#include <stdio.h>
#include <GLUT/glut.h>
#include <stdlib.h>
#include <math.h>

#define RND ((float)rand( )/RAND_MAX)

#define True  1
#define False 0
#define WINSIZE 2000
#define ROWSIZE 8000
#define MAX 200

void display(void);
void idle(void);
void init(void);
int  main(int argc, char** argv);

float j;

float distance(float x, float y)
{
    float i = pow(x, 2.0) + pow(y, 2.0);
    i       = sqrt(i);
    return i;
}

int mandel(float zx, float zy, float cx, float cy, int count)
{
    float new_zx, new_zy;

    if(distance(zx, zy) > 10)
    {
        return count;
    }
    else if(count > MAX)
    {
        return 1;
    }
    new_zx = pow(zx, 2.0) - pow(zy, 2.0) + cx;
    new_zy = 2*zx*zy + cy;
    return mandel(new_zx, new_zy, zx, zy, count + 1);
}

void display( )
{
    int i, out;
	float color;
    glPointSize(1.0);
    glBegin(GL_POINTS);
        for(i = 0; i < ROWSIZE; i++)
        {
            out = mandel(0,0, i*1.0/ROWSIZE + 0.3, j*1.0/ROWSIZE + 0.3, 0);
            if(out == 1)
            {
                glColor3f(0.0, 0.0, 0.0);
            }
            else
            {
				color = (float)out/MAX;
                glColor3f(0.3, color, color - 0.1);
            }
            glVertex3f(i*0.4 - WINSIZE/2, j, 0.0);
        }
    glEnd( );
    glutSwapBuffers( );
    j -= 0.6;
}

void idle( )
{
    glutPostRedisplay( );
}

void init( )
{
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glMatrixMode(GL_FLAT);
    glLoadIdentity( );
    glOrtho(- WINSIZE/2, WINSIZE/2, -WINSIZE, WINSIZE, -20.0, 20.0);
    glClear(GL_COLOR_BUFFER_BIT);
    j = WINSIZE;
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
    glutInitWindowSize(WINSIZE, WINSIZE);
    glutInitWindowPosition(0,0);
    glutCreateWindow("MandelBrot");
    init( );
    glutDisplayFunc(display);
    glutIdleFunc(idle);
    glutMainLoop( );
    return 0;
}