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