/* Copyright (C) 1992 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU 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 GNU Ghostscript General Public License for full details.
  
*/

/* gdevnp6.c */
/* NEC dot-matrix printer driver: */
/* tested on P6, should also work on P6+ and similar models. */
#include "gdevprn.h"

/* Thanks to Andreas Schwab (schwab@ls5.informatik.uni-dortmund.de) */
/* for improvements to this code. */

/* The device descriptors */
private dev_proc_print_page (necp6_print_page);
gx_device_printer gs_necp6_device =
  prn_device (prn_std_procs, "necp6",
	      DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
	      360, 360,
	      0, 0, 0.5, 0,	/* margins */
	      1, necp6_print_page);

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

/* Forward references */
private void necp6_output_run (P4 (byte *, int, int, FILE *));
private void necp6_improve_bitmap (P2 (byte *, int));

/* Send the page to the printer. */
private int
necp6_print_page (gx_device_printer *pdev, FILE *prn_stream)
{
  int xres = pdev->x_pixels_per_inch;
  int yres = pdev->y_pixels_per_inch;
  int x_high = (xres == 360);
  int y_high = (yres == 360);
  int bits_per_column = (y_high ? 48 : 24);
  uint line_size = gdev_prn_raster (pdev);
  uint in_size = line_size * bits_per_column;
  byte *in = (byte *) gs_malloc (in_size, 1, "necp6_print_page (in)");
  uint out_size = ((pdev->width + 7) & -8) * 3;
  byte *out = (byte *) gs_malloc (out_size, 1, "necp6_print_page (out)");
  int y_passes = (y_high ? 2 : 1);
  int dots_per_space = xres / 10;	/* pica space = 1/10" */
  int bytes_per_space = dots_per_space * 3;
  int skip = 0, lnum = 0, ypass;

  /* Check allocations */
  if (in == 0 || out == 0)
    {
      if (out)
	gs_free ((char *) out, out_size, 1, "necp6_print_page (out)");
      if (in)
	gs_free ((char *) in, in_size, 1, "necp6_print_page (in)");
      return_error (gs_error_VMerror);
    }

  /* Initialize the printer and reset the margins. */
#define init_string "\033@\033P\033l\000\r\034\063\001\033Q"
  fwrite (init_string, sizeof (init_string) - 1, sizeof (char), prn_stream);
  fputc ((int) (pdev->width / pdev->x_pixels_per_inch * 10) + 2,
	 prn_stream);

  /* Print lines of graphics */
  while (lnum < pdev->height)
    {
      byte *inp;
      byte *in_end;
      byte *out_end;
      byte *out_blk;
      register byte *outp;
      int lcnt;

      /* Copy 1 scan line and test for all zero. */
      gdev_prn_copy_scan_lines (pdev, lnum, in, line_size);
      if (in[0] == 0
	  && !memcmp ((char *) in, (char *) in + 1, line_size - 1))
	{
	  lnum++;
	  skip += 2 - y_high;
	  continue;
	}

      /* Vertical tab to the appropriate position. */
      while ((skip >> 1) > 255)
	{
	  fputs ("\033J\377", prn_stream);
	  skip -= 255 * 2;
	}

      if (skip)
	{
	  if (skip >> 1)
	    fprintf (prn_stream, "\033J%c", skip >> 1);
	  if (skip & 1)
	    fputc ('\n', prn_stream);
	}

      /* Copy the rest of the scan lines. */
      if (y_high)
	{
	  inp = in + line_size;
	  for (lcnt = 1; lcnt < 24; lcnt++, inp += line_size)
	    if (!gdev_prn_copy_scan_lines (pdev, lnum + lcnt * 2, inp,
					   line_size))
	      {
		memset (inp, 0, (24 - lcnt) * line_size);
		break;
	      }
	  inp = in + line_size * 24;
	  for (lcnt = 0; lcnt < 24; lcnt++, inp += line_size)
	    if (!gdev_prn_copy_scan_lines (pdev, lnum + lcnt * 2 + 1, inp,
					   line_size))
	      {
		memset (inp, 0, (24 - lcnt) * line_size);
		break;
	      }
	}
      else
	{
	  lcnt = 1 + gdev_prn_copy_scan_lines (pdev, lnum + 1, in + line_size,
					       in_size - line_size);
	  if (lcnt < 24)
	    /* Pad with lines of zeros. */
	    memset (in + lcnt * line_size, 0, in_size - lcnt * line_size);
	}

