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

gfx/layers/RotatedBuffer.cpp@b8a032363ba2 (annotated)

gfx/layers/RotatedBuffer.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

 /* -*- 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 "RotatedBuffer.h"
 #include <sys/types.h>                  // for int32_t
 #include <algorithm>                    // for max
 #include "BasicImplData.h"              // for BasicImplData
 #include "BasicLayersImpl.h"            // for ToData
 #include "BufferUnrotate.h"             // for BufferUnrotate
 #include "GeckoProfiler.h"              // for PROFILER_LABEL
 #include "Layers.h"                     // for ThebesLayer, Layer, etc
 #include "gfxPlatform.h"                // for gfxPlatform
 #include "gfxPrefs.h"                   // for gfxPrefs
 #include "gfxUtils.h"                   // for gfxUtils
 #include "mozilla/ArrayUtils.h"         // for ArrayLength
 #include "mozilla/gfx/BasePoint.h"      // for BasePoint
 #include "mozilla/gfx/BaseRect.h"       // for BaseRect
 #include "mozilla/gfx/BaseSize.h"       // for BaseSize
 #include "mozilla/gfx/Matrix.h"         // for Matrix
 #include "mozilla/gfx/Point.h"          // for Point, IntPoint
 #include "mozilla/gfx/Rect.h"           // for Rect, IntRect
 #include "mozilla/gfx/Types.h"          // for ExtendMode::ExtendMode::CLAMP, etc
 #include "mozilla/layers/ShadowLayers.h"  // for ShadowableLayer
 #include "mozilla/layers/TextureClient.h"  // for TextureClient
 #include "nsSize.h"                     // for nsIntSize
 #include "gfx2DGlue.h"
 namespace mozilla {
 using namespace gfx;
 namespace layers {
 nsIntRect
 RotatedBuffer::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;
 }
 Rect
 RotatedBuffer::GetSourceRectangle(XSide aXSide, YSide aYSide) const
 {
   Rect result;
   if (aXSide == LEFT) {
     result.x = 0;
     result.width = mBufferRotation.x;
   } else {
     result.x = mBufferRotation.x;
     result.width = mBufferRect.width - mBufferRotation.x;
   }
   if (aYSide == TOP) {
     result.y = 0;
     result.height = mBufferRotation.y;
   } else {
     result.y = mBufferRotation.y;
     result.height = mBufferRect.height - mBufferRotation.y;
   }
   return result;
 }
 /**
  * @param aXSide LEFT means we draw from the left side of the buffer (which
  * is drawn on the right side of mBufferRect). RIGHT means we draw from
  * the right side of the buffer (which is drawn on the left side of
  * mBufferRect).
  * @param aYSide TOP means we draw from the top side of the buffer (which
  * is drawn on the bottom side of mBufferRect). BOTTOM means we draw from
  * the bottom side of the buffer (which is drawn on the top side of
  * mBufferRect).
  */
 void
 RotatedBuffer::DrawBufferQuadrant(gfx::DrawTarget* aTarget,
                                   XSide aXSide, YSide aYSide,
                                   ContextSource aSource,
                                   float aOpacity,
                                   gfx::CompositionOp aOperator,
                                   gfx::SourceSurface* aMask,
                                   const gfx::Matrix* aMaskTransform) const
 {
   // The rectangle that we're going to fill. Basically we're going to
   // render the buffer at mBufferRect + quadrantTranslation to get the
   // pixels in the right place, but we're only going to paint within
   // mBufferRect
   nsIntRect quadrantRect = GetQuadrantRectangle(aXSide, aYSide);
   nsIntRect fillRect;
   if (!fillRect.IntersectRect(mBufferRect, quadrantRect))
     return;
   gfx::Point quadrantTranslation(quadrantRect.x, quadrantRect.y);
   MOZ_ASSERT(aOperator == CompositionOp::OP_OVER || aOperator == CompositionOp::OP_SOURCE);
   // direct2d is much slower when using OP_SOURCE so use OP_OVER and
   // (maybe) a clear instead. Normally we need to draw in a single operation
   // (to avoid flickering) but direct2d is ok since it defers rendering.
