implement spawn_doom() for windows

src/doompanning.cc

@@ -19,6 +19,7 @@
 
 #include <signal.h>
 #ifdef __WIN32
+#include <windows.h>
 #else
 #include <spawn.h>
 #include <sys/wait.h>
@@ -119,6 +120,37 @@ char **__environ = environ;
 #ifdef __WIN32
 inline void spawn_doom(ControllerContext &ctx)
 {
+    (void) ctx;
+
+    // Source: https://learn.microsoft.com/en-us/windows/win32/procthread/creating-processes
+    STARTUPINFO si;
+    PROCESS_INFORMATION pi;
+
+    ZeroMemory(&si, sizeof(si));
+    si.cb = sizeof(si);
+    ZeroMemory(&pi, sizeof(pi));
+
+    char cmdLine[256];
+    snprintf(cmdLine, sizeof(cmdLine), "%s", DOOM_EXECUTABLE);
+
+    // Start the child process.
+    if (!CreateProcess(NULL,    // No module name (use command line)
+                       cmdLine, // Command line
+                       NULL,    // Process handle not inheritable
+                       NULL,    // Thread handle not inheritable
+                       FALSE,   // Set handle inheritance to FALSE
+                       0,       // No creation flags
+                       NULL,    // Use parent's environment block
+                       NULL,    // Use parent's starting directory
+                       &si,     // Pointer to STARTUPINFO structure
+                       &pi)     // Pointer to PROCESS_INFORMATION structure
+    )
+    {
+        log_error("CreateProcess failed (%d)", GetLastError());
+        return;
+    }
+
+    log_info("Spawned new %s, pid=%d", cmdLine, pi.dwProcessId);
 }
 #else
 void spawn_doom_posix_spawn(ControllerContext &ctx)