/* Initialization code to talk to the X server */
#include<math.h>
#include<X11/Xlib.h>
#include<X11/Xutil.h>
#include<stdio.h>


#define BORDER_WIDTH  2

/* Global Variables */

Display         *theDisplay;
int             theScreen;
int             theDepth;
unsigned long   theBlackPixel;
unsigned long   theWhitePixel;
Colormap theColormap;

unsigned long pixel;

GC thDestinationGC;
unsigned long theplane,width,height;

 Window theWindow, openWindow();
 GC theGC;
 XImage *ximage;



// Establised a connection to the X server
nitX()
{

theDisplay = XOpenDisplay( NULL);

/* Check for connection */

if( theDisplay== NULL)
{

 fprintf(stderr, "Error :- %s \n", XDisplayName(NULL));
 exit(1);

}
//set default setting

theScreen     = DefaultScreen(theDisplay);
theDepth      = DefaultDepth(theDisplay, theScreen );
theBlackPixel = BlackPixel(theDisplay , theScreen);
theWhitePixel = WhitePixel(theDisplay , theScreen);
theColormap   = DefaultColormap(theDisplay,theScreen);

}//End of nitX Function


/* getxinfo prints information */

getXInfo()
{
printf("%s version %d of the X window system , X %d R %d \n ", 
ServerVendor(theDisplay),VendorRelease(theDisplay),
ProtocolVersion(theDisplay),ProtocolRevision(theDisplay));

   if(theDepth == 1)
   {
       printf("color planes depth...........%d(monochrome)\n",theDepth);
   }

   else
   {
     printf("color plane depth ............%d\n",theDepth); }

     printf("Display width..............%d\n",DisplayWidth(theDisplay ,theScreen));
     printf("Display heightwidth..............%d\n",DisplayHeight(theDisplay
     ,theScreen));


   }/*End Of Function GetXinfo */


//quitx function to destroy the window
quitX()
{
	
XCloseDisplay(theDisplay);

}//End of quit function


/*window function code*/
 Window openWindow( int x , int y ,  int width ,  int height,  int flag, GC *theNewGC)
 {
  XSetWindowAttributes theWindowAttributes;
  XSizeHints           theSizeHints;
  unsigned  long       theWindowMask;
  Window               theNewWindow;
  XWMHints             theWMHints;

  theWindowAttributes.border_pixel       =  BlackPixel(theDisplay,theScreen);
  theWindowAttributes.background_pixel   = WhitePixel(theDisplay,theScreen);
  theWindowAttributes.override_redirect  = True;
  theWindowMask =  CWBackPixel | CWBorderPixel | CWOverrideRedirect;

  theNewWindow = XCreateWindow(theDisplay, RootWindow(theDisplay,theScreen)
                 ,x,y,width,height,BORDER_WIDTH,theDepth,InputOutput,CopyFromParent,
		  
  theWindowMask,&theWindowAttributes);

  theWMHints.initial_state = NormalState;

  XSetWMHints(theDisplay ,theNewWindow ,&theWMHints);

  theSizeHints.flags = PPosition |PSize;
  theSizeHints.x = x;
  theSizeHints.y = y;
  theSizeHints.width = width;
  theSizeHints.height = height;

  XSetNormalHints(theDisplay ,theNewWindow, &theSizeHints);

  if(createGC (theNewWindow ,theNewGC ) == 0)
  {
  XDestroyWindow(theDisplay,theNewWindow );
  return((Window) 0);
  }

  XMapWindow(theDisplay ,theNewWindow);


  return(theNewWindow);
}//End of Window function



createGC(Window theNewWindow , GC *theNewGC)
{
  XGCValues theGCValues;
 *theNewGC = XCreateGC(theDisplay, theNewWindow,(unsigned long ) 0
            ,&theGCValues);

 if(*theNewGC == 0 )
 {
 return(0);
 }

 else
 {
 XSetForeground(theDisplay, *theNewGC ,theBlackPixel);
 XSetBackground(theDisplay, *theNewGC ,theWhitePixel);
 return(1);
 }

}//end of creategc



//Set Color Function
setColorWithName(GC theGC,char theName[])
{
XColor theRGBColor,theHardwareColor;
int theStatus;

    if (theDepth>1)
        {
             theStatus = XLookupColor(theDisplay,theColormap,
			     theName,&theRGBColor,&theHardwareColor);
	     
                  if(theStatus != 0)
                   {
                      theStatus = XAllocColor(theDisplay,theColormap,
				      &theHardwareColor);
		      
                        if(theStatus != 0)
                          {
				  XSetForeground(theDisplay,theGC,
						  theHardwareColor.pixel);
				  
                          } 
                  
		   }
        }

}//End of set Color function


main()
{
 nitX();
 getXInfo();
 
 /* u can change the width and height of the window */
 theWindow = openWindow(100,100,300,300,0, &theGC);
 
 //set the color if required  
 setColorWithName(theGC,"blue");

// call your function

 /* Get the pixel value to changed it to other value(basically used for
   flood fill or Boundary fill algorithms */
 ximage= XGetImage(theDisplay,theWindow,0,0,300,300,AllPlanes,XYPixmap);
 pixel=XGetPixel(ximage,10,10);
 printf("Pixel value is :- %u",pixel);
 
/* call for the function ( flood fill or boundary fill)  */
  sleep(2);

 /* Distroy the window and quit*/
  XDestroyWindow(theDisplay ,theWindow);
  quitX();
}//end of main


//Command to Compile the XWindow File
 
// $cc fin.c -L /usr/X11R6/lib -lX11 -lm