// (c) Dinko Korunic, 36355514, kreator@fly.srk.fer.hr
// Zadatak broj 9 iz predmeta Racunalna grafika

#include <iostream.h>
#include <stdlib.h>
#include <math.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <unistd.h>

#define MAXX 640 // max x
#define MAXY 480 // max y
#define MINT 0.09 // mnozi paletu
#define MYSTEP 1 // stepping za iscrtavanje pixela

class MyDisplay
{
	// klasa MyDisplay u kojoj se nalaze inicijalizacijske xlib
	// rutine, kao i postavljanje background i foreground boje, itd.
	XGCValues gcv;
	unsigned long wp, bp;
	int winx, winy;
	public:
		Display *disp;
		Window win;
		GC gc;
		XEvent ev;
		void MyWait(void);
		int winsx, winsy, screen;
		MyDisplay(int _winx, int _winy, int _winsx,
				int _winsy);
		~MyDisplay();
};

MyDisplay::MyDisplay(int _winx=0, int _winy=0, 
	int _winsx=MAXX, int _winsy=MAXY) :
	winx(_winx), winy(_winy), winsx(_winsx), winsy(_winsy)
{

	// konstruktor koji sluzi za misc. inicijalizaciju
	cout << "Initialising graphic subsystem.." << endl;
	// otvaranje displaya
	if ((disp=XOpenDisplay(NULL))==NULL)
	{
		cerr << "I can't open display." << endl;
		exit(EXIT_FAILURE);
	}
	screen=DefaultScreen(disp);
	// stvaranje prototipnog prozora
	win=XCreateSimpleWindow(disp, DefaultRootWindow(disp),
		winx, winy, winsx, winsy, 1, wp=WhitePixel(disp, screen),
		bp=BlackPixel(disp, screen));
	XSelectInput(disp, win, StructureNotifyMask | KeyPressMask
		| ExposureMask);
	// mapiranje prozora
	XMapWindow(disp, win);
	while(1)
	{
		// cekaj dok nije gotovo
		XNextEvent(disp, &ev);
		if (ev.type==MapNotify) break;
	}
	gcv.foreground=wp;
	gcv.background=bp;
	// stvori gc
	gc=XCreateGC(disp, win, GCForeground | GCBackground, &gcv);
	cout << "done." << endl;
}

MyDisplay::~MyDisplay()
{
	// destruktor za graficki engine
	cout << "Shutting graphic subsystem.." << endl;
	XFreeGC(disp, gc);
	XDestroyWindow(disp, win);
	XCloseDisplay(disp);
	cout << "done." << endl;
}

void MyDisplay::MyWait(void)
{
	// postavi wait na keypress
	XSelectInput(disp, win, KeyPressMask | ExposureMask);
	while(1)
	{
		XNextEvent(disp, &ev);
		if (ev.type==KeyPress) break;
	}
}

class MiscDraw : public MyDisplay
{
	Colormap cmap;
	XColor xcolor, colorcell;
	int darkcolor, lightcolor, black, white;
	public:
		XImage *image;
		long translate[4]; /* for converting colors */
		MiscDraw();
};

MiscDraw::MiscDraw()
{
	cmap=DefaultColormap(disp, screen);
	if (XAllocNamedColor(disp, cmap, "red", &colorcell, &xcolor))
		translate[0]=colorcell.pixel;
	if (XAllocNamedColor(disp, cmap, "green", &colorcell, &xcolor))
		translate[1]=colorcell.pixel;
	if (XAllocNamedColor(disp, cmap, "blue", &colorcell, &xcolor))
		translate[2]=colorcell.pixel;
	if (XAllocNamedColor(disp, cmap, "grey", &colorcell, &xcolor))
		translate[3]=colorcell.pixel;
	image=XGetImage(disp, win, 0, 0, MAXX, MAXY, AllPlanes, ZPixmap);
}

class MyDraw9 : public MiscDraw
{
	int Interate(double, double, int, double, double,
		double);
	public:
		MyDraw9();
};

int Iterate(double x, double y, int numiter, double bailout,
	double a, double b)
{
	// vraca 0 ako konvergira, ili broj iteracija ako divergira (ode
	// preko bailout vrijednosti)
	double xt;
	for (int it=0; it<numiter; ++it)
	{
		if (sqrt(x*x+y*y)>=bailout) return it;
		xt=x;
		x=x*x-y*y+a;
		y=2*xt*y+b;
	}
	return 0;
}

MyDraw9::MyDraw9()
{
	double bailout=2., a, b;
	int i, j, numiter=400;
	// crta mandelbrotov skup
	for (j=0; j<MAXY; j+=MYSTEP)
		for (i=0; i<MAXX; i+=MYSTEP)
			XPutPixel(image, i, j,
			Iterate(a=4./MAXX*i-2., b=-4./MAXY*j+2., numiter,
				bailout, a, b)*MINT);
	XPutImage(disp, win, gc, image, 0, 0, 0, 0, MAXX, MAXY);
	XDrawString(disp, win, gc, 10, 10, "Mandelbrot", 10);
	XFlush(disp);
	MyWait();
	XClearWindow(disp, win);
	// crta julijev skup u fiksnoj tocki (0.32, 0.043)
	for (j=0; j<MAXY; j+=MYSTEP)
		for (i=0; i<MAXX; i+=MYSTEP)
			XPutPixel(image, i, j,
			Iterate(4./MAXX*i-2., -4./MAXY*j+2., numiter,
				bailout, 0.32, 0.043)*MINT);
	XPutImage(disp, win, gc, image, 0, 0, 0, 0, MAXX, MAXY);
	XDrawString(disp, win, gc, 10, 10, "Julia", 5);
	XFlush(disp);
	MyWait();
}

int main(void)
{
	MyDraw9 MyOb;
	return EXIT_SUCCESS;
}