The Tor Browser: gfx/thebes/gfxWindowsNativeDrawing.cpp@97036ab72558 (annotated)

gfx/thebes/gfxWindowsNativeDrawing.cpp@97036ab72558 (annotated)

gfx/thebes/gfxWindowsNativeDrawing.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: 4 -*-
  * 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 <windows.h>
 #include "nsMathUtils.h"
 #include "gfxWindowsNativeDrawing.h"
 #include "gfxWindowsSurface.h"
 #include "gfxAlphaRecovery.h"
 #include "gfxPattern.h"
 #include "mozilla/gfx/2D.h"
 enum {
     RENDER_STATE_INIT,
     RENDER_STATE_NATIVE_DRAWING,
     RENDER_STATE_NATIVE_DRAWING_DONE,
     RENDER_STATE_ALPHA_RECOVERY_BLACK,
     RENDER_STATE_ALPHA_RECOVERY_BLACK_DONE,
     RENDER_STATE_ALPHA_RECOVERY_WHITE,
     RENDER_STATE_ALPHA_RECOVERY_WHITE_DONE,
     RENDER_STATE_DONE
 };
 gfxWindowsNativeDrawing::gfxWindowsNativeDrawing(gfxContext* ctx,
                                                  const gfxRect& nativeRect,
                                                  uint32_t nativeDrawFlags)
     : mContext(ctx), mNativeRect(nativeRect), mNativeDrawFlags(nativeDrawFlags), mRenderState(RENDER_STATE_INIT)
 {
 }
 HDC
 gfxWindowsNativeDrawing::BeginNativeDrawing()
 {
     if (mRenderState == RENDER_STATE_INIT) {
         nsRefPtr<gfxASurface> surf;
         if (mContext->GetCairo()) {
           surf = mContext->CurrentSurface(&mDeviceOffset.x, &mDeviceOffset.y);
         }
         if (surf && surf->CairoStatus())
             return nullptr;
         gfxMatrix m = mContext->CurrentMatrix();
         if (!m.HasNonTranslation())
             mTransformType = TRANSLATION_ONLY;
         else if (m.HasNonAxisAlignedTransform())
             mTransformType = COMPLEX;
         else
             mTransformType = AXIS_ALIGNED_SCALE;
         // if this is a native win32 surface, we don't have to
         // redirect rendering to our own HDC; in some cases,
         // we may be able to use the HDC from the surface directly.
         if (surf &&
             ((surf->GetType() == gfxSurfaceType::Win32 ||
               surf->GetType() == gfxSurfaceType::Win32Printing) &&
               (surf->GetContentType() == gfxContentType::COLOR ||
                (surf->GetContentType() == gfxContentType::COLOR_ALPHA &&
                (mNativeDrawFlags & CAN_DRAW_TO_COLOR_ALPHA)))))
         {
             // grab the DC. This can fail if there is a complex clipping path,
             // in which case we'll have to fall back.
             mWinSurface = static_cast<gfxWindowsSurface*>(static_cast<gfxASurface*>(surf.get()));
             mDC = mWinSurface->GetDCWithClip(mContext);
             if (mDC) {
                 if (mTransformType == TRANSLATION_ONLY) {
                     mRenderState = RENDER_STATE_NATIVE_DRAWING;
                     mTranslation = m.GetTranslation();
                 } else if (((mTransformType == AXIS_ALIGNED_SCALE)
                             && (mNativeDrawFlags & CAN_AXIS_ALIGNED_SCALE)) ||
                            (mNativeDrawFlags & CAN_COMPLEX_TRANSFORM))
                 {
                     mWorldTransform.eM11 = (FLOAT) m.xx;
                     mWorldTransform.eM12 = (FLOAT) m.yx;
                     mWorldTransform.eM21 = (FLOAT) m.xy;
                     mWorldTransform.eM22 = (FLOAT) m.yy;
                     mWorldTransform.eDx  = (FLOAT) m.x0;
                     mWorldTransform.eDy  = (FLOAT) m.y0;
                     mRenderState = RENDER_STATE_NATIVE_DRAWING;
                 }
             }
         }
         // If we couldn't do native drawing, then we have to do two-buffer drawing
         // and do alpha recovery
         if (mRenderState == RENDER_STATE_INIT) {
             mRenderState = RENDER_STATE_ALPHA_RECOVERY_BLACK;
             // We round out our native rect here, that way the snapping will
             // happen correctly.
             mNativeRect.RoundOut();
             // we only do the scale bit if we can do an axis aligned
             // scale; otherwise we scale (if necessary) after
