/* Copyright (C) 1989, 1995, 1996, 1997, 1998 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU Ghostscript is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility to
  anyone for the consequences of using it or for whether it serves any
  particular purpose or works at all, unless he says so in writing.  Refer to
  the GNU General Public License for full details.
  
  Everyone is granted permission to copy, modify and redistribute GNU
  Ghostscript, but only under the conditions described in the GNU General
  Public License.  A copy of this license is supposed to have been given to
  you along with GNU Ghostscript so you can know your rights and
  responsibilities.  It should be in a file named COPYING.  Among other
  things, the copyright notice and this notice must be preserved on all
  copies.
  
  Aladdin Enterprises is not affiliated with the Free Software Foundation or
  the GNU Project.  GNU Ghostscript, as distributed by Aladdin Enterprises,
  does not depend on any other GNU software.
*/

/*$Id: gschar.c,v 1.3 1999/04/01 05:31:24 fedor Exp $ */
/* Character writing operators for Ghostscript library */
#include "gx.h"
#include "memory_.h"
#include "string_.h"
#include "gserrors.h"
#include "gsstruct.h"
#include "gxfixed.h"		/* ditto */
#include "gxarith.h"
#include "gxmatrix.h"
#include "gzstate.h"
#include "gxcoord.h"
#include "gxdevice.h"
#include "gxdevmem.h"
#include "gxchar.h"
#include "gxfont.h"
#include "gxfont0.h"
#include "gxfcache.h"
#include "gspath.h"
#include "gzpath.h"

/* Define whether or not to cache characters rotated by angles other than */
/* multiples of 90 degrees. */
private bool CACHE_ROTATED_CHARS = true;

/* Define whether or not to oversample characters at small sizes. */
private bool OVERSAMPLE = true;

/* Define the maximum size of a full temporary bitmap when rasterizing, */
/* in bits (not bytes). */
private uint MAX_TEMP_BITMAP_BITS = 80000;

/* Structure descriptors */
private_st_gs_show_enum();
extern_st(st_gs_text_params);
#define eptr ((gs_show_enum *)vptr)
private 
ENUM_PTRS_BEGIN(show_enum_enum_ptrs)
{
    index -= 5;
    if (index <= eptr->fstack.depth)
	ENUM_RETURN(eptr->fstack.items[index].font);
    index -= eptr->fstack.depth + 1;
    return ENUM_USING(st_gs_text_params, vptr, size, index);
}
ENUM_PTR(0, gs_show_enum, pgs);
ENUM_PTR(1, gs_show_enum, show_gstate);
ENUM_PTR3(2, gs_show_enum, dev_cache, dev_cache2, dev_null);
ENUM_PTRS_END
private RELOC_PTRS_BEGIN(show_enum_reloc_ptrs)
{
    int i;

    RELOC_USING(st_gs_text_params, vptr, size);		/* superclass */
    RELOC_PTR(gs_show_enum, pgs);
    RELOC_PTR(gs_show_enum, show_gstate);
    RELOC_PTR3(gs_show_enum, dev_cache, dev_cache2, dev_null);
    for (i = 0; i <= eptr->fstack.depth; i++)
	RELOC_PTR(gs_show_enum, fstack.items[i].font);
}
RELOC_PTRS_END
#undef eptr

/* Forward declarations */
private int continue_kshow(P1(gs_show_enum *));
private int continue_show(P1(gs_show_enum *));
private int continue_show_update(P1(gs_show_enum *));
private int show_setup(P6(gs_show_enum *, gs_state *, const char *, uint,
			  uint, bool));
private void show_set_scale(P1(gs_show_enum *));
private int show_cache_setup(P1(gs_show_enum *));
private int show_state_setup(P1(gs_show_enum *));
private int show_origin_setup(P4(gs_state *, fixed, fixed, gs_char_path_mode));
private int stringwidth_setup(P4(gs_show_enum *, gs_state *, const char *,
				 uint));

