/* Copyright (C) 1995, 1996, 1999 Aladdin Enterprises.  All rights reserved.
  
  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License version 2
  as published by the Free Software Foundation.


  This software is provided AS-IS with no warranty, either express or
  implied. That is, this program is distributed in the hope that it will 
  be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  59 Temple Place, Suite 330, Boston, MA, 02111-1307.
  
  For more information about licensing, please refer to
  http://www.ghostscript.com/licensing/. For information on
  commercial licensing, go to http://www.artifex.com/licensing/ or
  contact Artifex Software, Inc., 101 Lucas Valley Road #110,
  San Rafael, CA  94903, U.S.A., +1(415)492-9861.
*/

/* $Id: sisparam.h,v 1.4 2002/02/21 22:24:54 giles Exp $ */
/* Generic image scaling stream definitions */
/* Requires strimpl.h */

#ifndef sisparam_INCLUDED
#  define sisparam_INCLUDED

/*
 * Image scaling streams all use a common set of parameters to define the
 * input and output data.  That is what we define here.
 */

/* Input values */
/*typedef byte PixelIn; */  /* per BitsPerComponentIn */
/*#define MaxValueIn 255 */  /* per MaxValueIn */

/* Output values */
/*typedef byte PixelOut; */  /* per BitsPerComponentOut */
/*#define MaxValueOut 255 */  /* per MaxValueOut */

/*
 * The 'support' S of a digital filter is the value such that the filter is
 * guaranteed to be zero for all arguments outside the range [-S..S].  We
 * limit the support so that we can put an upper bound on the time required
 * to compute an output value and on the amount of storage required for
 * X-filtered input data; this also allows us to use pre-scaled fixed-point
 * values for the weights if we wish.
 *
 * 8x8 pixels should be enough for any reasonable application....
 */
#define LOG2_MAX_ISCALE_SUPPORT 3
#define MAX_ISCALE_SUPPORT (1 << LOG2_MAX_ISCALE_SUPPORT)

/* Define image scaling stream parameters. */
typedef struct stream_image_scale_params_s {
    int Colors;			/* >= 1 */
    int BitsPerComponentIn;	/* bits per input value, 8 or 16 */
    uint MaxValueIn;		/* max value of input component, */
				/* 0 < MaxValueIn < 1 << BitsPerComponentIn */
    int WidthIn, HeightIn;	/* > 0 */
    int BitsPerComponentOut;	/* bits per output value, 8 or 16 */
    uint MaxValueOut;		/* max value of output component, */
				/* 0 < MaxValueOut < 1 << BitsPerComponentOut*/
    int WidthOut, HeightOut;	/* > 0 */
} stream_image_scale_params_t;

/* Define a generic image scaling stream state. */

#define stream_image_scale_state_common\
    stream_state_common;\
    stream_image_scale_params_t params

typedef struct stream_image_scale_state_s {
    stream_image_scale_state_common;
} stream_image_scale_state;

#endif /* sisparam_INCLUDED */