   // We should try abstract this logic in a helper when we have other use
   // cases.
   if (aTarget->GetType() == BackendType::DIRECT2D && aOperator == CompositionOp::OP_SOURCE) {
     aOperator = CompositionOp::OP_OVER;
     if (mDTBuffer->GetFormat() == SurfaceFormat::B8G8R8A8) {
       aTarget->ClearRect(ToRect(fillRect));
     }
   }
   RefPtr<gfx::SourceSurface> snapshot;
   if (aSource == BUFFER_BLACK) {
     snapshot = mDTBuffer->Snapshot();
   } else {
     MOZ_ASSERT(aSource == BUFFER_WHITE);
     snapshot = mDTBufferOnWhite->Snapshot();
   }
   if (aOperator == CompositionOp::OP_SOURCE) {
     // OP_SOURCE is unbounded in Azure, and we really don't want that behaviour here.
     // We also can't do a ClearRect+FillRect since we need the drawing to happen
     // as an atomic operation (to prevent flickering).
     aTarget->PushClipRect(gfx::Rect(fillRect.x, fillRect.y,
                                     fillRect.width, fillRect.height));
   }
   if (aMask) {
     Matrix oldTransform = aTarget->GetTransform();
     // Transform from user -> buffer space.
     Matrix transform;
     transform.Translate(quadrantTranslation.x, quadrantTranslation.y);
     Matrix inverseMask = *aMaskTransform;
     inverseMask.Invert();
     transform *= oldTransform;
     transform *= inverseMask;
 #ifdef MOZ_GFX_OPTIMIZE_MOBILE
     SurfacePattern source(snapshot, ExtendMode::CLAMP, transform, Filter::POINT);
 #else
     SurfacePattern source(snapshot, ExtendMode::CLAMP, transform);
 #endif
     aTarget->SetTransform(*aMaskTransform);
     aTarget->MaskSurface(source, aMask, Point(0, 0), DrawOptions(aOpacity, aOperator));
     aTarget->SetTransform(oldTransform);
   } else {
 #ifdef MOZ_GFX_OPTIMIZE_MOBILE
     DrawSurfaceOptions options(Filter::POINT);
 #else
     DrawSurfaceOptions options;
 #endif
     aTarget->DrawSurface(snapshot, ToRect(fillRect),
                          GetSourceRectangle(aXSide, aYSide),
                          options,
                          DrawOptions(aOpacity, aOperator));
   }
   if (aOperator == CompositionOp::OP_SOURCE) {
     aTarget->PopClip();
   }
 }
 void
 RotatedBuffer::DrawBufferWithRotation(gfx::DrawTarget *aTarget, ContextSource aSource,
                                       float aOpacity,
                                       gfx::CompositionOp aOperator,
                                       gfx::SourceSurface* aMask,
                                       const gfx::Matrix* aMaskTransform) const
 {
   PROFILER_LABEL("RotatedBuffer", "DrawBufferWithRotation");
   // See above, in Azure Repeat should always be a safe, even faster choice
   // though! Particularly on D2D Repeat should be a lot faster, need to look
   // into that. TODO[Bas]
   DrawBufferQuadrant(aTarget, LEFT, TOP, aSource, aOpacity, aOperator, aMask, aMaskTransform);
   DrawBufferQuadrant(aTarget, RIGHT, TOP, aSource, aOpacity, aOperator, aMask, aMaskTransform);
   DrawBufferQuadrant(aTarget, LEFT, BOTTOM, aSource, aOpacity, aOperator, aMask, aMaskTransform);
   DrawBufferQuadrant(aTarget, RIGHT, BOTTOM, aSource, aOpacity, aOperator,aMask, aMaskTransform);
 }
 /* static */ bool
 RotatedContentBuffer::IsClippingCheap(DrawTarget* aTarget, const nsIntRegion& aRegion)
 {
   // Assume clipping is cheap if the draw target just has an integer
   // translation, and the visible region is simple.
