discord: Add namespace and cleanup CMakeLists

3rdparty/discord-rpc/src/CMakeLists.txt

@@ -0,0 +1,41 @@
+set(DISCORD_RPC_SOURCES
+  ../include/discord_rpc.h
+  ../include/discord_register.h
+  discord_rpc.cpp
+  rpc_connection.h
+  rpc_connection.cpp
+  serialization.h
+  serialization.cpp
+  connection.h
+  backoff.h
+  msg_queue.h
+)
+
+if(UNIX)
+  list(APPEND DISCORD_RPC_SOURCES connection_unix.cpp)
+  if(APPLE)
+    list(APPEND DISCORD_RPC_SOURCES discord_register_osx.m)
+    add_definitions(-DDISCORD_OSX)
+  else()
+    list(APPEND DISCORD_RPC_SOURCES discord_register_linux.cpp)
+    add_definitions(-DDISCORD_LINUX)
+  endif()
+endif()
+
+if(WIN32)
+  list(APPEND DISCORD_RPC_SOURCES connection_win.cpp discord_register_win.cpp)
+  add_definitions(-DDISCORD_WINDOWS)
+endif()
+
+add_library(discord-rpc STATIC ${DISCORD_RPC_SOURCES})
+
+if(APPLE)
+  target_link_libraries(discord-rpc PRIVATE "-framework AppKit")
+endif()
+
+if(WIN32)
+  target_link_libraries(discord-rpc PRIVATE psapi advapi32)
+endif()
+
+target_include_directories(discord-rpc SYSTEM PRIVATE ${RapidJSON_INCLUDE_DIRS})
+target_include_directories(discord-rpc PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../include)

3rdparty/discord-rpc/src/backoff.h

@@ -0,0 +1,44 @@
+#pragma once
+
+#include <algorithm>
+#include <random>
+#include <cstdint>
+#include <ctime>
+
+namespace discord_rpc {
+
+struct Backoff {
+    int64_t minAmount;
+    int64_t maxAmount;
+    int64_t current;
+    int fails;
+    std::mt19937_64 randGenerator;
+    std::uniform_real_distribution<> randDistribution;
+
+    double rand01() { return randDistribution(randGenerator); }
+
+    Backoff(int64_t min, int64_t max)
+      : minAmount(min)
+      , maxAmount(max)
+      , current(min)
+      , fails(0)
+      , randGenerator(static_cast<uint64_t>(time(0)))
+    {
+    }
+
+    void reset()
+    {
+        fails = 0;
+        current = minAmount;
+    }
+
+    int64_t nextDelay()
+    {
+        ++fails;
+        int64_t delay = static_cast<int64_t>(static_cast<double>(current) * 2.0 * rand01());
+        current = std::min(current + delay, maxAmount);
+        return current;
+    }
+};
+
+}  // namespace discord_rpc

3rdparty/discord-rpc/src/connection.h

@@ -0,0 +1,22 @@
+#pragma once
+
+// This is to wrap the platform specific kinds of connect/read/write.
+
+#include <cstdlib>
+
+namespace discord_rpc {
+
+// not really connectiony, but need per-platform
+int GetProcessId();
+
+struct BaseConnection {
+  static BaseConnection *Create();
+  static void Destroy(BaseConnection *&);
+  bool isOpen { false };
+  bool Open();
+  bool Close();
+  bool Write(const void *data, size_t length);
+  bool Read(void *data, size_t length);
+};
+
+} // namespace discord_rpc

3rdparty/discord-rpc/src/connection_unix.cpp

@@ -0,0 +1,122 @@
+#include "connection.h"
+
+#include <cerrno>
+#include <fcntl.h>
+#include <cstdio>
+#include <cstring>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+namespace discord_rpc {
+
+int GetProcessId() {
+  return ::getpid();
+}
+
+struct BaseConnectionUnix : public BaseConnection {
+  int sock { -1 };
+};
+
+static BaseConnectionUnix Connection;
+static sockaddr_un PipeAddr {};
+#ifdef MSG_NOSIGNAL
+static int MsgFlags = MSG_NOSIGNAL;
+#else
+static int MsgFlags = 0;
+#endif
+
+static const char *GetTempPath() {
+  const char *temp = getenv("XDG_RUNTIME_DIR");
+  temp = temp ? temp : getenv("TMPDIR");
+  temp = temp ? temp : getenv("TMP");
+  temp = temp ? temp : getenv("TEMP");
+  temp = temp ? temp : "/tmp";
+  return temp;
+}
+
+/*static*/ BaseConnection *BaseConnection::Create() {
+  PipeAddr.sun_family = AF_UNIX;
+  return &Connection;
+}
+
+/*static*/ void BaseConnection::Destroy(BaseConnection *&c) {
+  auto self = reinterpret_cast<BaseConnectionUnix *>(c);
+  self->Close();
+  c = nullptr;
+}
+
+bool BaseConnection::Open() {
+  const char *tempPath = GetTempPath();
+  auto self = reinterpret_cast<BaseConnectionUnix *>(this);
+  self->sock = socket(AF_UNIX, SOCK_STREAM, 0);
+  if (self->sock == -1) {
+    return false;
+  }
+  fcntl(self->sock, F_SETFL, O_NONBLOCK);
+#ifdef SO_NOSIGPIPE
+  int optval = 1;
+  setsockopt(self->sock, SOL_SOCKET, SO_NOSIGPIPE, &optval, sizeof(optval));
+#endif
+
+  for (int pipeNum = 0; pipeNum < 10; ++pipeNum) {
+    snprintf(
+      PipeAddr.sun_path, sizeof(PipeAddr.sun_path), "%s/discord-ipc-%d", tempPath, pipeNum);
+    int err = connect(self->sock, reinterpret_cast<const sockaddr*>(&PipeAddr), sizeof(PipeAddr));
+    if (err == 0) {
+      self->isOpen = true;
+      return true;
+    }
+  }
+  self->Close();
+  return false;
+}
+
+bool BaseConnection::Close() {
+  auto self = reinterpret_cast<BaseConnectionUnix *>(this);
+  if (self->sock == -1) {
+    return false;
+  }
+  close(self->sock);
+  self->sock = -1;
+  self->isOpen = false;
+  return true;
+}
+
+bool BaseConnection::Write(const void *data, size_t length) {
+  auto self = reinterpret_cast<BaseConnectionUnix *>(this);
+
+  if (self->sock == -1) {
+    return false;
+  }
+
+  ssize_t sentBytes = send(self->sock, data, length, MsgFlags);
+  if (sentBytes < 0) {
+    Close();
+  }
+  return sentBytes == static_cast<ssize_t>(length);
+}
+
+bool BaseConnection::Read(void *data, size_t length) {
+  auto self = reinterpret_cast<BaseConnectionUnix *>(this);
+
+  if (self->sock == -1) {
+    return false;
+  }
+
+  long res = recv(self->sock, data, length, MsgFlags);
+  if (res < 0) {
+    if (errno == EAGAIN) {
+      return false;
+    }
+    Close();
+  }
+  else if (res == 0) {
+    Close();
+  }
+  return static_cast<size_t>(res) == length;
+}
+
+} // namespace discord_rpc
+

