/* Copyright (C) 1994 Aladdin Enterprises.  All rights reserved.
  
  This file is part of Aladdin Ghostscript.
  
  Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
  or distributor accepts any responsibility for the consequences of using it,
  or for whether it serves any particular purpose or works at all, unless he
  or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
  License (the "License") for full details.
  
  Every copy of Aladdin Ghostscript must include a copy of the License,
  normally in a plain ASCII text file named PUBLIC.  The License grants you
  the right to copy, modify and redistribute Aladdin Ghostscript, but only
  under certain conditions described in the License.  Among other things, the
  License requires that the copyright notice and this notice be preserved on
  all copies.
*/

/* zht1.c */
/* setcolorscreen operator */
#include "ghost.h"
#include "memory_.h"
#include "errors.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 "store.h"

/* Imported from zht.c */
int zscreen_params(P2(os_ptr, gs_screen_halftone *));
int zscreen_enum_init(P6(os_ptr, const gx_ht_order *, gs_screen_halftone *,
			 ref *, int, int (*)(P1(os_ptr))));

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

/* <red_freq> ... <gray_proc> setcolorscreen - */
private int setcolorscreen_finish(P1(os_ptr));
private int setcolorscreen_cleanup(P1(os_ptr));
private int
zsetcolorscreen(register os_ptr op)
{	gs_colorscreen_halftone cscreen;
	ref sprocs[4];
	gs_halftone *pht;
	gx_device_halftone *pdht;
	int i;
	int code = 0;
	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;
	}
	check_estack(8);		/* for sampling screens */
	pht = ialloc_struct(gs_halftone, &st_halftone, "setcolorscreen");
	pdht = ialloc_struct(gx_device_halftone, &st_device_halftone,
			     "setcolorscreen");
	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(op,
				&pdht->components[(i + 1) & 3].corder,
				&pht->params.colorscreen.screens.indexed[i],
				&sprocs[i], 0, 0);
			if ( code < 0 )
			{	esp = esp0;
				break;
			}
		}
	}
	if ( code < 0 )
	  {	ifree_object(pdht, "setcolorscreen");
		ifree_object(pht, "setcolorscreen");
		return code;
	  }
	pop(12);
	return o_push_estack;
}
/* Install the color screen after sampling. */
private int
setcolorscreen_finish(os_ptr op)
{	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(op);
	return o_pop_estack;
}
/* Clean up after installing the color screen. */
private int
setcolorscreen_cleanup(os_ptr op)
{	ifree_object(esp[7].value.pstruct,
		     "setcolorscreen_cleanup(device halftone)");
	ifree_object(esp[6].value.pstruct,
		     "setcolorscreen_cleanup(halftone)");
	return 0;
}

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

BEGIN_OP_DEFS(zht1_op_defs) {
	{"<setcolorscreen", zsetcolorscreen},
		/* Internal operators */
	{"0%setcolorscreen_finish", setcolorscreen_finish},
END_OP_DEFS(0) }
