The Tor Browser: gfx/layers/composite/ContentHost.cpp@97036ab72558 (annotated)

gfx/layers/composite/ContentHost.cpp@97036ab72558 (annotated)

gfx/layers/composite/ContentHost.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* 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 "mozilla/layers/ContentHost.h"
 #include "LayersLogging.h"              // for AppendToString
 #include "gfx2DGlue.h"                  // for ContentForFormat
 #include "mozilla/gfx/Point.h"          // for IntSize
 #include "mozilla/Assertions.h"         // for MOZ_ASSERT, etc
 #include "mozilla/gfx/BaseRect.h"       // for BaseRect
 #include "mozilla/layers/Compositor.h"  // for Compositor
 #include "mozilla/layers/Effects.h"     // for TexturedEffect, Effect, etc
 #include "mozilla/layers/LayersMessages.h"  // for ThebesBufferData
 #include "nsAString.h"
 #include "nsPrintfCString.h"            // for nsPrintfCString
 #include "nsString.h"                   // for nsAutoCString
 #include "mozilla/layers/TextureHostOGL.h"  // for TextureHostOGL
 namespace mozilla {
 namespace gfx {
 class Matrix4x4;
 }
 using namespace gfx;
 namespace layers {
 ContentHostBase::ContentHostBase(const TextureInfo& aTextureInfo)
   : ContentHost(aTextureInfo)
   , mPaintWillResample(false)
   , mInitialised(false)
 {}
 ContentHostBase::~ContentHostBase()
 {
 }
 struct AutoLockContentHost
 {
   AutoLockContentHost(ContentHostBase* aHost)
     : mHost(aHost)
   {
     mSucceeded = mHost->Lock();
   }
   ~AutoLockContentHost()
   {
     if (mSucceeded) {
       mHost->Unlock();
     }
   }
   bool Failed() { return !mSucceeded; }
   ContentHostBase* mHost;
   bool mSucceeded;
 };
 void
 ContentHostBase::Composite(EffectChain& aEffectChain,
                            float aOpacity,
                            const gfx::Matrix4x4& aTransform,
                            const Filter& aFilter,
                            const Rect& aClipRect,
                            const nsIntRegion* aVisibleRegion,
                            TiledLayerProperties* aLayerProperties)
 {
   NS_ASSERTION(aVisibleRegion, "Requires a visible region");
   AutoLockContentHost lock(this);
   if (lock.Failed()) {
     return;
   }
   RefPtr<NewTextureSource> source = GetTextureSource();
   RefPtr<NewTextureSource> sourceOnWhite = GetTextureSourceOnWhite();
   if (!source) {
     return;
   }
   RefPtr<TexturedEffect> effect =
     CreateTexturedEffect(source, sourceOnWhite, aFilter);
   if (!effect) {
     return;
   }
   aEffectChain.mPrimaryEffect = effect;
   nsIntRegion tmpRegion;
   const nsIntRegion* renderRegion;
   if (PaintWillResample()) {
     // If we're resampling, then the texture image will contain exactly the
     // entire visible region's bounds, and we should draw it all in one quad
     // to avoid unexpected aliasing.
