/* Copyright (C) 1997, 1998 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 supports the work of the GNU Project, but is not
  affiliated with the Free Software Foundation or the GNU Project.  GNU
  Ghostscript, as distributed by Aladdin Enterprises, does not require any
  GNU software to build or run it.
*/

/*$Id: gxiparam.h $ */
/* Definitions for implementors of image types */

#ifndef gxiparam_INCLUDED
#  define gxiparam_INCLUDED

#include "gxdevcli.h"

#ifndef gx_image_enum_common_t_DEFINED
#  define gx_image_enum_common_t_DEFINED
typedef struct gx_image_enum_common_s gx_image_enum_common_t;

#endif

/*
 * Define the procedures associated with an image enumerator.
 *
 * Note that image_plane_data and end_image used to be device procedures;
 * they still take the device argument first for compatibility.  However, in
 * order to make forwarding begin_image work, the intermediary routines
 * gx_image_[plane_]data and gx_image_end substitute the device from the
 * enumerator for the explicit device argument, which is ignored.
 * Eventually we should fix this by removing the device argument from
 * gx_device..., just as we have done for text enumeration; but this would
 * have caused major difficulties with 5.1x retrofitting of this code, and
 * it's too much work to fix right now.  ****** FIX THIS SOMEDAY ******
 */
typedef struct gx_image_enum_procs_s {

    /*
     * Pass the next batch of data for processing.
     * image_enum_proc_plane_data is defined in gxdevcli.h.
     */

    image_enum_proc_plane_data((*plane_data));

    /*
     * End processing an image.  We keep this procedure as the last one that
     * requires initialization, so that we can detect obsolete static
     * initializers.  dev_proc_end_image is defined in gxdevcli.h.
     */
#define image_enum_proc_end_image(proc)\
  dev_proc_end_image(proc)

    image_enum_proc_end_image((*end_image));

    /*
     * Flush any intermediate buffers to the target device.
     * We need this for situations where two images interact
     * (currently, only the mask and the data of ImageType 3).
     * This procedure is optional (may be 0).
     */
#define image_enum_proc_flush(proc)\
  int proc(P1(gx_image_enum_common_t *info))

    image_enum_proc_flush((*flush));

} gx_image_enum_procs_t;

/*
 * Define the common prefix of the image enumerator structure.  All
 * implementations of begin[_typed]_image must initialize all of the members
 * of this structure, by calling gx_image_enum_common_init and then filling
 * in whatever else they need to.
 *
 * Note that the structure includes a unique ID, so that the banding
 * machinery could in principle keep track of multiple enumerations that may
 * be in progress simultaneously.
 */
#define gx_image_enum_common\
	const gx_image_type_t *image_type;\
	const gx_image_enum_procs_t *procs;\
	gx_device *dev;\
	gs_id id;\
	int num_planes;\
	int plane_depths[gs_image_max_components]	/* [num_planes] */
struct gx_image_enum_common_s {
    gx_image_enum_common;
};

/*extern_st(st_gx_image_enum_common); */
#define public_st_gx_image_enum_common()	/* in gdevddrw.c */\
  gs_public_st_composite(st_gx_image_enum_common, gx_image_enum_common_t,\
    "gx_image_enum_common_t",\
     image_enum_common_enum_ptrs, image_enum_common_reloc_ptrs)

/*
 * Initialize the common part of an image enumerator.
 */
int gx_image_enum_common_init(P7(gx_image_enum_common_t * piec,
				 const gs_image_common_t * pic,
				 const gx_image_enum_procs_t * piep,
				 gx_device * dev,
				 int bits_per_component, int num_components,
				 gs_image_format_t format));

/*
 * Define the structure for defining image types.  An image type includes
 * not only the ImageType index, but also the default implementation of
 * begin_typed_image.
 */
#ifndef gx_image_type_DEFINED
#  define gx_image_type_DEFINED
typedef struct gx_image_type_s gx_image_type_t;
#endif
struct gx_image_type_s {

    dev_proc_begin_typed_image((*begin_typed_image));

    /*
     * Compute the width and height of the source data.  For images with
     * explicit data, this information is in the gs_data_image_t
     * structure, but ImageType 2 images must compute it.
     */
#define image_proc_source_size(proc)\
  int proc(P3(const gs_imager_state *pis, const gs_image_common_t *pim,\
    gs_int_point *psize))

    image_proc_source_size((*source_size));

    /*
     * We put index last so that if we add more procedures and some
     * implementor fails to initialize them, we'll get a type error.
     */
    int index;			/* PostScript ImageType */
};

/*
 * Define the procedure for getting the source size of an image with
 * explicit data.
 */
image_proc_source_size(gx_data_image_source_size);
/*
 * Define image_plane_data and end_image procedures for image types that
 * don't have any source data (ImageType 2 and composite images).
 */
image_enum_proc_plane_data(gx_no_plane_data);
image_enum_proc_end_image(gx_ignore_end_image);
/*
 * Define the procedures and type data for ImageType 1 images,
 * which are always included.
 */
dev_proc_begin_typed_image(gx_begin_image1);
image_enum_proc_plane_data(gx_image1_plane_data);
image_enum_proc_end_image(gx_image1_end_image);
image_enum_proc_flush(gx_image1_flush);

#endif /* gxiparam_INCLUDED */
