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/* Copyright (C) 1995, 1996 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 General Public License for full details.
Everyone is granted permission to copy, modify and redistribute GNU
Ghostscript, but only under the conditions described in the GNU General
Public License. A copy of this license is supposed to have been given to
you along with GNU 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.
Aladdin Enterprises is not affiliated with the Free Software Foundation or
the GNU Project. GNU Ghostscript, as distributed by Aladdin Enterprises,
does not depend on any other GNU software.
*/
/* gdevstc3.c */
/* Epson Stylus-Color Printer-Driver */
/***
This file holds the sample-implementation of a RGB-algorithm for
the stcolor-driver. It is available via
gs -sDEVICE=stcolor -sDithering=gsrgb ...
Actually this is no dithering-algorithm, it lets ghostscript do the job.
This achieved, by requesting BYTE-Values between 0 and 1 to be delivered,
which causes a depth of 1-Bit by default.
***/
/*
* gdevstc.h holds all the includes and the driver-specific definitions, so
* it is the only include you need. To add a new algorthim, STC_MODI in
* gdevstc.h should be extended. (see the instructions there)
*/
#include "gdevstc.h"
/*
* the routine required.
*/
/*ARGSUSED*/
int
stc_gsrgb(stcolor_device *sdev,int npixel,byte *ip,byte *buf,byte *out)
{
int error = 0;
/*
* There are basically 3 Types of calls:
* npixel < 0 => initialize buf, if this is required
* (happens only if requested)
* npixel > 0 => process next scanline, if the flag STC_WHITE is set, then
* in == NULL signals, that the basic-driver has decided
* that this scanline is white. (Useful for really dithering
* drivers)
*/
/* ============================================================= */
if(npixel > 0) { /* npixel > 0 -> scanline-processing */
/* ============================================================= */
int p;
/*
* simply merge the color-values into a single byte
* (RED, GREEN, BLUE are defined in gdevstc.h)
*/
for(p = 0; p < npixel; ++p,++out) { /* loop over pixels */
*out = 0;
if(*ip++) *out |= RED;
if(*ip++) *out |= GREEN;
if(*ip++) *out |= BLUE;
} /* loop over pixels */
/* ============================================================= */
} else { /* npixel <= 0 -> initialisation */
/* ============================================================= */
/*
* besides buffer-Initialisation, one may check the parameters in
* the algorithm-table of the driver.
*/
/* we didn't check for the white-calls above, so they would cause errors */
if(sdev->stc.dither->flags & STC_WHITE) error = -1;
/* if we're not setup for bytes, this is an error too */
if((sdev->stc.dither->flags & STC_TYPE) != STC_BYTE) error = -2;
/* and rgb-mode is the only supported mode */
if(sdev->color_info.num_components != 3) error = -3;
/* we can't deal with ghostscript-data directly. */
if(sdev->stc.dither->flags & STC_DIRECT) error = -4;
/* ============================================================= */
} /* scanline-processing or initialisation */
/* ============================================================= */
return error;
}
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