/*	stringart.c	1.3	84/04/22	*/

#include <osbind.h>
#define NUMLINES	343	/* number of vectors in a design */
#define NUM_FUNCTIONS	13	/* number of functions */

/*
	This demo creates random vector designs.  This is accomplished by
	randomly choosing a function for each coordinate halve of the two
	points describing a vector that moves through two dimensional
	space. Both x coordinate halves cannot be the same since the design
	would simply be a collection of vertical lines. Similarly both
	y coordinate halves cannot be the same.

	The functions are:
*/
/*
	The values of the functions were pre computed to have the demo
	run as fast as possible.  The program will only terminate on 
	interrupt since it is in an endless loop.
*/

extern	double cos(), sin();
int	func[13][NUMLINES];
int contrl[12], intin[256], ptsin[256], intout[256], ptsout[256];
int dummy,handle;
int xwidth,ywidth,height,width;
int pxy[4],t1,t2,t3,t4;
int i,j,k,l,m;
int mx;
long Randx=1;

main()
{
/* Set the system up to do GEM calls */
  appl_init();

/* Get the handle of the desktop */

handle=graf_handle(&height,&width,&dummy,&dummy);

  /* Open the workstation. */

  for(i=1; i<10; ++i)  intin[i] = 1;
  intin[10] = 2;

  v_opnvwk(intin, &handle, intout);
  pxy[0]=0; pxy[1]=0;pxy[2]=intout[0];pxy[3]=intout[1];
  xwidth=pxy[2]; ywidth= pxy[3];
  graf_mouse(0,i);
  v_clrwk(handle);
  v_gtext(handle,0,height,"Precomputing coefficients ... please wait");
  init();
  Srand((long) Gettime());
  while(!Bconstat(2)){
		v_clrwk(handle);
		i=Rand()%NUM_FUNCTIONS;
		while((j = Rand()%NUM_FUNCTIONS)==i);
		k=Rand()%NUM_FUNCTIONS;
		while((l = Rand()%NUM_FUNCTIONS)==k);
		/* only do NUMLINES-1 lines ... dont redraw first line */
		for(m=0;m<NUMLINES;m++) {
			t1 = func[i][m];
			t2 = (func[j][m]*40)/64;
			t3 = func[k][m];
			t4 = (func[l][m]*40)/64;
			Vector(t1,t2,t3,t4);
		}
		for(t1=0;t1 <1000;t1++){
			for(t2=0;t2 < 500;t2++);
		}
  }
  v_clsvwk(handle);
 /* Release GEM calls */

  appl_exit();

}

init()
{
	int x;
	double pi,v1,v2,v3,v4;
	pi=3.1415927;
	v4 = NUMLINES;
	v1 = 2*pi/NUMLINES;
	v2=xwidth/2;
	for(x=0;x<NUMLINES;x++){
	v3=x;
	func[0][x] = 2 * ( v3 - (v4/2) )*v2 /v4;
	if(func[0][x] < 0) func[0][x] = -func[0][x];
	func[0][x]=func[0][x]+320;
	func[1][x] = sin( v1*v3 )*v2 + 320;
	func[2][x] = -sin( v1*v3 )*v2 + 320;
	func[3][x] = cos( v1*v3 )*v2 + 320;
	func[4][x] = -cos( v1*v3 )*v2 + 320;
	func[5][x] = sin( 2*v1*v3 )*v2 + 320;
	func[6][x] = -sin( 2*v1*v3 )*v2 + 320;
	func[7][x] = cos( 2*v1*v3 )*v2 + 320;
	func[8][x] = -cos( 2*v1*v3 )*v2 + 320;
	func[9][x] = sin( 3*v1*v3 )*v2 + 320;
	func[10][x] = -sin( 3*v1*v3 )*v2 + 320;
	func[11][x] = cos( 3*v1*v3 )*v2 + 320;
	func[12][x] = -cos( 3*v1*v3 )*v2 + 320;
	}
}

Vector(a,b,c,d)
int a,b,c,d;
{
	ptsin[0] = a;
	ptsin[1] = b;
	ptsin[2] = c;
	ptsin[3] = d;
	v_pline(handle, 2, ptsin);
}

Srand(x)
long x;
{       Randx = x; }

Rand()
{       return((Randx = Randx * 505360173 + 907633385) & 0x00007fff); }
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