[idd] helper: add parser for mode settings in registry

idd/LGIdd/LGIdd.vcxproj.filters

@@ -85,6 +85,8 @@
     <ClInclude Include="CSettings.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)/LGCommon/*.h" />
+    <ClInclude Include="$(SolutionDir)/LGCommon/*.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="Device.cpp">
@@ -137,5 +139,6 @@
     <ClCompile Include="CSettings.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)LGCommon/*.cpp" />
   </ItemGroup>
 </Project>

idd/LGIddHelper/CRegistrySettings.cpp

@@ -0,0 +1,119 @@
+#include "CRegistrySettings.h"
+
+#include <optional>
+#include <regex>
+#include <CDebug.h>
+
+#define LGIDD_REGKEY L"SOFTWARE\\LookingGlass\\IDD"
+
+CRegistrySettings::CRegistrySettings() : hKey(nullptr) {}
+
+CRegistrySettings::~CRegistrySettings()
+{
+  if (hKey)
+    RegCloseKey(hKey);
+}
+
+LSTATUS CRegistrySettings::open()
+{
+  HKEY key;
+  LSTATUS result = RegOpenKeyEx(HKEY_LOCAL_MACHINE, LGIDD_REGKEY, 0, KEY_QUERY_VALUE, &key);
+
+  if (result == ERROR_SUCCESS)
+    hKey = key;
+  
+  return result;
+}
+
+template<class T>
+static std::basic_string<T> trim(const std::basic_string<T> &s)
+{
+  size_t b = 0, e = s.size();
+  while (b < e && iswspace(s[b]))
+    ++b;
+  while (e > b && iswspace(s[e - 1]))
+    --e;
+  return s.substr(b, e - b);
+}
+
+static std::wregex displayMode(L"(\\d+)x(\\d+)@(\\d+)(\\*)?");
+
+static std::optional<DisplayMode> parseDisplayMode(const std::wstring &str)
+{
+  std::wstring trimmed = trim(str);
+  std::wsmatch match;
+
+  if (!std::regex_match(trimmed, match, displayMode))
+    return {};
+
+  DisplayMode mode;
+  mode.width = std::stoul(match[1]);
+  mode.height = std::stoul(match[2]);
+  mode.refresh = std::stoul(match[3]);
+  mode.preferred = match[4] == L"*";
+  return mode;
+}
+
+std::optional<std::vector<DisplayMode>> CRegistrySettings::getModes()
+{
+  LSTATUS status;
+
+  DWORD type = 0, cb = 0;
+  status = RegGetValue(hKey, nullptr, L"Modes", RRF_RT_REG_MULTI_SZ, &type, nullptr, &cb);
+  if (status != ERROR_SUCCESS)
+  {
+    DEBUG_ERROR_HR(status, "RegGetValue(Modes) length computation");
+    return {};
+  }
+
+  LPWSTR buf = (LPWSTR) malloc(cb);
+  if (!buf)
+  {
+    DEBUG_ERROR("Failed to allocate memory for RegGetValue(Modes)");
+    return {};
+  }
+
+  status = RegGetValueW(hKey, nullptr, L"Modes", RRF_RT_REG_MULTI_SZ, &type, buf, &cb);
+  if (status != ERROR_SUCCESS)
+  {
+    DEBUG_ERROR_HR(status, "RegGetValue(Modes) read");
+    free(buf);
+    return {};
+  }
+
+  std::vector<DisplayMode> result;
+  for (LPWSTR s = buf; *s; s += wcslen(s) + 1)
+  {
+    auto mode = parseDisplayMode(s);
+    if (mode.has_value())
+      result.emplace_back(std::move(mode.value()));
+  }
+  free(buf);
+  return result;
+}
+
+LSTATUS CRegistrySettings::setModes(const std::vector<DisplayMode> &modes)
+{
+  std::wstring serialized;
+  for (auto mode : modes)
+  {
+    serialized.append(mode.toString());
+    serialized.push_back('\0');
+  }
+
+  return RegSetValueEx(hKey, L"Modes", 0, REG_MULTI_SZ, (PBYTE)serialized.c_str(),
+    (DWORD)(serialized.length() + 1) * sizeof(wchar_t));
+}
+
+std::wstring DisplayMode::toString()
+{
+  std::wstring serialized;
+  serialized.append(std::to_wstring(width));
+  serialized.push_back('x');
+  serialized.append(std::to_wstring(height));
+  serialized.push_back('@');
+  serialized.append(std::to_wstring(refresh));
+  if (preferred)
+    serialized.push_back('*');
+  return serialized;
+}

