/* Copyright (C) 1994, 1997, 1999 Aladdin Enterprises.  All rights reserved.
  
  This software is provided AS-IS with no warranty, either express or
  implied.
  
  This software is distributed under license and may not be copied,
  modified or distributed except as expressly authorized under the terms
  of the license contained in the file LICENSE in this distribution.
  
  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: zht1.c,v 1.6 2002/08/22 07:12:29 henrys Exp $ */
/* 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(i_ctx_t *);
private int setcolorscreen_cleanup(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.red, 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)
};
