//+-------------------------------------------------------------------------+
//+ Program STARSC.C - October 8, 1994                                      +
//+                                                                         +
//+ By Ramiro Perez (Panama), rperez@ns.pa (Original program in Turbo BASIC)+
//+ and Fausto A. A. Barbuto (Brazil), BJ06@C53000.PETROBRAS.ANRJ.BR (Turbo +
//+ BASIC to Borland C implementation and new formulations).                +
//+                                                                         +
//+ Plots... well, try it to see by yourself! :-)                           +
//+ Random number function by Michael Sargent (USA), msargent@moose.uvm.edu +
//+ No SVGA drivers needed.                                                 +
//+                                                                         +
//+ INSTRUCTIONS: press 'n' or 'N' to skip to the next plot; any other key  +
//+ will stop execution.                                                    +
//+ OBS: Not all images are interesting. Skip to the next, then.            +
//+-------------------------------------------------------------------------+
#include <math.h>
#include <graphics.h>
#include <conio.h>
#include <stdlib.h>

double qsrandom(void);

void main(void)
{
    int i, f, nx, ny, sign, GraphDriver=DETECT, GraphMode;
    int ipal1[13] = {0,1,1,9,9,25,25,11,11,31,31,63,63};
    int ipal2[13] = {0,4,4,36,36,52,52,38,38,54,54,62,63};
    char key;
    double a, b, c, d, rnd1, rnd2, pi, p2, p4, p6, x, y;
    double x1, y1, sx, sy, sx4, sy4;

    pi = 3.141592653589793;
    initgraph(&GraphDriver,&GraphMode,"C:\\BORLANDC\\BGI");

    do {
      rnd1 = qsrandom();
      if (rnd1 >= 0.5) for (i=0;i<=12;i++) setpalette(i,ipal1[i]);
      else    	       for (i=0;i<=12;i++) setpalette(i,ipal2[i]);
      rnd1 = qsrandom(); rnd2 = qsrandom();
      a = rnd2 - rnd1;
      rnd1 = qsrandom(); rnd2 = qsrandom();
      b = rnd2 - rnd1;
      rnd1 = qsrandom(); rnd2 = qsrandom();
      c = rnd2 - rnd1;
      rnd1 = qsrandom(); rnd2 = qsrandom();
      d = rnd2 - rnd1;
      x = qsrandom(); y = qsrandom();
      p2 = 2.0*pi; p4 = 4.0*pi; p6 = 6.0*pi;
      rnd1 = qsrandom();
      if (rnd1 >= 0.5) sign = 1; else sign = -1;

      do {
	sx  = p2*x; sy  = p2*y;
	sx4 = p4*x; sy4 = p4*y;
	x1 = a*sin(sx) + sign*b*sin(sx)*cos(sy) + c*sin(sx4) +
	     d*sin(p6*x)*cos(sy4);
	y1 = a*sin(sy) + sign*b*sin(sy)*cos(sx) + c*sin(sy4) +
	     d*sin(p6*y)*cos(sx4);
	nx = (int)(128.0*(x1 + 2.5));
	ny = (int)(480.0*(y1 + 1.6)/3.2);
	f = getpixel(nx,ny);
	if (f < 12) f++;
	putpixel (nx,ny,f);
	x = x1;	y = y1;
      } while (!kbhit());
      key = getch();
      cleardevice();
    } while ((key == 'n') || (key == 'N'));
    closegraph();
}

double qsrandom(void) //* Random number generator by Mike Sargent. *//
{
   int random_integer, temp_integer;
   double random_double, temp_double;

   random_integer = random(RAND_MAX);
   random_double = (double)random_integer / RAND_MAX;
   temp_integer = random(30519);
   temp_double = (double)temp_integer / 1000000000L;
   random_double += temp_double;
   return(random_double);
}