/* 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.
*/
/* $Id$ */
/* Functions for managing the device filter stack */

#include "ctype_.h"
#include "memory_.h"		/* for memchr, memcpy */
#include "string_.h"
#include "gx.h"
#include "gp.h"
#include "gscdefs.h"		/* for gs_lib_device_list */
#include "gserrors.h"
#include "gsfname.h"
#include "gsstruct.h"
#include "gspath.h"		/* gs_initclip prototype */
#include "gspaint.h"		/* gs_erasepage prototype */
#include "gsmatrix.h"		/* for gscoord.h */
#include "gscoord.h"		/* for gs_initmatrix */
#include "gzstate.h"
#include "gxcmap.h"
#include "gxdevice.h"
#include "gxdevmem.h"
#include "gxiodev.h"

#include "gsdfilt.h"

gs_private_st_ptrs3(st_gs_device_filter_stack, gs_device_filter_stack_t,
                    "gs_device_filter_stack",
                    gs_device_filter_stack_enum_ptrs,
                    gs_device_filter_stack_reloc_ptrs,
                    next, df, next_device);

gs_public_st_simple(st_gs_device_filter, gs_device_filter_t,
                    "gs_device_filter");

int
gs_push_device_filter(gs_memory_t *mem, gs_state *pgs, gs_device_filter_t *df)
{
    gs_device_filter_stack_t *dfs;
    gx_device *new_dev = NULL;
    int code;

    dfs = gs_alloc_struct(mem, gs_device_filter_stack_t,
                          &st_gs_device_filter_stack, "gs_push_device_filter");
    if (dfs == NULL)
        return_error(gs_error_VMerror);
    rc_increment(pgs->device);
    dfs->next_device = pgs->device;
    code = df->push(df, mem, pgs, &new_dev, pgs->device);
    if (code < 0) {
        gs_free_object(mem, dfs, "gs_push_device_filter");
        return code;
    }
    dfs->next = pgs->dfilter_stack;
    pgs->dfilter_stack = dfs;
    dfs->df = df;
    rc_init(dfs, mem, 1);
    gs_setdevice_no_init(pgs, new_dev);
    rc_decrement_only(new_dev, "gs_push_device_filter");
    return code;
}

int
gs_pop_device_filter(gs_memory_t *mem, gs_state *pgs)
{
    gs_device_filter_stack_t *dfs_tos = pgs->dfilter_stack;
    gx_device *tos_device = pgs->device;
    gs_device_filter_t *df;
    int code;

    if (dfs_tos == NULL)
        return_error(gs_error_rangecheck);
    df = dfs_tos->df;
    pgs->dfilter_stack = dfs_tos->next;
    code = df->prepop(df, mem, pgs, tos_device);
    rc_increment(tos_device);
    gs_setdevice_no_init(pgs, dfs_tos->next_device);
    rc_decrement_only(dfs_tos->next_device, "gs_pop_device_filter");
    dfs_tos->df = NULL;
    rc_decrement_only(dfs_tos, "gs_pop_device_filter");
    code = df->postpop(df, mem, pgs, tos_device);
    rc_decrement_only(tos_device, "gs_pop_device_filter");
    return code;
}

int
gs_clear_device_filters(gs_memory_t *mem, gs_state *pgs)
{
    int code;

    while (pgs->dfilter_stack != NULL) {
        if ((code = gs_pop_device_filter(mem, pgs)) < 0)
            return code;
    }
    return 0;
}