/* Copyright (C) 1989, 2000 artofcode LLC.  All rights reserved.
  
  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the
  Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  59 Temple Place, Suite 330, Boston, MA, 02111-1307.

*/

/*$Id: zchar.c,v 1.4.2.2.2.1 2003/01/17 00:49:05 giles Exp $ */
/* Character operators */
#include "ghost.h"
#include "oper.h"
#include "gsstruct.h"
#include "gstext.h"
#include "gxarith.h"
#include "gxfixed.h"
#include "gxmatrix.h"		/* for ifont.h */
#include "gxdevice.h"		/* for gxfont.h */
#include "gxfont.h"
#include "gzstate.h"
#include "dstack.h"		/* for stack depth */
#include "estack.h"
#include "ialloc.h"
#include "ichar.h"
#include "idict.h"
#include "ifont.h"
#include "igstate.h"
#include "ilevel.h"
#include "iname.h"
#include "ipacked.h"
#include "store.h"

/* Forward references */
private bool map_glyph_to_char(P3(const ref *, const ref *, ref *));
private int finish_show(P1(i_ctx_t *));
private int op_show_cleanup(P1(i_ctx_t *));
private int op_show_return_width(P3(i_ctx_t *, uint, double *));

/* <string> show - */
private int
zshow(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_text_enum_t *penum;
    int code = op_show_setup(i_ctx_p, op);

    if (code != 0 ||
	(code = gs_show_begin(igs, op->value.bytes, r_size(op), imemory, &penum)) < 0)
	return code;
    if ((code = op_show_finish_setup(i_ctx_p, penum, 1, finish_show)) < 0) {
	ifree_object(penum, "op_show_enum_setup");
	return code;
    }
    return op_show_continue_pop(i_ctx_p, 1);
}

/* <ax> <ay> <string> ashow - */
private int
zashow(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_text_enum_t *penum;
    double axy[2];
    int code = num_params(op - 1, 2, axy);

    if (code < 0 ||
	(code = op_show_setup(i_ctx_p, op)) != 0 ||
	(code = gs_ashow_begin(igs, axy[0], axy[1], op->value.bytes, r_size(op), imemory, &penum)) < 0)
	return code;
    if ((code = op_show_finish_setup(i_ctx_p, penum, 3, finish_show)) < 0) {
	ifree_object(penum, "op_show_enum_setup");
	return code;
    }
    return op_show_continue_pop(i_ctx_p, 3);
}

/* <cx> <cy> <char> <string> widthshow - */
private int
zwidthshow(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_text_enum_t *penum;
    double cxy[2];
    int code;

    check_type(op[-1], t_integer);
    if ((gs_char) (op[-1].value.intval) != op[-1].value.intval)
	return_error(e_rangecheck);
    if ((code = num_params(op - 2, 2, cxy)) < 0 ||
	(code = op_show_setup(i_ctx_p, op)) != 0 ||
	(code = gs_widthshow_begin(igs, cxy[0], cxy[1],
				   (gs_char) op[-1].value.intval,
				   op->value.bytes, r_size(op),
				   imemory, &penum)) < 0)
	return code;
    if ((code = op_show_finish_setup(i_ctx_p, penum, 4, finish_show)) < 0) {
	ifree_object(penum, "op_show_enum_setup");
	return code;
    }
    return op_show_continue_pop(i_ctx_p, 4);
}

/* <cx> <cy> <char> <ax> <ay> <string> awidthshow - */
private int
zawidthshow(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_text_enum_t *penum;
    double cxy[2], axy[2];
    int code;

    check_type(op[-3], t_integer);
    if ((gs_char) (op[-3].value.intval) != op[-3].value.intval)
	return_error(e_rangecheck);
    if ((code = num_params(op - 4, 2, cxy)) < 0 ||
	(code = num_params(op - 1, 2, axy)) < 0 ||
	(code = op_show_setup(i_ctx_p, op)) != 0 ||
	(code = gs_awidthshow_begin(igs, cxy[0], cxy[1],
				    (gs_char) op[-3].value.intval,
				    axy[0], axy[1],
				    op->value.bytes, r_size(op),
				    imemory, &penum)) < 0)
	return code;
    if ((code = op_show_finish_setup(i_ctx_p, penum, 6, finish_show)) < 0) {
	ifree_object(penum, "op_show_enum_setup");
	return code;
    }
    return op_show_continue_pop(i_ctx_p, 6);
}