3rdparty/discord-rpc/src/connection_win.cpp

@@ -0,0 +1,126 @@
+#include "connection.h"
+
+#define WIN32_LEAN_AND_MEAN
+#define NOMCX
+#define NOSERVICE
+#define NOIME
+#include <cassert>
+#include <windows.h>
+
+namespace discord_rpc {
+
+int GetProcessId() {
+  return static_cast<int>(::GetCurrentProcessId());
+}
+
+struct BaseConnectionWin : public BaseConnection {
+  HANDLE pipe { INVALID_HANDLE_VALUE };
+};
+
+static BaseConnectionWin Connection;
+
+/*static*/ BaseConnection *BaseConnection::Create() {
+  return &Connection;
+}
+
+/*static*/ void BaseConnection::Destroy(BaseConnection *&c) {
+  auto self = reinterpret_cast<BaseConnectionWin*>(c);
+  self->Close();
+  c = nullptr;
+}
+
+bool BaseConnection::Open() {
+  wchar_t pipeName[] { L"\\\\?\\pipe\\discord-ipc-0" };
+  const size_t pipeDigit = sizeof(pipeName) / sizeof(wchar_t) - 2;
+  pipeName[pipeDigit] = L'0';
+  auto self = reinterpret_cast<BaseConnectionWin *>(this);
+  for (;;) {
+    self->pipe = ::CreateFileW(
+      pipeName, GENERIC_READ | GENERIC_WRITE, 0, nullptr, OPEN_EXISTING, 0, nullptr);
+    if (self->pipe != INVALID_HANDLE_VALUE) {
+      self->isOpen = true;
+      return true;
+    }
+
+    auto lastError = GetLastError();
+    if (lastError == ERROR_FILE_NOT_FOUND) {
+      if (pipeName[pipeDigit] < L'9') {
+        pipeName[pipeDigit]++;
+        continue;
+      }
+    }
+    else if (lastError == ERROR_PIPE_BUSY) {
+      if (!WaitNamedPipeW(pipeName, 10000)) {
+        return false;
+      }
+      continue;
+    }
+    return false;
+  }
+}
+
+bool BaseConnection::Close() {
+  auto self = reinterpret_cast<BaseConnectionWin *>(this);
+  ::CloseHandle(self->pipe);
+  self->pipe = INVALID_HANDLE_VALUE;
+  self->isOpen = false;
+  return true;
+}
+
+bool BaseConnection::Write(const void *data, size_t length) {
+  if (length == 0) {
+    return true;
+  }
+  auto self = reinterpret_cast<BaseConnectionWin *>(this);
+  assert(self);
+  if (!self) {
+    return false;
+  }
+  if (self->pipe == INVALID_HANDLE_VALUE) {
+    return false;
+  }
+  assert(data);
+  if (!data) {
+    return false;
+  }
+  const DWORD bytesLength = static_cast<DWORD>(length);
+  DWORD bytesWritten = 0;
+  return ::WriteFile(self->pipe, data, bytesLength, &bytesWritten, nullptr) == TRUE &&
+    bytesWritten == bytesLength;
+}
+
+bool BaseConnection::Read(void *data, size_t length) {
+  assert(data);
+  if (!data) {
+    return false;
+  }
+  auto self = reinterpret_cast<BaseConnectionWin *>(this);
+  assert(self);
+  if (!self) {
+    return false;
+  }
+  if (self->pipe == INVALID_HANDLE_VALUE) {
+    return false;
+  }
+  DWORD bytesAvailable = 0;
+  if (::PeekNamedPipe(self->pipe, nullptr, 0, nullptr, &bytesAvailable, nullptr)) {
+    if (bytesAvailable >= length) {
+      DWORD bytesToRead = static_cast<DWORD>(length);
+      DWORD bytesRead = 0;
+      if (::ReadFile(self->pipe, data, bytesToRead, &bytesRead, nullptr) == TRUE) {
+        assert(bytesToRead == bytesRead);
+        return true;
+      }
+      else {
+        Close();
+      }
+    }
+  }
+  else {
+    Close();
+  }
+  return false;
+}
+
+}  // namespace discord_rpc
+

3rdparty/discord-rpc/src/discord_register_linux.cpp

@@ -0,0 +1,104 @@
+#include "discord_rpc.h"
+#include "discord_register.h"
+
+#include <cstdio>
+#include <errno.h>
+#include <cstdlib>
+#include <cstring>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+namespace {
+
+static bool Mkdir(const char *path) {
+  int result = mkdir(path, 0755);
+  if (result == 0) {
+    return true;
+  }
+  if (errno == EEXIST) {
+    return true;
+  }
+  return false;
+}
+
+}  // namespace
+
+// we want to register games so we can run them from Discord client as discord-<appid>://
+extern "C" void Discord_Register(const char *applicationId, const char *command) {
+  // Add a desktop file and update some mime handlers so that xdg-open does the right thing.
+
+  const char *home = getenv("HOME");
+  if (!home) {
+    return;
+  }
+
+  char exePath[1024];
+  if (!command || !command[0]) {
+    ssize_t size = readlink("/proc/self/exe", exePath, sizeof(exePath));
+    if (size <= 0 || size >= static_cast<ssize_t>(sizeof(exePath))) {
+      return;
+    }
+    exePath[size] = '\0';
+    command = exePath;
+  }
+
+  constexpr char desktopFileFormat[] = "[Desktop Entry]\n"
+                                  "Name=Game %s\n"
+                                  "Exec=%s %%u\n"  // note: it really wants that %u in there
+                                  "Type=Application\n"
+                                  "NoDisplay=true\n"
+                                  "Categories=Discord;Games;\n"
+                                  "MimeType=x-scheme-handler/discord-%s;\n";
+  char desktopFile[2048];
+  int fileLen = snprintf(
+    desktopFile, sizeof(desktopFile), desktopFileFormat, applicationId, command, applicationId);
+  if (fileLen <= 0) {
+    return;
+  }
+
+  char desktopFilename[256];
+  (void)snprintf(desktopFilename, sizeof(desktopFilename), "/discord-%s.desktop", applicationId);
+
+  char desktopFilePath[1024];
+  (void)snprintf(desktopFilePath, sizeof(desktopFilePath), "%s/.local", home);
+  if (!Mkdir(desktopFilePath)) {
+    return;
+  }
+  strcat(desktopFilePath, "/share");
+  if (!Mkdir(desktopFilePath)) {
+    return;
+  }
+  strcat(desktopFilePath, "/applications");
+  if (!Mkdir(desktopFilePath)) {
+    return;
+  }
+  strcat(desktopFilePath, desktopFilename);
+
+  FILE *fp = fopen(desktopFilePath, "w");
+  if (fp) {
+    fwrite(desktopFile, 1, fileLen, fp);
+    fclose(fp);
+  }
+  else {
+    return;
+  }
+
+  char xdgMimeCommand[1024];
+  snprintf(xdgMimeCommand,
+           sizeof(xdgMimeCommand),
+           "xdg-mime default discord-%s.desktop x-scheme-handler/discord-%s",
+           applicationId,
+           applicationId);
+  if (system(xdgMimeCommand) < 0) {
+    fprintf(stderr, "Failed to register mime handler\n");
+  }
+}
+
+extern "C" void Discord_RegisterSteamGame(const char *applicationId,
+                                          const char *steamId) {
+  char command[256];
+  sprintf(command, "xdg-open steam://rungameid/%s", steamId);
+  Discord_Register(applicationId, command);
+}
+

