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 #include <wingdi.h>
   9 #include <optional>
  10 #include <vector>
  11
  12 #include "DisplayConfigWindows.h"
  13
  14 namespace mozilla {
  15 namespace gfx {
  16
  17 using namespace std;
  18
  19 struct DisplayConfig {
  20   vector<DISPLAYCONFIG_PATH_INFO> mPaths;
  21   vector<DISPLAYCONFIG_MODE_INFO> mModes;
  22 };
  23
  24 optional<DisplayConfig> GetDisplayConfig() {
  25   LONG result;
  26
  27   UINT32 numPaths;
  28   UINT32 numModes;
  29   vector<DISPLAYCONFIG_PATH_INFO> paths;
  30   vector<DISPLAYCONFIG_MODE_INFO> modes;
  31   do {
  32     result = GetDisplayConfigBufferSizes(QDC_ONLY_ACTIVE_PATHS, &numPaths,
  33                                          &numModes);
  34     if (result != ERROR_SUCCESS) {
  35       return {};
  36     }
  37     // allocate the recommended amount of space
  38     paths.resize(numPaths);
  39     modes.resize(numModes);
  40
  41     result = QueryDisplayConfig(QDC_ONLY_ACTIVE_PATHS, &numPaths, paths.data(),
  42                                 &numModes, modes.data(), NULL);
  43     // try again if there wasn't enough space
  44   } while (result == ERROR_INSUFFICIENT_BUFFER);
  45
  46   if (result != ERROR_SUCCESS) return {};
  47
  48   // shrink to fit the actual number of modes and paths returned
  49   modes.resize(numModes);
  50   paths.resize(numPaths);
  51
  52   return DisplayConfig{paths, modes};
  53 }
  54
  55 bool HasScaledResolution() {
  56   auto config = GetDisplayConfig();
  57   if (config) {
  58     for (auto& path : config->mPaths) {
  59       auto& modes = config->mModes;
  60       int targetModeIndex = path.targetInfo.modeInfoIdx;
  61       int sourceModeIndex = path.sourceInfo.modeInfoIdx;
  62
  63       // Check if the source and target resolutions are different
  64       if ((modes[targetModeIndex]
  65                .targetMode.targetVideoSignalInfo.activeSize.cx !=
  66            modes[sourceModeIndex].sourceMode.width) ||
  67           (modes[targetModeIndex]
  68                .targetMode.targetVideoSignalInfo.activeSize.cy !=
  69            modes[sourceModeIndex].sourceMode.height)) {
  70         return true;
  71       }
  72     }
  73   }
  74   return false;
  75 }
  76
  77 void GetScaledResolutions(ScaledResolutionSet& aRv) {
  78   auto config = GetDisplayConfig();
  79   if (config) {
  80     for (auto& path : config->mPaths) {
  81       auto& modes = config->mModes;
  82       int targetModeIndex = path.targetInfo.modeInfoIdx;
  83       int sourceModeIndex = path.sourceInfo.modeInfoIdx;
  84
  85       // Check if the source and target resolutions are different
  86       IntSize src(modes[sourceModeIndex].sourceMode.width,
  87                   modes[sourceModeIndex].sourceMode.height);
  88       IntSize dst(
  89           modes[targetModeIndex].targetMode.targetVideoSignalInfo.activeSize.cx,
  90           modes[targetModeIndex]
  91               .targetMode.targetVideoSignalInfo.activeSize.cy);
  92       if (src != dst) {
  93         aRv.AppendElement(std::pair<IntSize, IntSize>{src, dst});
  94       }
  95     }
  96   }
  97 }
  98
  99 }  // namespace gfx
 100 }  // namespace mozilla