
   ContainerLayer* displayPortParentParent = displayPortParent->GetParent() ?
     displayPortParent->GetParent()->GetParent() : nullptr;
   for (ContainerLayer* parent = scrollParent->GetParent();
        parent != displayPortParentParent;
        parent = parent->GetParent()) {
     transform = transform * parent->GetTransform();
   }
   gfx3DMatrix layoutDeviceToScrollParentLayer;
   gfx::To3DMatrix(transform, layoutDeviceToScrollParentLayer);
   layoutDeviceToScrollParentLayer.ScalePost(scrollMetrics.mCumulativeResolution.scale,
                                             scrollMetrics.mCumulativeResolution.scale,
 .f);
   mPaintData.mTransformParentLayerToLayoutDevice = layoutDeviceToScrollParentLayer.Inverse();
   // Compute the critical display port of the display port layer in
   // LayoutDevice space of this layer.
   ParentLayerRect criticalDisplayPort =
     (displayportMetrics.mCriticalDisplayPort + displayportMetrics.GetScrollOffset()) *
     displayportMetrics.GetZoomToParent();
   mPaintData.mCriticalDisplayPort = LayoutDeviceIntRect::ToUntyped(RoundedOut(
     ApplyParentLayerToLayoutTransform(mPaintData.mTransformParentLayerToLayoutDevice,
                                       criticalDisplayPort)));
   // Compute the viewport of the display port layer in LayoutDevice space of
   // this layer.
   ParentLayerRect viewport =
     (displayportMetrics.mViewport + displayportMetrics.GetScrollOffset()) *
     displayportMetrics.GetZoomToParent();
   mPaintData.mViewport = ApplyParentLayerToLayoutTransform(
     mPaintData.mTransformParentLayerToLayoutDevice, viewport);
   // Store the scroll parent resolution. Because this is Gecko-side, before any
   // async transforms have occurred, we can use the zoom for this.
   mPaintData.mResolution = displayportMetrics.GetZoomToParent();
   // Store the parent composition bounds in LayoutDevice units.
   // This is actually in LayoutDevice units of the scrollParent's parent layer,
   // but because there is no transform, we can assume that these are the same.
   mPaintData.mCompositionBounds =
     scrollMetrics.mCompositionBounds / scrollMetrics.GetParentResolution();
   // Calculate the scroll offset since the last transaction
   mPaintData.mScrollOffset = displayportMetrics.GetScrollOffset() * displayportMetrics.GetZoomToParent();
 }
 void
 ClientTiledThebesLayer::EndPaint(bool aFinish)
 {
   if (!aFinish && !mPaintData.mPaintFinished) {
     return;
   }
   mPaintData.mLastScrollOffset = mPaintData.mScrollOffset;
   mPaintData.mPaintFinished = true;
   mPaintData.mFirstPaint = false;
 }
 void
 ClientTiledThebesLayer::RenderLayer()
 {
   LayerManager::DrawThebesLayerCallback callback =
     ClientManager()->GetThebesLayerCallback();
   void *data = ClientManager()->GetThebesLayerCallbackData();
   if (!callback) {
     ClientManager()->SetTransactionIncomplete();
     return;
   }
   if (!mContentClient) {
     mContentClient = new TiledContentClient(this, ClientManager());
     mContentClient->Connect();
     ClientManager()->AsShadowForwarder()->Attach(mContentClient, this);
     MOZ_ASSERT(mContentClient->GetForwarder());
   }
   if (mContentClient->mTiledBuffer.HasFormatChanged()) {
     mValidRegion = nsIntRegion();
   }
   nsIntRegion invalidRegion = mVisibleRegion;
   invalidRegion.Sub(invalidRegion, mValidRegion);
   if (invalidRegion.IsEmpty()) {
     EndPaint(true);
     return;
   }
   // Only paint the mask layer on the first transaction.
