/*
* setgetscreenres.m
* 
* juanfc 2009-04-13
* Based on newscreen
*    Created by Jeffrey Osterman on 10/30/07.
*    Copyright 2007 Jeffrey Osterman. All rights reserved. 
*    PROVIDED AS IS AND WITH NO WARRANTIES WHATSOEVER
*    http://forums.macosxhints.com/showthread.php?t=59575
*
* COMPILE:
*    c++ setgetscreenres.m -framework ApplicationServices -o setgetscreenres
* USE:
*    setgetscreenres 1440 900
*/

#include <ApplicationServices/ApplicationServices.h>

bool MyDisplaySwitchToMode (CGDirectDisplayID display, CFDictionaryRef mode);

int main (int argc, const char * argv[])
{
	int	h; 							// horizontal resolution
	int v; 							// vertical resolution
	CFDictionaryRef switchMode; 	// mode to switch to
	CGDirectDisplayID mainDisplay;  // ID of main display

	CFDictionaryRef CGDisplayCurrentMode(CGDirectDisplayID display);

	if (argc == 1) {
	    CGRect screenFrame = CGDisplayBounds(kCGDirectMainDisplay);
		CGSize screenSize  = screenFrame.size;
		printf("%d %d\n", screenSize.width, screenSize.height);
		return 0;
	}
	if (argc != 3 || !(h = atoi(argv[1])) || !(v = atoi(argv[2])) ) {
		fprintf(stderr, "ERROR: Use %s horres vertres\n", argv[0]);
		return -1;
	}

	mainDisplay = CGMainDisplayID();

	switchMode = CGDisplayBestModeForParameters(mainDisplay, 32, h, v, NULL);

	if (! MyDisplaySwitchToMode(mainDisplay, switchMode)) {
	    fprintf(stderr, "Error changing resolution to %d %d\n", h, v);
		return 1;
	}

	return 0;
}

bool MyDisplaySwitchToMode (CGDirectDisplayID display, CFDictionaryRef mode)
{
	CGDisplayConfigRef config;
	if (CGBeginDisplayConfiguration(&config) == kCGErrorSuccess) {
		CGConfigureDisplayMode(config, display, mode);
		CGCompleteDisplayConfiguration(config, kCGConfigureForSession );
		return true;
	}
	return false;
}