/* This is a very simple program to create the mandelbrot set */
/* compile is g++ mand.cpp -o mand */

/* sample paths to try are */
/* -2 -1 1 -1 10000 */
/* -1.3 -1.2 0.1 -0.1 256 */

#include <iostream>
#include <fstream>
#include <math.h>
using namespace std;

const int width = 1024;
const int height = 768;

int computeData(int xstart, int xend, int ystart, int yend, int iter, char (&pic)[height][width][3]);
bool outputFile(char (&pic)[height][width][3]);

int main()
{
	double xstart, xend, ystart, yend;
	int iter;

	char pic[height][width][3]; //actual pic

	// get data
	cout << "Enter xstart, xend, ystart, yend, iterations: " << endl;
	cin >> xstart >> xend >> ystart >> yend >> iter;

	computeData(xstart, xend, ystart, yend, iter, pic);
	// create an output stream for the file


	if (outputFile(pic) == false)
	{
		cout << "Error Opening File" << endl;
		return 1;
  	}


	return 0;
}

int computeData(int xstart, int xend, int ystart, int yend, int iter, char (&pic)[height][width][3])
{
	double x, y, xstep, ystep, z, zi, newz, newzi, colour;
	int i, j, k, inset, fd;
	long col;

	// compute the step relative to the resolution of the image
  	xstep = (xend-xstart)/width;
  	ystep = (yend-ystart)/height;

	// do the calculation
  	x = xstart;
  	y = ystart;
  	for (i=0; i<height; i++)
  	{
    		for (j=0; j<width; j++)
    		{
      			z = 0;
      			zi = 0;
      			inset = 1;
      			for (k=0; k<iter; k++)
      			{
				newz = (z*z)-(zi*zi) + x;
				newzi = 2*z*zi + y;
        			z = newz;
        			zi = newzi;
				if(((z*z)+(zi*zi)) > 4)
				{
					inset = 0;
					colour = k;
					k = iter;
				}
	  		}
			if (inset)
			{
				pic[i][j][0] = 0;
				pic[i][j][1] = 0;
				pic[i][j][2] = 0;
      			}
      			else
      			{
				pic[i][j][0] = (char) (colour / iter * 255);
				pic[i][j][1] = (char) (colour / iter * 255 / 2);
				pic[i][j][2] = (char) (colour / iter * 255 / 2);
      			}
      			x += xstep;
    		}
    		y += ystep;
    		x = xstart;
  	}

}

bool outputFile(char (&pic)[height][width][3]) // stuff
{
	ofstream ofs;
	ofs.open("image.tga", ios::out);

	if(ofs.good())
	{
		char buffer[100];

		// prepare the buffer for the TGA format.

	  	buffer[0] = 0;
	  	buffer[1] = 0;
	  	buffer[2] = 2;
	  	buffer[8] = 0; buffer[9] = 0;
	  	buffer[10] = 0; buffer[11] = 0;
	  	buffer[12] = (width & 0x00FF); buffer[13] = (width & 0xFF00) >> 8;
	  	buffer[14] = (height & 0x00FF); buffer[15] = (height & 0xFF00) >> 8;
	  	buffer[16] = 24;
	  	buffer[17] = 0;

		// write the entire buffer out i.e. tga header

	  	ofs.write((char*)buffer, 18);

		// now write the pic out which is stored in pic

	  	ofs.write((char*)pic, width*height*3);
	  	ofs.close();

	  	return true;
	  }
	  else
	  {
	  	return false;
	  }
}