   if (GetMaskLayer() && !ClientManager()->IsRepeatTransaction()) {
     ToClientLayer(GetMaskLayer())->RenderLayer();
   }
   bool isFixed = GetIsFixedPosition() || GetParent()->GetIsFixedPosition();
   // Fast path for no progressive updates, no low-precision updates and no
   // critical display-port set, or no display-port set, or this is a fixed
   // position layer/contained in a fixed position layer
   const FrameMetrics& parentMetrics = GetParent()->GetFrameMetrics();
   if ((!gfxPrefs::UseProgressiveTilePainting() &&
        !gfxPrefs::UseLowPrecisionBuffer() &&
        parentMetrics.mCriticalDisplayPort.IsEmpty()) ||
        parentMetrics.mDisplayPort.IsEmpty() ||
        isFixed) {
     mValidRegion = mVisibleRegion;
     NS_ASSERTION(!ClientManager()->IsRepeatTransaction(), "Didn't paint our mask layer");
     mContentClient->mTiledBuffer.PaintThebes(mValidRegion, invalidRegion,
                                              callback, data);
     ClientManager()->Hold(this);
     mContentClient->UseTiledLayerBuffer(TiledContentClient::TILED_BUFFER);
     return;
   }
   // Calculate everything we need to perform the paint.
   BeginPaint();
   if (mPaintData.mPaintFinished) {
     return;
   }
   // Make sure that tiles that fall outside of the visible region are
   // discarded on the first update.
   if (!ClientManager()->IsRepeatTransaction()) {
     mValidRegion.And(mValidRegion, mVisibleRegion);
     if (!mPaintData.mCriticalDisplayPort.IsEmpty()) {
       // Make sure that tiles that fall outside of the critical displayport are
       // discarded on the first update.
       mValidRegion.And(mValidRegion, mPaintData.mCriticalDisplayPort);
     }
   }
   nsIntRegion lowPrecisionInvalidRegion;
   if (!mPaintData.mCriticalDisplayPort.IsEmpty()) {
     if (gfxPrefs::UseLowPrecisionBuffer()) {
       // Calculate the invalid region for the low precision buffer
       lowPrecisionInvalidRegion.Sub(mVisibleRegion, mLowPrecisionValidRegion);
       // Remove the valid region from the low precision valid region (we don't
       // validate this part of the low precision buffer).
       lowPrecisionInvalidRegion.Sub(lowPrecisionInvalidRegion, mValidRegion);
     }
     // Clip the invalid region to the critical display-port
     invalidRegion.And(invalidRegion, mPaintData.mCriticalDisplayPort);
     if (invalidRegion.IsEmpty() && lowPrecisionInvalidRegion.IsEmpty()) {
       EndPaint(true);
       return;
     }
   }
   if (!invalidRegion.IsEmpty() && mPaintData.mLowPrecisionPaintCount == 0) {
     bool updatedBuffer = false;
     // Only draw progressively when the resolution is unchanged.
     if (gfxPrefs::UseProgressiveTilePainting() &&
         !ClientManager()->HasShadowTarget() &&
         mContentClient->mTiledBuffer.GetFrameResolution() == mPaintData.mResolution) {
       // Store the old valid region, then clear it before painting.
       // We clip the old valid region to the visible region, as it only gets
       // used to decide stale content (currently valid and previously visible)
       nsIntRegion oldValidRegion = mContentClient->mTiledBuffer.GetValidRegion();
       oldValidRegion.And(oldValidRegion, mVisibleRegion);
       if (!mPaintData.mCriticalDisplayPort.IsEmpty()) {
         oldValidRegion.And(oldValidRegion, mPaintData.mCriticalDisplayPort);
       }
       updatedBuffer =
         mContentClient->mTiledBuffer.ProgressiveUpdate(mValidRegion, invalidRegion,
                                                        oldValidRegion, &mPaintData,
                                                        callback, data);
     } else {
       updatedBuffer = true;
       mValidRegion = mVisibleRegion;
       if (!mPaintData.mCriticalDisplayPort.IsEmpty()) {
         mValidRegion.And(mValidRegion, mPaintData.mCriticalDisplayPort);
       }
       mContentClient->mTiledBuffer.SetFrameResolution(mPaintData.mResolution);
       mContentClient->mTiledBuffer.PaintThebes(mValidRegion, invalidRegion,
                                                callback, data);
     }
     if (updatedBuffer) {
       ClientManager()->Hold(this);
       mContentClient->UseTiledLayerBuffer(TiledContentClient::TILED_BUFFER);
       // If there are low precision updates, mark the paint as unfinished and
       // request a repeat transaction.