idd/LGIddHelper/CRegistrySettings.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <optional>
+#include <vector>
+#include <string>
+#include <windows.h>
+
+struct DisplayMode {
+  unsigned width;
+  unsigned height;
+  unsigned refresh;
+  bool     preferred;
+
+  std::wstring toString();
+};
+
+class CRegistrySettings {
+  HKEY hKey;
+
+public:
+  CRegistrySettings();
+  ~CRegistrySettings();
+
+  LSTATUS open();
+  bool isOpen() { return !!hKey; }
+
+  std::optional<std::vector<DisplayMode>> getModes();
+  LSTATUS setModes(const std::vector<DisplayMode> &modes);
+};

idd/LGIddHelper/LGIddHelper.vcxproj

@@ -78,6 +78,7 @@
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;WIN32_LEAN_AND_MEAN;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>$(SolutionDir)LGCommon;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <LanguageStandard>stdcpp17</LanguageStandard>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -102,6 +103,7 @@ copy /Y "$(ProjectDir)VERSION" "$(SolutionDir)$(Platform)\$(Configuration)\LGIdd
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;WIN32_LEAN_AND_MEAN;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>$(SolutionDir)LGCommon;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <LanguageStandard>stdcpp17</LanguageStandard>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -125,7 +127,7 @@ copy /Y "$(ProjectDir)VERSION" "$(SolutionDir)$(Platform)\$(Configuration)\LGIdd
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>_DEBUG;_CONSOLE;WIN32_LEAN_AND_MEAN;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <LanguageStandard>Default</LanguageStandard>
+      <LanguageStandard>stdcpp17</LanguageStandard>
       <LanguageStandard_C>Default</LanguageStandard_C>
       <AdditionalIncludeDirectories>$(SolutionDir)LGCommon;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
@@ -153,7 +155,7 @@ copy /Y "$(ProjectDir)VERSION" "$(SolutionDir)$(Platform)\$(Configuration)\LGIdd
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>NDEBUG;_CONSOLE;WIN32_LEAN_AND_MEAN;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <LanguageStandard>Default</LanguageStandard>
+      <LanguageStandard>stdcpp17</LanguageStandard>
       <LanguageStandard_C>Default</LanguageStandard_C>
       <AdditionalIncludeDirectories>$(SolutionDir)LGCommon;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
@@ -180,6 +182,7 @@ copy /Y "$(ProjectDir)VERSION" "$(SolutionDir)$(Platform)\$(Configuration)\LGIdd
     <ClCompile Include="CConfigWindow.cpp" />
     <ClCompile Include="CNotifyWindow.cpp" />
     <ClCompile Include="CPipeClient.cpp" />
+    <ClCompile Include="CRegistrySettings.cpp" />
     <ClCompile Include="CStaticWidget.cpp" />
     <ClCompile Include="CWidget.cpp" />
     <ClCompile Include="CWindow.cpp" />
@@ -190,6 +193,7 @@ copy /Y "$(ProjectDir)VERSION" "$(SolutionDir)$(Platform)\$(Configuration)\LGIdd
     <ClInclude Include="CConfigWindow.h" />
     <ClInclude Include="CNotifyWindow.h" />
     <ClInclude Include="CPipeClient.h" />
+    <ClInclude Include="CRegistrySettings.h" />
     <ClInclude Include="CStaticWidget.h" />
     <ClInclude Include="CWidget.h" />
     <ClInclude Include="UIHelpers.h" />

idd/LGIddHelper/LGIddHelper.vcxproj.filters

@@ -39,6 +39,10 @@
     <ClCompile Include="CWidget.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)LGCommon\*.cpp" />
+    <ClCompile Include="CRegistrySettings.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <CLInclude Include="$(SolutionDir)LGCommon\*.h" />
@@ -67,6 +71,11 @@
     <ClInclude Include="UIHelpers.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <CLInclude Include="$(SolutionDir)LGCommon\*.h" />
+    <CLInclude Include="$(SolutionDir)LGCommon\*.h" />
+    <ClInclude Include="CRegistrySettings.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="packages.config" />