/* Copyright (C) 2001-2023 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 the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact

   Artifex Software, Inc.,  39 Mesa Street, Suite 108A, San Francisco,

   CA 94129, USA, for further information.

*/

/* Miscellaneous LanguageLevel 3 operators */

#include "ghost.h"

#include "gscspace.h"   /* for gscolor2.h */

#include "gsmatrix.h"   /* ditto */

#include "gsclipsr.h"

#include "gscolor2.h"

#include "oper.h"

#include "igstate.h"

#include "store.h"

/* - clipsave - */

static int

zclipsave(i_ctx_t *i_ctx_p)

{

    return gs_clipsave(igs);

}

/* - cliprestore - */

static int

zcliprestore(i_ctx_t *i_ctx_p)

{

    return gs_cliprestore(igs);

}

static inline bool

eqproc_check_type(ref *r)

{

    return r_has_type(r, t_array)

           || r_has_type(r, t_mixedarray)

           || r_has_type(r, t_shortarray)

           || r_has_type(r, t_oparray);

}

/* <proc1> <proc2> .eqproc <bool> */

/*

 * Test whether two procedures are equal to depth 10.

 * This is the equality test used by idiom recognition in 'bind'.

 */

/* Adobe specifies maximum depth of 10 but 12 is needed */

/* to reproduce the observed behavior. CET 31-01-05 */

#define MAX_DEPTH 12

typedef struct ref2_s {

    ref proc1, proc2;

} ref2_t;

static int

zeqproc(i_ctx_t *i_ctx_p)

{

    os_ptr op = osp;

    ref2_t stack[MAX_DEPTH + 1];

    ref2_t *top = stack;

    check_op(2);

    if (!eqproc_check_type(op -1) || !eqproc_check_type(op)) {

        make_false(op - 1);

        pop(1);

        return 0;

    }

    make_array(&stack[0].proc1, 0, 1, op - 1);

    make_array(&stack[0].proc2, 0, 1, op);

    for (;;) {

        long i;

        if (r_size(&top->proc1) == 0) {

            /* Finished these arrays, go up to next level. */

            if (top == stack) {

                /* We're done matching: it succeeded. */

                make_true(op - 1);

                pop(1);

                return 0;

            }

            --top;

            continue;

        }

        /* Look at the next elements of the arrays. */

        i = r_size(&top->proc1) - 1;

        array_get(imemory, &top->proc1, i, &top[1].proc1);

        array_get(imemory, &top->proc2, i, &top[1].proc2);

        r_dec_size(&top->proc1, 1);

        ++top;

        /*

         * Amazingly enough, the objects' executable attributes are not

         * required to match.  This means { x load } will match { /x load },

         * even though this is clearly wrong.

         */

#if 0

        if (r_has_attr(&top->proc1, a_executable) !=

            r_has_attr(&top->proc2, a_executable)

            )

            break;

#endif

        if (obj_eq(imemory, &top->proc1, &top->proc2)) {

            /* Names don't match strings. */

            if (r_type(&top->proc1) != r_type(&top->proc2) &&

                (r_type(&top->proc1) == t_name ||

                 r_type(&top->proc2) == t_name)

                )

                break;

            --top;    /* no recursion */

            continue;

        }

        if (r_is_array(&top->proc1) && r_is_array(&top->proc2) &&

            r_size(&top->proc1) == r_size(&top->proc2) &&

            top < stack + (MAX_DEPTH - 1)

            ) {

            /* Descend into the arrays. */

            continue;

        }

        break;

    }

    /* An exit from the loop indicates that matching failed. */

    make_false(op - 1);

    pop(1);

    return 0;

}

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

const op_def zmisc3_op_defs[] =

{

    op_def_begin_ll3(),

    {"0cliprestore", zcliprestore},

    {"0clipsave", zclipsave},

    {"2.eqproc", zeqproc},

    op_def_end(0)

};