   return !aTarget->GetTransform().HasNonIntegerTranslation() &&
          aRegion.GetNumRects() <= 1;
 }
 void
 RotatedContentBuffer::DrawTo(ThebesLayer* aLayer,
                              DrawTarget* aTarget,
                              float aOpacity,
                              CompositionOp aOp,
                              SourceSurface* aMask,
                              const Matrix* aMaskTransform)
 {
   if (!EnsureBuffer()) {
     return;
   }
   bool clipped = false;
   // If the entire buffer is valid, we can just draw the whole thing,
   // no need to clip. But we'll still clip if clipping is cheap ---
   // that might let us copy a smaller region of the buffer.
   // Also clip to the visible region if we're told to.
   if (!aLayer->GetValidRegion().Contains(BufferRect()) ||
       (ToData(aLayer)->GetClipToVisibleRegion() &&
        !aLayer->GetVisibleRegion().Contains(BufferRect())) ||
       IsClippingCheap(aTarget, aLayer->GetEffectiveVisibleRegion())) {
     // We don't want to draw invalid stuff, so we need to clip. Might as
     // well clip to the smallest area possible --- the visible region.
     // Bug 599189 if there is a non-integer-translation transform in aTarget,
     // we might sample pixels outside GetEffectiveVisibleRegion(), which is wrong
     // and may cause gray lines.
     gfxUtils::ClipToRegionSnapped(aTarget, aLayer->GetEffectiveVisibleRegion());
     clipped = true;
   }
   DrawBufferWithRotation(aTarget, BUFFER_BLACK, aOpacity, aOp, aMask, aMaskTransform);
   if (clipped) {
     aTarget->PopClip();
   }
 }
 DrawTarget*
 RotatedContentBuffer::BorrowDrawTargetForQuadrantUpdate(const nsIntRect& aBounds,
                                                         ContextSource aSource,
                                                         DrawIterator* aIter)
 {
   nsIntRect bounds = aBounds;
   if (aIter) {
     // If an iterator was provided, then BeginPaint must have been run with
     // PAINT_CAN_DRAW_ROTATED, and the draw region might cover multiple quadrants.
     // Iterate over each of them, and return an appropriate buffer each time we find
     // one that intersects the draw region. The iterator mCount value tracks which
     // quadrants we have considered across multiple calls to this function.
     aIter->mDrawRegion.SetEmpty();
     while (aIter->mCount < 4) {
       nsIntRect quadrant = GetQuadrantRectangle((aIter->mCount & 1) ? LEFT : RIGHT,
         (aIter->mCount & 2) ? TOP : BOTTOM);
       aIter->mDrawRegion.And(aBounds, quadrant);
       aIter->mCount++;
       if (!aIter->mDrawRegion.IsEmpty()) {
         break;
       }
     }
     if (aIter->mDrawRegion.IsEmpty()) {
       return nullptr;
     }
     bounds = aIter->mDrawRegion.GetBounds();
   }
   if (!EnsureBuffer()) {
     return nullptr;
   }
   MOZ_ASSERT(!mLoanedDrawTarget, "draw target has been borrowed and not returned");
   if (aSource == BUFFER_BOTH && HaveBufferOnWhite()) {
     if (!EnsureBufferOnWhite()) {
       return nullptr;
     }
     MOZ_ASSERT(mDTBuffer && mDTBufferOnWhite);
     mLoanedDrawTarget = Factory::CreateDualDrawTarget(mDTBuffer, mDTBufferOnWhite);
   } else if (aSource == BUFFER_WHITE) {
     if (!EnsureBufferOnWhite()) {
       return nullptr;
     }
     mLoanedDrawTarget = mDTBufferOnWhite;
   } else {
     // BUFFER_BLACK, or BUFFER_BOTH with a single buffer.