      for (ypass = 0; ypass < y_passes; ypass++)
	{
	  out_end = out;
	  inp = in;
	  if (ypass)
	    inp += line_size * 24;
	  in_end = inp + line_size;

	  for (; inp < in_end; inp++, out_end += 24)
	    {
	      memflip8x8 (inp, line_size, out_end, 3);
	      memflip8x8 (inp + line_size * 8, line_size, out_end + 1, 3);
	      memflip8x8 (inp + line_size * 16, line_size, out_end + 2, 3);
	    }
	  /* Remove trailing 0s. */
	  while (out_end - 3 >= out && out_end[-1] == 0
		 && out_end[-2] == 0 && out_end[-3] == 0)
	    out_end -= 3;

	  for (out_blk = outp = out; outp < out_end;)
	    {
	      /* Skip a run of leading 0s. */
	      /* At least 10 are needed to make tabbing worth it. */

	      if (outp[0] == 0 && outp + 12 <= out_end
		  && outp[1] == 0 && outp[2] == 0
		  && outp[3] == 0 && outp[4] == 0 && outp[5] == 0
		  && outp[6] == 0 && outp[7] == 0 && outp[8] == 0
		  && outp[9] == 0 && outp[10] == 0 && outp[11] == 0)
		{
		  byte *zp = outp;
		  int tpos;
		  byte *newp;
		  outp += 12;
		  while (outp + 3 <= out_end
			 && outp[0] == 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. */
		      /* only false at beginning of line */
		      if (zp > out_blk)
			{
			  if (x_high)
			    necp6_improve_bitmap (out_blk, (int) (zp - out_blk));
			  necp6_output_run (out_blk, (int) (zp - out_blk),
					  x_high, prn_stream);
			}
		      /* Tab over to the appropriate position. */
		      fprintf (prn_stream, "\033D%c%c\t", tpos, 0);
		      out_blk = outp = newp;
		    }
		}
	      else
		outp += 3;
	    }
	  if (outp > out_blk)
	    {
	      if (x_high)
		necp6_improve_bitmap (out_blk, (int) (outp - out_blk));
	      necp6_output_run (out_blk, (int) (outp - out_blk), x_high,
			      prn_stream);
	    }

	  fputc ('\r', prn_stream);
	  if (ypass < y_passes - 1)
	    fputc ('\n', prn_stream);
	}
      skip = 48 - y_high;
      lnum += bits_per_column;
    }

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

  gs_free ((char *) out, out_size, 1, "necp6_print_page (out)");
  gs_free ((char *) in, in_size, 1, "necp6_print_page (in)");

  return 0;
}

/* Output a single graphics command. */
private void
necp6_output_run (byte *data, int count, int x_high, FILE *prn_stream)
{
  int xcount = count / 3;
  fputc (033, prn_stream);
  fputc ('*', prn_stream);
  fputc ((x_high ? 40 : 39), prn_stream);
  fputc (xcount & 0xff, prn_stream);
  fputc (xcount >> 8, prn_stream);
  fwrite (data, 1, count, prn_stream);
}

/* If xdpi == 360, the NEC P6 cannot print adjacent pixels.  Clear the
   second last pixel of every run of set pixels, so that the last pixel
   is always printed.  */
private void
necp6_improve_bitmap (byte *data, int count)
{
  int i;
  register byte *p = data + 6;

      for (i = 6; i < count; i += 3, p += 3)
	{
	  p[-6] &= ~(~p[0] & p[-3]);
	  p[-5] &= ~(~p[1] & p[-2]);
	  p[-4] &= ~(~p[2] & p[-1]);
	}
      p[-6] &= ~p[-3];
      p[-5] &= ~p[-2];
      p[-4] &= ~p[-1];

}
