/* Raster output for the PostScript printer; language PostScript. 
	Done by wtaylor@euclid.colorado.edu  11/99 
            This is an example with random dithering. In other
	words, it implements section 2.7 including
	the probabilistic filter of section 2.7.2.
*/

/* Always check that output ends with `showpage.' */

#define UNIX 1         /*  change to  0  if not a unix system  */

#define TITLE "Gray wedge"   
			/* for none, use "".  NO UNBALANCED PARENS  */

/* There is also an option of calling a once-only startup routine called
setup(argv[1]) which reads files, sets some global variables, and so on.
This routine will be called only if SETUP is defined to be something other
than  0.  Definition of  setup  should be in the file containing  f.    */

#define SETUP 0                     /* make this  0  unless setup routine
                                       is desired                        */

#include <math.h>
#include <stdio.h>

			/* Recommended size is .8, 1.6, 2.4 (small
			   multiples of .8 inches.) Can go up to 6.4
			   for final copy. Recommended coarseness is
			   2, 4 or 8. Can go down to 1 for final copy. */

#define MESH 300                  /*  dots per inch ; don't change  */
#define SIZE 4.0                  /*  width = height of picture, in inches  */
#define DOTCOUNT (MESH*SIZE)      /*  width = height of picture
                                                        measured in dots   */
#define POINTS_PER_INCH 72	  /* don't change this */

#define COARSENESS 4      /* should be 1, 2, 4, 8, 16 or 32 */

/* Best to keep the picture coarse (4 or above) until you get the
hang of it. Also small, 4 inches or less. */

main(argc,argv)
int argc;
char *argv[];
{
			/* The picture will be scaled so that
			   X,Y,j,k,m will all enumerate pixels */

int X,Y;  int  m, j, k; int CODE;
char c; char temp[300];
int f(), ff, i, ii, total;
double x, y;

				/* Comment: According to what is written
				   in the PostScript manual, on any
				   device, one could simply write ONE bitmap
				   and be done with it. Physical limitations
				   exist, however, on the length of a string.
				   (p. 260: limit = 64K) */

#if SETUP
setup(argv[1]);
#endif

begin_picture();
for (Y=0;Y < DOTCOUNT;Y+=32) for (X=0;X < DOTCOUNT;X+=32)
{
	/*
	Bitmap begins here; reserved for later delivery, however.
	*/
	i=0; total=0;
	for (m=0;m <32;m+=COARSENESS)
	{
		/* Each  j-value corresponds to one row of the bitmap */
		for  (j=0;j<32;j+=(8*COARSENESS))
		{	
			/* And each k-value corresponds to an 8-bit character
			   describing 8 bits of the row. If the row length is
			   less than eight, then padding is added below. */
			CODE=0;
			for  (k=0;((k<(8*COARSENESS))&&(k<32));k+=COARSENESS)
			{
				x  =  (X + j + k)/DOTCOUNT;
				y  =  (Y + m)/DOTCOUNT;
				ff  =   f(x,y);
				CODE = (2*CODE) + ff;
				total += ff;
			}
				/* Padding for each row of the bitmap, as
				   specified in footnote 6 on page 74 of
				   the PostScript manual: */
			   if(COARSENESS== 8) CODE*= 16;
			   if(COARSENESS==16) CODE*= 64;
			   if(COARSENESS==32) CODE*=128;
			/* Here the 8-bit character CODE is delivered as
			   two hexadecimal digits: */
			c = CODE/16;
			if (c<10) temp[i]=c+'0'; else temp[i]=c-10+'A';
				i++;
			c = CODE%16;
			if (c<10) temp[i]=c+'0'; else temp[i]=c-10+'A';
				i++;
		}
	}
/*
printf("\nTotal = %d\n",total);
*/
	if (total==0)
	{
		begin_small_bitmap(X,Y); 
		printf("00");
		end_bitmap();
	}
	else if(total==((32/COARSENESS)*(32/COARSENESS)))
	{
		begin_small_bitmap(X,Y); 
		printf("80");
		end_bitmap();
	}
	else
	{
		begin_bitmap(X,Y); 
		for (ii=0;ii<i;ii++)
		{
				/* Enough newlines so that one can easily
				   examine output when necessary: */
			if ((ii%64==0)&&(ii>0)) putchar('\n');
			putchar(temp[ii]);
		}
		end_bitmap();
	}
}
showpage();
}

char months[12][20] = {"January", "February", "March", "April", "May",
		"June", "July", "August", "September", "October",
		"November", "December"};
char days[7][20] = {"Sunday", "Monday", "Tuesday", "Wednesday",
			"Thursday", "Friday", "Saturday"};

begin_picture()
{
#if(UNIX)
char *getlogin();
#include <sys/types.h>
#include <sys/time.h>
char month[20];
char day[20];
struct tm *localtime(), *tp;
struct timeval tv;
struct timezone tz;