     mLoanedDrawTarget = mDTBuffer;
   }
   // Figure out which quadrant to draw in
   int32_t xBoundary = mBufferRect.XMost() - mBufferRotation.x;
   int32_t yBoundary = mBufferRect.YMost() - mBufferRotation.y;
   XSide sideX = bounds.XMost() <= xBoundary ? RIGHT : LEFT;
   YSide sideY = bounds.YMost() <= yBoundary ? BOTTOM : TOP;
   nsIntRect quadrantRect = GetQuadrantRectangle(sideX, sideY);
   NS_ASSERTION(quadrantRect.Contains(bounds), "Messed up quadrants");
   mLoanedTransform = mLoanedDrawTarget->GetTransform();
   mLoanedTransform.Translate(-quadrantRect.x, -quadrantRect.y);
   mLoanedDrawTarget->SetTransform(mLoanedTransform);
   mLoanedTransform.Translate(quadrantRect.x, quadrantRect.y);
   return mLoanedDrawTarget;
 }
 void
 BorrowDrawTarget::ReturnDrawTarget(gfx::DrawTarget*& aReturned)
 {
   MOZ_ASSERT(aReturned == mLoanedDrawTarget);
   mLoanedDrawTarget->SetTransform(mLoanedTransform);
   mLoanedDrawTarget = nullptr;
   aReturned = nullptr;
 }
 gfxContentType
 RotatedContentBuffer::BufferContentType()
 {
   if (mBufferProvider || mDTBuffer) {
     SurfaceFormat format;
     if (mBufferProvider) {
       format = mBufferProvider->GetFormat();
     } else if (mDTBuffer) {
       format = mDTBuffer->GetFormat();
     }
     return ContentForFormat(format);
   }
   return gfxContentType::SENTINEL;
 }
 bool
 RotatedContentBuffer::BufferSizeOkFor(const nsIntSize& aSize)
 {
   return (aSize == mBufferRect.Size() ||
           (SizedToVisibleBounds != mBufferSizePolicy &&
            aSize < mBufferRect.Size()));
 }
 bool
 RotatedContentBuffer::EnsureBuffer()
 {
   NS_ASSERTION(!mLoanedDrawTarget, "Loaned draw target must be returned");
   if (!mDTBuffer) {
     if (mBufferProvider) {
       mDTBuffer = mBufferProvider->GetAsDrawTarget();
     }
   }
   NS_WARN_IF_FALSE(mDTBuffer, "no buffer");
   return !!mDTBuffer;
 }
 bool
 RotatedContentBuffer::EnsureBufferOnWhite()
 {
   NS_ASSERTION(!mLoanedDrawTarget, "Loaned draw target must be returned");
   if (!mDTBufferOnWhite) {
     if (mBufferProviderOnWhite) {
       mDTBufferOnWhite =
         mBufferProviderOnWhite->GetAsDrawTarget();
     }
   }
   NS_WARN_IF_FALSE(mDTBufferOnWhite, "no buffer");
   return mDTBufferOnWhite;
 }
 bool
 RotatedContentBuffer::HaveBuffer() const
 {
   return mDTBuffer || mBufferProvider;
 }
 bool
 RotatedContentBuffer::HaveBufferOnWhite() const
 {
   return mDTBufferOnWhite || mBufferProviderOnWhite;
 }
 static void
 WrapRotationAxis(int32_t* aRotationPoint, int32_t aSize)
 {
   if (*aRotationPoint < 0) {
     *aRotationPoint += aSize;
   } else if (*aRotationPoint >= aSize) {
     *aRotationPoint -= aSize;
   }
 }
 static nsIntRect
 ComputeBufferRect(const nsIntRect& aRequestedRect)
 {
   nsIntRect rect(aRequestedRect);
   // Set a minimum width to guarantee a minimum size of buffers we
   // allocate (and work around problems on some platforms with smaller
   // dimensions).  64 is the magic number needed to work around the
   // rendering glitch, and guarantees image rows can be SIMD'd for
   // even r5g6b5 surfaces pretty much everywhere.
   rect.width = std::max(aRequestedRect.width, 64);
 #ifdef MOZ_WIDGET_GONK
   // Set a minumum height to guarantee a minumum height of buffers we
   // allocate. Some GL implementations fail to render gralloc textures
   // with a height 9px-16px. It happens on Adreno 200. Adreno 320 does not
   // have this problem. 32 is choosed as alignment of gralloc buffers.