/* <proc> <string> kshow - */
private int
zkshow(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_text_enum_t *penum;
    int code;

    check_proc(op[-1]);
    if ((code = op_show_setup(i_ctx_p, op)) != 0 ||
	(code = gs_kshow_begin(igs, op->value.bytes, r_size(op),
			       imemory, &penum)) < 0)
	return code;
    if ((code = op_show_finish_setup(i_ctx_p, penum, 2, finish_show)) < 0) {
	ifree_object(penum, "op_show_enum_setup");
	return code;
    }
    sslot = op[-1];		/* save kerning proc */
    return op_show_continue_pop(i_ctx_p, 2);
}

/* Common finish procedure for all show operations. */
/* Doesn't have to do anything. */
private int
finish_show(i_ctx_t *i_ctx_p)
{
    return 0;
}

/* <string> stringwidth <wx> <wy> */
private int
zstringwidth(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_text_enum_t *penum;
    int code = op_show_setup(i_ctx_p, op);

    if (code != 0 ||
	(code = gs_stringwidth_begin(igs, op->value.bytes, r_size(op),
				     imemory, &penum)) < 0)
	return code;
    if ((code = op_show_finish_setup(i_ctx_p, penum, 1, finish_stringwidth)) < 0) {
	ifree_object(penum, "op_show_enum_setup");
	return code;
    }
    return op_show_continue_pop(i_ctx_p, 1);
}
/* Finishing procedure for stringwidth. */
/* Pushes the accumulated width. */
/* This is exported for .glyphwidth (in zcharx.c). */
int
finish_stringwidth(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_point width;

    gs_text_total_width(senum, &width);
    push(2);
    make_real(op - 1, width.x);
    make_real(op, width.y);
    return 0;
}

/* Common code for charpath and .charboxpath. */
private int
zchar_path(i_ctx_t *i_ctx_p,
	   int (*begin)(P6(gs_state *, const byte *, uint,
			   bool, gs_memory_t *, gs_text_enum_t **)))
{
    os_ptr op = osp;
    gs_text_enum_t *penum;
    int code;

    check_type(*op, t_boolean);
    code = op_show_setup(i_ctx_p, op - 1);
    if (code != 0 ||
	(code = begin(igs, op[-1].value.bytes, r_size(op - 1),
		      op->value.boolval, imemory, &penum)) < 0)
	return code;
    if ((code = op_show_finish_setup(i_ctx_p, penum, 2, finish_show)) < 0) {
	ifree_object(penum, "op_show_enum_setup");
	return code;
    }
    return op_show_continue_pop(i_ctx_p, 2);
}
/* <string> <outline_bool> charpath - */
private int
zcharpath(i_ctx_t *i_ctx_p)
{
    return zchar_path(i_ctx_p, gs_charpath_begin);
}
/* <string> <box_bool> .charboxpath - */
private int
zcharboxpath(i_ctx_t *i_ctx_p)
{
    return zchar_path(i_ctx_p, gs_charboxpath_begin);
}

/* <wx> <wy> <llx> <lly> <urx> <ury> setcachedevice - */
int
zsetcachedevice(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    double wbox[6];
    gs_text_enum_t *penum = op_show_find(i_ctx_p);
    int code = num_params(op, 6, wbox);

    if (penum == 0)
	return_error(e_undefined);
    if (code < 0)
	return code;
    if (zchar_show_width_only(penum))
	return op_show_return_width(i_ctx_p, 6, &wbox[0]);
    code = gs_text_setcachedevice(penum, wbox);
    if (code < 0)
	return code;
    pop(6);
    if (code == 1)
	clear_pagedevice(istate);
    return 0;
}

/* <w0x> <w0y> <llx> <lly> <urx> <ury> <w1x> <w1y> <vx> <vy> setcachedevice2 - */
int
zsetcachedevice2(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    double wbox[10];
    gs_text_enum_t *penum = op_show_find(i_ctx_p);
    int code = num_params(op, 10, wbox);

    if (penum == 0)
	return_error(e_undefined);
    if (code < 0)
	return code;
    if (zchar_show_width_only(penum))
	return op_show_return_width(i_ctx_p, 10,
				    (gs_rootfont(igs)->WMode ?
				     &wbox[6] : &wbox[0]));
    code = gs_text_setcachedevice2(penum, wbox);
    if (code < 0)
	return code;
    pop(10);
    if (code == 1)
	clear_pagedevice(istate);
    return 0;
}