#endif
	double scaling_factor = (((double)POINTS_PER_INCH)/MESH);
	int size = 32/COARSENESS;
	printf("%%!PS\n");   /* PS added 11/10/99 wt  */

printf("\t(\\tRaster picture");
#if(UNIX)
printf(" by %s",getlogin());
#endif
printf(",\\n) print\n");
printf("\t(\\tprepared with software by W. Taylor. See Section\\n) print\n");
printf("\t(\\t2.7 of his \"Geometry of Computer Graphics,\"\\n)      print\n");
printf("\t(\\tpublished by Wadsworth-Brooks-Cole, 1991.\\n)        print\n");
printf("\t(\\t                 * * * *                 \\n)        print\n");
printf("\t(\\tSize: "); printf("%2.1f",SIZE);
		printf(" inches.\\n)                                print\n");
printf("\t(\\tPixel resolution: "); printf("%d",COARSENESS);
		printf("\\n)                              print\n");
printf("\t(\\tName of picture: "); printf(TITLE);
		printf("\\n)    print\n");

printf("save 214.2 88.2 moveto                       ");
printf("%%location of the label\n");
printf("/Times-Roman findfont 14 scalefont setfont   %%font for the label\n");
printf("("); printf(TITLE); printf(") show    %%the label itself\n");

#if(UNIX)
printf("restore save 400.2 48.2 moveto               ");
printf("%%location of the username\n");
printf("/Times-Roman findfont  8 scalefont");
printf(" setfont   %%font for the username\n");
printf("(Login name: %s) show\n",getlogin());
	gettimeofday(&tv, &tz);
	tp = localtime(&tv.tv_sec);
printf("400.2 33.2 moveto               ");
printf("%%location of the date\n");
printf("(%s, %s %d, %d) show restore\n",
	days[tp->tm_wday], months[tp->tm_mon], tp->tm_mday, 1900+tp->tm_year);
/*
if (tp->tm_hour==0)
printf("             %d:%d  AM\n",   12      ,tp->tm_min);
if (tp->tm_hour<12)
printf("             %d:%d  AM\n",tp->tm_hour,tp->tm_min);
if (tp->tm_hour==12)
printf("             %d:%d  PM\n",    0      ,tp->tm_min);
if (tp->tm_hour>12)
printf("             %d:%d  PM\n",tp->tm_hour -12,tp->tm_min);
*/
#endif

printf("%%%%\n%%%%\n");

printf("000.0 150.00 translate\n");

	printf("%3.2f %3.2f scale ", scaling_factor, scaling_factor);
	printf("%% This makes one unit = one pixel, at 300 DPI\n");
	printf("/x {image restore save} def\n");
	printf("/y {translate %d %d 1",size,size);
	printf(" [%4.5f 0 0 %4.5f 0 0]",(float)size/32,
						     (float)size/32);
	printf("} def\n");
	printf("/z {translate 1 1 1 [0.03125 0 0");
					printf(" 0.03125 0 0]} def\n");
	printf("save\n");
}

begin_small_bitmap(X,Y)
int X,Y;
{
	int size = 32/COARSENESS;
	printf("%d %d ",X+200,Y+200);
	printf("z\n");
	printf("{<\n");
}

begin_bitmap(X,Y)
int X,Y;
{
	int size = 32/COARSENESS;
	printf("%d %d ",X+200,Y+200);
	printf("y\n");
	printf("{<\n");
}

end_bitmap()
{
	printf(">}\n");
	printf("x ");
}

showpage()
{
	printf("\nshowpage\n");
}


f(r,s)
double r, s;
{
double y, z, w;
double g();
y  =  rand()%1000;
w  =  y/1000;
if  (g(r,s) >= w) return (1);
return (0);
}

double g(r,s)
double r, s;
{
double z;
z = 0.5 * (r+s);
return(z);
}