tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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screen_capturer_helper.cc (3157B)

      1 /*
      2 *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
      3 *
      4 *  Use of this source code is governed by a BSD-style license
      5 *  that can be found in the LICENSE file in the root of the source
      6 *  tree. An additional intellectual property rights grant can be found
      7 *  in the file PATENTS.  All contributing project authors may
      8 *  be found in the AUTHORS file in the root of the source tree.
      9 */
     10 
     11 #include "modules/desktop_capture/screen_capturer_helper.h"
     12 
     13 #include "modules/desktop_capture/desktop_geometry.h"
     14 #include "modules/desktop_capture/desktop_region.h"
     15 #include "rtc_base/checks.h"
     16 #include "rtc_base/synchronization/mutex.h"
     17 
     18 namespace webrtc {
     19 
     20 void ScreenCapturerHelper::ClearInvalidRegion() {
     21  MutexLock scoped_invalid_region_lock(&invalid_region_mutex_);
     22  invalid_region_.Clear();
     23 }
     24 
     25 void ScreenCapturerHelper::InvalidateRegion(
     26    const DesktopRegion& invalid_region) {
     27  MutexLock scoped_invalid_region_lock(&invalid_region_mutex_);
     28  invalid_region_.AddRegion(invalid_region);
     29 }
     30 
     31 void ScreenCapturerHelper::InvalidateScreen(const DesktopSize& size) {
     32  MutexLock scoped_invalid_region_lock(&invalid_region_mutex_);
     33  invalid_region_.AddRect(DesktopRect::MakeSize(size));
     34 }
     35 
     36 void ScreenCapturerHelper::TakeInvalidRegion(DesktopRegion* invalid_region) {
     37  invalid_region->Clear();
     38 
     39  {
     40    MutexLock scoped_invalid_region_lock(&invalid_region_mutex_);
     41    invalid_region->Swap(&invalid_region_);
     42  }
     43 
     44  if (log_grid_size_ > 0) {
     45    DesktopRegion expanded_region;
     46    ExpandToGrid(*invalid_region, log_grid_size_, &expanded_region);
     47    expanded_region.Swap(invalid_region);
     48 
     49    invalid_region->IntersectWith(DesktopRect::MakeSize(size_most_recent_));
     50  }
     51 }
     52 
     53 void ScreenCapturerHelper::SetLogGridSize(int log_grid_size) {
     54  log_grid_size_ = log_grid_size;
     55 }
     56 
     57 const DesktopSize& ScreenCapturerHelper::size_most_recent() const {
     58  return size_most_recent_;
     59 }
     60 
     61 void ScreenCapturerHelper::set_size_most_recent(const DesktopSize& size) {
     62  size_most_recent_ = size;
     63 }
     64 
     65 // Returns the largest multiple of `n` that is <= `x`.
     66 // `n` must be a power of 2. `nMask` is ~(`n` - 1).
     67 static int DownToMultiple(int x, int nMask) {
     68  return (x & nMask);
     69 }
     70 
     71 // Returns the smallest multiple of `n` that is >= `x`.
     72 // `n` must be a power of 2. `nMask` is ~(`n` - 1).
     73 static int UpToMultiple(int x, int n, int nMask) {
     74  return ((x + n - 1) & nMask);
     75 }
     76 
     77 void ScreenCapturerHelper::ExpandToGrid(const DesktopRegion& region,
     78                                        int log_grid_size,
     79                                        DesktopRegion* result) {
     80  RTC_DCHECK_GE(log_grid_size, 1);
     81  int grid_size = 1 << log_grid_size;
     82  int grid_size_mask = ~(grid_size - 1);
     83 
     84  result->Clear();
     85  for (DesktopRegion::Iterator it(region); !it.IsAtEnd(); it.Advance()) {
     86    int left = DownToMultiple(it.rect().left(), grid_size_mask);
     87    int right = UpToMultiple(it.rect().right(), grid_size, grid_size_mask);
     88    int top = DownToMultiple(it.rect().top(), grid_size_mask);
     89    int bottom = UpToMultiple(it.rect().bottom(), grid_size, grid_size_mask);
     90    result->AddRect(DesktopRect::MakeLTRB(left, top, right, bottom));
     91  }
     92 }
     93 
     94 }  // namespace webrtc