/* <wx> <wy> setcharwidth - */
private int
zsetcharwidth(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    double width[2];
    gs_text_enum_t *penum = op_show_find(i_ctx_p);
    int code = num_params(op, 2, width);

    if (penum == 0)
	return_error(e_undefined);
    if (code < 0)
	return code;
    if (zchar_show_width_only(penum))
	return op_show_return_width(i_ctx_p, 2, &width[0]);
    code = gs_text_setcharwidth(penum, width);
    if (code < 0)
	return code;
    pop(2);
    return 0;
}

/* <dict> .fontbbox <llx> <lly> <urx> <ury> -true- */
/* <dict> .fontbbox -false- */
private int
zfontbbox(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    double bbox[4];
    int code;

    check_type(*op, t_dictionary);
    check_dict_read(*op);
    code = font_bbox_param(op, bbox);
    if (code < 0)
	return code;
    if (bbox[0] < bbox[2] && bbox[1] < bbox[3]) {
	push(4);
	make_reals(op - 4, bbox, 4);
	make_true(op);
    } else {			/* No bbox, or an empty one. */
	make_false(op);
    }
    return 0;
}

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

const op_def zchar_op_defs[] =
{
    {"3ashow", zashow},
    {"6awidthshow", zawidthshow},
    {"2charpath", zcharpath},
    {"2.charboxpath", zcharboxpath},
    {"2kshow", zkshow},
    {"6setcachedevice", zsetcachedevice},
    {":setcachedevice2", zsetcachedevice2},
    {"2setcharwidth", zsetcharwidth},
    {"1show", zshow},
    {"1stringwidth", zstringwidth},
    {"4widthshow", zwidthshow},
		/* Extensions */
    {"1.fontbbox", zfontbbox},
		/* Internal operators */
    {"0%finish_show", finish_show},
    {"0%finish_stringwidth", finish_stringwidth},
    {"0%op_show_continue", op_show_continue},
    op_def_end(0)
};

/* ------ Subroutines ------ */

/* Most of these are exported for zchar2.c. */

/* Convert a glyph to a ref. */
void
glyph_ref(gs_glyph glyph, ref * gref)
{
    if (glyph < gs_min_cid_glyph)
	name_index_ref(glyph, gref);
    else
	make_int(gref, glyph - gs_min_cid_glyph);
}

/* Prepare to set up for a text operator. */
/* Don't change any state yet. */
int
op_show_setup(i_ctx_t *i_ctx_p, os_ptr op)
{
    check_read_type(*op, t_string);
    return op_show_enum_setup(i_ctx_p);
}
int
op_show_enum_setup(i_ctx_t *i_ctx_p)
{
    check_estack(snumpush + 2);
    return 0;
}

/* Finish setting up a text operator. */
int
op_show_finish_setup(i_ctx_t *i_ctx_p, gs_text_enum_t * penum, int npop,
		     op_proc_t endproc /* end procedure */ )
{
    gs_text_enum_t *osenum = op_show_find(i_ctx_p);
    es_ptr ep = esp + snumpush;
    gs_glyph glyph;

    /*
     * If we are in the procedure of a cshow for a CID font and this is
     * a show operator, do something special, per the Red Book.
     */
    if (osenum &&
	SHOW_IS_ALL_OF(osenum,
		       TEXT_FROM_STRING | TEXT_DO_NONE | TEXT_INTERVENE) &&
	SHOW_IS_ALL_OF(penum, TEXT_FROM_STRING | TEXT_RETURN_WIDTH) &&
	(glyph = gs_text_current_glyph(osenum)) != gs_no_glyph &&
	glyph >= gs_min_cid_glyph &&

        /* According to PLRM, we don't need to raise a rangecheck error,
           if currentfont is changed in the proc of the operator 'cshow'. */
	gs_default_same_font (gs_text_current_font(osenum), 
			      gs_text_current_font(penum), true)
	) {
	gs_text_params_t text;

	if (!(penum->text.size == 1 &&
	      penum->text.data.bytes[0] ==
	        (gs_text_current_char(osenum) & 0xff))
	    )
	    return_error(e_rangecheck);
	text = penum->text;
	text.operation =
	    (text.operation &
	     ~(TEXT_FROM_STRING | TEXT_FROM_BYTES | TEXT_FROM_CHARS |
	       TEXT_FROM_GLYPHS | TEXT_FROM_SINGLE_CHAR)) |
	    TEXT_FROM_SINGLE_GLYPH;
	text.data.d_glyph = glyph;
	text.size = 1;
	gs_text_restart(penum, &text);
    }
    make_mark_estack(ep - (snumpush - 1), es_show, op_show_cleanup);
    if (endproc == NULL)
	endproc = finish_show;
    make_null(&esslot(ep));
    make_int(&esodepth(ep), ref_stack_count_inline(&o_stack) - npop); /* Save stack depth for */
    make_int(&esddepth(ep), ref_stack_count_inline(&d_stack));        /* correct interrupt processing */
    make_int(&esgslevel(ep), igs->level);
    make_null(&essfont(ep));
    make_null(&esrfont(ep));
    make_op_estack(&eseproc(ep), endproc);
    make_istruct(ep, 0, penum);
    esp = ep;
    return 0;
}