3rdparty/discord-rpc/src/discord_register_osx.m

@@ -0,0 +1,80 @@
+#include <stdio.h>
+#include <sys/stat.h>
+
+#import <AppKit/AppKit.h>
+
+#include "discord_register.h"
+
+static void RegisterCommand(const char* applicationId, const char* command)
+{
+    // There does not appear to be a way to register arbitrary commands on OSX, so instead we'll save the command
+    // to a file in the Discord config path, and when it is needed, Discord can try to load the file there, open
+    // the command therein (will pass to js's window.open, so requires a url-like thing)
+
+    // Note: will not work for sandboxed apps
+  	NSString *home = NSHomeDirectory();
+    if (!home) {
+        return;
+    }
+
+    NSString *path = [[[[[[home stringByAppendingPathComponent:@"Library"]
+                                stringByAppendingPathComponent:@"Application Support"]
+                                stringByAppendingPathComponent:@"discord"]
+                                stringByAppendingPathComponent:@"games"]
+                                stringByAppendingPathComponent:[NSString stringWithUTF8String:applicationId]]
+                                stringByAppendingPathExtension:@"json"];
+    [[NSFileManager defaultManager] createDirectoryAtPath:[path stringByDeletingLastPathComponent] withIntermediateDirectories:YES attributes:nil error:nil];
+
+    NSString *jsonBuffer = [NSString stringWithFormat:@"{\"command\": \"%s\"}", command];
+    [jsonBuffer writeToFile:path atomically:NO encoding:NSUTF8StringEncoding error:nil];
+}
+
+static void RegisterURL(const char* applicationId)
+{
+    char url[256];
+    snprintf(url, sizeof(url), "discord-%s", applicationId);
+    CFStringRef cfURL = CFStringCreateWithCString(NULL, url, kCFStringEncodingUTF8);
+
+    NSString* myBundleId = [[NSBundle mainBundle] bundleIdentifier];
+    if (!myBundleId) {
+        fprintf(stderr, "No bundle id found\n");
+        return;
+    }
+
+    NSURL* myURL = [[NSBundle mainBundle] bundleURL];
+    if (!myURL) {
+        fprintf(stderr, "No bundle url found\n");
+        return;
+    }
+
+    OSStatus status = LSSetDefaultHandlerForURLScheme(cfURL, (__bridge CFStringRef)myBundleId);
+    if (status != noErr) {
+        fprintf(stderr, "Error in LSSetDefaultHandlerForURLScheme: %d\n", (int)status);
+        return;
+    }
+
+    status = LSRegisterURL((__bridge CFURLRef)myURL, true);
+    if (status != noErr) {
+        fprintf(stderr, "Error in LSRegisterURL: %d\n", (int)status);
+    }
+}
+
+void Discord_Register(const char* applicationId, const char* command)
+{
+    if (command) {
+        RegisterCommand(applicationId, command);
+    }
+    else {
+        // raii lite
+        @autoreleasepool {
+            RegisterURL(applicationId);
+        }
+    }
+}
+
+void Discord_RegisterSteamGame(const char* applicationId, const char* steamId)
+{
+    char command[256];
+    snprintf(command, 256, "steam://rungameid/%s", steamId);
+    Discord_Register(applicationId, command);
+}

3rdparty/discord-rpc/src/discord_register_win.cpp

@@ -0,0 +1,183 @@
+#include "discord_rpc.h"
+#include "discord_register.h"
+
+#define WIN32_LEAN_AND_MEAN
+#define NOMCX
+#define NOSERVICE
+#define NOIME
+#include <windows.h>
+#include <psapi.h>
+#include <cstdio>
+
+/**
+ * Updated fixes for MinGW and WinXP
+ * This block is written the way it does not involve changing the rest of the code
+ * Checked to be compiling
+ * 1) strsafe.h belongs to Windows SDK and cannot be added to MinGW
+ * #include guarded, functions redirected to <string.h> substitutes
+ * 2) RegSetKeyValueW and LSTATUS are not declared in <winreg.h>
+ * The entire function is rewritten
+ */
+#ifdef __MINGW32__
+#  include <wchar.h>
+/// strsafe.h fixes
+static HRESULT StringCbPrintfW(LPWSTR pszDest, size_t cbDest, LPCWSTR pszFormat, ...) {
+  HRESULT ret;
+  va_list va;
+  va_start(va, pszFormat);
+  cbDest /= 2;  // Size is divided by 2 to convert from bytes to wide characters - causes segfault
+                // othervise
+  ret = vsnwprintf(pszDest, cbDest, pszFormat, va);
+  pszDest[cbDest - 1] = 0;  // Terminate the string in case a buffer overflow; -1 will be returned
+  va_end(va);
+  return ret;
+}
+#else
+#  include <cwchar>
+#  include <strsafe.h>
+#endif  // __MINGW32__
+
+/// winreg.h fixes
+#ifndef LSTATUS
+#  define LSTATUS LONG
+#endif
+#ifdef RegSetKeyValueW
+#  undefine RegSetKeyValueW
+#endif
+#define RegSetKeyValueW regset
+
+static LSTATUS regset(HKEY hkey,
+                      LPCWSTR subkey,
+                      LPCWSTR name,
+                      DWORD type,
+                      const void *data,
+                      DWORD len) {
+  HKEY htkey = hkey, hsubkey = nullptr;
+  LSTATUS ret;
+  if (subkey && subkey[0]) {
+    if ((ret = RegCreateKeyExW(hkey, subkey, 0, 0, 0, KEY_ALL_ACCESS, 0, &hsubkey, 0)) !=
+        ERROR_SUCCESS)
+      return ret;
+    htkey = hsubkey;
+  }
+  ret = RegSetValueExW(htkey, name, 0, type, static_cast<const BYTE*>(data), len);
+  if (hsubkey && hsubkey != hkey)
+    RegCloseKey(hsubkey);
+  return ret;
+}
+
+static void Discord_RegisterW(const wchar_t *applicationId, const wchar_t *command) {
+  // https://msdn.microsoft.com/en-us/library/aa767914(v=vs.85).aspx
+  // we want to register games so we can run them as discord-<appid>://
+  // Update the HKEY_CURRENT_USER, because it doesn't seem to require special permissions.
+
+  wchar_t exeFilePath[MAX_PATH];
+  DWORD exeLen = GetModuleFileNameW(nullptr, exeFilePath, MAX_PATH);
+  wchar_t openCommand[1024];
+
+  if (command && command[0]) {
+    StringCbPrintfW(openCommand, sizeof(openCommand), L"%s", command);
+  }
+  else {
+    // StringCbCopyW(openCommand, sizeof(openCommand), exeFilePath);
+    StringCbPrintfW(openCommand, sizeof(openCommand), L"%s", exeFilePath);
+  }
+
+  wchar_t protocolName[64];
+  StringCbPrintfW(protocolName, sizeof(protocolName), L"discord-%s", applicationId);
+  wchar_t protocolDescription[128];
+  StringCbPrintfW(
+    protocolDescription, sizeof(protocolDescription), L"URL:Run game %s protocol", applicationId);
+  wchar_t urlProtocol = 0;
+
+  wchar_t keyName[256];
+  StringCbPrintfW(keyName, sizeof(keyName), L"Software\\Classes\\%s", protocolName);
+  HKEY key;
+  auto status =
+    RegCreateKeyExW(HKEY_CURRENT_USER, keyName, 0, nullptr, 0, KEY_WRITE, nullptr, &key, nullptr);
+  if (status != ERROR_SUCCESS) {
+    fprintf(stderr, "Error creating key\n");
+    return;
+  }
+  DWORD len;
+  LSTATUS result;
+  len = static_cast<DWORD>(lstrlenW(protocolDescription) + 1);
+  result =
+    RegSetKeyValueW(key, nullptr, nullptr, REG_SZ, protocolDescription, len * sizeof(wchar_t));
+  if (FAILED(result)) {
+    fprintf(stderr, "Error writing description\n");
+  }
+
+  len = static_cast<DWORD>(lstrlenW(protocolDescription) + 1);
+  result = RegSetKeyValueW(key, nullptr, L"URL Protocol", REG_SZ, &urlProtocol, sizeof(wchar_t));
+  if (FAILED(result)) {
+    fprintf(stderr, "Error writing description\n");
+  }
+
+  result = RegSetKeyValueW(
+    key, L"DefaultIcon", nullptr, REG_SZ, exeFilePath, (exeLen + 1) * sizeof(wchar_t));
+  if (FAILED(result)) {
+    fprintf(stderr, "Error writing icon\n");
+  }
+
+  len = static_cast<DWORD>(lstrlenW(openCommand) + 1);
+  result = RegSetKeyValueW(
+    key, L"shell\\open\\command", nullptr, REG_SZ, openCommand, len * sizeof(wchar_t));
+  if (FAILED(result)) {
+    fprintf(stderr, "Error writing command\n");
+  }
+  RegCloseKey(key);
+}
+
+extern "C" void Discord_Register(const char *applicationId, const char *command) {
+  wchar_t appId[32];
+  MultiByteToWideChar(CP_UTF8, 0, applicationId, -1, appId, 32);
+
+  wchar_t openCommand[1024];
+  const wchar_t *wcommand = nullptr;
+  if (command && command[0]) {
+    const auto commandBufferLen = sizeof(openCommand) / sizeof(*openCommand);
+    MultiByteToWideChar(CP_UTF8, 0, command, -1, openCommand, commandBufferLen);
+    wcommand = openCommand;
+  }
+
+  Discord_RegisterW(appId, wcommand);
+}
+
+extern "C" void Discord_RegisterSteamGame(const char *applicationId,
+                                          const char *steamId) {
+  wchar_t appId[32];
+  MultiByteToWideChar(CP_UTF8, 0, applicationId, -1, appId, 32);
+
+  wchar_t wSteamId[32];
+  MultiByteToWideChar(CP_UTF8, 0, steamId, -1, wSteamId, 32);
+
+  HKEY key;
+  auto status = RegOpenKeyExW(HKEY_CURRENT_USER, L"Software\\Valve\\Steam", 0, KEY_READ, &key);
+  if (status != ERROR_SUCCESS) {
+    fprintf(stderr, "Error opening Steam key\n");
+    return;
+  }
+
+  wchar_t steamPath[MAX_PATH];
+  DWORD pathBytes = sizeof(steamPath);
+  status = RegQueryValueExW(key, L"SteamExe", nullptr, nullptr, (BYTE *)steamPath, &pathBytes);
+  RegCloseKey(key);
+  if (status != ERROR_SUCCESS || pathBytes < 1) {
+    fprintf(stderr, "Error reading SteamExe key\n");
+    return;
+  }
+
+  DWORD pathChars = pathBytes / sizeof(wchar_t);
+  for (DWORD i = 0; i < pathChars; ++i) {
+    if (steamPath[i] == L'/') {
+      steamPath[i] = L'\\';
+    }
+  }
+
+  wchar_t command[1024];
+  StringCbPrintfW(command, sizeof(command), L"\"%s\" steam://rungameid/%s", steamPath, wSteamId);
+
+  Discord_RegisterW(appId, command);
+}
+