     tmpRegion = aVisibleRegion->GetBounds();
     renderRegion = &tmpRegion;
   } else {
     renderRegion = aVisibleRegion;
   }
   nsIntRegion region(*renderRegion);
   nsIntPoint origin = GetOriginOffset();
   // translate into TexImage space, buffer origin might not be at texture (0,0)
   region.MoveBy(-origin);
   // Figure out the intersecting draw region
   gfx::IntSize texSize = source->GetSize();
   nsIntRect textureRect = nsIntRect(0, 0, texSize.width, texSize.height);
   textureRect.MoveBy(region.GetBounds().TopLeft());
   nsIntRegion subregion;
   subregion.And(region, textureRect);
   if (subregion.IsEmpty()) {
     // Region is empty, nothing to draw
     return;
   }
   nsIntRegion screenRects;
   nsIntRegion regionRects;
   // Collect texture/screen coordinates for drawing
   nsIntRegionRectIterator iter(subregion);
   while (const nsIntRect* iterRect = iter.Next()) {
     nsIntRect regionRect = *iterRect;
     nsIntRect screenRect = regionRect;
     screenRect.MoveBy(origin);
     screenRects.Or(screenRects, screenRect);
     regionRects.Or(regionRects, regionRect);
   }
   TileIterator* tileIter = source->AsTileIterator();
   TileIterator* iterOnWhite = nullptr;
   if (tileIter) {
     tileIter->BeginTileIteration();
   }
   if (sourceOnWhite) {
     iterOnWhite = sourceOnWhite->AsTileIterator();
     MOZ_ASSERT(!tileIter || tileIter->GetTileCount() == iterOnWhite->GetTileCount(),
                "Tile count mismatch on component alpha texture");
     if (iterOnWhite) {
       iterOnWhite->BeginTileIteration();
     }
   }
   bool usingTiles = (tileIter && tileIter->GetTileCount() > 1);
   do {
     if (iterOnWhite) {
       MOZ_ASSERT(iterOnWhite->GetTileRect() == tileIter->GetTileRect(),
                  "component alpha textures should be the same size.");
     }
     nsIntRect texRect = tileIter ? tileIter->GetTileRect()
                                  : nsIntRect(0, 0,
                                              texSize.width,
                                              texSize.height);
     // Draw texture. If we're using tiles, we do repeating manually, as texture
     // repeat would cause each individual tile to repeat instead of the
     // compound texture as a whole. This involves drawing at most 4 sections,
     // 2 for each axis that has texture repeat.
     for (int y = 0; y < (usingTiles ? 2 : 1); y++) {
       for (int x = 0; x < (usingTiles ? 2 : 1); x++) {
         nsIntRect currentTileRect(texRect);
         currentTileRect.MoveBy(x * texSize.width, y * texSize.height);
         nsIntRegionRectIterator screenIter(screenRects);
         nsIntRegionRectIterator regionIter(regionRects);
         const nsIntRect* screenRect;
         const nsIntRect* regionRect;
         while ((screenRect = screenIter.Next()) &&
                (regionRect = regionIter.Next())) {
           nsIntRect tileScreenRect(*screenRect);
           nsIntRect tileRegionRect(*regionRect);
           // When we're using tiles, find the intersection between the tile
           // rect and this region rect. Tiling is then handled by the
           // outer for-loops and modifying the tile rect.
           if (usingTiles) {
             tileScreenRect.MoveBy(-origin);
             tileScreenRect = tileScreenRect.Intersect(currentTileRect);
             tileScreenRect.MoveBy(origin);
             if (tileScreenRect.IsEmpty())
               continue;
             tileRegionRect = regionRect->Intersect(currentTileRect);
             tileRegionRect.MoveBy(-currentTileRect.TopLeft());
           }
           gfx::Rect rect(tileScreenRect.x, tileScreenRect.y,
                          tileScreenRect.width, tileScreenRect.height);
           effect->mTextureCoords = Rect(Float(tileRegionRect.x) / texRect.width,
                                         Float(tileRegionRect.y) / texRect.height,
                                         Float(tileRegionRect.width) / texRect.width,
