gfx/thebes/DisplayConfigWindows.cpp

   1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include <windows.h>
   7
   8 #include "DisplayConfigWindows.h"
   9
  10 namespace mozilla {
  11 namespace gfx {
  12
  13 using namespace std;
  14
  15 optional<DisplayConfig> GetDisplayConfig() {
  16   LONG result;
  17
  18   UINT32 numPaths;
  19   UINT32 numModes;
  20   vector<DISPLAYCONFIG_PATH_INFO> paths;
  21   vector<DISPLAYCONFIG_MODE_INFO> modes;
  22   do {
  23     result = GetDisplayConfigBufferSizes(QDC_ONLY_ACTIVE_PATHS, &numPaths,
  24                                          &numModes);
  25     if (result != ERROR_SUCCESS) {
  26       return {};
  27     }
  28     // allocate the recommended amount of space
  29     paths.resize(numPaths);
  30     modes.resize(numModes);
  31
  32     result = QueryDisplayConfig(QDC_ONLY_ACTIVE_PATHS, &numPaths, paths.data(),
  33                                 &numModes, modes.data(), NULL);
  34     // try again if there wasn't enough space
  35   } while (result == ERROR_INSUFFICIENT_BUFFER);
  36
  37   if (result != ERROR_SUCCESS) return {};
  38
  39   // shrink to fit the actual number of modes and paths returned
  40   modes.resize(numModes);
  41   paths.resize(numPaths);
  42
  43   return DisplayConfig{paths, modes};
  44 }
  45
  46 bool HasScaledResolution() {
  47   auto config = GetDisplayConfig();
  48   if (config) {
  49     for (auto& path : config->mPaths) {
  50       auto& modes = config->mModes;
  51       int targetModeIndex = path.targetInfo.modeInfoIdx;
  52       int sourceModeIndex = path.sourceInfo.modeInfoIdx;
  53
  54       // Check if the source and target resolutions are different
  55       if ((modes[targetModeIndex]
  56                .targetMode.targetVideoSignalInfo.activeSize.cx !=
  57            modes[sourceModeIndex].sourceMode.width) ||
  58           (modes[targetModeIndex]
  59                .targetMode.targetVideoSignalInfo.activeSize.cy !=
  60            modes[sourceModeIndex].sourceMode.height)) {
  61         return true;
  62       }
  63     }
  64   }
  65   return false;
  66 }
  67
  68 void GetScaledResolutions(ScaledResolutionSet& aRv) {
  69   auto config = GetDisplayConfig();
  70   if (config) {
  71     for (auto& path : config->mPaths) {
  72       auto& modes = config->mModes;
  73       int targetModeIndex = path.targetInfo.modeInfoIdx;
  74       int sourceModeIndex = path.sourceInfo.modeInfoIdx;
  75
  76       // Check if the source and target resolutions are different
  77       IntSize src(modes[sourceModeIndex].sourceMode.width,
  78                   modes[sourceModeIndex].sourceMode.height);
  79       IntSize dst(
  80           modes[targetModeIndex].targetMode.targetVideoSignalInfo.activeSize.cx,
  81           modes[targetModeIndex]
  82               .targetMode.targetVideoSignalInfo.activeSize.cy);
  83       if (src != dst) {
  84         aRv.AppendElement(std::pair<IntSize, IntSize>{src, dst});
  85       }
  86     }
  87   }
  88 }
  89
  90 }  // namespace gfx
  91 }  // namespace mozilla