xref: /plan9/sys/src/cmd/gs/src/zicc.c (revision 593dc095aefb2a85c828727bbfa9da139a49bdf4)

/* Copyright (C) 2001 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: zicc.c,v 1.7 2004/08/04 19:36:13 stefan Exp $ */
/* ICCBased color operators */

#include "math_.h"
#include "memory_.h"
#include "ghost.h"
#include "oper.h"
#include "gsstruct.h"
#include "gxcspace.h"		/* gscolor2.h requires gscspace.h */
#include "stream.h"
#include "files.h"
#include "gscolor2.h"
#include "gsicc.h"
#include "estack.h"
#include "idict.h"
#include "idparam.h"
#include "igstate.h"
#include "icie.h"
#include "ialloc.h"

/*
 *   <dict>  .seticcspace  -
 *
 * Create an ICCBased color space and set it to be the current color space.
 *
 * The PostScript structure of an ICCBased color space is that same as that
 * for a CIEBased* color space:
 *
 *     [ /ICCBased <dictionary> ]
 *
 * As is the for other .setcie*space operators, the operand dictionary rather
 * than the complete color space array is on the stack when this operator
 * is inovked.
 *
 * At the time this procedure is called, the alternative color space for
 * the ICCBased color space is expected to be the current color space,
 * whether that space was explicitly specified or implied by the number
 * of components in the ICCBased color space dictionary. This is consistent
 * with the handling of alternative spaces in Separation, DeviceN, and
 * Indexed color spaces. Unlike the "zset*space" routines for those spaces,
 * however, the current code does not attempt to build the color space
 * "in place" in the graphic state.
 *
 * The procedure that invokes this operator will already have checked that
 * the operand is a dictionary, is readable, and defines the key /N
 * (number of components).
 */
private int
zseticcspace(i_ctx_t * i_ctx_p)
{
    os_ptr                  op = osp;
    int edepth = ref_stack_count(&e_stack);
    int                     code;
    gs_color_space *        pcs;
    const gs_color_space *  palt_cs;
    ref *                   pnval;
    ref *                   pstrmval;
    stream *                s;
    int                     i, ncomps;
    gs_cie_icc *            picc_info;
    float                   range_buff[8];
    static const float      dflt_range[8] = { 0, 1,   0, 1,   0, 1,   0, 1 };

    dict_find_string(op, "N", &pnval);
    ncomps = pnval->value.intval;

    /* verify the DataSource entry */
    if (dict_find_string(op, "DataSource", &pstrmval) <= 0)
        return_error(e_undefined);
    check_read_file(s, pstrmval);

    /*
     * Verify that the current color space can be a alternative color space.
     * The check for ICCBased color space is a hack to avoid introducing yet
     * another category indicator into the gs_color_space_type structur.
     */
    palt_cs = gs_currentcolorspace(igs);
    if ( !palt_cs->type->can_be_alt_space                                ||
         gs_color_space_get_index(palt_cs) == gs_color_space_index_CIEICC  )
        return_error(e_rangecheck);

    /*
     * Fetch and verify the Range array.
     *
     * The PDF documentation is unclear as to the purpose of this array.
     * Essentially all that is stated is that "These values must match the
     * information in the ICC profile" (PDF Reference, 2nd ed., p. 174).
     * If that is the case, why not use the information in the profile?
     * The only reason we can think of is range specification is intended
     * to be used to limit the range of values passed to the alternate
     * color space (the range may be smaller than the native range of values
     * provided by that color space).
     *
     * Because the icclib code will perform normalization based on color
     * space, we use the range values only to restrict the set of input
     * values; they are not used for normalization.
     */
    code = dict_floats_param( imemory,
			      op,
                              "Range",
                              2 * ncomps,
                              range_buff,
                              dflt_range );
    for (i = 0; i < 2 * ncomps && range_buff[i + 1] >= range_buff[i]; i += 2)
        ;
    if (i != 2 * ncomps)
        return_error(e_rangecheck);

    /* build the color space object */
    code = gs_cspace_build_CIEICC(&pcs, NULL, gs_state_memory(igs));
    if (code < 0)
        return code;
    picc_info = pcs->params.icc.picc_info;
    picc_info->num_components = ncomps;
    picc_info->instrp = s;
    picc_info->file_id = (s->read_id | s->write_id);
    for (i = 0; i < ncomps; i++) {
        picc_info->Range.ranges[i].rmin = range_buff[2 * i];
        picc_info->Range.ranges[i].rmax = range_buff[2 * i + 1];

    }

    /* record the current space as the alternative color space */
    memmove( &pcs->params.icc.alt_space,
             palt_cs,
             sizeof(pcs->params.icc.alt_space) );
    /*
     * Increment reference counts for current cspace since it is the
     * alternate color space for the ICC space.
     */
    gx_increment_cspace_count(palt_cs);

    code = gx_load_icc_profile(picc_info);
    if (code < 0)
	return code;

    code = cie_cache_joint(i_ctx_p, &istate->colorrendering.procs,
			   (gs_cie_common *)picc_info, igs);
    if (code < 0)
	return code;

    return cie_set_finish( i_ctx_p,
                           pcs,
                           &istate->colorspace.procs.cie,
                           edepth,
                           code );
}


const op_def    zicc_ll3_op_defs[] = {
    op_def_begin_ll3(),
    { "1.seticcspace", zseticcspace },
    op_def_end(0)
};