                                         Float(tileRegionRect.height) / texRect.height);
           GetCompositor()->DrawQuad(rect, aClipRect, aEffectChain, aOpacity, aTransform);
           if (usingTiles) {
             DiagnosticTypes diagnostics = DIAGNOSTIC_CONTENT | DIAGNOSTIC_BIGIMAGE;
             diagnostics |= iterOnWhite ? DIAGNOSTIC_COMPONENT_ALPHA : 0;
             GetCompositor()->DrawDiagnostics(diagnostics, rect, aClipRect,
                                              aTransform, mFlashCounter);
           }
         }
       }
     }
     if (iterOnWhite) {
       iterOnWhite->NextTile();
     }
   } while (usingTiles && tileIter->NextTile());
   if (tileIter) {
     tileIter->EndTileIteration();
   }
   if (iterOnWhite) {
     iterOnWhite->EndTileIteration();
   }
   DiagnosticTypes diagnostics = DIAGNOSTIC_CONTENT;
   diagnostics |= iterOnWhite ? DIAGNOSTIC_COMPONENT_ALPHA : 0;
   GetCompositor()->DrawDiagnostics(diagnostics, *aVisibleRegion, aClipRect,
                                    aTransform, mFlashCounter);
 }
 void
 ContentHostTexture::UseTextureHost(TextureHost* aTexture)
 {
   ContentHostBase::UseTextureHost(aTexture);
   mTextureHost = aTexture;
   mTextureHostOnWhite = nullptr;
 }
 void
 ContentHostTexture::UseComponentAlphaTextures(TextureHost* aTextureOnBlack,
                                               TextureHost* aTextureOnWhite)
 {
   ContentHostBase::UseComponentAlphaTextures(aTextureOnBlack, aTextureOnWhite);
   mTextureHost = aTextureOnBlack;
   mTextureHostOnWhite = aTextureOnWhite;
 }
 void
 ContentHostTexture::SetCompositor(Compositor* aCompositor)
 {
   ContentHostBase::SetCompositor(aCompositor);
   if (mTextureHost) {
     mTextureHost->SetCompositor(aCompositor);
   }
   if (mTextureHostOnWhite) {
     mTextureHostOnWhite->SetCompositor(aCompositor);
   }
 }
 #ifdef MOZ_DUMP_PAINTING
 void
 ContentHostTexture::Dump(FILE* aFile,
                          const char* aPrefix,
                          bool aDumpHtml)
 {
   if (!aDumpHtml) {
     return;
   }
   if (!aFile) {
     aFile = stderr;
   }
   fprintf(aFile, "<ul>");
   if (mTextureHost) {
     fprintf(aFile, "%s", aPrefix);
     fprintf(aFile, "<li> <a href=");
     DumpTextureHost(aFile, mTextureHost);
     fprintf(aFile, "> Front buffer </a></li> ");
   }
   if (mTextureHostOnWhite) {
     fprintf(aFile, "%s", aPrefix);
     fprintf(aFile, "<li> <a href=");
     DumpTextureHost(aFile, mTextureHostOnWhite);
     fprintf(aFile, "> Front buffer on white </a> </li> ");
   }
   fprintf(aFile, "</ul>");
 }
 #endif
 static inline void
 AddWrappedRegion(const nsIntRegion& aInput, nsIntRegion& aOutput,
                  const nsIntSize& aSize, const nsIntPoint& aShift)
 {
   nsIntRegion tempRegion;
   tempRegion.And(nsIntRect(aShift, aSize), aInput);
   tempRegion.MoveBy(-aShift);
   aOutput.Or(aOutput, tempRegion);
 }
 bool
 ContentHostSingleBuffered::UpdateThebes(const ThebesBufferData& aData,
                                         const nsIntRegion& aUpdated,
                                         const nsIntRegion& aOldValidRegionBack,
                                         nsIntRegion* aUpdatedRegionBack)
 {
   aUpdatedRegionBack->SetEmpty();
   if (!mTextureHost) {
     mInitialised = false;
     return true; // FIXME should we return false? Returning true for now
   }              // to preserve existing behavior of NOT causing IPC errors.
   // updated is in screen coordinates. Convert it to buffer coordinates.
   nsIntRegion destRegion(aUpdated);
   destRegion.MoveBy(-aData.rect().TopLeft());
   if (!aData.rect().Contains(aUpdated.GetBounds()) ||
       aData.rotation().x > aData.rect().width ||
       aData.rotation().y > aData.rect().height) {
     NS_ERROR("Invalid update data");
     return false;
   }
   // destRegion is now in logical coordinates relative to the buffer, but we
   // need to account for rotation. We do that by moving the region to the
   // rotation offset and then wrapping any pixels that extend off the
   // bottom/right edges.