   // See Bug 873937.
   // Increase the height only when the requested height is more than 0.
   // See Bug 895976.
   // XXX it might be better to disable it on the gpu that does not have
   // the height problem.
   if (rect.height > 0) {
     rect.height = std::max(aRequestedRect.height, 32);
   }
 #endif
   return rect;
 }
 void
 RotatedContentBuffer::FlushBuffers()
 {
   if (mDTBuffer) {
     mDTBuffer->Flush();
   }
   if (mDTBufferOnWhite) {
     mDTBufferOnWhite->Flush();
   }
 }
 RotatedContentBuffer::PaintState
 RotatedContentBuffer::BeginPaint(ThebesLayer* aLayer,
                                  uint32_t aFlags)
 {
   PaintState result;
   // We need to disable rotation if we're going to be resampled when
   // drawing, because we might sample across the rotation boundary.
   bool canHaveRotation = gfxPlatform::BufferRotationEnabled() &&
                          !(aFlags & (PAINT_WILL_RESAMPLE | PAINT_NO_ROTATION));
   nsIntRegion validRegion = aLayer->GetValidRegion();
   bool canUseOpaqueSurface = aLayer->CanUseOpaqueSurface();
   ContentType layerContentType =
     canUseOpaqueSurface ? gfxContentType::COLOR :
                           gfxContentType::COLOR_ALPHA;
   SurfaceMode mode;
   nsIntRegion neededRegion;
   bool canReuseBuffer;
   nsIntRect destBufferRect;
   while (true) {
     mode = aLayer->GetSurfaceMode();
     neededRegion = aLayer->GetVisibleRegion();
     canReuseBuffer = HaveBuffer() && BufferSizeOkFor(neededRegion.GetBounds().Size());
     result.mContentType = layerContentType;
     if (canReuseBuffer) {
       if (mBufferRect.Contains(neededRegion.GetBounds())) {
         // We don't need to adjust mBufferRect.
         destBufferRect = mBufferRect;
       } else if (neededRegion.GetBounds().Size() <= mBufferRect.Size()) {
         // The buffer's big enough but doesn't contain everything that's
         // going to be visible. We'll move it.
         destBufferRect = nsIntRect(neededRegion.GetBounds().TopLeft(), mBufferRect.Size());
       } else {
         destBufferRect = neededRegion.GetBounds();
       }
     } else {
       // We won't be reusing the buffer.  Compute a new rect.
       destBufferRect = ComputeBufferRect(neededRegion.GetBounds());
     }
     if (mode == SurfaceMode::SURFACE_COMPONENT_ALPHA) {
 #if defined(MOZ_GFX_OPTIMIZE_MOBILE) || defined(MOZ_WIDGET_GONK)
       mode = SurfaceMode::SURFACE_SINGLE_CHANNEL_ALPHA;
 #else
       if (!aLayer->GetParent() ||
           !aLayer->GetParent()->SupportsComponentAlphaChildren() ||
           !aLayer->Manager()->IsCompositingCheap() ||
           !aLayer->AsShadowableLayer() ||
           !aLayer->AsShadowableLayer()->HasShadow() ||
           !gfxPrefs::ComponentAlphaEnabled()) {
         mode = SurfaceMode::SURFACE_SINGLE_CHANNEL_ALPHA;
       } else {
         result.mContentType = gfxContentType::COLOR;
       }
 #endif
     }
     if ((aFlags & PAINT_WILL_RESAMPLE) &&
         (!neededRegion.GetBounds().IsEqualInterior(destBufferRect) ||
          neededRegion.GetNumRects() > 1)) {
       // The area we add to neededRegion might not be painted opaquely
       if (mode == SurfaceMode::SURFACE_OPAQUE) {
         result.mContentType = gfxContentType::COLOR_ALPHA;
         mode = SurfaceMode::SURFACE_SINGLE_CHANNEL_ALPHA;
       }
       // We need to validate the entire buffer, to make sure that only valid
       // pixels are sampled
       neededRegion = destBufferRect;
     }
     // If we have an existing buffer, but the content type has changed or we
     // have transitioned into/out of component alpha, then we need to recreate it.