3rdparty/discord-rpc/src/discord_rpc.cpp

@@ -0,0 +1,479 @@
+#include "discord_rpc.h"
+
+#include "backoff.h"
+#include "discord_register.h"
+#include "msg_queue.h"
+#include "rpc_connection.h"
+#include "serialization.h"
+
+#include <atomic>
+#include <chrono>
+#include <mutex>
+
+#include <condition_variable>
+#include <thread>
+
+namespace discord_rpc {
+
+constexpr size_t MaxMessageSize { 16 * 1024 };
+constexpr size_t MessageQueueSize { 8 };
+constexpr size_t JoinQueueSize { 8 };
+
+struct QueuedMessage {
+  size_t length;
+  char buffer[MaxMessageSize];
+
+  void Copy(const QueuedMessage &other) {
+    length = other.length;
+    if (length) {
+      memcpy(buffer, other.buffer, length);
+    }
+  }
+};
+
+struct User {
+  // snowflake (64bit int), turned into a ascii decimal string, at most 20 chars +1 null
+  // terminator = 21
+  char userId[32];
+  // 32 unicode glyphs is max name size => 4 bytes per glyph in the worst case, +1 for null
+  // terminator = 129
+  char username[344];
+  // 4 decimal digits + 1 null terminator = 5
+  char discriminator[8];
+  // optional 'a_' + md5 hex digest (32 bytes) + null terminator = 35
+  char avatar[128];
+  // Rounded way up because I'm paranoid about games breaking from future changes in these sizes
+};
+
+static RpcConnection *Connection { nullptr };
+static DiscordEventHandlers QueuedHandlers {};
+static DiscordEventHandlers Handlers {};
+static std::atomic_bool WasJustConnected { false };
+static std::atomic_bool WasJustDisconnected { false };
+static std::atomic_bool GotErrorMessage { false };
+static std::atomic_bool WasJoinGame { false };
+static std::atomic_bool WasSpectateGame { false };
+static std::atomic_bool UpdatePresence { false };
+static char JoinGameSecret[256];
+static char SpectateGameSecret[256];
+static int LastErrorCode { 0 };
+static char LastErrorMessage[256];
+static int LastDisconnectErrorCode { 0 };
+static char LastDisconnectErrorMessage[256];
+static std::mutex PresenceMutex;
+static std::mutex HandlerMutex;
+static QueuedMessage QueuedPresence {};
+static MsgQueue<QueuedMessage, MessageQueueSize> SendQueue;
+static MsgQueue<User, JoinQueueSize> JoinAskQueue;
+static User connectedUser;
+
+// We want to auto connect, and retry on failure, but not as fast as possible. This does expoential
+// backoff from 0.5 seconds to 1 minute
+static Backoff ReconnectTimeMs(500, 60 * 1000);
+static auto NextConnect = std::chrono::system_clock::now();
+static int Pid { 0 };
+static int Nonce { 1 };
+
+static void Discord_UpdateConnection(void);
+class IoThreadHolder {
+ private:
+  std::atomic_bool keepRunning { true };
+  std::mutex waitForIOMutex;
+  std::condition_variable waitForIOActivity;
+  std::thread ioThread;
+
+ public:
+  void Start() {
+    keepRunning.store(true);
+    ioThread = std::thread([&]() {
+      const std::chrono::duration<int64_t, std::milli> maxWait { 500LL };
+      Discord_UpdateConnection();
+      while (keepRunning.load()) {
+        std::unique_lock<std::mutex> lock(waitForIOMutex);
+        waitForIOActivity.wait_for(lock, maxWait);
+        Discord_UpdateConnection();
+      }
+    });
+  }
+
+  void Notify() { waitForIOActivity.notify_all(); }
+
+  void Stop() {
+    keepRunning.exchange(false);
+    Notify();
+    if (ioThread.joinable()) {
+      ioThread.join();
+    }
+  }
+
+  ~IoThreadHolder() { Stop(); }
+};
+static IoThreadHolder *IoThread { nullptr };
+
+static void UpdateReconnectTime() {
+  NextConnect = std::chrono::system_clock::now() +
+    std::chrono::duration<int64_t, std::milli> { ReconnectTimeMs.nextDelay() };
+}
+
+static void Discord_UpdateConnection(void) {
+  if (!Connection) {
+    return;
+  }
+
+  if (!Connection->IsOpen()) {
+    if (std::chrono::system_clock::now() >= NextConnect) {
+      UpdateReconnectTime();
+      Connection->Open();
+    }
+  }
+  else {
+    // reads
+
+    for (;;) {
+      JsonDocument message;
+
+      if (!Connection->Read(message)) {
+        break;
+      }
+
+      const char *evtName = GetStrMember(&message, "evt");
+      const char *nonce = GetStrMember(&message, "nonce");
+
+      if (nonce) {
+        // in responses only -- should use to match up response when needed.
+
+        if (evtName && strcmp(evtName, "ERROR") == 0) {
+          auto data = GetObjMember(&message, "data");
+          LastErrorCode = GetIntMember(data, "code");
+          StringCopy(LastErrorMessage, GetStrMember(data, "message", ""));
+          GotErrorMessage.store(true);
+        }
+      }
+      else {
+        // should have evt == name of event, optional data
+        if (evtName == nullptr) {
+          continue;
+        }
+
+        auto data = GetObjMember(&message, "data");
+
+        if (strcmp(evtName, "ACTIVITY_JOIN") == 0) {
+          auto secret = GetStrMember(data, "secret");
+          if (secret) {
+            StringCopy(JoinGameSecret, secret);
+            WasJoinGame.store(true);
+          }
+        }
+        else if (strcmp(evtName, "ACTIVITY_SPECTATE") == 0) {
+          auto secret = GetStrMember(data, "secret");
+          if (secret) {
+            StringCopy(SpectateGameSecret, secret);
+            WasSpectateGame.store(true);
+          }
+        }
+        else if (strcmp(evtName, "ACTIVITY_JOIN_REQUEST") == 0) {
+          auto user = GetObjMember(data, "user");
+          auto userId = GetStrMember(user, "id");
+          auto username = GetStrMember(user, "username");
+          auto avatar = GetStrMember(user, "avatar");
+          auto joinReq = JoinAskQueue.GetNextAddMessage();
+          if (userId && username && joinReq) {
+            StringCopy(joinReq->userId, userId);
+            StringCopy(joinReq->username, username);
+            auto discriminator = GetStrMember(user, "discriminator");
+            if (discriminator) {
+              StringCopy(joinReq->discriminator, discriminator);
+            }
+            if (avatar) {
+              StringCopy(joinReq->avatar, avatar);
+            }
+            else {
+              joinReq->avatar[0] = 0;
+            }
+            JoinAskQueue.CommitAdd();
+          }
+        }
+      }
+    }
+
+    // writes
+    if (UpdatePresence.exchange(false) && QueuedPresence.length) {
+      QueuedMessage local;
+      {
+        std::lock_guard<std::mutex> guard(PresenceMutex);
+        local.Copy(QueuedPresence);
+      }
+      if (!Connection->Write(local.buffer, local.length)) {
+        // if we fail to send, requeue
+        std::lock_guard<std::mutex> guard(PresenceMutex);
+        QueuedPresence.Copy(local);
+        UpdatePresence.exchange(true);
+      }
+    }
+
+    while (SendQueue.HavePendingSends()) {
+      auto qmessage = SendQueue.GetNextSendMessage();
+      Connection->Write(qmessage->buffer, qmessage->length);
+      SendQueue.CommitSend();
+    }
+  }
+}
+
+static void SignalIOActivity() {
+  if (IoThread != nullptr) {
+    IoThread->Notify();
+  }
+}
+
+static bool RegisterForEvent(const char *evtName) {
+  auto qmessage = SendQueue.GetNextAddMessage();
+  if (qmessage) {
+    qmessage->length =
+      JsonWriteSubscribeCommand(qmessage->buffer, sizeof(qmessage->buffer), Nonce++, evtName);
+    SendQueue.CommitAdd();
+    SignalIOActivity();
+    return true;
+  }
+  return false;
+}
+
+static bool DeregisterForEvent(const char *evtName) {
+  auto qmessage = SendQueue.GetNextAddMessage();
+  if (qmessage) {
+    qmessage->length =
