/* Copyright (C) 1989, 1992 Aladdin Enterprises.  All rights reserved.

This file is part of Ghostscript.

Ghostscript is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
to anyone for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing.  Refer
to the Ghostscript General Public License for full details.

Everyone is granted permission to copy, modify and redistribute
Ghostscript, but only under the conditions described in the Ghostscript
General Public License.  A copy of this license is supposed to have been
given to you along with Ghostscript so you can know your rights and
responsibilities.  It should be in a file named COPYING.  Among other
things, the copyright notice and this notice must be preserved on all
copies.  */

/* gdevepsc.c */
/* Epson color dot-matrix printer driver for Ghostscript by dave@exlog.com */
#include "gdevprn.h"

/*
 * For 9-pin printers, you may select
 *   X_DPI = 60, 120, or 240
 *   Y_DPI = 60 or 72
 * For 24-pin printers, you may select
 *   X_DPI = 60, 120, 180, 240, or 360
 *   Y_DPI = 60, 72, 180, or 216
 * Note that a given printer implements *either* Y_DPI = 60 | 180 *or*
 * Y_DPI = 72 | 216; no attempt is made to check this here.
 * Note that X_DPI = 180 or 360 requires Y_DPI > 100;
 * this isn't checked either.  Finally, note that X_DPI=240 and
 * X_DPI=360 are double-density modes requiring two passes to print.
 *
 * The values of X_DPI and Y_DPI may be set at compile time:
 * see gdevs.mak.
 * 
 * At some time in the future, we could simulate 24-bit output on
 * 9-pin printers by using fractional vertical positioning;
 * we could even implement an X_DPI=360 mode by using the
 * ESC++ command that spaces vertically in units of 1/360"
 * (not supported on many printers.)
 */

#ifndef X_DPI
#  define X_DPI 180			/* pixels per inch */
#endif
#ifndef Y_DPI
#  define Y_DPI 180			/* pixels per inch */
#endif

/*
**	Colors for EPSON LQ-2550.
**
**	We map VIOLET to BLUE since this is the best we can do.
*/
#define BLACK	0
#define MAGENTA 1
#define CYAN	2
#define VIOLET	3
#define YELLOW	4
#define RED		5
#define GREEN	6
#define WHITE	7

/*
**	The offset in this array correspond to
**	the ESC-r n value
*/
static char rgb_color[2][2][2] =	{
	BLACK, VIOLET, GREEN,
	CYAN, RED, MAGENTA,
	YELLOW, WHITE,
	};

/* Map an RGB color to a printer color. */
#define cv_shift (sizeof(gx_color_value) * 8 - 1)
private gx_color_index
epson_map_rgb_color(gx_device *dev,
  gx_color_value r, gx_color_value g, gx_color_value b)
{
if (gx_device_has_color(dev))
	{
/* use ^7 so WHITE is 0 for internal calculations */
	return (gx_color_index)rgb_color[r >> cv_shift][g >> cv_shift][b >> cv_shift] ^ 7;	
	}
else
	{
	return gx_default_map_rgb_color(dev, r, g, b);
	}
}

/* Map the printer color back to RGB. */
private int
epson_map_color_rgb(gx_device *dev, gx_color_index color,
  gx_color_value prgb[3])
{
#define c1 gx_max_color_value
if (gx_device_has_color(dev))
	switch ((ushort)color ^ 7)
		{
		case BLACK:
			prgb[0] = 0; prgb[1] = 0; prgb[2] = 0; break;
		case VIOLET:
			prgb[0] = 0; prgb[1] = 0; prgb[2] = c1; break;
		case GREEN:
			prgb[0] = 0; prgb[1] = c1; prgb[2] = 0; break;
		case CYAN:
			prgb[0] = 0; prgb[1] = c1; prgb[2] = c1; break;
		case  RED:
			prgb[0] = c1; prgb[1] = 0; prgb[2] = 0; break;
		case  MAGENTA:
			prgb[0] = c1; prgb[1] = 0; prgb[2] = c1; break;
		case YELLOW:
			prgb[0] = c1; prgb[1] = c1; prgb[2] = 0; break;
		case  WHITE:
			prgb[0] = c1; prgb[1] = c1; prgb[2] = c1; break;
		}
	else
		return gx_default_map_color_rgb(dev, color, prgb);
	return 0;
}

