/* Grayscale scanned output for the PostScript printer; language PostScript. 
	Done by wtaylor@euclid.colorado.edu  12/17/99 
               Not very thoroughly tested. */

/* The grayscale has 256 values (8 bits). According to the PostScript
manual, this is the maximum possible in this format. Other formats,
such as jpeg, are probably required to get a smoother range of
colors. */

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

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

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

/*  Should be compiled with a definition of a function  g(x,y).  The
range of  x  and  y  is assumed to be  [0,1]. The range of  g  should
be the integers  {0,1, ... ,255} (0=black, 255 = white). */

/* 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  g.    */

#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 */

double g(double x, double y);

int f(x,y)
double x, y;
{
double w;
int k;
w = 256*g(x,y);
k = (int) w;
if (k<=0) k = 0;
if (k>=255) k = 255;
return(k);
}

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[10000];
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+=(COARSENESS))    
		{	
			CODE=0;
				x  =  (X + j)/DOTCOUNT;
				y  =  (Y + m)/DOTCOUNT;
				ff  =   f(x,y);  /* 0 <= ff < 255 */
				CODE =  ff;
				total += ff;
			/* 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++;
		}
	}
	if (total==0)
	{
		begin_small_bitmap(X,Y); 
		printf("00");
		end_bitmap();
	}
	else if(total==(255*(32/COARSENESS)*(32/COARSENESS))) 
	{
		begin_small_bitmap(X,Y); 
		printf("FF");
		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(\\t8-bit sampled image in PostScript");
#if(UNIX)
printf(" by %s",getlogin());
#endif
printf(",\\n) print\n");
printf("\t(\\tprepared with 8-bit sampling software by W. Taylor.\\n) print\n");
printf("\t(\\tFor similar sampling-ware for 1-bit (black and white)\\n) print\n");
printf("\t(\\timages, see Section 2.7 of his \"Geometry of Computer\\n) print\n");
printf("\t(\\tGraphics,\" published by Wadsworth-Brooks-Cole, 1991.\\n) print\n");
printf("\t(\\t                 * * * *                 \\n)        print\n");
printf("\t(\\tThe 8-bit sampling software was prepared in 1999.\\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");
#if(UNIX)
	gettimeofday(&tv, &tz);
	tp = localtime(&tv.tv_sec);
printf("\t(\\t%s, %s %d, 19%d",
	days[tp->tm_wday], months[tp->tm_mon], tp->tm_mday, tp->tm_year);
if (tp->tm_hour==0)
printf("       %d:%d  AM",   12      ,tp->tm_min);
if (tp->tm_hour<12)
printf("       %d:%d  AM",tp->tm_hour,tp->tm_min);
if (tp->tm_hour==12)
printf("       %d:%d  PM",    0      ,tp->tm_min);
if (tp->tm_hour>12)
printf("       %d:%d  PM",tp->tm_hour -12,tp->tm_min);
printf("\\n) print\n");
#endif

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());
printf("400.2 33.2 moveto               ");
printf("%%location of the date\n");
printf("(%s, %s %d, 19%d) show restore\n",
	days[tp->tm_wday], months[tp->tm_mon], tp->tm_mday, 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 8",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 8 [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");
}