+      JsonWriteUnsubscribeCommand(qmessage->buffer, sizeof(qmessage->buffer), Nonce++, evtName);
+    SendQueue.CommitAdd();
+    SignalIOActivity();
+    return true;
+  }
+  return false;
+}
+
+extern "C" void Discord_Initialize(const char *applicationId,
+                                   DiscordEventHandlers *handlers,
+                                   int autoRegister,
+                                   const char *optionalSteamId) {
+  IoThread = new (std::nothrow) IoThreadHolder();
+  if (IoThread == nullptr) {
+    return;
+  }
+
+  if (autoRegister) {
+    if (optionalSteamId && optionalSteamId[0]) {
+      Discord_RegisterSteamGame(applicationId, optionalSteamId);
+    }
+    else {
+      Discord_Register(applicationId, nullptr);
+    }
+  }
+
+  Pid = GetProcessId();
+
+  {
+    std::lock_guard<std::mutex> guard(HandlerMutex);
+
+    if (handlers) {
+      QueuedHandlers = *handlers;
+    }
+    else {
+      QueuedHandlers = {};
+    }
+
+    Handlers = {};
+  }
+
+  if (Connection) {
+    return;
+  }
+
+  Connection = RpcConnection::Create(applicationId);
+  Connection->onConnect = [](JsonDocument &readyMessage) {
+    Discord_UpdateHandlers(&QueuedHandlers);
+    if (QueuedPresence.length > 0) {
+      UpdatePresence.exchange(true);
+      SignalIOActivity();
+    }
+    auto data = GetObjMember(&readyMessage, "data");
+    auto user = GetObjMember(data, "user");
+    auto userId = GetStrMember(user, "id");
+    auto username = GetStrMember(user, "username");
+    auto avatar = GetStrMember(user, "avatar");
+    if (userId && username) {
+      StringCopy(connectedUser.userId, userId);
+      StringCopy(connectedUser.username, username);
+      auto discriminator = GetStrMember(user, "discriminator");
+      if (discriminator) {
+        StringCopy(connectedUser.discriminator, discriminator);
+      }
+      if (avatar) {
+        StringCopy(connectedUser.avatar, avatar);
+      }
+      else {
+        connectedUser.avatar[0] = 0;
+      }
+    }
+    WasJustConnected.exchange(true);
+    ReconnectTimeMs.reset();
+  };
+  Connection->onDisconnect = [](int err, const char *message) {
+    LastDisconnectErrorCode = err;
+    StringCopy(LastDisconnectErrorMessage, message);
+    WasJustDisconnected.exchange(true);
+    UpdateReconnectTime();
+  };
+
+  IoThread->Start();
+}
+
+extern "C" void Discord_Shutdown(void) {
+  if (!Connection) {
+    return;
+  }
+  Connection->onConnect = nullptr;
+  Connection->onDisconnect = nullptr;
+  Handlers = {};
+  QueuedPresence.length = 0;
+  UpdatePresence.exchange(false);
+  if (IoThread != nullptr) {
+    IoThread->Stop();
+    delete IoThread;
+    IoThread = nullptr;
+  }
+
+  RpcConnection::Destroy(Connection);
+}
+
+extern "C" void Discord_UpdatePresence(const DiscordRichPresence *presence) {
+  {
+    std::lock_guard<std::mutex> guard(PresenceMutex);
+    QueuedPresence.length = JsonWriteRichPresenceObj(
+      QueuedPresence.buffer, sizeof(QueuedPresence.buffer), Nonce++, Pid, presence);
+    UpdatePresence.exchange(true);
+  }
+  SignalIOActivity();
+}
+
+extern "C" void Discord_ClearPresence(void) {
+  Discord_UpdatePresence(nullptr);
+}
+
+extern "C" void Discord_Respond(const char *userId, /* DISCORD_REPLY_ */ int reply) {
+  // if we are not connected, let's not batch up stale messages for later
+  if (!Connection || !Connection->IsOpen()) {
+    return;
+  }
+  auto qmessage = SendQueue.GetNextAddMessage();
+  if (qmessage) {
+    qmessage->length =
+      JsonWriteJoinReply(qmessage->buffer, sizeof(qmessage->buffer), userId, reply, Nonce++);
+    SendQueue.CommitAdd();
+    SignalIOActivity();
+  }
+}
+
+extern "C" void Discord_RunCallbacks(void) {
+  // Note on some weirdness: internally we might connect, get other signals, disconnect any number
+  // of times inbetween calls here. Externally, we want the sequence to seem sane, so any other
+  // signals are book-ended by calls to ready and disconnect.
+
+  if (!Connection) {
+    return;
+  }
+
+  bool wasDisconnected = WasJustDisconnected.exchange(false);
+  bool isConnected = Connection->IsOpen();
+
+  if (isConnected) {
+    // if we are connected, disconnect cb first
+    std::lock_guard<std::mutex> guard(HandlerMutex);
+    if (wasDisconnected && Handlers.disconnected) {
+      Handlers.disconnected(LastDisconnectErrorCode, LastDisconnectErrorMessage);
+    }
+  }
+
+  if (WasJustConnected.exchange(false)) {
+    std::lock_guard<std::mutex> guard(HandlerMutex);
+    if (Handlers.ready) {
+      DiscordUser du { connectedUser.userId,
+                       connectedUser.username,
+                       connectedUser.discriminator,
+                       connectedUser.avatar };
+      Handlers.ready(&du);
+    }
+  }
+
+  if (GotErrorMessage.exchange(false)) {
+    std::lock_guard<std::mutex> guard(HandlerMutex);
+    if (Handlers.errored) {
+      Handlers.errored(LastErrorCode, LastErrorMessage);
+    }
+  }
+
+  if (WasJoinGame.exchange(false)) {
+    std::lock_guard<std::mutex> guard(HandlerMutex);
+    if (Handlers.joinGame) {
+      Handlers.joinGame(JoinGameSecret);
+    }
+  }
+
+  if (WasSpectateGame.exchange(false)) {
+    std::lock_guard<std::mutex> guard(HandlerMutex);
+    if (Handlers.spectateGame) {
+      Handlers.spectateGame(SpectateGameSecret);
+    }
+  }
+
+  // Right now this batches up any requests and sends them all in a burst; I could imagine a world
+  // where the implementer would rather sequentially accept/reject each one before the next invite
+  // is sent. I left it this way because I could also imagine wanting to process these all and
+  // maybe show them in one common dialog and/or start fetching the avatars in parallel, and if
+  // not it should be trivial for the implementer to make a queue themselves.
+  while (JoinAskQueue.HavePendingSends()) {
+    auto req = JoinAskQueue.GetNextSendMessage();
+    {
+      std::lock_guard<std::mutex> guard(HandlerMutex);
+      if (Handlers.joinRequest) {
+        DiscordUser du { req->userId, req->username, req->discriminator, req->avatar };
+        Handlers.joinRequest(&du);
+      }
+    }
+    JoinAskQueue.CommitSend();
+  }
+
+  if (!isConnected) {
+    // if we are not connected, disconnect message last
+    std::lock_guard<std::mutex> guard(HandlerMutex);
+    if (wasDisconnected && Handlers.disconnected) {
+      Handlers.disconnected(LastDisconnectErrorCode, LastDisconnectErrorMessage);
+    }
+  }
+}
+
+extern "C" void Discord_UpdateHandlers(DiscordEventHandlers *newHandlers) {
+  if (newHandlers) {
+#define HANDLE_EVENT_REGISTRATION(handler_name, event)            \
+  if (!Handlers.handler_name && newHandlers->handler_name) {      \
+    RegisterForEvent(event);                                      \
+  }                                                               \
+  else if (Handlers.handler_name && !newHandlers->handler_name) { \
+    DeregisterForEvent(event);                                    \
+  }
+
+    std::lock_guard<std::mutex> guard(HandlerMutex);
+    HANDLE_EVENT_REGISTRATION(joinGame, "ACTIVITY_JOIN")
+    HANDLE_EVENT_REGISTRATION(spectateGame, "ACTIVITY_SPECTATE")
+    HANDLE_EVENT_REGISTRATION(joinRequest, "ACTIVITY_JOIN_REQUEST")
+
+#undef HANDLE_EVENT_REGISTRATION
+
+    Handlers = *newHandlers;
+  }
+  else {
+    std::lock_guard<std::mutex> guard(HandlerMutex);
+    Handlers = {};
+  }
+  return;
+}
+
+}  // namespace discord_rpc
+

