/* Copyright (C) 1993 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.  */

/* gdevoki.c */
/* Okidata Microline 182 printer driver for Ghostscript */

/* Contributed by Maarten Koning (smeg@bnr.ca) April 4, 1993 */

#if 0

I use this driver from Unix with the following aliases:

alias psp "gs -q -sDEVICE=oki182 -sOutputFile=\|lpr - <\!*"
alias psphigh "gs -q -sDEVICE=oki182 -r144 -sOutputFile=\|lpr - <\!*"

ps. I have my printer DIP switches set to the following (as viewed
	while standing in front of your printer looking down into the
	config access hatch located at the top of your printer
	in the centre back).

Upper  Upper   Bottom
Left   Right   (at right)

 x      x        x
 x       x      x
 x       x       x
x        x      x
 x      x        x
 x      x        x
x        x      x
 x      x        x

The upper DIP switches are on a SuperSpeed Serial
card that will do 19200 baud.  I have it set at 9600
baud since that seems sufficient to keep the printer
busy.

The important thing is to be in 8-bit mode so that
the graphics data can't match any Okidata commands
(This driver sets the high bit of graphics data to 1).

#endif

#include "gdevprn.h"

/*
 *  Available resolutions are 72x72 or 144x144;
 *  (144x72) would be possible to do also, but I didn't bother)
 */

/* The device descriptor */

private dev_proc_print_page(oki_print_page);

gx_device_printer gs_oki182_device =
  prn_device(prn_std_procs, "oki182",
	80,				/* width_10ths, 8.0" */
	110,				/* height_10ths, 11" */
	72,				/* x_dpi */
	72,				/* y_dpi */
	0, 0, 0, 0,			/* margins */
	1, oki_print_page);

/* ------ internal routines ------ */

/* out is a pointer to an array of 7 scan lines,
   lineSize is the number of bytes between a pixel and
   the pixel directly beneath it.
   scanBits is the number of bits in each scan line
   out is a pointer to an array of column data, which
   is how the Okidata wants the graphics image.

   each column of graphics data is 7 bits high and
   is encoded in a byte - highest pixel in the column
   is the lowest bit in the byte.  The upper bit of the
   byte is set so that the okidata doesn't mistake
   graphic image data for graphic commands.
*/

private void
oki_transpose(byte *in, byte *out, int scanBits, register int lineSize)
{
	register bitMask = 0x80;
	register byte *inPtr;
	register byte outByte;

	while (scanBits-- > 0) {

		inPtr = in;

		if (*inPtr & bitMask)
			outByte = 0x81;
		else
			outByte = 0x80;
		if (*(inPtr += lineSize) & bitMask)
			outByte += 0x02;
		if (*(inPtr += lineSize) & bitMask)
			outByte += 0x04;
		if (*(inPtr += lineSize) & bitMask)
			outByte += 0x08;
		if (*(inPtr += lineSize) & bitMask)
			outByte += 0x10;
		if (*(inPtr += lineSize) & bitMask)
			outByte += 0x20;
		if (*(inPtr += lineSize) & bitMask)
			outByte += 0x40;

		*out++ = outByte;

		if ((bitMask >>= 1) == 0) {
			bitMask = 0x80;
			in ++;
		}
	}
}

/* This routine tries to compress a sequence of okidata
   graphic bytes by trimming off leading and trailing
   zeros.  Trailing zeros can be thrown away and leading
   zeros can be replaced with a much smaller number of spaces.

   'in' is a pointer to the graphic bytes to be compressed.
   origWidth is the number of bytes pointed to by 'in'.
   highRes is non-zero when 144x144 mode is being used.

   numSpaces is set to the number of spaces that should
   be printed before the compressed image. newWidth is
   the new number of bytes that the return value of this
   function points to.

   xxx - A future enhancement would be to replace long sequences
   of embedded zeros with exit.graphics-<n> spaces-enter.graphics
*/
private byte *
oki_compress(byte *in, int origWidth, int highRes,
			int *numSpaces, int *newWidth)
{
	int spaces = 0;
	int columns_per_space = 6;

	byte *in_end = in + origWidth;

	/* remove trailing zeros (which are realy 0x80's) */
	while (in_end > in && in_end[-1] == 0x80)
		in_end --;

	if (highRes)
		columns_per_space = 12;