/* Continuation operator for character rendering. */
int
op_show_continue(i_ctx_t *i_ctx_p)
{
    return op_show_continue_dispatch(i_ctx_p, 0, gs_text_process(senum));
}
int
op_show_continue_pop(i_ctx_t *i_ctx_p, int npop)
{
    return op_show_continue_dispatch(i_ctx_p, npop, gs_text_process(senum));
}
/*
 * Note that op_show_continue_dispatch sets osp = op explicitly iff the
 * dispatch succeeds.  This is so that the show operators don't pop anything
 * from the o-stack if they don't succeed.  Note also that if it returns an
 * error, it has freed the enumerator.
 */
int
op_show_continue_dispatch(i_ctx_t *i_ctx_p, int npop, int code)
{
    os_ptr op = osp - npop;
    gs_text_enum_t *penum = senum;

    switch (code) {
	case 0: {		/* all done */
	    os_ptr save_osp = osp;

	    osp = op;
	    code = (*real_opproc(&seproc)) (i_ctx_p);
	    op_show_free(i_ctx_p, code);
	    if (code < 0) {
		osp = save_osp;
		return code;
	    }
	    return o_pop_estack;
	}
	case TEXT_PROCESS_INTERVENE: {
	    ref *pslot = &sslot; /* only used for kshow */

	    push(2);
	    make_int(op - 1, gs_text_current_char(penum)); /* previous char */
	    make_int(op, gs_text_next_char(penum));
	    push_op_estack(op_show_continue);	/* continue after kerning */
	    *++esp = *pslot;	/* kerning procedure */
	    return o_push_estack;
	}
	case TEXT_PROCESS_RENDER: {
	    gs_font *pfont = gs_currentfont(igs);
	    font_data *pfdata = pfont_data(pfont);
	    gs_char chr = gs_text_current_char(penum);
	    gs_glyph glyph = gs_text_current_glyph(penum);

	    push(2);
	    op[-1] = pfdata->dict;	/* push the font */
	    /*
	     * For Type 1 and Type 4 fonts, prefer BuildChar to BuildGlyph
	     * if there is no glyph, or if there is both a character and a
	     * glyph and the glyph is the one that corresponds to the
	     * character in the Encoding, so that PostScript procedures
	     * appearing in the CharStrings dictionary will receive the
	     * character code rather than the character name; for Type 3
	     * fonts, prefer BuildGlyph to BuildChar.  For other font types
	     * (such as CID fonts), only BuildGlyph will be present.
	     */
	    if (pfont->FontType == ft_user_defined) {
		/* Type 3 font, prefer BuildGlyph. */
		if (level2_enabled &&
		    !r_has_type(&pfdata->BuildGlyph, t_null) &&
		    glyph != gs_no_glyph
		    ) {
		    glyph_ref(glyph, op);
		    esp[2] = pfdata->BuildGlyph;
		} else if (r_has_type(&pfdata->BuildChar, t_null))
		    goto err;
		else if (chr == gs_no_char) {
		    /* glyphshow, reverse map the character */
		    /* through the Encoding */
		    ref gref;
		    const ref *pencoding = &pfdata->Encoding;

		    glyph_ref(glyph, &gref);
		    if (!map_glyph_to_char(&gref, pencoding,
					   (ref *) op)
			) {	/* Not found, try .notdef */
			name_enter_string(".notdef", &gref);
			if (!map_glyph_to_char(&gref,
					       pencoding,
					       (ref *) op)
			    )
			    goto err;
		    }
		    esp[2] = pfdata->BuildChar;
		} else {
		    make_int(op, chr & 0xff);
		    esp[2] = pfdata->BuildChar;
		}
	    } else {
		/*
		 * For a Type 1 or Type 4 font, prefer BuildChar or
		 * BuildGlyph as described above: we know that both
		 * BuildChar and BuildGlyph are present.  For other font
		 * types, only BuildGlyph is available.
		 */
		ref eref, gref;