   // Shift to the rotation point
   destRegion.MoveBy(aData.rotation());
   nsIntSize bufferSize = aData.rect().Size();
   // Select only the pixels that are still within the buffer.
   nsIntRegion finalRegion;
   finalRegion.And(nsIntRect(nsIntPoint(), bufferSize), destRegion);
   // For each of the overlap areas (right, bottom-right, bottom), select those
   // pixels and wrap them around to the opposite edge of the buffer rect.
   AddWrappedRegion(destRegion, finalRegion, bufferSize, nsIntPoint(aData.rect().width, 0));
   AddWrappedRegion(destRegion, finalRegion, bufferSize, nsIntPoint(aData.rect().width, aData.rect().height));
   AddWrappedRegion(destRegion, finalRegion, bufferSize, nsIntPoint(0, aData.rect().height));
   MOZ_ASSERT(nsIntRect(0, 0, aData.rect().width, aData.rect().height).Contains(finalRegion.GetBounds()));
   mTextureHost->Updated(&finalRegion);
   if (mTextureHostOnWhite) {
     mTextureHostOnWhite->Updated(&finalRegion);
   }
   mInitialised = true;
   mBufferRect = aData.rect();
   mBufferRotation = aData.rotation();
   return true;
 }
 bool
 ContentHostDoubleBuffered::UpdateThebes(const ThebesBufferData& aData,
                                         const nsIntRegion& aUpdated,
                                         const nsIntRegion& aOldValidRegionBack,
                                         nsIntRegion* aUpdatedRegionBack)
 {
   if (!mTextureHost) {
     mInitialised = false;
     *aUpdatedRegionBack = aUpdated;
     return true;
   }
   // We don't need to calculate an update region because we assume that if we
   // are using double buffering then we have render-to-texture and thus no
   // upload to do.
   mTextureHost->Updated();
   if (mTextureHostOnWhite) {
     mTextureHostOnWhite->Updated();
   }
   mInitialised = true;
   mBufferRect = aData.rect();
   mBufferRotation = aData.rotation();
   *aUpdatedRegionBack = aUpdated;
   // Save the current valid region of our front buffer, because if
   // we're double buffering, it's going to be the valid region for the
   // next back buffer sent back to the renderer.
   //
   // NB: we rely here on the fact that mValidRegion is initialized to
   // empty, and that the first time Swap() is called we don't have a
   // valid front buffer that we're going to return to content.
   mValidRegionForNextBackBuffer = aOldValidRegionBack;
   return true;
 }
 ContentHostIncremental::ContentHostIncremental(const TextureInfo& aTextureInfo)
   : ContentHostBase(aTextureInfo)
   , mDeAllocator(nullptr)
   , mLocked(false)
 {
 }
 ContentHostIncremental::~ContentHostIncremental()
 {
 }
 bool
 ContentHostIncremental::CreatedIncrementalTexture(ISurfaceAllocator* aAllocator,
                                                   const TextureInfo& aTextureInfo,
                                                   const nsIntRect& aBufferRect)
 {
   mUpdateList.AppendElement(new TextureCreationRequest(aTextureInfo,
                                                        aBufferRect));
   mDeAllocator = aAllocator;
   FlushUpdateQueue();
   return true;
 }
 void
 ContentHostIncremental::UpdateIncremental(TextureIdentifier aTextureId,
                                           SurfaceDescriptor& aSurface,
                                           const nsIntRegion& aUpdated,
                                           const nsIntRect& aBufferRect,
                                           const nsIntPoint& aBufferRotation)
 {
   mUpdateList.AppendElement(new TextureUpdateRequest(mDeAllocator,
                                                      aTextureId,
                                                      aSurface,
                                                      aUpdated,
                                                      aBufferRect,
                                                      aBufferRotation));
   FlushUpdateQueue();
 }
 void
 ContentHostIncremental::FlushUpdateQueue()
 {
   // If we're not compositing for some reason (the window being minimized
   // is one example), then we never process these updates and it can consume
   // huge amounts of memory. Instead we forcibly process the updates (during the
   // transaction) if the list gets too long.
