harvey/sys/src/cmd/gs/src/gsdfilt.c

/*
  Copyright (C) 2001 artofcode LLC.
  
  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.

  Author: Raph Levien <raph@artofcode.com>
*/
/* $Id: gsdfilt.c,v 1.9 2004/03/11 14:50:50 igor Exp $ */
/* 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;
}