Show or flip font smoothing setting using SystemParameterInfo API

fontsmoothing.cpp

/*
 * shows font smoothing setting, which is true by default.
 * flips font smoothing setting if "flip" was specified on command line.
 * compilation: cl fontsmoothing.cpp user32.lib
 */
#include <windows.h>
#include <stdio.h>

BOOL fontSmoothingStatus()
{
  BOOL theState = FALSE;
  SystemParametersInfo(SPI_GETFONTSMOOTHING, 0, &theState, 0);
  return theState;
}

BOOL flipFontSmoothing()
{
  BOOL iState = fontSmoothingStatus();
  BOOL newState = !iState;
  printf("set param: %s\n", newState ? "true" : "false");
  BOOL rv = SystemParametersInfo(SPI_SETFONTSMOOTHING,
      newState, NULL, SPIF_UPDATEINIFILE|SPIF_SENDCHANGE);
  if (rv == 0) {
    DWORD lerr = GetLastError();
    fprintf(stderr, "SystemParametersInfo(SPI_SETFONTSMOOTHING,...) failed, error code: %d %#x\n", lerr, lerr);
  }
  return fontSmoothingStatus();
}

#if 0
void setupConsole() {
  if (!::AttachConsole(ATTACH_PARENT_PROCESS)) {
    // open new console if this was not invoked in a console
    ::AllocConsole();
  }
  freopen("CON", "r", stdin);     // assign stdin
  freopen("CON", "w", stdout);    // assign stdout
  freopen("CON", "w", stderr);    // assign stdout
}

void cleanupConsole() {
  ::FreeConsole();
}


int WINAPI WinMain(HINSTANCE hi, HINSTANCE hp, LPSTR cl, int cs) {
  setupConsole();
  printf("cl: %s, cs %d\n", cl, cs);
  BOOL currentState = fontSmoothingStatus();
  printf("current status: %s\n", currentState ? "true" : "false");

  /*
  BOOL newState = flipFontSmoothing();
  printf("new status: %s\n", newState ? "true" : "false");
  */
  cleanupConsole();
  PostQuitMessage(0);
  return 0;
}
#endif

int main(int argc, char *argv[]) {
  BOOL currentState = fontSmoothingStatus();
  printf("current status: %s\n", currentState ? "true" : "false");

  BOOL doFlip = FALSE;
  if (argc > 1) {
    if (strncmp(argv[1], "flip", strlen("flip")) == 0) {
      doFlip = TRUE;
    } else {
      fprintf(stderr, "E: unexpected argument: %s\n", argv[1]);
    }
  }

  if (doFlip) {
    BOOL newState = flipFontSmoothing();
    printf("new status: %s\n", newState ? "true" : "false");
  }

  return 0;
}