       if (!lowPrecisionInvalidRegion.IsEmpty() && mPaintData.mPaintFinished) {
         ClientManager()->SetRepeatTransaction();
         mPaintData.mLowPrecisionPaintCount = 1;
         mPaintData.mPaintFinished = false;
       }
       // Return so that low precision updates aren't performed in the same
       // transaction as high-precision updates.
       EndPaint(false);
       return;
     }
   }
   // Render the low precision buffer, if there's area to invalidate and the
   // visible region is larger than the critical display port.
   bool updatedLowPrecision = false;
   if (!lowPrecisionInvalidRegion.IsEmpty() &&
       !nsIntRegion(mPaintData.mCriticalDisplayPort).Contains(mVisibleRegion)) {
     nsIntRegion oldValidRegion =
       mContentClient->mLowPrecisionTiledBuffer.GetValidRegion();
     oldValidRegion.And(oldValidRegion, mVisibleRegion);
     // If the frame resolution or format have changed, invalidate the buffer
     if (mContentClient->mLowPrecisionTiledBuffer.GetFrameResolution() != mPaintData.mResolution ||
         mContentClient->mLowPrecisionTiledBuffer.HasFormatChanged()) {
       if (!mLowPrecisionValidRegion.IsEmpty()) {
         updatedLowPrecision = true;
       }
       oldValidRegion.SetEmpty();
       mLowPrecisionValidRegion.SetEmpty();
       mContentClient->mLowPrecisionTiledBuffer.SetFrameResolution(mPaintData.mResolution);
       lowPrecisionInvalidRegion = mVisibleRegion;
     }
     // Invalidate previously valid content that is no longer visible
     if (mPaintData.mLowPrecisionPaintCount == 1) {
       mLowPrecisionValidRegion.And(mLowPrecisionValidRegion, mVisibleRegion);
     }
     mPaintData.mLowPrecisionPaintCount++;
     // Remove the valid high-precision region from the invalid low-precision
     // region. We don't want to spend time drawing things twice.
     lowPrecisionInvalidRegion.Sub(lowPrecisionInvalidRegion, mValidRegion);
     if (!lowPrecisionInvalidRegion.IsEmpty()) {
       updatedLowPrecision = mContentClient->mLowPrecisionTiledBuffer
                               .ProgressiveUpdate(mLowPrecisionValidRegion,
                                                  lowPrecisionInvalidRegion,
                                                  oldValidRegion, &mPaintData,
                                                  callback, data);
     }
   } else if (!mLowPrecisionValidRegion.IsEmpty()) {
     // Clear the low precision tiled buffer
     updatedLowPrecision = true;
     mLowPrecisionValidRegion.SetEmpty();
     mContentClient->mLowPrecisionTiledBuffer.PaintThebes(mLowPrecisionValidRegion,
                                                          mLowPrecisionValidRegion,
                                                          callback, data);
   }
   // We send a Painted callback if we clear the valid region of the low
   // precision buffer, so that the shadow buffer's valid region can be updated
   // and the associated resources can be freed.
   if (updatedLowPrecision) {
     ClientManager()->Hold(this);
     mContentClient->UseTiledLayerBuffer(TiledContentClient::LOW_PRECISION_TILED_BUFFER);
   }
   EndPaint(false);
 }
 } // mozilla
 } // layers

The Tor Browser / annotate

gfx/layers/client/ClientTiledThebesLayer.cpp@b8a032363ba2 (annotated)

gfx/layers/client/ClientTiledThebesLayer.cpp