/* Copyright (C) 1989, 2000 artofcode LLC.  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 as published by the
  Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  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.

*/

/*$Id: igstate.h,v 1.3.6.1.2.1 2003/01/17 00:49:04 giles Exp $ */
/* Interpreter graphics state definition */

#ifndef igstate_INCLUDED
#  define igstate_INCLUDED

#include "gsstate.h"
#include "gxstate.h"		/* for 'client data' access */
#include "imemory.h"
#include "istruct.h"		/* for gstate obj definition */

/*
 * From the interpreter's point of view, the graphics state is largely opaque,
 * i.e., the interpreter is just another client of the library.
 * The interpreter does require additional items in the graphics state;
 * these are "client data" from the library's point of view.
 * Most of the complexity in this added state comes from
 * the parameters associated with the various Level 2 color spaces.
 * Note that the added information consists entirely of refs.
 */

/*
 * The interpreter represents graphics state objects in a slightly
 * unnatural way, namely, by a t_astruct ref that points to an object
 * of type st_igstate_obj, which is essentially a t_struct ref that in turn
 * points to a real graphics state (object of type st_gs_state).
 * We do this so that save and restore can manipulate the intermediate
 * object and not have to worry about copying entire gs_states.
 *
 * Because a number of different operators must test whether an object
 * is a gstate, we make an exception to our convention of declaring
 * structure descriptors only in the place where the structure itself
 * is defined (see gsstruct.h for more information on this).
 */
typedef struct igstate_obj_s {
    ref gstate;			/* t_struct / st_gs_state */
} igstate_obj;

extern_st(st_igstate_obj);
#define public_st_igstate_obj()	/* in zdps1.c */\
  gs_public_st_ref_struct(st_igstate_obj, igstate_obj, "gstatetype")
#define igstate_ptr(rp) r_ptr(&r_ptr(rp, igstate_obj)->gstate, gs_state)

/* DeviceN names and tint transform */
typedef struct ref_device_n_params_s {
    ref layer_names, tint_transform;
} ref_device_n_params;

/* CIE transformation procedures */
typedef struct ref_cie_procs_s {
    union {
	ref DEFG;
	ref DEF;
    } PreDecode;
    union {
	ref ABC;
	ref A;
    } Decode;
    ref DecodeLMN;
} ref_cie_procs;

/* CIE rendering transformation procedures */
typedef struct ref_cie_render_procs_s {
    ref TransformPQR, EncodeLMN, EncodeABC, RenderTableT;
} ref_cie_render_procs;

/* Separation name and tint transform */
typedef struct ref_separation_params_s {
    ref layer_name, tint_transform;
} ref_separation_params;

/* All color space parameters. */
/* All of these are optional. */
/* Note that they may actually be the parameters for an underlying or */
/* alternate space for a special space. */
typedef struct ref_color_procs_s {
    ref_cie_procs cie;
    union {
	ref_device_n_params device_n;
	ref_separation_params separation;
	ref index_proc;
    } special;
} ref_color_procs;
typedef struct ref_colorspace_s {
    ref array;			/* color space (array), only relevant if */
				/* the current color space has parameters */
				/* associated with it. */
    ref_color_procs procs;	/* associated procedures/parameters, */
				/* only relevant for DeviceN, CIE, */
				/* Separation, Indexed/CIE, */
				/* Indexed with procedure, or a Pattern */
				/* with one of these. */
} ref_colorspace;

#ifndef int_remap_color_info_DEFINED
#  define int_remap_color_info_DEFINED
typedef struct int_remap_color_info_s int_remap_color_info_t;
#endif

typedef struct int_gstate_s {
    ref dash_pattern;		/* (array) */
    /* Screen_procs are only relevant if setscreen was */
    /* executed more recently than sethalftone */
    /* (for this graphics context). */
    union {
	ref indexed[4];
	struct {
	    /* The components must be in this order: */
	    ref red, green, blue, gray;
	} colored;
    } screen_procs,		/* halftone screen procedures */
          transfer_procs;	/* transfer procedures */
    ref black_generation;	/* (procedure) */
    ref undercolor_removal;	/* (procedure) */
    ref_colorspace colorspace;
    /*
     * Pattern is relevant only if the current color space
     * is a pattern space.
     */
    ref pattern;		/* pattern (dictionary) */
    struct {
	ref dict;		/* CIE color rendering dictionary */
	ref_cie_render_procs procs;	/* (see above) */
    } colorrendering;
    /*
     * Halftone is relevant only if sethalftone was executed
     * more recently than setscreen for this graphics context.
     * setscreen sets it to null.
     */
    ref halftone;		/* halftone (dictionary) */
    /*
     * Pagedevice is only relevant if setpagedevice was executed more
     * recently than nulldevice, setcachedevice, or setdevice with a
     * non-page device (for this graphics context).  If the current device
     * is not a page device, pagedevice is null.
     */
    ref pagedevice;		/* page device (dictionary|null) */
    /*
     * Remap_color_info is used temporarily to communicate the need for
     * Pattern or DeviceNcolor remapping to the interpreter.  See
     * e_RemapColor in errors.h.  The extra level of indirection through a
     * structure is needed because the gstate passed to the PaintProc is
     * different from the current gstate in the graphics state, and because
     * the DeviceN color being remapped is not necessarily the current color
     * in the graphics state (for shading or images): the structure is
     * shared, so that the interpreter can get its hands on the remapping
     * procedure.
     */
    ref remap_color_info;	/* t_struct (int_remap_color_info_t) */
    /*
     * The opacity and shape masks are a PDF 1.4 transparency feature,
     * not standard PostScript.
     */
    ref opacity_mask, shape_mask; /* dictionary|null */
} int_gstate;

#define clear_pagedevice(pigs) make_null(&(pigs)->pagedevice)
/*
 * Even though the interpreter's part of the graphics state actually
 * consists of refs, allocating it as refs tends to create sandbars;
 * since it is always allocated and freed as a unit, we can treat it
 * as an ordinary structure.
 */
#define private_st_int_gstate()	/* in zgstate.c */\
  gs_private_st_ref_struct(st_int_gstate, int_gstate, "int_gstate")

/* Enumerate the refs in an int_gstate. */
/* Since all the elements of an int_gstate are refs, this is simple. */
#define int_gstate_map_refs(p,m)\
 { register ref *rp_ = (ref *)(p);\
   register int i = sizeof(int_gstate) / sizeof(ref);\
   do { m(rp_); ++rp_; } while ( --i );\
 }

/* Create the gstate for a new context. */
/* We export this so that fork can use it. */
gs_state *int_gstate_alloc(P1(const gs_dual_memory_t * dmem));

/* Get the int_gstate from a gs_state. */
#define gs_int_gstate(pgs) ((int_gstate *)gs_state_client_data(pgs))

/* The current instances for operators. */
#define igs (i_ctx_p->pgs)
#define istate gs_int_gstate(igs)

#endif /* igstate_INCLUDED */