   static const uint32_t kMaxUpdateCount = 6;
   if (mUpdateList.Length() >= kMaxUpdateCount) {
     ProcessTextureUpdates();
   }
 }
 void
 ContentHostIncremental::ProcessTextureUpdates()
 {
   for (uint32_t i = 0; i < mUpdateList.Length(); i++) {
     mUpdateList[i]->Execute(this);
   }
   mUpdateList.Clear();
 }
 NewTextureSource*
 ContentHostIncremental::GetTextureSource()
 {
   MOZ_ASSERT(mLocked);
   return mSource;
 }
 NewTextureSource*
 ContentHostIncremental::GetTextureSourceOnWhite()
 {
   MOZ_ASSERT(mLocked);
   return mSourceOnWhite;
 }
 void
 ContentHostIncremental::TextureCreationRequest::Execute(ContentHostIncremental* aHost)
 {
   Compositor* compositor = aHost->GetCompositor();
   MOZ_ASSERT(compositor);
   RefPtr<DataTextureSource> temp =
     compositor->CreateDataTextureSource(mTextureInfo.mTextureFlags);
   MOZ_ASSERT(temp->AsSourceOGL() &&
              temp->AsSourceOGL()->AsTextureImageTextureSource());
   RefPtr<TextureImageTextureSourceOGL> newSource =
     temp->AsSourceOGL()->AsTextureImageTextureSource();
   RefPtr<TextureImageTextureSourceOGL> newSourceOnWhite;
   if (mTextureInfo.mTextureFlags & TEXTURE_COMPONENT_ALPHA) {
     temp =
       compositor->CreateDataTextureSource(mTextureInfo.mTextureFlags);
     MOZ_ASSERT(temp->AsSourceOGL() &&
                temp->AsSourceOGL()->AsTextureImageTextureSource());
     newSourceOnWhite = temp->AsSourceOGL()->AsTextureImageTextureSource();
   }
   if (mTextureInfo.mDeprecatedTextureHostFlags & TEXTURE_HOST_COPY_PREVIOUS) {
     MOZ_ASSERT(aHost->mSource);
     MOZ_ASSERT(aHost->mSource->IsValid());
     nsIntRect bufferRect = aHost->mBufferRect;
     nsIntPoint bufferRotation = aHost->mBufferRotation;
     nsIntRect overlap;
     // The buffer looks like:
     //  ______
     // |1  |2 |  Where the center point is offset by mBufferRotation from the top-left corner.
     // |___|__|
     // |3  |4 |
     // |___|__|
     //
     // This is drawn to the screen as:
     //  ______
     // |4  |3 |  Where the center point is { width - mBufferRotation.x, height - mBufferRotation.y } from
     // |___|__|  from the top left corner - rotationPoint.
     // |2  |1 |
     // |___|__|
     //
     // The basic idea below is to take all quadrant rectangles from the src and transform them into rectangles
     // in the destination. Unfortunately, it seems it is overly complex and could perhaps be simplified.
