/* Copyright (C) 1994, 1997, 1999 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.
*/

/*$RCSfile: zht1.c,v $ $Revision: 1.2.2.1 $ */
/* setcolorscreen operator */
#include "ghost.h"
#include "memory_.h"
#include "oper.h"
#include "estack.h"
#include "gsstruct.h"		/* must precede igstate.h, */
					/* because of #ifdef in gsht.h */
#include "ialloc.h"
#include "igstate.h"
#include "gsmatrix.h"
#include "gxdevice.h"		/* for gzht.h */
#include "gzht.h"
#include "gsstate.h"
#include "iht.h"
#include "store.h"

/* Dummy spot function */
private float
spot_dummy(floatp x, floatp y)
{
    return (x + y) / 2;
}

/* <red_freq> ... <gray_proc> setcolorscreen - */
private int setcolorscreen_finish(P1(i_ctx_t *));
private int setcolorscreen_cleanup(P1(i_ctx_t *));
private int
zsetcolorscreen(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_colorscreen_halftone cscreen;
    ref sprocs[4];
    gs_halftone *pht;
    gx_device_halftone *pdht;
    int i;
    int code = 0;
    int space = 0;
    gs_memory_t *mem;

    for (i = 0; i < 4; i++) {
	os_ptr op1 = op - 9 + i * 3;
	int code = zscreen_params(op1, &cscreen.screens.indexed[i]);

	if (code < 0)
	    return code;
	cscreen.screens.indexed[i].spot_function = spot_dummy;
	sprocs[i] = *op1;
	space = max(space, r_space_index(op1));
    }
    mem = (gs_memory_t *)idmemory->spaces_indexed[space];
    check_estack(8);		/* for sampling screens */
    rc_alloc_struct_0(pht, gs_halftone, &st_halftone,
		      mem, pht = 0, "setcolorscreen(halftone)");
    rc_alloc_struct_0(pdht, gx_device_halftone, &st_device_halftone,
		      mem, pdht = 0, "setcolorscreen(device halftone)");
    if (pht == 0 || pdht == 0)
	code = gs_note_error(e_VMerror);
    else {
	pht->type = ht_type_colorscreen;
	pht->params.colorscreen = cscreen;
	code = gs_sethalftone_prepare(igs, pht, pdht);
    }
    if (code >= 0) {		/* Schedule the sampling of the screens. */
	es_ptr esp0 = esp;	/* for backing out */

	esp += 8;
	make_mark_estack(esp - 7, es_other, setcolorscreen_cleanup);
	memcpy(esp - 6, sprocs, sizeof(ref) * 4);	/* procs */
	make_istruct(esp - 2, 0, pht);
	make_istruct(esp - 1, 0, pdht);
	make_op_estack(esp, setcolorscreen_finish);
	for (i = 0; i < 4; i++) {
	    /* Shuffle the indices to correspond to */
	    /* the component order. */
	    code = zscreen_enum_init(i_ctx_p,
				     &pdht->components[(i + 1) & 3].corder,
				&pht->params.colorscreen.screens.indexed[i],
				     &sprocs[i], 0, 0, mem);
	    if (code < 0) {
		esp = esp0;
		break;
	    }
	}
    }
    if (code < 0) {
	gs_free_object(mem, pdht, "setcolorscreen(device halftone)");
	gs_free_object(mem, pht, "setcolorscreen(halftone)");
	return code;
    }
    pop(12);
    return o_push_estack;
}
/* Install the color screen after sampling. */
private int
setcolorscreen_finish(i_ctx_t *i_ctx_p)
{
    gx_device_halftone *pdht = r_ptr(esp, gx_device_halftone);
    int code;

    pdht->order = pdht->components[0].corder;
    code = gx_ht_install(igs, r_ptr(esp - 1, gs_halftone), pdht);
    if (code < 0)
	return code;
    memcpy(istate->screen_procs.indexed, esp - 5, sizeof(ref) * 4);
    make_null(&istate->halftone);
    esp -= 7;
    setcolorscreen_cleanup(i_ctx_p);
    return o_pop_estack;
}
/* Clean up after installing the color screen. */
private int
setcolorscreen_cleanup(i_ctx_t *i_ctx_p)
{
    gs_halftone *pht = r_ptr(esp + 6, gs_halftone);
    gx_device_halftone *pdht = r_ptr(esp + 7, gx_device_halftone);

    gs_free_object(pdht->rc.memory, pdht,
		   "setcolorscreen_cleanup(device halftone)");
    gs_free_object(pht->rc.memory, pht,
		   "setcolorscreen_cleanup(halftone)");
    return 0;
}

/* ------ Initialization procedure ------ */

const op_def zht1_op_defs[] =
{
    {"<setcolorscreen", zsetcolorscreen},
		/* Internal operators */
    {"0%setcolorscreen_finish", setcolorscreen_finish},
    op_def_end(0)
};