             // rendering with cairo.  Note that if we're doing alpha recovery,
             // we cannot do a full complex transform with win32 (I mean, we could, but
             // it would require more code that's not here.)
             if (mTransformType == TRANSLATION_ONLY || !(mNativeDrawFlags & CAN_AXIS_ALIGNED_SCALE)) {
                 mScale = gfxSize(1.0, 1.0);
                 // Add 1 to the surface size; it's guaranteed to not be incorrect,
                 // and it fixes bug 382458
                 // There's probably a better fix, but I haven't figured out
                 // the root cause of the problem.
                 mTempSurfaceSize =
                     gfxIntSize((int32_t) ceil(mNativeRect.Width() + 1),
                                (int32_t) ceil(mNativeRect.Height() + 1));
             } else {
                 // figure out the scale factors
                 mScale = m.ScaleFactors(true);
                 mWorldTransform.eM11 = (FLOAT) mScale.width;
                 mWorldTransform.eM12 = 0.0f;
                 mWorldTransform.eM21 = 0.0f;
                 mWorldTransform.eM22 = (FLOAT) mScale.height;
                 mWorldTransform.eDx  = 0.0f;
                 mWorldTransform.eDy  = 0.0f;
                 // See comment above about "+1"
                 mTempSurfaceSize =
                     gfxIntSize((int32_t) ceil(mNativeRect.Width() * mScale.width + 1),
                                (int32_t) ceil(mNativeRect.Height() * mScale.height + 1));
             }
         }
     }
     if (mRenderState == RENDER_STATE_NATIVE_DRAWING) {
         // we can just do native drawing directly to the context's surface
         // do we need to use SetWorldTransform?
         if (mTransformType != TRANSLATION_ONLY) {
             SetGraphicsMode(mDC, GM_ADVANCED);
             GetWorldTransform(mDC, &mOldWorldTransform);
             SetWorldTransform(mDC, &mWorldTransform);
         }
         GetViewportOrgEx(mDC, &mOrigViewportOrigin);
         SetViewportOrgEx(mDC,
                          mOrigViewportOrigin.x + (int)mDeviceOffset.x,
                          mOrigViewportOrigin.y + (int)mDeviceOffset.y,
                          nullptr);
         return mDC;
     } else if (mRenderState == RENDER_STATE_ALPHA_RECOVERY_BLACK ||
                mRenderState == RENDER_STATE_ALPHA_RECOVERY_WHITE)
     {
         // we're going to use mWinSurface to create our temporary surface here
         // get us a RGB24 DIB; DIB is important, because
         // we can later call GetImageSurface on it.
         mWinSurface = new gfxWindowsSurface(mTempSurfaceSize);
         mDC = mWinSurface->GetDC();
         RECT r = { 0, 0, mTempSurfaceSize.width, mTempSurfaceSize.height };
         if (mRenderState == RENDER_STATE_ALPHA_RECOVERY_BLACK)
             FillRect(mDC, &r, (HBRUSH)GetStockObject(BLACK_BRUSH));
         else
             FillRect(mDC, &r, (HBRUSH)GetStockObject(WHITE_BRUSH));
         if ((mTransformType != TRANSLATION_ONLY) &&
             (mNativeDrawFlags & CAN_AXIS_ALIGNED_SCALE))
         {
             SetGraphicsMode(mDC, GM_ADVANCED);
             SetWorldTransform(mDC, &mWorldTransform);
         }
         return mDC;
     } else {
         NS_ERROR("Bogus render state!");
         return nullptr;
     }
 }
 bool
 gfxWindowsNativeDrawing::IsDoublePass()
 {
     if (!mContext->IsCairo() &&
         (mContext->GetDrawTarget()->GetType() != mozilla::gfx::BackendType::CAIRO ||
          mContext->GetDrawTarget()->IsDualDrawTarget())) {
       return true;
     }
     nsRefPtr<gfxASurface> surf = mContext->CurrentSurface(&mDeviceOffset.x, &mDeviceOffset.y);
     if (!surf || surf->CairoStatus())
         return false;
     if (surf->GetType() != gfxSurfaceType::Win32 &&
         surf->GetType() != gfxSurfaceType::Win32Printing) {
 	return true;
     }
     if ((surf->GetContentType() != gfxContentType::COLOR ||
          (surf->GetContentType() == gfxContentType::COLOR_ALPHA &&
           !(mNativeDrawFlags & CAN_DRAW_TO_COLOR_ALPHA))))
         return true;
     return false;
