/* 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.
*/


/* Composite font-related character operators */
#include "ghost.h"
#include "oper.h"
#include "gsmatrix.h"		/* for gxfont.h */
#include "gxfixed.h"		/* for gxfont.h */
#include "gxfont.h"
#include "gxtext.h"
#include "estack.h"
#include "ichar.h"
#include "ifont.h"
#include "igstate.h"
#include "store.h"

/* Forward references */
static int cshow_continue(i_ctx_t *);
static int cshow_restore_font(i_ctx_t *);

/* <proc> <string> cshow - */
static int
zcshow(i_ctx_t *i_ctx_p)
{
    es_ptr ep = esp;        /* Save in case of error */
    os_ptr op = osp;
    os_ptr proc_op = op - 1;
    os_ptr str_op = op;
    gs_text_enum_t *penum;
    int code;

    check_op(2);
    /*
     * Even though this is not documented anywhere by Adobe,
     * some Adobe interpreters apparently allow the string and
     * the procedure to be provided in either order!
     */
    if (r_is_proc(proc_op))
        ;
    else if (r_is_proc(op)) {	/* operands reversed */
        proc_op = op;
        str_op = op - 1;
    } else {
        check_op(2);
        return_error(gs_error_typecheck);
    }
    if ((code = op_show_setup(i_ctx_p, str_op)) != 0 ||
        (code = gs_cshow_begin(igs, str_op->value.bytes, r_size(str_op),
                               imemory, &penum)) < 0)
        return code;
    if ((code = op_show_finish_setup(i_ctx_p, penum, 2, NULL)) < 0) {
        ifree_object(penum, "op_show_enum_setup");
        return code;
    }
    sslot = *proc_op;		/* save kerning proc */
    ref_stack_pop(&o_stack, 2);
    code = cshow_continue(i_ctx_p);
    if (code < 0) {
        /* We must restore the exec stack pointer back to the point where we entered, in case
         * we 'retry' the operation (eg having increased the operand stack).
         * We'll rely on gc to handle the enumerator.
         *  Bug 706868 (fix from zchar.c: Bug #700618)
         */
        esp = ep;
    }
    return code;
}
static int
cshow_continue(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_text_enum_t *penum = senum;
    int code;

    check_estack(4);		/* in case we call the procedure */
    code = gs_text_process(penum);
    if (code != TEXT_PROCESS_INTERVENE) {
        code = op_show_continue_dispatch(i_ctx_p, 0, code);
        if (code == o_push_estack)	/* must be TEXT_PROCESS_RENDER */
            make_op_estack(esp - 1, cshow_continue);
        return code;
    }
    /* Push the character code and width, and call the procedure. */
    {
        ref *pslot = &sslot;
        gs_point wpt;
        gs_font *font = gs_text_current_font(penum);
        gs_font *root_font = gs_rootfont(igs);
        gs_font *scaled_font;
        uint font_space = r_space(pfont_dict(font));
        uint root_font_space = r_space(pfont_dict(root_font));
        int fdepth = penum->fstack.depth;

        gs_text_current_width(penum, &wpt);
        if (font == root_font)
            scaled_font = font;
        else if (fdepth > 0) {
          /* Construct a scaled version of the leaf font.
             If font stack is deep enough, get the matrix for scaling
             from the immediate parent of current font.
             (The font matrix of root font is not good for the purpose
             in some case.)
             assert_(penum->fstack.items[fdepth].font == font
                     && penum->fstack.items[0].font == root_font); */
          uint save_space = idmemory->current_space;
          gs_font * immediate_parent = penum->fstack.items[fdepth - 1].font;

          ialloc_set_space(idmemory, font_space);
          code = gs_makefont(font->dir, font,
                             &immediate_parent->FontMatrix,
                             &scaled_font);
          ialloc_set_space(idmemory, save_space);
          if (code < 0)
            return code;
        }
        else {
            /* Construct a scaled version of the leaf font. */
            uint save_space = idmemory->current_space;

            ialloc_set_space(idmemory, font_space);
            code = gs_makefont(font->dir, font, &root_font->FontMatrix,
                               &scaled_font);
            ialloc_set_space(idmemory, save_space);
            if (code < 0)
                return code;
        }
        push(3);
        make_int(op - 2, gs_text_current_char(penum) & 0xff);
        make_real(op - 1, wpt.x);
        make_real(op, wpt.y);
        make_struct(&ssfont, font_space, font);
        make_struct(&srfont, root_font_space, root_font);
        push_op_estack(cshow_restore_font);
        /* cshow does not change rootfont for user procedure */
        gs_set_currentfont(igs, scaled_font);
        *++esp = *pslot;	/* user procedure */
    }
    return o_push_estack;
}
static int
cshow_restore_font(i_ctx_t *i_ctx_p)
{
    /* We must restore both the root font and the current font. */
    gs_setfont(igs, r_ptr(&srfont, gs_font));
    gs_set_currentfont(igs, r_ptr(&ssfont, gs_font));
    return cshow_continue(i_ctx_p);
}

/* - rootfont <font> */
static int
zrootfont(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;

    push(1);
    *op = *pfont_dict(gs_rootfont(igs));
    return 0;
}

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

const op_def zcfont_op_defs[] =
{
    {"2cshow", zcshow},
    {"0rootfont", zrootfont},
                /* Internal operators */
    {"0%cshow_continue", cshow_continue},
    {"0%cshow_restore_font", cshow_restore_font},
    op_def_end(0)
};