     nsIntRect srcBufferSpaceBottomRight(bufferRotation.x, bufferRotation.y, bufferRect.width - bufferRotation.x, bufferRect.height - bufferRotation.y);
     nsIntRect srcBufferSpaceTopRight(bufferRotation.x, 0, bufferRect.width - bufferRotation.x, bufferRotation.y);
     nsIntRect srcBufferSpaceTopLeft(0, 0, bufferRotation.x, bufferRotation.y);
     nsIntRect srcBufferSpaceBottomLeft(0, bufferRotation.y, bufferRotation.x, bufferRect.height - bufferRotation.y);
     overlap.IntersectRect(bufferRect, mBufferRect);
     nsIntRect srcRect(overlap), dstRect(overlap);
     srcRect.MoveBy(- bufferRect.TopLeft() + bufferRotation);
     nsIntRect srcRectDrawTopRight(srcRect);
     nsIntRect srcRectDrawTopLeft(srcRect);
     nsIntRect srcRectDrawBottomLeft(srcRect);
     // transform into the different quadrants
     srcRectDrawTopRight  .MoveBy(-nsIntPoint(0, bufferRect.height));
     srcRectDrawTopLeft   .MoveBy(-nsIntPoint(bufferRect.width, bufferRect.height));
     srcRectDrawBottomLeft.MoveBy(-nsIntPoint(bufferRect.width, 0));
     // Intersect with the quadrant
     srcRect               = srcRect              .Intersect(srcBufferSpaceBottomRight);
     srcRectDrawTopRight   = srcRectDrawTopRight  .Intersect(srcBufferSpaceTopRight);
     srcRectDrawTopLeft    = srcRectDrawTopLeft   .Intersect(srcBufferSpaceTopLeft);
     srcRectDrawBottomLeft = srcRectDrawBottomLeft.Intersect(srcBufferSpaceBottomLeft);
     dstRect = srcRect;
     nsIntRect dstRectDrawTopRight(srcRectDrawTopRight);
     nsIntRect dstRectDrawTopLeft(srcRectDrawTopLeft);
     nsIntRect dstRectDrawBottomLeft(srcRectDrawBottomLeft);
     // transform back to src buffer space
     dstRect              .MoveBy(-bufferRotation);
     dstRectDrawTopRight  .MoveBy(-bufferRotation + nsIntPoint(0, bufferRect.height));
     dstRectDrawTopLeft   .MoveBy(-bufferRotation + nsIntPoint(bufferRect.width, bufferRect.height));
     dstRectDrawBottomLeft.MoveBy(-bufferRotation + nsIntPoint(bufferRect.width, 0));
     // transform back to draw coordinates
     dstRect              .MoveBy(bufferRect.TopLeft());
     dstRectDrawTopRight  .MoveBy(bufferRect.TopLeft());
     dstRectDrawTopLeft   .MoveBy(bufferRect.TopLeft());
     dstRectDrawBottomLeft.MoveBy(bufferRect.TopLeft());
     // transform to destBuffer space
     dstRect              .MoveBy(-mBufferRect.TopLeft());
     dstRectDrawTopRight  .MoveBy(-mBufferRect.TopLeft());
     dstRectDrawTopLeft   .MoveBy(-mBufferRect.TopLeft());
     dstRectDrawBottomLeft.MoveBy(-mBufferRect.TopLeft());
     newSource->EnsureBuffer(mBufferRect.Size(),
                            ContentForFormat(aHost->mSource->GetFormat()));
     aHost->mSource->CopyTo(srcRect, newSource, dstRect);
     if (bufferRotation != nsIntPoint(0, 0)) {
       // Draw the remaining quadrants. We call BlitTextureImage 3 extra
       // times instead of doing a single draw call because supporting that
       // with a tiled source is quite tricky.
       if (!srcRectDrawTopRight.IsEmpty())
         aHost->mSource->CopyTo(srcRectDrawTopRight,
                                newSource, dstRectDrawTopRight);
       if (!srcRectDrawTopLeft.IsEmpty())
         aHost->mSource->CopyTo(srcRectDrawTopLeft,
                                newSource, dstRectDrawTopLeft);
       if (!srcRectDrawBottomLeft.IsEmpty())
         aHost->mSource->CopyTo(srcRectDrawBottomLeft,
                                newSource, dstRectDrawBottomLeft);
     }
     if (newSourceOnWhite) {
       newSourceOnWhite->EnsureBuffer(mBufferRect.Size(),
                                     ContentForFormat(aHost->mSourceOnWhite->GetFormat()));
       aHost->mSourceOnWhite->CopyTo(srcRect, newSourceOnWhite, dstRect);