/* Print the ctm if debugging */
#define print_ctm(s,pgs)\
  dlprintf7("[p]%sctm=[%g %g %g %g %g %g]\n", s,\
	    pgs->ctm.xx, pgs->ctm.xy, pgs->ctm.yx, pgs->ctm.yy,\
	    pgs->ctm.tx, pgs->ctm.ty)

/* ------ Driver procedure ------ */

/*
 * When actually implemented, this will be moved further down in the file
 * and will replace other code that is there now....
 */

int
gx_default_text_begin(gx_device * dev, gs_imager_state * pis,
		      const gs_text_params_t * text, const gs_font * font,
gx_path * path, const gx_device_color * pdcolor, const gx_clip_path * pcpath,
		      gs_memory_t * memory, gs_text_enum_t ** ppenum)
{
    return_error(gs_error_undefined);
}

/* ------ Font procedures ------ */

/* Dummy (ineffective) BuildChar/BuildGlyph procedure */
int
gs_no_build_char(gs_show_enum * penum, gs_state * pgs,
		 gs_font * pfont, gs_char chr, gs_glyph glyph)
{
    return 1;			/* failure, but not error */
}

/* Dummy character encoding procedure */
gs_glyph
gs_no_encode_char(gs_show_enum * penum,
		  gs_font * pfont, gs_char * pchr)
{
    return gs_no_glyph;
}

/* ------ String writing operators ------ */

/* Allocate a show enumerator. */
gs_show_enum *
gs_show_enum_alloc(gs_memory_t * mem, gs_state * pgs, client_name_t cname)
{
    gs_show_enum *penum;

    rc_alloc_struct_1(penum, gs_show_enum, &st_gs_show_enum, mem,
		      return 0, cname);
    /* Initialize pointers for GC */
    penum->text.operation = 0;	/* no pointers relevant */
    penum->dev = 0;
    penum->pgs = pgs;
    penum->dev_cache = 0;
    penum->dev_cache2 = 0;
    penum->dev_null = 0;
    penum->fstack.depth = -1;
    return penum;
}

/* Free the contents of a show enumerator. */
void
gs_show_enum_release(gs_show_enum * penum, gs_memory_t * emem)
{
    penum->cc = 0;
    if (penum->dev_cache2 != 0) {
	rc_decrement_only(penum->dev_cache2,
			  "gs_show_enum_release(dev_cache2)");
	penum->dev_cache2 = 0;
    }
    if (penum->dev_cache != 0) {
	rc_decrement_only(penum->dev_cache,
			  "gs_show_enum_release(dev_cache)");
	penum->dev_cache = 0;
    }
    if (penum->dev_null != 0) {
	rc_decrement_only(penum->dev_null,
			  "gs_show_enum_release(dev_null)");
	penum->dev_null = 0;
    }
    if (emem != 0)
	gs_free_object(emem, penum, "gs_show_enum_release(enum)");
}

/* show[_n] */
int
gs_show_n_init(gs_show_enum * penum, gs_state * pgs,
	       const char *str, uint size)
{
    return show_setup(penum, pgs, str, size,
		      TEXT_FROM_STRING | TEXT_DO_DRAW | TEXT_RETURN_WIDTH,
		      true);
}

/* ashow[_n] */
int
gs_ashow_n_init(gs_show_enum * penum, gs_state * pgs,
		floatp ax, floatp ay, const char *str, uint size)
{
    penum->text.delta_all.x = ax;
    penum->text.delta_all.y = ay;
    return show_setup(penum, pgs, str, size,
		      TEXT_FROM_STRING | TEXT_ADD_TO_ALL_WIDTHS |
		      TEXT_DO_DRAW | TEXT_RETURN_WIDTH,
		      true);
}

/* widthshow[_n] */
int
gs_widthshow_n_init(gs_show_enum * penum, gs_state * pgs,
		    floatp cx, floatp cy, gs_char chr,
		    const char *str, uint size)
{
    penum->text.delta_space.x = cx;
    penum->text.delta_space.y = cy;
    penum->text.space.s_char = chr;
    return show_setup(penum, pgs, str, size,
		      TEXT_FROM_STRING | TEXT_ADD_TO_SPACE_WIDTH |
		      TEXT_DO_DRAW | TEXT_RETURN_WIDTH,
		      true);
}

