#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include "type-def.h"
#include "util.h"
#include "imageio.h"

#define NX 1000
#define NY 1000

#define MIN(a, b) ((a)<(b)?(a):(b))

double a[4] = {0.0,0.2,-0.15,0.75};
double b[4] = {0.0,-0.26,0.28,0.04};
double c[4] = {0.0,0.0023,0.0026,-0.04};
double d[4] = {0.16,0.22,0.24,0.85};
double e[4] = {0.0,0.0,0.0,0.0};
double f[4] = {0.0,1.6,0.44,1.6};

int main(int argc,char **argv)
{
  int i,j,k;
  int n = 1000;
  int ix,iy;
  double r,x,y,xlast=0,ylast=0;
  double xmin=1e32,xmax=-1e32,ymin=1e32,ymax=-1e32,scale,xmid,ymid;
  char fname[256];
  
  IMAGEINT_MBAND image;
  
  
  if (argc < 2) {
    fprintf(stderr,"Usage: %s nsteps\n",argv[0]);
    exit(0);
  }
  n = atoi(argv[1]);
  if (argc < 3) {
    strcpy(fname,"fern.pgm");
  }
  else {
    strcpy(fname,argv[2]);
  }
  image.nband = 0;
  Create_Image_MBAND(&image, (int)NY, (int)NX, 3);
  for (i=0; i < image.nrow; i++) {
    for (j=0; j < image.ncol; j++) {
      for (k=0; k < image.nband; k++) {
	image.bands[k].data[i][j] = 255;
      }
    }
  }
  /* EraseBitmap(image,NX,NY,white); */
  
  for (j=0;j<2;j++) {
    for (i=0;i<n;i++) {
      r = rand() % 100;
      if (r < 10)
	k = 0;
      else if (r < 18)
	k = 1;
      else if (r < 26)
	k = 2;
      else
	k = 3;
      x = a[k] * xlast + b[k] * ylast + e[k];
      y = c[k] * xlast + d[k] * ylast + f[k];
      xlast = x;
      ylast = y;
      if (x < xmin) xmin = x;
      if (y < ymin) ymin = y;
      if (x > xmax) xmax = x;
      if (y > ymax) ymax = y;
      if (j == 1) {
	scale = MIN(NX / (xmax - xmin),NY / (ymax - ymin));
	xmid = (xmin + xmax) / 2;
	ymid = (ymin + ymax) / 2;
	ix = NX / 2 + (x - xmid) * scale-1;
	iy = NY / 2 + (y - ymid) * scale-1;
	for (k=0; k < image.nband; k++) {
	  if (iy < image.bands[k].nrow && iy >= 0 &&
	      ix < image.bands[k].ncol && ix >=0 ) {
	    image.bands[k].data[image.bands[k].nrow-iy-1][ix] =
	      (k==1)*255;
	  }
	  else {
	    printf("Pixel position (%d, %d) is out of range.\n",
		   ix, iy);
	  }
	}
	/* DrawPixel(image,NX,NY,ix,iy,black); */
      }
    }
  }
  WriteP6Char(fname, &image, (int)1);
  /* WriteBitmap(stdout,image,NX,NY,2); */
  return 0;
}