       if (bufferRotation != nsIntPoint(0, 0)) {
         // draw the remaining quadrants
         if (!srcRectDrawTopRight.IsEmpty())
           aHost->mSourceOnWhite->CopyTo(srcRectDrawTopRight,
                                         newSourceOnWhite, dstRectDrawTopRight);
         if (!srcRectDrawTopLeft.IsEmpty())
           aHost->mSourceOnWhite->CopyTo(srcRectDrawTopLeft,
                                         newSourceOnWhite, dstRectDrawTopLeft);
         if (!srcRectDrawBottomLeft.IsEmpty())
           aHost->mSourceOnWhite->CopyTo(srcRectDrawBottomLeft,
                                         newSourceOnWhite, dstRectDrawBottomLeft);
       }
     }
   }
   aHost->mSource = newSource;
   aHost->mSourceOnWhite = newSourceOnWhite;
   aHost->mBufferRect = mBufferRect;
   aHost->mBufferRotation = nsIntPoint();
 }
 nsIntRect
 ContentHostIncremental::TextureUpdateRequest::GetQuadrantRectangle(XSide aXSide,
                                                                    YSide aYSide) const
 {
   // quadrantTranslation is the amount we translate the top-left
   // of the quadrant by to get coordinates relative to the layer
   nsIntPoint quadrantTranslation = -mBufferRotation;
   quadrantTranslation.x += aXSide == LEFT ? mBufferRect.width : 0;
   quadrantTranslation.y += aYSide == TOP ? mBufferRect.height : 0;
   return mBufferRect + quadrantTranslation;
 }
 void
 ContentHostIncremental::TextureUpdateRequest::Execute(ContentHostIncremental* aHost)
 {
   nsIntRect drawBounds = mUpdated.GetBounds();
   aHost->mBufferRect = mBufferRect;
   aHost->mBufferRotation = mBufferRotation;
   // Figure out which quadrant to draw in
   int32_t xBoundary = mBufferRect.XMost() - mBufferRotation.x;
   int32_t yBoundary = mBufferRect.YMost() - mBufferRotation.y;
   XSide sideX = drawBounds.XMost() <= xBoundary ? RIGHT : LEFT;
   YSide sideY = drawBounds.YMost() <= yBoundary ? BOTTOM : TOP;
   nsIntRect quadrantRect = GetQuadrantRectangle(sideX, sideY);
   NS_ASSERTION(quadrantRect.Contains(drawBounds), "Messed up quadrants");
   mUpdated.MoveBy(-nsIntPoint(quadrantRect.x, quadrantRect.y));
   IntPoint offset = ToIntPoint(-mUpdated.GetBounds().TopLeft());
   RefPtr<DataSourceSurface> surf = GetSurfaceForDescriptor(mDescriptor);
   if (mTextureId == TextureFront) {
     aHost->mSource->Update(surf, &mUpdated, &offset);
   } else {
     aHost->mSourceOnWhite->Update(surf, &mUpdated, &offset);
   }
 }
 void
 ContentHostTexture::PrintInfo(nsACString& aTo, const char* aPrefix)
 {
   aTo += aPrefix;
   aTo += nsPrintfCString("ContentHost (0x%p)", this);
   AppendToString(aTo, mBufferRect, " [buffer-rect=", "]");
   AppendToString(aTo, mBufferRotation, " [buffer-rotation=", "]");
   if (PaintWillResample()) {
     aTo += " [paint-will-resample]";
   }
   nsAutoCString pfx(aPrefix);
   pfx += "  ";
   if (mTextureHost) {
     aTo += "\n";
     mTextureHost->PrintInfo(aTo, pfx.get());
   }
 }
 LayerRenderState
 ContentHostTexture::GetRenderState()
 {
   if (!mTextureHost) {
     return LayerRenderState();
   }
   LayerRenderState result = mTextureHost->GetRenderState();
   if (mBufferRotation != nsIntPoint()) {
     result.mFlags |= LAYER_RENDER_STATE_BUFFER_ROTATION;
   }
   result.SetOffset(GetOriginOffset());
   return result;
 }
 #ifdef MOZ_DUMP_PAINTING
 TemporaryRef<gfx::DataSourceSurface>
 ContentHostTexture::GetAsSurface()
 {
   if (!mTextureHost) {
     return nullptr;
   }
   return mTextureHost->GetAsSurface();
 }
 #endif
 } // namespace
 } // namespace

The Tor Browser / annotate

gfx/layers/composite/ContentHost.cpp@97036ab72558 (annotated)

gfx/layers/composite/ContentHost.cpp