/* The device descriptor */
private dev_proc_print_page(eps_print_page);

private gx_device_procs epson_procs =
  prn_color_procs(gdev_prn_open, gdev_prn_output_page, gdev_prn_close,
    epson_map_rgb_color, epson_map_color_rgb); 

gx_device_printer far_data gs_epsonc_device =
  prn_device(epson_procs, "epsonc",
	85,				/* width_10ths, 8.5" */
	110,				/* height_10ths, 11" */
	X_DPI, Y_DPI,
	0, 0, 0.25, 0,		/* margins */
	3, eps_print_page);

/* ------ Internal routines ------ */

/* Forward references */
private void eps_output_run(P6(byte *, int, int, char, FILE *, int));

/* Send the page to the printer. */
#define DD 0x80				/* double density flag */
private int
eps_print_page(gx_device_printer *pdev, FILE *prn_stream)
{	static char graphics_modes_9[5] =
	   {	-1, 0 /*60*/, 1 /*120*/, -1, DD+3 /*240*/
	   };
	static char graphics_modes_24[7] =
	   {	-1, 32 /*60*/, 33 /*120*/, 39 /*180*/,
		-1, -1, DD+40 /*360*/
	   };
	int y_24pin = pdev->y_pixels_per_inch > 72;
	int y_mult = (y_24pin ? 3 : 1);
	int line_size = (pdev->width + 7) >> 3;	/* always mono */
	int in_size = line_size * (8 * y_mult);
	byte *in = (byte *)gs_malloc(in_size, 1, "eps_print_page(in)");
	int out_size = ((pdev->width + 7) & -8) * y_mult;
	byte *out = (byte *)gs_malloc(out_size, 1, "eps_print_page(out)");
	int x_dpi = pdev->x_pixels_per_inch;
	char start_graphics =
		(y_24pin ? graphics_modes_24 : graphics_modes_9)[x_dpi / 60];
	int first_pass = (start_graphics & DD ? 1 : 0);
	int last_pass = first_pass * 2;
	int dots_per_space = x_dpi / 10;	/* pica space = 1/10" */
	int bytes_per_space = dots_per_space * y_mult;
	int skip = 0, lnum = 0, pass;
/* declare color buffer and related vars */
	byte *color_in;
	int color_line_size, color_in_size;
	int spare_bits = (pdev->width % 8);	/* left over bits to go to margin */
	int whole_bits = pdev->width - spare_bits;

	/* Check allocations */
	if ( in == 0 || out == 0 )
	   {	if ( in ) gs_free((char *)in, in_size, 1, "eps_print_page(in)");
		if ( out ) gs_free((char *)out, out_size, 1, "eps_print_page(out)");
		return -1;
	   }

	/* Initialize the printer and reset the margins. */
	fwrite("\033@\033P\033l\000\033Q\377\033U\001\r", 1, 14, prn_stream);

/*	Create color buffer */
	if (gx_device_has_color(pdev))
		{
		color_line_size = gdev_mem_bytes_per_scan_line((gx_device *)pdev);
		color_in_size = color_line_size * (8 * y_mult);
		if((color_in = (byte *)gs_malloc(color_in_size, 1,
			"eps_print_page(color)")) == 0)
			{
			gs_free((char *)in, in_size, 1, "eps_print_page(in)");
			gs_free((char *)out, out_size, 1, "eps_print_page(out)");
			return(-1);
			}
		}
	else
		{
		color_in = in;
		color_in_size = in_size;
		color_line_size = line_size;
		}

	/* Print lines of graphics */
	while ( lnum < pdev->height )
	   {
		int lcnt;
		byte *nextcolor = NULL;	/* position where next color appears */
		byte *nextmono = NULL;	/* position to map next color */