3rdparty/discord-rpc/src/msg_queue.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <atomic>
+
+// A simple queue. No locks, but only works with a single thread as producer and a single thread as
+// a consumer. Mutex up as needed.
+
+namespace discord_rpc {
+
+template <typename ElementType, std::size_t QueueSize>
+class MsgQueue {
+    ElementType queue_[QueueSize];
+    std::atomic_uint nextAdd_{0};
+    std::atomic_uint nextSend_{0};
+    std::atomic_uint pendingSends_{0};
+
+public:
+    MsgQueue() {}
+
+    ElementType* GetNextAddMessage()
+    {
+        // if we are falling behind, bail
+        if (pendingSends_.load() >= QueueSize) {
+            return nullptr;
+        }
+        auto index = (nextAdd_++) % QueueSize;
+        return &queue_[index];
+    }
+    void CommitAdd() { ++pendingSends_; }
+
+    bool HavePendingSends() const { return pendingSends_.load() != 0; }
+    ElementType* GetNextSendMessage()
+    {
+        auto index = (nextSend_++) % QueueSize;
+        return &queue_[index];
+    }
+    void CommitSend() { --pendingSends_; }
+};
+
+}  // namespace discord_rpc

3rdparty/discord-rpc/src/rpc_connection.cpp

@@ -0,0 +1,133 @@
+#include "rpc_connection.h"
+#include "serialization.h"
+
+namespace discord_rpc {
+
+static const int RpcVersion = 1;
+static RpcConnection Instance;
+
+/*static*/ RpcConnection *RpcConnection::Create(const char *applicationId) {
+  Instance.connection = BaseConnection::Create();
+  StringCopy(Instance.appId, applicationId);
+  return &Instance;
+}
+
+/*static*/ void RpcConnection::Destroy(RpcConnection *&c) {
+  c->Close();
+  BaseConnection::Destroy(c->connection);
+  c = nullptr;
+}
+
+void RpcConnection::Open() {
+  if (state == State::Connected) {
+    return;
+  }
+
+  if (state == State::Disconnected && !connection->Open()) {
+    return;
+  }
+
+  if (state == State::SentHandshake) {
+    JsonDocument message;
+    if (Read(message)) {
+      auto cmd = GetStrMember(&message, "cmd");
+      auto evt = GetStrMember(&message, "evt");
+      if (cmd && evt && !strcmp(cmd, "DISPATCH") && !strcmp(evt, "READY")) {
+        state = State::Connected;
+        if (onConnect) {
+          onConnect(message);
+        }
+      }
+    }
+  }
+  else {
+    sendFrame.opcode = Opcode::Handshake;
+    sendFrame.length = static_cast<uint32_t>(JsonWriteHandshakeObj(sendFrame.message, sizeof(sendFrame.message), RpcVersion, appId));
+
+    if (connection->Write(&sendFrame, sizeof(MessageFrameHeader) + sendFrame.length)) {
+      state = State::SentHandshake;
+    }
+    else {
+      Close();
+    }
+  }
+}
+
+void RpcConnection::Close() {
+  if (onDisconnect && (state == State::Connected || state == State::SentHandshake)) {
+    onDisconnect(lastErrorCode, lastErrorMessage);
+  }
+  connection->Close();
+  state = State::Disconnected;
+}
+
+bool RpcConnection::Write(const void *data, size_t length) {
+  sendFrame.opcode = Opcode::Frame;
+  memcpy(sendFrame.message, data, length);
+  sendFrame.length = static_cast<uint32_t>(length);
+  if (!connection->Write(&sendFrame, sizeof(MessageFrameHeader) + length)) {
+    Close();
+    return false;
+  }
+  return true;
+}
+
+bool RpcConnection::Read(JsonDocument &message) {
+  if (state != State::Connected && state != State::SentHandshake) {
+    return false;
+  }
+  MessageFrame readFrame;
+  for (;;) {
+    bool didRead = connection->Read(&readFrame, sizeof(MessageFrameHeader));
+    if (!didRead) {
+      if (!connection->isOpen) {
+        lastErrorCode = static_cast<int>(ErrorCode::PipeClosed);
+        StringCopy(lastErrorMessage, "Pipe closed");
+        Close();
+      }
+      return false;
+    }
+
+    if (readFrame.length > 0) {
+      didRead = connection->Read(readFrame.message, readFrame.length);
+      if (!didRead) {
+        lastErrorCode = static_cast<int>(ErrorCode::ReadCorrupt);
+        StringCopy(lastErrorMessage, "Partial data in frame");
+        Close();
+        return false;
+      }
+      readFrame.message[readFrame.length] = 0;
+    }
+
+    switch (readFrame.opcode) {
+      case Opcode::Close: {
+        message.ParseInsitu(readFrame.message);
+        lastErrorCode = GetIntMember(&message, "code");
+        StringCopy(lastErrorMessage, GetStrMember(&message, "message", ""));
+        Close();
+        return false;
+      }
+      case Opcode::Frame:
+        message.ParseInsitu(readFrame.message);
+        return true;
+      case Opcode::Ping:
+        readFrame.opcode = Opcode::Pong;
+        if (!connection->Write(&readFrame, sizeof(MessageFrameHeader) + readFrame.length)) {
+          Close();
+        }
+        break;
+      case Opcode::Pong:
+        break;
+      case Opcode::Handshake:
+      default:
+        // something bad happened
+        lastErrorCode = static_cast<int>(ErrorCode::ReadCorrupt);
+        StringCopy(lastErrorMessage, "Bad ipc frame");
+        Close();
+        return false;
+    }
+  }
+}
+
+}  // namespace discord_rpc
+