/* awidthshow[_n] */
int
gs_awidthshow_n_init(gs_show_enum * penum, gs_state * pgs,
		     floatp cx, floatp cy, gs_char chr, floatp ax, floatp ay,
		     const char *str, uint size)
{
    penum->text.delta_space.x = cx;
    penum->text.delta_space.y = cy;
    penum->text.space.s_char = chr;
    penum->text.delta_all.x = ax;
    penum->text.delta_all.y = ay;
    return show_setup(penum, pgs, str, size,
		      TEXT_FROM_STRING |
		      TEXT_ADD_TO_ALL_WIDTHS | TEXT_ADD_TO_SPACE_WIDTH |
		      TEXT_DO_DRAW | TEXT_RETURN_WIDTH,
		      true);
}

/* kshow[_n] */
int
gs_kshow_n_init(register gs_show_enum * penum,
		gs_state * pgs, const char *str, uint size)
{
    if (pgs->font->FontType == ft_composite)
	return_error(gs_error_invalidfont);
    return show_setup(penum, pgs, str, size,
		      TEXT_FROM_STRING | TEXT_DO_DRAW | TEXT_INTERVENE |
		      TEXT_RETURN_WIDTH,
		      true);
}

/* xyshow[_n] */
int
gs_xyshow_n_init(register gs_show_enum * penum,
		 gs_state * pgs, const char *str, uint size)
{
    return show_setup(penum, pgs, str, size,
		      TEXT_FROM_STRING |
		      TEXT_REPLACE_X_WIDTHS | TEXT_REPLACE_Y_WIDTHS |
		      TEXT_DO_DRAW | TEXT_INTERVENE | TEXT_RETURN_WIDTH,
		      true);
}

/* glyphshow */
private int setup_glyph(P4(gs_show_enum *, gs_state *, gs_glyph, uint));
private font_proc_encode_char(gs_glyphshow_encode_char);
int
gs_glyphshow_init(gs_show_enum * penum, gs_state * pgs, gs_glyph glyph)
{
    return setup_glyph(penum, pgs, glyph, TEXT_DO_DRAW);
}
int
gs_glyphpath_init(gs_show_enum * penum, gs_state * pgs, gs_glyph glyph,
		  bool stroke_path)
{
    int code = setup_glyph(penum, pgs, glyph,
			   (stroke_path ? TEXT_DO_TRUE_CHARPATH :
			    TEXT_DO_FALSE_CHARPATH));

    penum->can_cache = -1;
    if_debug1('k', "[k]glyphpath, can_cache=%d", penum->can_cache);
    return code;
}
private int
setup_glyph(gs_show_enum * penum, gs_state * pgs, gs_glyph glyph,
	    uint operation)
{
    int code;

    if (pgs->font->FontType == ft_composite)
	return_error(gs_error_invalidfont);
    code = show_setup(penum, pgs, "\000" /* arbitrary char */ , 1,
		      TEXT_FROM_GLYPHS | TEXT_RETURN_WIDTH | operation,
		      true);
    penum->current_glyph = glyph;
    penum->encode_char = gs_glyphshow_encode_char;
    return code;
}
private gs_glyph
gs_glyphshow_encode_char(gs_show_enum * penum, gs_font * pfont, gs_char * pchr)
{
    /* We just nil out the character, and return the pre-loaded glyph. */
    *pchr = gs_no_char;
    return penum->current_glyph;
}

/* ------ Related operators ------ */

/* cshow[_n] */
int
gs_cshow_n_init(register gs_show_enum * penum,
		gs_state * pgs, const char *str, uint size)
{
    return show_setup(penum, pgs, str, size,
		      TEXT_FROM_STRING | TEXT_DO_NONE | TEXT_INTERVENE,
		      false);
}