     if (HaveBuffer() &&
         (result.mContentType != BufferContentType() ||
         (mode == SurfaceMode::SURFACE_COMPONENT_ALPHA) != HaveBufferOnWhite())) {
       // We're effectively clearing the valid region, so we need to draw
       // the entire needed region now.
       result.mRegionToInvalidate = aLayer->GetValidRegion();
       validRegion.SetEmpty();
       Clear();
       // Restart decision process with the cleared buffer. We can only go
       // around the loop one more iteration, since mDTBuffer is null now.
       continue;
     }
     break;
   }
   NS_ASSERTION(destBufferRect.Contains(neededRegion.GetBounds()),
                "Destination rect doesn't contain what we need to paint");
   result.mRegionToDraw.Sub(neededRegion, validRegion);
   if (result.mRegionToDraw.IsEmpty())
     return result;
   // Do not modify result.mRegionToDraw or result.mContentType after this call.
   // Do not modify mBufferRect, mBufferRotation, or mDidSelfCopy,
   // or call CreateBuffer before this call.
   FinalizeFrame(result.mRegionToDraw);
   nsIntRect drawBounds = result.mRegionToDraw.GetBounds();
   RefPtr<DrawTarget> destDTBuffer;
   RefPtr<DrawTarget> destDTBufferOnWhite;
   uint32_t bufferFlags = canHaveRotation ? ALLOW_REPEAT : 0;
   if (mode == SurfaceMode::SURFACE_COMPONENT_ALPHA) {
     bufferFlags |= BUFFER_COMPONENT_ALPHA;
   }
   if (canReuseBuffer) {
     if (!EnsureBuffer()) {
       return result;
     }
     nsIntRect keepArea;
     if (keepArea.IntersectRect(destBufferRect, mBufferRect)) {
       // Set mBufferRotation so that the pixels currently in mDTBuffer
       // will still be rendered in the right place when mBufferRect
       // changes to destBufferRect.
       nsIntPoint newRotation = mBufferRotation +
         (destBufferRect.TopLeft() - mBufferRect.TopLeft());
       WrapRotationAxis(&newRotation.x, mBufferRect.width);
       WrapRotationAxis(&newRotation.y, mBufferRect.height);
       NS_ASSERTION(nsIntRect(nsIntPoint(0,0), mBufferRect.Size()).Contains(newRotation),
                    "newRotation out of bounds");
       int32_t xBoundary = destBufferRect.XMost() - newRotation.x;
       int32_t yBoundary = destBufferRect.YMost() - newRotation.y;
       bool drawWrapsBuffer = (drawBounds.x < xBoundary && xBoundary < drawBounds.XMost()) ||
                              (drawBounds.y < yBoundary && yBoundary < drawBounds.YMost());
       if ((drawWrapsBuffer && !(aFlags & PAINT_CAN_DRAW_ROTATED)) ||
           (newRotation != nsIntPoint(0,0) && !canHaveRotation)) {
         // The stuff we need to redraw will wrap around an edge of the
         // buffer (and the caller doesn't know how to support that), so
         // move the pixels we can keep into a position that lets us
         // redraw in just one quadrant.
