Mac Display

main.cpp

#include <ApplicationServices/ApplicationServices.h>

#include <vector>

// void MyDisplaySwitchToMode (CGDirectDisplayID display, CFDictionaryRef mode)
// {
//   CGDisplayConfigRef config; // 1
//   CGBeginDisplayConfiguration (&config); // 2
//   CGConfigureDisplayMode (config, display, mode); // 3

//   CGCompleteDisplayConfiguration (config, kCGConfigureForSession ); // 5
// }


int main(int argc, char * argv[])
{

  CGError cgret;

  uint32_t num_displays = 0;
  cgret = CGGetActiveDisplayList(0, NULL, &num_displays);
  //cgret = CGGetOnlineDisplayList(0, NULL, &num_displays);

  std::vector<CGDirectDisplayID> displays(num_displays);
  cgret = CGGetActiveDisplayList(num_displays, displays.begin().base(), &num_displays);
  //cgret = CGGetOnlineDisplayList(num_displays, displays.begin().base(), &num_displays);


  fprintf(stderr, "num_displays: %d\n", num_displays);

  for(uint32_t d=0; d<num_displays; ++d) {

    fprintf(stderr, "display id: %u\n", displays[d]);
    CGDisplayModeRef mode = CGDisplayCopyDisplayMode(displays[d]);
    uint32_t ioflags = CGDisplayModeGetIOFlags(mode);
    fprintf(stderr, " ioflags: %d\n", ioflags);
    bool gui = CGDisplayModeIsUsableForDesktopGUI(mode);
    fprintf(stderr, " gui: %d\n", gui);
    CGDisplayModeRelease(mode);
  }

  // cgret = CGDisplayCaptureWithOptions(displays[1], 0);
  // sleep(10);
  // cgret = CGDisplayRelease (displays[1]);

  if(false) {
    fprintf(stderr, "all display modes\n");
  
    CFIndex index, count;
    CFArrayRef modeList;
  
    modeList = CGDisplayCopyAllDisplayModes (displays[1], NULL); 
    count = CFArrayGetCount (modeList);

    for (index = 0; index < count; index++) {
      CGDisplayModeRef mode;

      mode = (CGDisplayModeRef)CFArrayGetValueAtIndex (modeList, index);
      uint32_t ioflags = CGDisplayModeGetIOFlags(mode);
      fprintf(stderr, " ioflags: %d\n", ioflags);
      bool gui = CGDisplayModeIsUsableForDesktopGUI(mode);
      fprintf(stderr, " gui: %d\n", gui);
      if(ioflags==513) {
        // CGDisplaySetDisplayMode(displays[1], mode, NULL);
        // sleep(10);
        // CGDisplayModeRelease(mode); 
        // break;
      }
      else {
        CGDisplayModeRelease(mode); 
      }
    }
    CFRelease(modeList);
  }

  CGDisplayConfigRef config;
  CGDisplayErr err = noErr;

  err = CGBeginDisplayConfiguration(&config);
  err = CGConfigureDisplayMirrorOfDisplay(config, displays[0],  kCGNullDirectDisplay );
  err = CGCompleteDisplayConfiguration(config, kCGConfigurePermanently);


  // int h = 1280; //horizontal resolution
  // int v = 800; //vertical resolution

  // CGDirectDisplayID mainDisplay; //ID of main display
  // mainDisplay = CGMainDisplayID();

  // CFDictionaryRef switchMode; //mode to swich to
  // switchMode = CGDisplayBestModeForParameters(displays[1], 32, 0, 0, NULL);
  
  // MyDisplaySwitchToMode(displays[1], switchMode);


  return 0;

}