		/* Copy 1 scan line and test for all zero. */
		gdev_prn_copy_scan_lines(pdev, lnum, color_in, color_line_size);

		if ( color_in[0] == 0 &&
		     !memcmp((char *)color_in, (char *)color_in + 1, color_line_size - 1)
		   )
		   {	lnum++;
			skip += 3 / y_mult;
			continue;
		   }

		/* Vertical tab to the appropriate position. */
		while ( skip > 255 )
		   {	fputs("\033J\377", prn_stream);
			skip -= 255;
		   }
		if ( skip )
			fprintf(prn_stream, "\033J%c", skip);

		/* Copy the rest of the scan lines. */
		lcnt = 1 + gdev_prn_copy_scan_lines(pdev, lnum + 1, 
			color_in + color_line_size, color_in_size - color_line_size);

		if ( lcnt < 8 * y_mult )
			{
			memset((char *)(color_in + lcnt * color_line_size), 0,
				color_in_size - lcnt * color_line_size);
			if (gx_device_has_color(pdev))	/* clear the work buffer */
				memset((char *)(in + lcnt * line_size), 0,
					in_size - lcnt * line_size);
			}
			
/*
**	We need to create a normal epson scan line from our color scan line
**	We do this by setting a bit in the "in" buffer if the pixel byte is set
**	to any color.  We then search for any more pixels of that color, setting
**	"in" accordingly.  If any other color is found, we save it for the next
**	pass.  There may be up to 7 passes.
**	In the future, we should make the passes so as to maximize the
**	life of the color ribbon (i.e. go lightest to darkest).
*/
		do
		{
		byte *inp = in;
		byte *in_end = in + line_size;
		byte *out_end = out;
		byte *out_blk;
		register byte *outp;

		if (gx_device_has_color(pdev))
			{
			register i,j;
			register byte *outbuf, *realbuf;
			byte current_color;
			int end_next_bits = whole_bits;
			int lastbits;
			
/*	Move to the point in the scanline that has a new color */
			if (nextcolor)
				{
				realbuf = nextcolor;
				outbuf = nextmono;
				memset((char *)in, 0, (nextmono - in));
				i = nextcolor - color_in;
				nextcolor = NULL;
				end_next_bits = (i / color_line_size) * color_line_size
					+ whole_bits;
				}
			else
				{
				i = 0;
				realbuf = color_in;
				outbuf = in;
				nextcolor = NULL;
				}
/*	move thru the color buffer, turning on the appropriate
**	bit in the "mono" buffer", setting pointers to the next
**	color and changing the color output of the epson
*/
			for (current_color = 0; i <= color_in_size; outbuf++)
				{
/*	Remember, line_size is rounded up to next whole byte
**	whereas color_line_size is the proper length
**	We only want to set the proper bits in the last line_size byte.
*/
				if (spare_bits && i == end_next_bits)
					{
					end_next_bits = whole_bits + i + spare_bits;
					lastbits = 8 - spare_bits;
					}
				else
					lastbits = 0;

				for (*outbuf = 0, j = 8; --j >= lastbits && i <= color_in_size;
					realbuf++,i++)
					{
					if (*realbuf)
						{
						if (current_color > 0)
							{
							if (*realbuf == current_color)
								{
								*outbuf |= 1 << j;
								*realbuf = 0;	/* throw this byte away */
								}
					/* save this location for next pass */
							else if (nextcolor == NULL)
								{
								nextcolor = realbuf - (7 - j);
								nextmono = outbuf;
								}
							}
						else 
							{
							*outbuf |= 1 << j;
							current_color = *realbuf;	/* set color */
							*realbuf = 0;
							}
						}
					}
				}
			*outbuf = 0;		/* zero the end, for safe keeping */
/*	Change color on the EPSON, current_color must be set
**	but lets check anyway
*/
			if (current_color)
				fprintf(prn_stream,"\033r%d",current_color ^ 7);
			}

