Mandelbrot

mandelbrot.cpp

#include "iostream"
#include "cmath"
#define DIM 1024
#define DM1 DIM-1
#define _sq(x) ((x)*(x)) // Square
#define _cb(x) abs((x)*(x)*(x)) // Cube
#define _cr (unsigned short) (pow((x), 1.0/3.0)) // Cube root

unsigned char GR(int,int);
unsigned char BL(int,int);

unsigned char RD(int i,int j){
   double a=0,b=0,c,d,n=0;
   while((c=a*a)+(d=b*b)<4&&n++<880)
   {b=2*a*b+j*8e-9-.645411;a=c-d+i*8e-9+.356888;}
   return 255*pow((n-80)/800,3.);
}
unsigned char GR(int i,int j){
   double a=0,b=0,c,d,n=0;
   while((c=a*a)+(d=b*b)<4&&n++<880)
   {b=2*a*b+j*8e-9-.645411;a=c-d+i*8e-9+.356888;}
   return 255*pow((n-80)/800,.7);
}
unsigned char BL(int i,int j){
   double a=0,b=0,c,d,n=0;
   while((c=a*a)+(d=b*b)<4&&n++<880)
   {b=2*a*b+j*8e-9-.645411;a=c-d+i*8e-9+.356888;}
   return 255*pow((n-80)/800,.5);
}

void pixel_write(int,int);
FILE *fp;

int main(){
   fp = fopen("MathPic", "wb");
   fprintf(fp, "P6\n%d %d\n1023\n", DIM, DIM);
   for (int j = 0; j < DIM; j++)
   {
      for (int i = 0; i < DIM; i++)
      {
         pixel_write(i,j);
      }
   }
   fclose(fp);
   return 0;
}

void pixel_write(int i, int j){
   static unsigned char color[3];
   color[0] = RD(i,j)&DM1;
   color[1] = GR(i,j)&DM1;
   color[2] = BL(i,j)&DM1;
   fwrite(color,1,3,fp);
}