         if (mBufferRotation == nsIntPoint(0,0)) {
           nsIntRect srcRect(nsIntPoint(0, 0), mBufferRect.Size());
           nsIntPoint dest = mBufferRect.TopLeft() - destBufferRect.TopLeft();
           MOZ_ASSERT(mDTBuffer);
           mDTBuffer->CopyRect(IntRect(srcRect.x, srcRect.y, srcRect.width, srcRect.height),
                               IntPoint(dest.x, dest.y));
           if (mode == SurfaceMode::SURFACE_COMPONENT_ALPHA) {
             if (!EnsureBufferOnWhite()) {
               return result;
             }
             MOZ_ASSERT(mDTBufferOnWhite);
             mDTBufferOnWhite->CopyRect(IntRect(srcRect.x, srcRect.y, srcRect.width, srcRect.height),
                                        IntPoint(dest.x, dest.y));
           }
           result.mDidSelfCopy = true;
           mDidSelfCopy = true;
           // Don't set destBuffer; we special-case self-copies, and
           // just did the necessary work above.
           mBufferRect = destBufferRect;
         } else {
           // With azure and a data surface perform an buffer unrotate
           // (SelfCopy).
           unsigned char* data;
           IntSize size;
           int32_t stride;
           SurfaceFormat format;
           if (mDTBuffer->LockBits(&data, &size, &stride, &format)) {
             uint8_t bytesPerPixel = BytesPerPixel(format);
             BufferUnrotate(data,
                            size.width * bytesPerPixel,
                            size.height, stride,
                            newRotation.x * bytesPerPixel, newRotation.y);
             mDTBuffer->ReleaseBits(data);
             if (mode == SurfaceMode::SURFACE_COMPONENT_ALPHA) {
               if (!EnsureBufferOnWhite()) {
                 return result;
               }
               MOZ_ASSERT(mDTBufferOnWhite);
               mDTBufferOnWhite->LockBits(&data, &size, &stride, &format);
               uint8_t bytesPerPixel = BytesPerPixel(format);
               BufferUnrotate(data,
                              size.width * bytesPerPixel,
                              size.height, stride,
                              newRotation.x * bytesPerPixel, newRotation.y);
               mDTBufferOnWhite->ReleaseBits(data);
             }
             // Buffer unrotate moves all the pixels, note that
             // we self copied for SyncBackToFrontBuffer
             result.mDidSelfCopy = true;
             mDidSelfCopy = true;
             mBufferRect = destBufferRect;
             mBufferRotation = nsIntPoint(0, 0);
           }
           if (!result.mDidSelfCopy) {
             destBufferRect = ComputeBufferRect(neededRegion.GetBounds());
             CreateBuffer(result.mContentType, destBufferRect, bufferFlags,
                          &destDTBuffer, &destDTBufferOnWhite);
             if (!destDTBuffer) {
               return result;
             }
           }
         }
       } else {
         mBufferRect = destBufferRect;
         mBufferRotation = newRotation;
       }
     } else {
       // No pixels are going to be kept. The whole visible region
       // will be redrawn, so we don't need to copy anything, so we don't
       // set destBuffer.
       mBufferRect = destBufferRect;
       mBufferRotation = nsIntPoint(0,0);
     }
   } else {
     // The buffer's not big enough, so allocate a new one
     CreateBuffer(result.mContentType, destBufferRect, bufferFlags,
                  &destDTBuffer, &destDTBufferOnWhite);
     if (!destDTBuffer) {
       return result;
     }
   }
   NS_ASSERTION(!(aFlags & PAINT_WILL_RESAMPLE) || destBufferRect == neededRegion.GetBounds(),
                "If we're resampling, we need to validate the entire buffer");
   // If we have no buffered data already, then destBuffer will be a fresh buffer
   // and we do not need to clear it below.