	/* remove leading zeros that can be replaced by spaces */
	while(in < in_end && in[0] == 0x80 && memcmp((char *)in,
				(char *)in + 1, columns_per_space - 1) == 0) {
		spaces++;
		in += columns_per_space;
	}

	*numSpaces = spaces;

	/* just in case we compressed this line out of existance */
	if (in_end > in)
		*newWidth = in_end - in;
	else
		*newWidth = 0;

	return(in);
}

/* Send the page to the printer. */

private int
oki_print_page(gx_device_printer *pdev, FILE *prn_stream)
{
	int highRes = pdev->y_pixels_per_inch > 100;
	int bits_per_column = 7;
	int i, spaces, width;
	int lcnt;

	int line_size = gdev_prn_raster((gx_device_printer *)pdev);

	byte *in = (byte *)gs_malloc(16, line_size, "oki_print_page(in)");

	byte *out1 = (byte *)gs_malloc(8, line_size, "oki_print_page(out1)");
	byte *out2 = (byte *)gs_malloc(8, line_size, "oki_print_page(out2)");

	byte *out3;

	int lnum = 0;
	int skip = 0;
	int code = 0;

	if ( in == 0 || out1 == 0 || out2 == 0)
	{	code = gs_error_VMerror;
		gs_note_error(code);
		goto bail;
	}

	/* Initialize the printer. */
	/* CAN; 72x72; left margin = 001; disable skip over perforation */
	fwrite("\030\034\033%C001\033%S0", 1, 12, prn_stream);

	if (highRes) {
		fwrite("\033R", 1, 2, prn_stream);
		bits_per_column = 14;
	}

	/* Transfer pixels to printer */
	while ( lnum < pdev->height ) {

		/* Copy 1 scan line and test for all zero. */
		code = gdev_prn_copy_scan_lines(pdev, lnum, in, line_size);
		if ( code < 0 )
			goto xit;

		/* if line is all zero, skip */
		if ( in[0] == 0 && !memcmp((char *)in, (char *)in + 1,
							line_size - 1)) {
			lnum++;
			if (highRes)
				skip++;
			else
				skip += 2;
			continue;
		}

		/* use fine line feed to get to the appropriate position. */
		while ( skip > 127 ) {
			fputs("\033%5\177", prn_stream);
			skip -= 127;
		}
		if ( skip )
			fprintf(prn_stream, "\033%%5%c",
					(char) (skip & 0xff));
		skip = 0;

		/* get the rest of the scan lines */
		code = gdev_prn_copy_scan_lines(pdev, lnum + 1,
			in + line_size, (bits_per_column - 1) * line_size);

		if ( code < 0 )
			goto xit;

		lcnt = code + 1; /* since we already grabbed one line */

		if ( lcnt < bits_per_column )
			memset(in + lcnt * line_size, 0,
					(bits_per_column - lcnt) * line_size);

		if (highRes) {
			oki_transpose(in, out1, pdev->width, 2 * line_size);
			oki_transpose(in + line_size, out2,
						pdev->width, 2 * line_size);
		} else
			oki_transpose(in, out1, pdev->width, line_size);

		out3 = oki_compress(out1, pdev->width, highRes,
						&spaces, &width);

		for (i=0; i < spaces; i++)
			putc(' ', prn_stream);

		fwrite("\003", 1, 1, prn_stream);
		fwrite(out3, 1, width, prn_stream);

		if (highRes) {
			/* exit graphics; carriage return; 1 bit line feed */
			fprintf(prn_stream, "\003\002\015\033%%5%c", (char) 1);
			out3 = oki_compress(out2, pdev->width, highRes,
							&spaces, &width);
			for (i=0; i < spaces; i++)
				putc(' ', prn_stream);
			fwrite("\003", 1, 1, prn_stream);
			fwrite(out3, 1, width, prn_stream);
			fprintf(prn_stream, "\003\002\015\033%%5%c", (char) 13);
		} else
			fwrite("\003\016\003\002", 1, 4, prn_stream);

		lnum += bits_per_column;
	   }

	/* Eject the page */
xit:
	fputc(014, prn_stream);	/* form feed */
	fflush(prn_stream);

bail:
	if ( out1 != 0 )
		gs_free((char *)out1, 8, line_size, "oki_print_page(out1)");

	if ( out2 != 0 )
		gs_free((char *)out2, 8, line_size, "oki_print_page(out2)");

	if ( in != 0 )
		gs_free((char *)in, 16, line_size, "oki_print_page(in)");

	return code;
}