/* Copyright (C) 2001-2006 Artifex Software, Inc.
   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 that
   license.  Refer to licensing information at http://www.artifex.com/
   or contact Artifex Software, Inc.,  7 Mt. Lassen Drive - Suite A-134,
   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
*/

/* $Id: zht1.c 8250 2007-09-25 13:31:24Z giles $ */
/* 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 */
static float
spot_dummy(floatp x, floatp y)
{
    return (x + y) / 2;
}

/* <red_freq> ... <gray_proc> setcolorscreen - */
static int setcolorscreen_finish(i_ctx_t *);
static int setcolorscreen_cleanup(i_ctx_t *);
static 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, space);
	    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. */
static 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. */
static 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)
};