   bool isClear = !HaveBuffer();
   if (destDTBuffer) {
     if (!isClear && (mode != SurfaceMode::SURFACE_COMPONENT_ALPHA || HaveBufferOnWhite())) {
       // Copy the bits
       nsIntPoint offset = -destBufferRect.TopLeft();
       Matrix mat;
       mat.Translate(offset.x, offset.y);
       destDTBuffer->SetTransform(mat);
       if (!EnsureBuffer()) {
         return result;
       }
        MOZ_ASSERT(mDTBuffer, "Have we got a Thebes buffer for some reason?");
       DrawBufferWithRotation(destDTBuffer, BUFFER_BLACK, 1.0, CompositionOp::OP_SOURCE);
       destDTBuffer->SetTransform(Matrix());
       if (mode == SurfaceMode::SURFACE_COMPONENT_ALPHA) {
         NS_ASSERTION(destDTBufferOnWhite, "Must have a white buffer!");
         destDTBufferOnWhite->SetTransform(mat);
         if (!EnsureBufferOnWhite()) {
           return result;
         }
         MOZ_ASSERT(mDTBufferOnWhite, "Have we got a Thebes buffer for some reason?");
         DrawBufferWithRotation(destDTBufferOnWhite, BUFFER_WHITE, 1.0, CompositionOp::OP_SOURCE);
         destDTBufferOnWhite->SetTransform(Matrix());
       }
     }
     mDTBuffer = destDTBuffer.forget();
     mDTBufferOnWhite = destDTBufferOnWhite.forget();
     mBufferRect = destBufferRect;
     mBufferRotation = nsIntPoint(0,0);
   }
   NS_ASSERTION(canHaveRotation || mBufferRotation == nsIntPoint(0,0),
                "Rotation disabled, but we have nonzero rotation?");
   nsIntRegion invalidate;
   invalidate.Sub(aLayer->GetValidRegion(), destBufferRect);
   result.mRegionToInvalidate.Or(result.mRegionToInvalidate, invalidate);
   result.mClip = DrawRegionClip::DRAW_SNAPPED;
   result.mMode = mode;
   return result;
 }
 DrawTarget*
 RotatedContentBuffer::BorrowDrawTargetForPainting(const PaintState& aPaintState,
                                                   DrawIterator* aIter /* = nullptr */)
 {
   if (aPaintState.mMode == SurfaceMode::SURFACE_NONE) {
     return nullptr;
   }
   DrawTarget* result = BorrowDrawTargetForQuadrantUpdate(aPaintState.mRegionToDraw.GetBounds(),
                                                          BUFFER_BOTH, aIter);
   if (!result) {
     return nullptr;
   }
   const nsIntRegion* drawPtr = &aPaintState.mRegionToDraw;
   if (aIter) {
     // The iterators draw region currently only contains the bounds of the region,
     // this makes it the precise region.
     aIter->mDrawRegion.And(aIter->mDrawRegion, aPaintState.mRegionToDraw);
     drawPtr = &aIter->mDrawRegion;
   }
   if (aPaintState.mMode == SurfaceMode::SURFACE_COMPONENT_ALPHA) {
     MOZ_ASSERT(mDTBuffer && mDTBufferOnWhite);
     nsIntRegionRectIterator iter(*drawPtr);
     const nsIntRect *iterRect;
     while ((iterRect = iter.Next())) {
       mDTBuffer->FillRect(Rect(iterRect->x, iterRect->y, iterRect->width, iterRect->height),
                           ColorPattern(Color(0.0, 0.0, 0.0, 1.0)));
       mDTBufferOnWhite->FillRect(Rect(iterRect->x, iterRect->y, iterRect->width, iterRect->height),
                                  ColorPattern(Color(1.0, 1.0, 1.0, 1.0)));
     }
   } else if (aPaintState.mContentType == gfxContentType::COLOR_ALPHA && HaveBuffer()) {
     // HaveBuffer() => we have an existing buffer that we must clear
     nsIntRegionRectIterator iter(*drawPtr);
     const nsIntRect *iterRect;
     while ((iterRect = iter.Next())) {
       result->ClearRect(Rect(iterRect->x, iterRect->y, iterRect->width, iterRect->height));
     }
   }
   return result;
 }
 }
 }

The Tor Browser / annotate

gfx/layers/RotatedBuffer.cpp@b8a032363ba2 (annotated)

gfx/layers/RotatedBuffer.cpp