		if (chr != gs_no_char &&
		    !r_has_type(&pfdata->BuildChar, t_null) &&
		    (glyph == gs_no_glyph ||
		     (array_get(&pfdata->Encoding, (long)(chr & 0xff), &eref) >= 0 &&
		      (glyph_ref(glyph, &gref), obj_eq(&gref, &eref))))
		    ) {
		    make_int(op, chr & 0xff);
		    esp[2] = pfdata->BuildChar;
		} else {
		    /* We might not have a glyph: substitute 0. **HACK** */
		    if (glyph == gs_no_glyph)
			make_int(op, 0);
		    else
			glyph_ref(glyph, op);
		    esp[2] = pfdata->BuildGlyph;
		}
	    }
	    /* Save the stack depths in case we bail out. */
	    sodepth.value.intval = ref_stack_count(&o_stack) - 2;
	    sddepth.value.intval = ref_stack_count(&d_stack);
	    push_op_estack(op_show_continue);
	    ++esp;		/* skip BuildChar or BuildGlyph proc */
	    return o_push_estack;
	}
	default:		/* error */
err:
	    if (code >= 0)
		code = gs_note_error(e_invalidfont);
	    return op_show_free(i_ctx_p, code);
    }
}
/* Reverse-map a glyph name to a character code for glyphshow. */
private bool
map_glyph_to_char(const ref * pgref, const ref * pencoding, ref * pch)
{
    uint esize = r_size(pencoding);
    uint ch;
    ref eref;

    for (ch = 0; ch < esize; ch++) {
	array_get(pencoding, (long)ch, &eref);
	if (obj_eq(pgref, &eref)) {
	    make_int(pch, ch);
	    return true;
	}
    }
    return false;
}

/* Find the index of the e-stack mark for the current show enumerator. */
/* Return 0 if we can't find the mark. */
private uint
op_show_find_index(i_ctx_t *i_ctx_p)
{
    ref_stack_enum_t rsenum;
    uint count = 0;

    ref_stack_enum_begin(&rsenum, &e_stack);
    do {
	es_ptr ep = rsenum.ptr;
	uint size = rsenum.size;

	for (ep += size - 1; size != 0; size--, ep--, count++)
	    if (r_is_estack_mark(ep) && estack_mark_index(ep) == es_show)
		return count;
    } while (ref_stack_enum_next(&rsenum));
    return 0;		/* no mark */
}

/* Find the current show enumerator on the e-stack. */
gs_text_enum_t *
op_show_find(i_ctx_t *i_ctx_p)
{
    uint index = op_show_find_index(i_ctx_p);

    if (index == 0)
	return 0;		/* no mark */
    return r_ptr(ref_stack_index(&e_stack, index - (snumpush - 1)),
		 gs_text_enum_t);
}

/*
 * Return true if we only need the width from the rasterizer
 * and can short-circuit the full rendering of the character,
 * false if we need the actual character bits.  This is only safe if
 * we know the character is well-behaved, i.e., is not defined by an
 * arbitrary PostScript procedure.
 */
bool
zchar_show_width_only(const gs_text_enum_t * penum)
{
    if (!gs_text_is_width_only(penum))
	return false;
    switch (penum->orig_font->FontType) {
    case ft_encrypted:
    case ft_encrypted2:
    case ft_CID_encrypted:
    case ft_CID_TrueType:
    case ft_CID_bitmap:
    case ft_TrueType:
	return true;
    default:
	return false;
    }
}

/* Shortcut the BuildChar or BuildGlyph procedure at the point */
/* of the setcharwidth or the setcachedevice[2] if we are in */
/* a stringwidth or cshow, or if we are only collecting the scalable */
/* width for an xfont character. */
private int
op_show_return_width(i_ctx_t *i_ctx_p, uint npop, double *pwidth)
{
    uint index = op_show_find_index(i_ctx_p);
    es_ptr ep = (es_ptr) ref_stack_index(&e_stack, index - (snumpush - 1));
    int code = gs_text_setcharwidth(esenum(ep), pwidth);
    uint ocount, dsaved, dcount;

    if (code < 0)
	return code;
    /* Restore the operand and dictionary stacks. */
    ocount = ref_stack_count(&o_stack) - (uint) esodepth(ep).value.intval;
    if (ocount < npop)
	return_error(e_stackunderflow);
    dsaved = (uint) esddepth(ep).value.intval;
    dcount = ref_stack_count(&d_stack);
    if (dcount < dsaved)
	return_error(e_dictstackunderflow);
    while (dcount > dsaved) {
	code = zend(i_ctx_p);
	if (code < 0)
	    return code;
	dcount--;
    }
    ref_stack_pop(&o_stack, ocount);
    /* We don't want to pop the mark or the continuation */
    /* procedure (op_show_continue or cshow_continue). */
    pop_estack(i_ctx_p, index - snumpush);
    return o_pop_estack;
}

