| /* |
| * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #ifndef WEBRTC_MODULES_DESKTOP_CAPTURE_SCREEN_CAPTURER_HELPER_H_ |
| #define WEBRTC_MODULES_DESKTOP_CAPTURE_SCREEN_CAPTURER_HELPER_H_ |
| |
| #include <memory> |
| |
| #include "webrtc/base/constructormagic.h" |
| #include "webrtc/modules/desktop_capture/desktop_geometry.h" |
| #include "webrtc/modules/desktop_capture/desktop_region.h" |
| #include "webrtc/system_wrappers/include/rw_lock_wrapper.h" |
| |
| namespace webrtc { |
| |
| // ScreenCapturerHelper is intended to be used by an implementation of the |
| // ScreenCapturer interface. It maintains a thread-safe invalid region, and |
| // the size of the most recently captured screen, on behalf of the |
| // ScreenCapturer that owns it. |
| class ScreenCapturerHelper { |
| public: |
| ScreenCapturerHelper(); |
| ~ScreenCapturerHelper(); |
| |
| // Clear out the invalid region. |
| void ClearInvalidRegion(); |
| |
| // Invalidate the specified region. |
| void InvalidateRegion(const DesktopRegion& invalid_region); |
| |
| // Invalidate the entire screen, of a given size. |
| void InvalidateScreen(const DesktopSize& size); |
| |
| // Copies current invalid region to |invalid_region| clears invalid region |
| // storage for the next frame. |
| void TakeInvalidRegion(DesktopRegion* invalid_region); |
| |
| // Access the size of the most recently captured screen. |
| const DesktopSize& size_most_recent() const; |
| void set_size_most_recent(const DesktopSize& size); |
| |
| // Lossy compression can result in color values leaking between pixels in one |
| // block. If part of a block changes, then unchanged parts of that block can |
| // be changed in the compressed output. So we need to re-render an entire |
| // block whenever part of the block changes. |
| // |
| // If |log_grid_size| is >= 1, then this function makes TakeInvalidRegion() |
| // produce an invalid region expanded so that its vertices lie on a grid of |
| // size 2 ^ |log_grid_size|. The expanded region is then clipped to the size |
| // of the most recently captured screen, as previously set by |
| // set_size_most_recent(). |
| // If |log_grid_size| is <= 0, then the invalid region is not expanded. |
| void SetLogGridSize(int log_grid_size); |
| |
| // Expands a region so that its vertices all lie on a grid. |
| // The grid size must be >= 2, so |log_grid_size| must be >= 1. |
| static void ExpandToGrid(const DesktopRegion& region, |
| int log_grid_size, |
| DesktopRegion* result); |
| |
| private: |
| // A region that has been manually invalidated (through InvalidateRegion). |
| // These will be returned as dirty_region in the capture data during the next |
| // capture. |
| DesktopRegion invalid_region_; |
| |
| // A lock protecting |invalid_region_| across threads. |
| std::unique_ptr<RWLockWrapper> invalid_region_lock_; |
| |
| // The size of the most recently captured screen. |
| DesktopSize size_most_recent_; |
| |
| // The log (base 2) of the size of the grid to which the invalid region is |
| // expanded. |
| // If the value is <= 0, then the invalid region is not expanded to a grid. |
| int log_grid_size_; |
| |
| RTC_DISALLOW_COPY_AND_ASSIGN(ScreenCapturerHelper); |
| }; |
| |
| } // namespace webrtc |
| |
| #endif // WEBRTC_MODULES_DESKTOP_CAPTURE_SCREEN_CAPTURER_HELPER_H_ |