screen_resolution.cc revision 90dce4d38c5ff5333bea97d859d4e484e27edf0c 
1// Copyright (c) 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "remoting/host/screen_resolution.h"
6
7#include <algorithm>
8#include <limits>
9
10#include "base/logging.h"
11
12namespace remoting {
13
14ScreenResolution::ScreenResolution()
15    : dimensions_(webrtc::DesktopSize(0, 0)),
16      dpi_(webrtc::DesktopVector(0, 0)) {
17}
18
19ScreenResolution::ScreenResolution(const webrtc::DesktopSize& dimensions,
20                                   const webrtc::DesktopVector& dpi)
21    : dimensions_(dimensions),
22      dpi_(dpi) {
23  // Check that dimensions are not negative.
24  DCHECK(!dimensions.is_empty() || dimensions.equals(webrtc::DesktopSize()));
25  DCHECK_GE(dpi.x(), 0);
26  DCHECK_GE(dpi.y(), 0);
27}
28
29webrtc::DesktopSize ScreenResolution::ScaleDimensionsToDpi(
30    const webrtc::DesktopVector& new_dpi) const {
31  int64 width = dimensions_.width();
32  int64 height = dimensions_.height();
33
34  // Scale the screen dimensions to new DPI.
35  width = std::min(width * new_dpi.x() / dpi_.x(),
36                   static_cast<int64>(std::numeric_limits<int32>::max()));
37  height = std::min(height * new_dpi.y() / dpi_.y(),
38                    static_cast<int64>(std::numeric_limits<int32>::max()));
39  return webrtc::DesktopSize(width, height);
40}
41
42bool ScreenResolution::IsEmpty() const {
43  return dimensions_.is_empty() || dpi_.is_zero();
44}
45
46}  // namespace remoting
47