/*
 * Restore state after finishing, or unwinding from an error within, a show
 * operation.  Note that we assume op == osp, and may reset osp.
 */
private int
op_show_restore(i_ctx_t *i_ctx_p, bool for_error)
{
    register es_ptr ep = esp + snumpush;
    gs_text_enum_t *penum = esenum(ep);
    int saved_level = esgslevel(ep).value.intval;
    int code = 0;

    if (for_error) {
	uint saved_count = esodepth(ep).value.intval;
	uint count = ref_stack_count(&o_stack);

	if (count > saved_count)	/* if <, we're in trouble */
	    ref_stack_pop(&o_stack, count - saved_count);
    }
    if (SHOW_IS_STRINGWIDTH(penum)) {	/* stringwidth does an extra gsave */
	--saved_level;
    }
    if (penum->text.operation & TEXT_REPLACE_WIDTHS) {
	gs_free_const_object(penum->memory, penum->text.y_widths, "y_widths");
	if (penum->text.x_widths != penum->text.y_widths)
	    gs_free_const_object(penum->memory, penum->text.x_widths, "x_widths");
    }
    /*
     * We might have been inside a cshow, in which case currentfont was
     * reset temporarily, as though we were inside a BuildChar/ BuildGlyph
     * procedure.  To handle this case, set currentfont back to its original
     * state.  NOTE: this code previously used fstack[0] in the enumerator
     * for the root font: we aren't sure that this change is correct.
     */
    gs_set_currentfont(igs, penum->orig_font);
    while (igs->level > saved_level && code >= 0) {
	if (igs->saved == 0 || igs->saved->saved == 0) {
	    /*
	     * Bad news: we got an error inside a save inside a BuildChar or
	     * BuildGlyph.  Don't attempt to recover.
	     */
	    code = gs_note_error(e_Fatal);
	} else
	    code = gs_grestore(igs);
    }
    gs_text_release(penum, "op_show_restore");
    return code;
}
/* Clean up after an error. */
private int
op_show_cleanup(i_ctx_t *i_ctx_p)
{
    return op_show_restore(i_ctx_p, true);
}
/* Clean up after termination of a show operation. */
int
op_show_free(i_ctx_t *i_ctx_p, int code)
{
    int rcode;

    esp -= snumpush;
    rcode = op_show_restore(i_ctx_p, code < 0);
    return (rcode < 0 ? rcode : code);
}

/* Get a FontBBox parameter from a font dictionary. */
int
font_bbox_param(const ref * pfdict, double bbox[4])
{
    ref *pbbox;

    /*
     * Pre-clear the bbox in case it's invalid.  The Red Books say that
     * FontBBox is required, but the Adobe interpreters don't require
     * it, and a few user-written fonts don't supply it, or supply one
     * of the wrong size (!); also, PageMaker 5.0 (an Adobe product!)
     * sometimes emits an absurd bbox for Type 1 fonts converted from
     * TrueType.
     */
    bbox[0] = bbox[1] = bbox[2] = bbox[3] = 0.0;
    if (dict_find_string(pfdict, "FontBBox", &pbbox) > 0) {
	if (!r_is_array(pbbox))
	    return_error(e_typecheck);
	if (r_size(pbbox) == 4) {
	    const ref_packed *pbe = pbbox->value.packed;
	    ref rbe[4];
	    int i;
	    int code;
	    float dx, dy, ratio;

	    for (i = 0; i < 4; i++) {
		packed_get(pbe, rbe + i);
		pbe = packed_next(pbe);
	    }
	    if ((code = num_params(rbe + 3, 4, bbox)) < 0)
		return code;
	    /* Require "reasonable" values.  Thanks to Ray */
	    /* Johnston for suggesting the following test. */
	    dx = bbox[2] - bbox[0];
	    dy = bbox[3] - bbox[1];
	    if (dx <= 0 || dy <= 0 ||
		(ratio = dy / dx) < 0.125 || ratio > 8.0
		)
		bbox[0] = bbox[1] = bbox[2] = bbox[3] = 0.0;
	}
    }
    return 0;
}