3rdparty/discord-rpc/src/rpc_connection.h

@@ -0,0 +1,64 @@
+#pragma once
+
+#include "connection.h"
+#include "serialization.h"
+
+namespace discord_rpc {
+
+// I took this from the buffer size libuv uses for named pipes; I suspect ours would usually be much
+// smaller.
+constexpr size_t MaxRpcFrameSize = 64 * 1024;
+
+struct RpcConnection {
+  enum class ErrorCode : int {
+    Success = 0,
+    PipeClosed = 1,
+    ReadCorrupt = 2,
+  };
+
+  enum class Opcode : uint32_t {
+    Handshake = 0,
+    Frame = 1,
+    Close = 2,
+    Ping = 3,
+    Pong = 4,
+  };
+
+  struct MessageFrameHeader {
+    Opcode opcode;
+    uint32_t length;
+  };
+
+  struct MessageFrame : public MessageFrameHeader {
+    char message[MaxRpcFrameSize - sizeof(MessageFrameHeader)];
+  };
+
+  enum class State : uint32_t {
+    Disconnected,
+    SentHandshake,
+    AwaitingResponse,
+    Connected,
+  };
+
+  BaseConnection *connection { nullptr };
+  State state { State::Disconnected };
+  void (*onConnect)(JsonDocument &message) { nullptr };
+  void (*onDisconnect)(int errorCode, const char *message) { nullptr };
+  char appId[64] {};
+  int lastErrorCode { 0 };
+  char lastErrorMessage[256] {};
+  RpcConnection::MessageFrame sendFrame;
+
+  static RpcConnection *Create(const char *applicationId);
+  static void Destroy(RpcConnection *&);
+
+  inline bool IsOpen() const { return state == State::Connected; }
+
+  void Open();
+  void Close();
+  bool Write(const void *data, size_t length);
+  bool Read(JsonDocument &message);
+};
+
+}  // namespace discord_rpc
+

3rdparty/discord-rpc/src/serialization.cpp

@@ -0,0 +1,249 @@
+#include "serialization.h"
+#include "connection.h"
+#include "discord_rpc.h"
+
+namespace discord_rpc {
+
+template<typename T>
+void NumberToString(char *dest, T number) {
+  if (!number) {
+    *dest++ = '0';
+    *dest++ = 0;
+    return;
+  }
+  if (number < 0) {
+    *dest++ = '-';
+    number = -number;
+  }
+  char temp[32];
+  int place = 0;
+  while (number) {
+    auto digit = number % 10;
+    number = number / 10;
+    temp[place++] = '0' + static_cast<char>(digit);
+  }
+  for (--place; place >= 0; --place) {
+    *dest++ = temp[place];
+  }
+  *dest = 0;
+}
+
+// it's ever so slightly faster to not have to strlen the key
+template<typename T>
+void WriteKey(JsonWriter &w, T &k) {
+  w.Key(k, sizeof(T) - 1);
+}
+
+struct WriteObject {
+  JsonWriter &writer;
+  WriteObject(JsonWriter &w)
+      : writer(w) {
+    writer.StartObject();
+  }
+  template<typename T>
+  WriteObject(JsonWriter &w, T &name)
+      : writer(w) {
+    WriteKey(writer, name);
+    writer.StartObject();
+  }
+  ~WriteObject() { writer.EndObject(); }
+};
+
+struct WriteArray {
+  JsonWriter &writer;
+  template<typename T>
+  WriteArray(JsonWriter &w, T &name)
+      : writer(w) {
+    WriteKey(writer, name);
+    writer.StartArray();
+  }
+  ~WriteArray() { writer.EndArray(); }
+};
+
+template<typename T>
+void WriteOptionalString(JsonWriter &w, T &k, const char *value) {
+  if (value && value[0]) {
+    w.Key(k, sizeof(T) - 1);
+    w.String(value);
+  }
+}
+
+static void JsonWriteNonce(JsonWriter &writer, int nonce) {
+  WriteKey(writer, "nonce");
+  char nonceBuffer[32];
+  NumberToString(nonceBuffer, nonce);
+  writer.String(nonceBuffer);
+}
+
+size_t JsonWriteRichPresenceObj(char *dest,
+                                size_t maxLen,
+                                int nonce,
+                                int pid,
+                                const DiscordRichPresence *presence) {
+  JsonWriter writer(dest, maxLen);
+
+  {
+    WriteObject top(writer);
+
+    JsonWriteNonce(writer, nonce);
+
+    WriteKey(writer, "cmd");
+    writer.String("SET_ACTIVITY");
+
+    {
+      WriteObject args(writer, "args");
+
+      WriteKey(writer, "pid");
+      writer.Int(pid);
+
+      if (presence != nullptr) {
+        WriteObject activity(writer, "activity");
+
+        if (presence->type >= 0 && presence->type <= 5) {
+          WriteKey(writer, "type");
+          writer.Int(presence->type);
+        }
+
+        WriteOptionalString(writer, "name", presence->name);
+        WriteOptionalString(writer, "state", presence->state);
+        WriteOptionalString(writer, "details", presence->details);
+
+        if (presence->startTimestamp || presence->endTimestamp) {
+          WriteObject timestamps(writer, "timestamps");
+
+          if (presence->startTimestamp) {
+            WriteKey(writer, "start");
+            writer.Int64(presence->startTimestamp);
+          }
+
+          if (presence->endTimestamp) {
+            WriteKey(writer, "end");
+            writer.Int64(presence->endTimestamp);
+          }
+        }
+
+        if ((presence->largeImageKey && presence->largeImageKey[0]) ||
+            (presence->largeImageText && presence->largeImageText[0]) ||
+            (presence->smallImageKey && presence->smallImageKey[0]) ||
+            (presence->smallImageText && presence->smallImageText[0])) {
+          WriteObject assets(writer, "assets");
+          WriteOptionalString(writer, "large_image", presence->largeImageKey);
+          WriteOptionalString(writer, "large_text", presence->largeImageText);
+          WriteOptionalString(writer, "small_image", presence->smallImageKey);
+          WriteOptionalString(writer, "small_text", presence->smallImageText);
+        }
+
+        if ((presence->partyId && presence->partyId[0]) || presence->partySize ||
+            presence->partyMax || presence->partyPrivacy) {
+          WriteObject party(writer, "party");
+          WriteOptionalString(writer, "id", presence->partyId);
+          if (presence->partySize && presence->partyMax) {
+            WriteArray size(writer, "size");
+            writer.Int(presence->partySize);
+            writer.Int(presence->partyMax);
+          }
+
+          if (presence->partyPrivacy) {
+            WriteKey(writer, "privacy");
+            writer.Int(presence->partyPrivacy);
+          }
+        }
+
+        if ((presence->matchSecret && presence->matchSecret[0]) ||
+            (presence->joinSecret && presence->joinSecret[0]) ||
+            (presence->spectateSecret && presence->spectateSecret[0])) {
+          WriteObject secrets(writer, "secrets");
+          WriteOptionalString(writer, "match", presence->matchSecret);
+          WriteOptionalString(writer, "join", presence->joinSecret);
+          WriteOptionalString(writer, "spectate", presence->spectateSecret);
+        }
+
+        writer.Key("instance");
+        writer.Bool(presence->instance != 0);
+      }
+    }
+  }
+
+  return writer.Size();
+}
+
+size_t JsonWriteHandshakeObj(char *dest, size_t maxLen, int version, const char *applicationId) {
+  JsonWriter writer(dest, maxLen);
+
+  {
+    WriteObject obj(writer);
+    WriteKey(writer, "v");
+    writer.Int(version);
+    WriteKey(writer, "client_id");
+    writer.String(applicationId);
+  }
+
+  return writer.Size();
+}
+
+size_t JsonWriteSubscribeCommand(char *dest, size_t maxLen, int nonce, const char *evtName) {
+  JsonWriter writer(dest, maxLen);
+
+  {
+    WriteObject obj(writer);
+
+    JsonWriteNonce(writer, nonce);
+
+    WriteKey(writer, "cmd");
+    writer.String("SUBSCRIBE");
+
+    WriteKey(writer, "evt");
+    writer.String(evtName);
+  }
+
+  return writer.Size();
+}
+
+size_t JsonWriteUnsubscribeCommand(char *dest, size_t maxLen, int nonce, const char *evtName) {
+  JsonWriter writer(dest, maxLen);
+
+  {
+    WriteObject obj(writer);
+
+    JsonWriteNonce(writer, nonce);
+
+    WriteKey(writer, "cmd");
+    writer.String("UNSUBSCRIBE");
+
+    WriteKey(writer, "evt");
+    writer.String(evtName);
+  }
+
+  return writer.Size();
+}
+
+size_t JsonWriteJoinReply(char *dest, size_t maxLen, const char *userId, int reply, int nonce) {
+  JsonWriter writer(dest, maxLen);
+
+  {
+    WriteObject obj(writer);
+
+    WriteKey(writer, "cmd");
+    if (reply == DISCORD_REPLY_YES) {
+      writer.String("SEND_ACTIVITY_JOIN_INVITE");
+    }
+    else {
+      writer.String("CLOSE_ACTIVITY_JOIN_REQUEST");
+    }
+
+    WriteKey(writer, "args");
+    {
+      WriteObject args(writer);
+
+      WriteKey(writer, "user_id");
+      writer.String(userId);
+    }
+
+    JsonWriteNonce(writer, nonce);
+  }
+
+  return writer.Size();
+}
+
+}  // namespace discord_rpc
+