		/* We have to 'transpose' blocks of 8 pixels x 8 lines, */
		/* because that's how the printer wants the data. */
		/* If we are in a 24-pin mode, we have to transpose */
		/* groups of 3 lines at a time. */

		if ( y_24pin )
		 { for ( ; inp < in_end; inp++, out_end += 24 )
		    { gdev_prn_transpose_8x8(inp, line_size, out_end, 3);
		      gdev_prn_transpose_8x8(inp + line_size * 8, line_size, out_end + 1, 3);
		      gdev_prn_transpose_8x8(inp + line_size * 16, line_size, out_end + 2, 3);
		    }
		   /* Remove trailing 0s. */
		   while ( out_end > out && out_end[-1] == 0 &&
			   out_end[-2] == 0 && out_end[-3] == 0
			 )
		     out_end -= 3;
		 }
		else
		 { for ( ; inp < in_end; inp++, out_end += 8 )
		    { gdev_prn_transpose_8x8(inp, line_size, out_end, 1);
		    }
		   /* Remove trailing 0s. */
		   while ( out_end > out && out_end[-1] == 0 )
		     out_end--;
		 }

		for ( pass = first_pass; pass <= last_pass; pass++ )
		   {
		for ( out_blk = outp = out; outp < out_end; )
		 { /* Skip a run of leading 0s. */
		   /* At least 10 are needed to make tabbing worth it. */
		   /* We do everything by 3's to avoid having to make */
		   /* different cases for 9- and 24-pin. */

		   if ( *outp == 0 && outp + 12 <= out_end &&
			outp[1] == 0 && outp[2] == 0 &&
			(outp[3] | outp[4] | outp[5]) == 0 &&
			(outp[6] | outp[7] | outp[8]) == 0 &&
			(outp[9] | outp[10] | outp[11]) == 0
		      )
		    {	byte *zp = outp;
			int tpos;
			byte *newp;
			outp += 12;
			while ( outp + 3 <= out_end && *outp == 0 &&
				outp[1] == 0 && outp[2] == 0
			      )
				outp += 3;
			tpos = (outp - out) / bytes_per_space;
			newp = out + tpos * bytes_per_space;
			if ( newp > zp + 10 )
			 { /* Output preceding bit data. */
			   if ( zp > out_blk )	/* only false at */
						/* beginning of line */
			     eps_output_run(out_blk, (int)(zp - out_blk),
					    y_mult, start_graphics,
					    prn_stream, pass);
			   /* Tab over to the appropriate position. */
			   fprintf(prn_stream, "\033D%c%c\t", tpos, 0);
			   out_blk = outp = newp;
			 }
		   }
		  else
			outp += y_mult;
		 }
		if ( outp > out_blk )
			eps_output_run(out_blk, (int)(outp - out_blk),
				       y_mult, start_graphics,
				       prn_stream, pass);

			fputc('\r', prn_stream);
		   }
			} while (nextcolor);
		skip = 24;
		lnum += 8 * y_mult;
	   }

	/* Eject the page and reinitialize the printer */
	fputs("\f\033@", prn_stream);


	gs_free((char *)out, out_size, 1, "eps_print_page(out)");
	gs_free((char *)in, in_size, 1, "eps_print_page(in)");
	if (gx_device_has_color(pdev))
		gs_free((char *)color_in, color_in_size, 1, "eps_print_page(rin)");
	return 0;
}

/* Output a single graphics command. */
/* pass=0 for all columns, 1 for even columns, 2 for odd columns. */
private void
eps_output_run(byte *data, int count, int y_mult,
  char start_graphics, FILE *prn_stream, int pass)
{	int xcount = count / y_mult;
	fputc(033, prn_stream);
	if ( !(start_graphics & ~3) )
	   {	fputc("KLYZ"[start_graphics], prn_stream);
	   }
	else
	   {	fputc('*', prn_stream);
		fputc(start_graphics & ~DD, prn_stream);
	   }
	fputc(xcount & 0xff, prn_stream);
	fputc(xcount >> 8, prn_stream);
	if ( !pass )
		fwrite((char *)data, 1, count, prn_stream);
	else
	   {	/* Only write every other column of y_mult bytes. */
		int which = pass;
		byte *dp = data;
		register int i, j;
		for ( i = 0; i < xcount; i++, which++ )
		  for ( j = 0; j < y_mult; j++, dp++ )
		   {	putc(((which & 1) ? *dp : 0), prn_stream);
		   }
	   }
}
