Rename Capturer to VideoFrameCapturer.

remoting/host/video_frame_capturer_helper.cc

Index: remoting/host/video_frame_capturer_helper.cc
diff --git a/remoting/host/video_frame_capturer_helper.cc b/remoting/host/video_frame_capturer_helper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..44b086809f166c015df9f7eb2bb2e2bd4e596c1a
--- /dev/null
+++ b/remoting/host/video_frame_capturer_helper.cc
@@ -0,0 +1,118 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "remoting/host/video_frame_capturer_helper.h"
+
+#include <algorithm>
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+
+namespace remoting {
+
+VideoFrameCapturerHelper::VideoFrameCapturerHelper() :
+    size_most_recent_(SkISize::Make(0, 0)),
+    log_grid_size_(0) {
+}
+
+VideoFrameCapturerHelper::~VideoFrameCapturerHelper() {
+}
+
+void VideoFrameCapturerHelper::ClearInvalidRegion() {
+  base::AutoLock auto_invalid_region_lock(invalid_region_lock_);
+  invalid_region_.setEmpty();
+}
+
+void VideoFrameCapturerHelper::InvalidateRegion(
+    const SkRegion& invalid_region) {
+  base::AutoLock auto_invalid_region_lock(invalid_region_lock_);
+  invalid_region_.op(invalid_region, SkRegion::kUnion_Op);
+}
+
+void VideoFrameCapturerHelper::InvalidateScreen(const SkISize& size) {
+  base::AutoLock auto_invalid_region_lock(invalid_region_lock_);
+  invalid_region_.op(SkIRect::MakeWH(size.width(), size.height()),
+                     SkRegion::kUnion_Op);
+}
+
+void VideoFrameCapturerHelper::InvalidateFullScreen() {
+  if (!size_most_recent_.isZero())
+    InvalidateScreen(size_most_recent_);
+}
+
+void VideoFrameCapturerHelper::SwapInvalidRegion(SkRegion* invalid_region) {
+  {
+    base::AutoLock auto_invalid_region_lock(invalid_region_lock_);
+    invalid_region->swap(invalid_region_);
+  }
+  if (log_grid_size_ > 0) {
+    scoped_ptr<SkRegion> expanded_region(
+        ExpandToGrid(*invalid_region, log_grid_size_));
+    invalid_region->swap(*expanded_region);
+    invalid_region->op(SkRegion(SkIRect::MakeSize(size_most_recent_)),
+                       SkRegion::kIntersect_Op);
+  }
+}
+
+void VideoFrameCapturerHelper::SetLogGridSize(int log_grid_size) {
+  log_grid_size_ = log_grid_size;
+}
+
+const SkISize& VideoFrameCapturerHelper::size_most_recent() const {
+  return size_most_recent_;
+}
+
+void VideoFrameCapturerHelper::set_size_most_recent(const SkISize& size) {
+  size_most_recent_ = size;
+}
+
+// Returns the largest multiple of |n| that is <= |x|.
+// |n| must be a power of 2. |nMask| is ~(|n| - 1).
+static int DownToMultiple(int x, int nMask) {
+  return (x & nMask);
+}
+
+// Returns the smallest multiple of |n| that is >= |x|.
+// |n| must be a power of 2. |nMask| is ~(|n| - 1).
+static int UpToMultiple(int x, int n, int nMask) {
+  return ((x + n - 1) & nMask);
+}
+
+scoped_ptr<SkRegion> VideoFrameCapturerHelper::ExpandToGrid(
+    const SkRegion& region,
+    int log_grid_size) {
+  DCHECK(log_grid_size >= 1);
+  int grid_size = 1 << log_grid_size;
+  int grid_size_mask = ~(grid_size - 1);
+  // Count the rects in the region.
+  int rectNum = 0;
+  SkRegion::Iterator iter(region);
+  while (!iter.done()) {
+    iter.next();
+    ++rectNum;
+  }
+  // Expand each rect.
+  scoped_array<SkIRect> rects(new SkIRect[rectNum]);
+  iter.rewind();
+  int rectI = 0;
+  while (!iter.done()) {
+    SkIRect rect = iter.rect();
+    iter.next();
+    int left = std::min(rect.left(), rect.right());
+    int right = std::max(rect.left(), rect.right());
+    int top = std::min(rect.top(), rect.bottom());
+    int bottom = std::max(rect.top(), rect.bottom());
+    left = DownToMultiple(left, grid_size_mask);
+    right = UpToMultiple(right, grid_size, grid_size_mask);
+    top = DownToMultiple(top, grid_size_mask);
+    bottom = UpToMultiple(bottom, grid_size, grid_size_mask);
+    rects[rectI++] = SkIRect::MakeLTRB(left, top, right, bottom);
+  }
+  // Make the union of the expanded rects.
+  scoped_ptr<SkRegion> regionNew(new SkRegion());
+  regionNew->setRects(rects.get(), rectNum);
+  return regionNew.Pass();
+}
+
+}  // namespace remoting