3rdparty/discord-rpc/src/serialization.h

@@ -0,0 +1,197 @@
+#pragma once
+
+#ifdef _MSC_VER
+#  pragma warning(push)
+
+#  pragma warning(disable : 4061)  // enum is not explicitly handled by a case label
+#  pragma warning(disable : 4365)  // signed/unsigned mismatch
+#  pragma warning(disable : 4464)  // relative include path contains
+#  pragma warning(disable : 4668)  // is not defined as a preprocessor macro
+#  pragma warning(disable : 6313)  // Incorrect operator
+#endif
+
+#include <rapidjson/document.h>
+#include <rapidjson/stringbuffer.h>
+#include <rapidjson/writer.h>
+
+#ifdef _MSC_VER
+#  pragma warning(pop)
+#endif
+
+namespace discord_rpc {
+
+// if only there was a standard library function for this
+template<size_t Len>
+inline size_t StringCopy(char (&dest)[Len], const char *src) {
+  if (!src || !Len) {
+    return 0;
+  }
+  size_t copied;
+  char *out = dest;
+  for (copied = 1; *src && copied < Len; ++copied) {
+    *out++ = *src++;
+  }
+  *out = 0;
+  return copied - 1;
+}
+
+size_t JsonWriteHandshakeObj(char *dest, size_t maxLen, int version, const char *applicationId);
+
+// Commands
+struct DiscordRichPresence;
+size_t JsonWriteRichPresenceObj(char *dest,
+                                size_t maxLen,
+                                int nonce,
+                                int pid,
+                                const DiscordRichPresence *presence);
+size_t JsonWriteSubscribeCommand(char *dest, size_t maxLen, int nonce, const char *evtName);
+
+size_t JsonWriteUnsubscribeCommand(char *dest, size_t maxLen, int nonce, const char *evtName);
+
+size_t JsonWriteJoinReply(char *dest, size_t maxLen, const char *userId, int reply, int nonce);
+
+// I want to use as few allocations as I can get away with, and to do that with RapidJson, you need
+// to supply some of your own allocators for stuff rather than use the defaults
+
+class LinearAllocator {
+ public:
+  char *buffer_;
+  char *end_;
+  LinearAllocator() {
+    assert(0);  // needed for some default case in rapidjson, should not use
+  }
+  LinearAllocator(char *buffer, size_t size)
+      : buffer_(buffer), end_(buffer + size) {
+  }
+  static const bool kNeedFree = false;
+  void *Malloc(size_t size) {
+    char *res = buffer_;
+    buffer_ += size;
+    if (buffer_ > end_) {
+      buffer_ = res;
+      return nullptr;
+    }
+    return res;
+  }
+  void *Realloc(void *originalPtr, size_t originalSize, size_t newSize) {
+    if (newSize == 0) {
+      return nullptr;
+    }
+    // allocate how much you need in the first place
+    assert(!originalPtr && !originalSize);
+    // unused parameter warning
+    (void)(originalPtr);
+    (void)(originalSize);
+    return Malloc(newSize);
+  }
+  static void Free(void *ptr) {
+    /* shrug */
+    (void)ptr;
+  }
+};
+
+template<size_t Size>
+class FixedLinearAllocator : public LinearAllocator {
+ public:
+  char fixedBuffer_[Size];
+  FixedLinearAllocator()
+      : LinearAllocator(fixedBuffer_, Size) {
+  }
+  static const bool kNeedFree = false;
+};
+
+// wonder why this isn't a thing already, maybe I missed it
+class DirectStringBuffer {
+ public:
+  using Ch = char;
+  char *buffer_;
+  char *end_;
+  char *current_;
+
+  DirectStringBuffer(char *buffer, size_t maxLen)
+      : buffer_(buffer), end_(buffer + maxLen), current_(buffer) {
+  }
+
+  void Put(char c) {
+    if (current_ < end_) {
+      *current_++ = c;
+    }
+  }
+  void Flush() {}
+  size_t GetSize() const { return static_cast<size_t>(current_ - buffer_); }
+};
+
+using MallocAllocator = rapidjson::CrtAllocator;
+using PoolAllocator = rapidjson::MemoryPoolAllocator<MallocAllocator>;
+using UTF8 = rapidjson::UTF8<char>;
+// Writer appears to need about 16 bytes per nested object level (with 64bit size_t)
+using StackAllocator = FixedLinearAllocator<2048>;
+constexpr size_t WriterNestingLevels = 2048 / (2 * sizeof(size_t));
+using JsonWriterBase =
+  rapidjson::Writer<DirectStringBuffer, UTF8, UTF8, StackAllocator, rapidjson::kWriteNoFlags>;
+class JsonWriter : public JsonWriterBase {
+ public:
+  DirectStringBuffer stringBuffer_;
+  StackAllocator stackAlloc_;
+
+  JsonWriter(char *dest, size_t maxLen)
+      : JsonWriterBase(stringBuffer_, &stackAlloc_, WriterNestingLevels), stringBuffer_(dest, maxLen), stackAlloc_() {
+  }
+
+  size_t Size() const { return stringBuffer_.GetSize(); }
+};
+
+using JsonDocumentBase = rapidjson::GenericDocument<UTF8, PoolAllocator, StackAllocator>;
+class JsonDocument : public JsonDocumentBase {
+ public:
+  static const int kDefaultChunkCapacity = 32 * 1024;
+  // json parser will use this buffer first, then allocate more if needed; I seriously doubt we
+  // send any messages that would use all of this, though.
+  char parseBuffer_[32 * 1024];
+  MallocAllocator mallocAllocator_;
+  PoolAllocator poolAllocator_;
+  StackAllocator stackAllocator_;
+  JsonDocument()
+      : JsonDocumentBase(rapidjson::kObjectType,
+                         &poolAllocator_,
+                         sizeof(stackAllocator_.fixedBuffer_),
+                         &stackAllocator_),
+        poolAllocator_(parseBuffer_, sizeof(parseBuffer_), kDefaultChunkCapacity, &mallocAllocator_), stackAllocator_() {
+  }
+};
+
+using JsonValue = rapidjson::GenericValue<UTF8, PoolAllocator>;
+
+inline JsonValue *GetObjMember(JsonValue *obj, const char *name) {
+  if (obj) {
+    auto member = obj->FindMember(name);
+    if (member != obj->MemberEnd() && member->value.IsObject()) {
+      return &member->value;
+    }
+  }
+  return nullptr;
+}
+
+inline int GetIntMember(JsonValue *obj, const char *name, int notFoundDefault = 0) {
+  if (obj) {
+    auto member = obj->FindMember(name);
+    if (member != obj->MemberEnd() && member->value.IsInt()) {
+      return member->value.GetInt();
+    }
+  }
+  return notFoundDefault;
+}
+
+inline const char *GetStrMember(JsonValue *obj,
+                                const char *name,
+                                const char *notFoundDefault = nullptr) {
+  if (obj) {
+    auto member = obj->FindMember(name);
+    if (member != obj->MemberEnd() && member->value.IsString()) {
+      return member->value.GetString();
+    }
+  }
+  return notFoundDefault;
+}
+
+}  // namespace discord_rpc