/* Filename: fract3.c  */

#include <osbind.h>

	extern double sqrt();
	int contrl[12], intin[256], ptsin[256], intout[256], ptsout[256];

	int x_boundary;
	int y_boundary;
	double x_change;
	double y_change;
	double start_x;
	double start_y;
	double x_realpart;
	double y_imagpart;
	double x_plus_y_squared;
	double window_size;
	double temp_x,temp_y,temp1,temp2,temp3;
	double x,y,tempr;
	int i,plot_x,plot_y,count,num_random;
	int dummy,handle,pxy[4],kbak;
	int rgb_in[3],clr_count;
	int mx,my,width,height;
	int pen_color;
	char decimal[80];

main()

	{


		x=0.50001;
		y=0.;

/* The following is the setup to use the VDI and AES */

/* Set the system up to do GEM calls*/
/* the appl_init() call initials the application, and */
/* is required for us to use GEM/VDI.  */

  appl_init();

/* Get the handle of the desktop */
/* The 'handle' is the way we refer to a GEM virtual device, */
/* without having to know what that device is, how it works  */
/* internally, or even what type of device it is (screen,    */
/* plotter, or something else.).  We can use GEM calls, such as */
/* line drawing, fill, and plot commands, without regards as to */
/* how those commands are actually implemented, or how they  */
/* show up.  Notice also that later on we read the device's  */
/* resolution, in terms of pixels.  This allows us to write  */
/* screen resolution independent code, which will work on all */
/* current and future versions of the ST, (both b/w and color) */
/* since although the program plots points, it only plots points */
/* within the capable resolution of the device...  HIGHLY */
/* RECOMMENDED as a way of writing code, sinc it ensures  */
/* future compability, with very little extra work.       */

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

/* Open the workstation. */
/* This does a series of setup commands, which initial the  */
/* physical device, set up what kind of write mode we're in, */
/* and performs other random stuff.  Read the GEM VDI programmer's */
/* reference guide for further info.  */

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

/* This opens the device as a virtual workstation... See GEM VDI.  */

  v_opnvwk(intin, &handle, intout);

/* read in the device's actual screen resolution here, and save  */
/* it for future use...  */

  pxy[0]=0; pxy[1]=0; pxy[2]=intout[0]; pxy[3]=intout[1];
		x_boundary=pxy[2]/2;
		y_boundary=pxy[3]/2;

/* This command sets up automatic clipping by the device.  */
/* This means that any point drawn outside the screen, in  */
/* pixel coordinates, will simply not show up, but will also  */
/* not detonate the program, by writing to program RAM, or some */
/* other nasty kind of error.  Very handy, since it means that */
/* our program itself doesn't have to do boundary checking...  */

  vs_clip(handle,1,pxy);  /*turn on clipping*/

/* define the mouse graphics to be the pointing hand. */

  graf_mouse(3,&dummy);

/* Setup the pen colors here */

		for(count=2;count<16;count=count + 2)
			{
				rgb_in[0]=125 * ((count-2)/2);
				rgb_in[1]=125 * (count/2);
				rgb_in[2]=0;
				vs_color(handle,count,rgb_in);
				rgb_in[0]=125 * (count/2);
				rgb_in[1]=125 * (count/2);
				rgb_in[2]=0;
				vs_color(handle,count+1,rgb_in);
			}

				

/* The setup is now complete */

restart:	pen_color=2;
		rgb_in[0]=1000;
		rgb_in[1]=1000;
		rgb_in[2]=1000;
		vs_color(handle,0,rgb_in);

		v_hide_cursor(handle);
		v_clrwk(handle);
		vst_effect(handle,32);
		v_gtext(handle,0,height*10,"Fractal slice drawing program by");
		v_gtext(handle,0,height*11,"Alex Leavens and Leonard Tramiel");
		v_gtext(handle,0,height*13,"Please enter x,y and window size, using");
		v_gtext(handle,0,height*14,"the mouse and the bar.  Left edge is 0,");
		v_gtext(handle,0,height*15,"right edge of bar is 4.");
		v_gtext(handle,0,height*17,"To input new starting values,");
		v_gtext(handle,0,height*18,"press any key while program is");
		v_gtext(handle,0,height*19,"drawing.  To exit, press F1.");
		v_gtext(handle,0,height*21,"Note: This program DOES take a while");
		v_gtext(handle,0,height*22,"to run, and works ONLY IN LORES COLOR");
		v_gtext(handle,0,height*23,"mode.  Just hang in there!");

