/*
 * Bryan Ward
 * mpi_movie.c - generate the frames for a julia set movie
 * this program uses mpi and distributes among n given processors
 */

#include <stdio.h>
#include <complex.h>
#include <math.h>
#include <float.h>
#include <stdlib.h>
#include <mpi.h>

#define width 1280
#define height 1024
#define iter 255
#define frames 100
#define xmin -2.0
#define xmax 2.0
#define ymin -2.0
#define ymax 2.0

int main(int argc, char *argv[])
{
//	Output variables
	FILE *fl;
	char file[4];

//	MPI Variables
	int rank,size,mpistate;
	MPI_Status mpistatus;

//Fractal Variables
	double xpix, ypix;
	double complex c,z;
	int escape;
	int *image = NULL;
	int *imagbuf = NULL;
//Other Variables
	int i,f;

//	Start MPI
	MPI_Init( &argc, &argv );
	MPI_Comm_size( MPI_COMM_WORLD, &size );
	MPI_Comm_rank( MPI_COMM_WORLD, &rank );


//	initialize the image in memory
	if((image = (int *)malloc(sizeof(int)*width*height))==NULL)
		fprintf(stderr,"Could not allocate the necessary memory\n");


//	Set some variable values
	ypix = (ymax - ymin) / height;
	xpix = (xmax - xmin) / width;


//	Set the image to 0 everywhere
	for(i = 0;i<width*height;i++)
		image[i] = 0;


//	Create a new file variable for everyone
//	sprintf(file,"movie/%d-mpi",rank);


//Put everyone on the same sheet of music
	MPI_Barrier(MPI_COMM_WORLD);

//Iterate over the plane

	for(f = 0;f < 500;f++)
	{
		c = f*.0004+rank*.0001;
		//printf("%f\n",creal(c));
		sprintf(file,"movie/%04d",f*size+rank);
		for(i = 0;i<width*height;i++)
		{
			z = xmin + (i%width * xpix) +(ymin + (i/height *ypix)) * I;
			image[i] = checkPoint(z, c);
		}
	
	//Open the file for writing
		if ((fl = fopen (file, "w")) == NULL)
			fprintf(stderr, "Cannot open %s\n",file);
	
	//Setup the image file
	        fprintf (fl, "P2\n");
	        fprintf (fl, "#Copyright (C) 2007 Bryan Ward\n");
	        fprintf (fl, "%d\t%d\n", width, height);
	        fprintf (fl, "255\n");
	
	
	//Write to the file
		for(i = 0; i < width * height; i++)
			fprintf(fl,"%d\n",image[i]);
	
	
	//Close the file
		fclose(fl);
	}
	

	MPI_Finalize();
	return 0;
}

int checkPoint(double complex z, double complex c)
{
	int j = 0;

	while(creal(z) * creal(z) + cimag(z) * cimag(z) < 4 && j < iter)
	{
		z = z * z + c;
		j++;
	}

	return j;
}