#include <math.h>
#include "paulslib.h"
#include "bitmaplib.h"

// Vary this for different attractors
#define m 4

// Total number of iterations
#define n 10000000

// Width and height of image
#define nxy 800

int main(int argc,char **argv)
{
   int i,k,ix,iy;
   double a[2*m],b[2*m];
   double x=1,y=1,x1,y1;
   BITMAP4 *image,white={255,255,255,0},black={0,0,0,0};
   char fname[64];
   FILE *fptr;

   /* Create control points */
   for (i=0;i<m;i++) {
      a[2*i] = cos(TWOPI*i/m + PI/4);
      b[2*i] = sin(TWOPI*i/m + PI/4);
   }
   for (i=0;i<m;i++) {
      a[2*i+1] = (cos(TWOPI*i/m+PI/4) + cos(TWOPI*(i-1)/m+PI/4))/2;
      b[2*i+1] = (sin(TWOPI*i/m+PI/4) + sin(TWOPI*(i-1)/m+PI/4))/2;
   }

   /* Form the image in memory */
   image = Create_Bitmap(nxy,nxy);
   Erase_Bitmap(image,nxy,nxy,white);

   /* Iterate, draw points on the attractor */
   for (i=0;i<n;i++) {
      k = rand() % (2*m);
      x1 = x/3 + a[k];
      y1 = y/3 + b[k];
      if (i > 10) {
         ix = nxy/2 + 0.45 * x1 * nxy;
         iy = nxy/2 + 0.45 * y1 * nxy;
         Draw_Pixel(image,nxy,nxy,ix,iy,black);
      }
      x = x1;
      y = y1;
   }

   /* Write the image */
   sprintf(fname,"ifs.tga");
   if ((fptr = fopen(fname,"w")) == NULL) {
      fprintf(stderr,"Unable to open bitmap file\n");
      exit(0);
   }
   Write_Bitmap(fptr,image,nxy,nxy,12);
   fclose(fptr);

   exit(0);
}