/* Set color of polyline used to draw points   */

		vsl_color(handle,pen_color);
		pen_color=pen_color+1;

		v_show_cursor(handle,0);
		initial();

/*Now clear the screen*/
		v_clrwk(handle);
		rgb_in[0]=0;
		rgb_in[1]=0;
		rgb_in[2]=0;
		vs_color(handle,0,rgb_in);


		while((evnt_multi(0x0021,
			0,0,0,
			0,0,0,0,0,
			0,0,0,0,0,
			&dummy,
			0,0,
			&dummy,&dummy,&dummy,
			&dummy,&kbak,&dummy))==0x0020)

			{

whango:			for(count=0;count<10;++count)
				{
					function();
				}


/* Now plot points  */

			vsl_color(handle,pen_color);
			pen_color=pen_color+1;
			for(count=0;count<10000;++count)
				{
					plotpoint();
					function();
				}
			start_x=start_x + x_change;
			start_y=start_y + y_change;
			x=.50001;
			y=0;
			x_realpart=start_x;
			y_imagpart=start_y;
			x_plus_y_squared=x_realpart * x_realpart + y_imagpart * y_imagpart;
			x_realpart=4 * x_realpart / x_plus_y_squared;
			y_imagpart=(-4) * y_imagpart / x_plus_y_squared;
	
			if(pen_color!=16) goto whango;

/* ok, we're done drawing it.  just sit and wait...  */

			plotpoint();

			}

		if (kbak!=0x3b00) goto restart;

		rgb_in[0]=1000;
		rgb_in[1]=1000;
		rgb_in[2]=1000;
		vs_color(handle,0,rgb_in);
	}

/*-----------------End of main()---------------------*/

function()

	{
	
		temp_x=x;
		temp_y=y;
		x=temp_x * x_realpart - temp_y * y_imagpart;
		y=temp_x * y_imagpart + temp_y * x_realpart;
		x=1.-x;
	

		temp1=y;
		x_plus_y_squared=(x * x) + (y * y);
		x_plus_y_squared=sqrt(x_plus_y_squared);
		temp3=(x_plus_y_squared - x) / 2.;
		if(temp3<0.)
			temp3=temp3 * (-1.);
		y=sqrt(temp3);
		temp3=(-x) + x_plus_y_squared;
		if(temp3<0.)
			y=y * (-1.);
		temp3=(x + x_plus_y_squared) / 2.;
		if(temp3<0.)
		        temp3=temp3 * (-1.);
		x=sqrt(temp3);
		temp3=x  + x_plus_y_squared;
		if(temp3<0.)
			x=x * (-1.);
		if(temp1<0.)
			x=x * (-1.);
		num_random=rand();
		if(num_random<16000)
			{
				x=x * (-1.);
				y=y * (-1.);
			}
		x=1.-x;
		x=x/2.;
		y=y/2.;

	}
/*-----------------End of Doroot()----------------------*/

plotpoint()

	{
		temp1=window_size * (x - .5) + x_boundary;
		temp2=y_boundary - window_size * y;
		plot_x=temp1;
		plot_y=temp2;
		Plot(plot_x,plot_y);
	}

/*---------------END plotpoint()---------------------*/

initial()
    	{
		temp3=x_boundary * 2.;
		temp3=temp3 / 4.;

/* Get the x value for the equation... */

		v_hide_cursor(handle);
		v_gtext(handle,0,height,"what is x-->");
		pxy[0]=0;pxy[1]=2*height;pxy[2]=2*x_boundary;pxy[3]=3*height;
		v_bar(handle,pxy);
		v_show_cursor(handle,0);
		evnt_button(1,1,1,&mx,&my,&dummy,&dummy);
		evnt_button(1,1,0,&dummy,&dummy,&dummy,&dummy);
		v_hide_cursor(handle);
		x_realpart=mx;
		x_realpart=x_realpart / temp3; /*scale 0-200 to real # 0-4  */
		start_x=x_realpart;
		ftoa(x_realpart,decimal,6); 
		decimal[79]=0; v_gtext(handle,width,4*height,decimal);