 }
 bool
 gfxWindowsNativeDrawing::ShouldRenderAgain()
 {
     switch (mRenderState) {
         case RENDER_STATE_NATIVE_DRAWING_DONE:
             return false;
         case RENDER_STATE_ALPHA_RECOVERY_BLACK_DONE:
             mRenderState = RENDER_STATE_ALPHA_RECOVERY_WHITE;
             return true;
         case RENDER_STATE_ALPHA_RECOVERY_WHITE_DONE:
             return false;
         default:
             NS_ERROR("Invalid RenderState in gfxWindowsNativeDrawing::ShouldRenderAgain");
             break;
     }
     return false;
 }
 void
 gfxWindowsNativeDrawing::EndNativeDrawing()
 {
     if (mRenderState == RENDER_STATE_NATIVE_DRAWING) {
         // we drew directly to the HDC in the context; undo our changes
         SetViewportOrgEx(mDC, mOrigViewportOrigin.x, mOrigViewportOrigin.y, nullptr);
         if (mTransformType != TRANSLATION_ONLY)
             SetWorldTransform(mDC, &mOldWorldTransform);
         mWinSurface->MarkDirty();
         mRenderState = RENDER_STATE_NATIVE_DRAWING_DONE;
     } else if (mRenderState == RENDER_STATE_ALPHA_RECOVERY_BLACK) {
         mBlackSurface = mWinSurface;
         mWinSurface = nullptr;
         mRenderState = RENDER_STATE_ALPHA_RECOVERY_BLACK_DONE;
     } else if (mRenderState == RENDER_STATE_ALPHA_RECOVERY_WHITE) {
         mWhiteSurface = mWinSurface;
         mWinSurface = nullptr;
         mRenderState = RENDER_STATE_ALPHA_RECOVERY_WHITE_DONE;
     } else {
         NS_ERROR("Invalid RenderState in gfxWindowsNativeDrawing::EndNativeDrawing");
     }
 }
 void
 gfxWindowsNativeDrawing::PaintToContext()
 {
     if (mRenderState == RENDER_STATE_NATIVE_DRAWING_DONE) {
         // nothing to do, it already went to the context
         mRenderState = RENDER_STATE_DONE;
     } else if (mRenderState == RENDER_STATE_ALPHA_RECOVERY_WHITE_DONE) {
         nsRefPtr<gfxImageSurface> black = mBlackSurface->GetAsImageSurface();
         nsRefPtr<gfxImageSurface> white = mWhiteSurface->GetAsImageSurface();
         if (!gfxAlphaRecovery::RecoverAlpha(black, white)) {
             NS_ERROR("Alpha recovery failure");
             return;
         }
         nsRefPtr<gfxImageSurface> alphaSurface =
             new gfxImageSurface(black->Data(), black->GetSize(),
                                 black->Stride(),
                                 gfxImageFormat::ARGB32);
         mContext->Save();
         mContext->Translate(mNativeRect.TopLeft());
         mContext->NewPath();
         mContext->Rectangle(gfxRect(gfxPoint(0.0, 0.0), mNativeRect.Size()));
         nsRefPtr<gfxPattern> pat = new gfxPattern(alphaSurface);
         gfxMatrix m;
         m.Scale(mScale.width, mScale.height);
         pat->SetMatrix(m);
         if (mNativeDrawFlags & DO_NEAREST_NEIGHBOR_FILTERING)
             pat->SetFilter(GraphicsFilter::FILTER_FAST);
         pat->SetExtend(gfxPattern::EXTEND_PAD);
         mContext->SetPattern(pat);
         mContext->Fill();
         mContext->Restore();
         mRenderState = RENDER_STATE_DONE;
     } else {
         NS_ERROR("Invalid RenderState in gfxWindowsNativeDrawing::PaintToContext");
     }
 }
 void
 gfxWindowsNativeDrawing::TransformToNativeRect(const gfxRect& r,
                                                RECT& rout)
 {
     /* If we're doing native drawing, then we're still in the coordinate space
      * of the context; otherwise, we're in our own little world,
      * relative to the passed-in nativeRect.
      */
     gfxRect roundedRect(r);
     if (mRenderState == RENDER_STATE_NATIVE_DRAWING) {
         if (mTransformType == TRANSLATION_ONLY) {
             roundedRect.MoveBy(mTranslation);
         }
     } else {
         roundedRect.MoveBy(-mNativeRect.TopLeft());
     }
     roundedRect.Round();
     rout.left   = LONG(roundedRect.X());
     rout.right  = LONG(roundedRect.XMost());
     rout.top    = LONG(roundedRect.Y());
     rout.bottom = LONG(roundedRect.YMost());
 }

The Tor Browser / annotate

gfx/thebes/gfxWindowsNativeDrawing.cpp@97036ab72558 (annotated)

gfx/thebes/gfxWindowsNativeDrawing.cpp