/* Get the y value for the equation... */

		v_gtext(handle,0,height,"what is y-->");
		pxy[0]=0;pxy[1]=2*height;pxy[2]=2*x_boundary;pxy[3]=3*height;
		v_bar(handle,pxy);
		v_show_cursor(handle,0);
	        evnt_button(1,1,1,&mx,&my,&dummy,&dummy);
		evnt_button(1,1,0,&dummy,&dummy,&dummy,&dummy);
		v_hide_cursor(handle);
		y_imagpart=mx;
 		y_imagpart=y_imagpart / temp3; /*scale 0-200 to real # 0-4   */
		start_y=y_imagpart;
		ftoa(y_imagpart,decimal,6); 
		decimal[79]=0; v_gtext(handle,width,4*height,decimal);

		x_plus_y_squared=(x_realpart * x_realpart) + (y_imagpart * y_imagpart);
		x_realpart=4 * x_realpart/x_plus_y_squared;
		y_imagpart=(-4) * y_imagpart/x_plus_y_squared;

/*  Get the change value for X  */

		temp2=x_boundary * 2.;
		v_gtext(handle,0,height,"what is change value for x-->");
		pxy[0]=0;pxy[1]=2*height;pxy[2]=2*x_boundary;pxy[3]=3*height;
		v_bar(handle,pxy);
		v_show_cursor(handle,0);
	        evnt_button(1,1,1,&mx,&my,&dummy,&dummy);
		evnt_button(1,1,0,&dummy,&dummy,&dummy,&dummy);
		v_hide_cursor(handle);
		x_change=mx;
 		x_change=x_change / temp2;  /*scale 0-200 to real # 0-4   */
		ftoa(x_change,decimal,6); 
		decimal[79]=0; v_gtext(handle,width,4*height,decimal);

/* Get the change value for y  */

		v_gtext(handle,0,height,"what is change value for y-->");
		pxy[0]=0;pxy[1]=2*height;pxy[2]=2*x_boundary;pxy[3]=3*height;
		v_bar(handle,pxy);
		v_show_cursor(handle,0);
	        evnt_button(1,1,1,&mx,&my,&dummy,&dummy);
		evnt_button(1,1,0,&dummy,&dummy,&dummy,&dummy);
		v_hide_cursor(handle);
		y_change=mx;
 		y_change=y_change / temp2; /*scale 0-200 to real # 0-4   */
		ftoa(y_change,decimal,6); 
		decimal[79]=0; v_gtext(handle,width,4*height,decimal);

/* Get the window size for the fractal  */

		v_gtext(handle,0,height,"what's the window size-->");
	        pxy[0]=0;pxy[1]=2*height;pxy[2]=2*x_boundary;pxy[3]=3*height;
		v_bar(handle,pxy);
		v_show_cursor(handle,0);
		evnt_button(1,1,1,&mx,&my,&dummy,&dummy);
		evnt_button(1,1,0,&dummy,&dummy,&dummy,&dummy);
		window_size=mx;
		temp3=x_boundary * 2.;
		temp3=temp3 / 4.;
		window_size=window_size / temp3;   /* scale number to 0-4 real  */
		tempr=2.; tempr=tempr * x_boundary;
		window_size=tempr/ window_size;
		ftoa(window_size,decimal,6); 
		v_hide_cursor(handle);
		decimal[79]=0; v_gtext(handle,width,4*height,decimal);

	}
	
/*------------------rand()-----------------*/
/*This function will return a 16 bit random number*/
rand()
{
return(Random()&0xffff);
}
/*__________End of rand_________________*/

/*------------Plot(x,y)------------------*/
Plot(x,y)
{
int pxy[4];

pxy[0]=x; pxy[1]=y; pxy[2]=x; pxy[3]=y;
v_pline(handle,2, pxy);
}

/*------------------End of Plot (x,y)---------------*/
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ?ÿÿÿÿÿÿ