/* stringwidth[_n] */
int
gs_stringwidth_n_init(gs_show_enum * penum, gs_state * pgs,
		      const char *str, uint size)
{
    return stringwidth_setup(penum, pgs, str, size);
}

/* Common code for stringwidth[_n] */
private int
stringwidth_setup(gs_show_enum * penum, gs_state * pgs, const char *str,
		  uint size)
{
    int code = show_setup(penum, pgs, str, size,
			TEXT_FROM_STRING | TEXT_DO_NONE | TEXT_RETURN_WIDTH,
			  false);
    gs_memory_t *mem = pgs->memory;
    gx_device_null *dev_null;

    if (code < 0)
	return code;
    dev_null = gs_alloc_struct(mem, gx_device_null, &st_device_null,
			       "stringwidth_setup(dev_null)");
    if (dev_null == 0)
	return_error(gs_error_VMerror);
    /* Do an extra gsave and suppress output */
    if ((code = gs_gsave(pgs)) < 0)
	return code;
    penum->level = pgs->level;	/* for level check in show_update */
    /* Set up a null device that forwards xfont requests properly. */
    gs_make_null_device(dev_null, mem);
    dev_null->target = gs_currentdevice_inline(pgs);
    pgs->ctm_default_set = false;
    penum->dev_null = dev_null;
    /* Account for the extra reference from the enumerator. */
    rc_increment(dev_null);
    gs_setdevice_no_init(pgs, (gx_device *) dev_null);
    /* Establish an arbitrary translation and current point. */
    gs_newpath(pgs);
    gx_translate_to_fixed(pgs, fixed_0, fixed_0);
    return gx_path_add_point(pgs->path, fixed_0, fixed_0);
}

/* charpath[_n] */
int
gs_charpath_n_init(gs_show_enum * penum, gs_state * pgs,
		   const char *str, uint size, bool stroke_path)
{
    int code = show_setup(penum, pgs, str, size,
			  TEXT_FROM_STRING |
			  (stroke_path ? TEXT_DO_TRUE_CHARPATH :
			   TEXT_DO_FALSE_CHARPATH),
			  false);

    penum->can_cache = -1;
    if_debug1('k', "[k]charpath, can_cache=%d", penum->can_cache);
    return code;
}

/* charboxpath[_n] */
int
gs_charboxpath_n_init(gs_show_enum * penum, gs_state * pgs,
		      const char *str, uint size, bool use_boxes)
{
    int code = show_setup(penum, pgs, str, size,
			  TEXT_FROM_STRING |
			  (use_boxes ? TEXT_DO_TRUE_CHARBOXPATH :
			   TEXT_DO_FALSE_CHARBOXPATH),
			  false);

    penum->can_cache = 0;	/* different from charpath! */
    if_debug1('k', "[k]charboxpath, can_cache=%d", penum->can_cache);
    return code;
}

/* ------ Width/cache operators ------ */

private int set_cache_device(P6(gs_show_enum * penum, gs_state * pgs,
			   floatp llx, floatp lly, floatp urx, floatp ury));

/* setcachedevice */
/* The elements of pw are: wx, wy, llx, lly, urx, ury. */
/* Note that this returns 1 if we just set up the cache device. */
int
gs_setcachedevice_double(gs_show_enum * penum, gs_state * pgs, const double *pw)
{
    int code = gs_setcharwidth(penum, pgs, pw[0], pw[1]);	/* default is don't cache */

    if (code < 0)
	return code;
    return set_cache_device(penum, pgs, pw[2], pw[3], pw[4], pw[5]);
}
/* The _float procedure is strictly for backward compatibility. */
int
gs_setcachedevice_float(gs_show_enum * penum, gs_state * pgs, const float *pw)
{
    double w[6];
    int i;

    for (i = 0; i < 6; ++i)
	w[i] = pw[i];
    return gs_setcachedevice_double(penum, pgs, w);
}

/* setcachedevice2 */
/* The elements of pw2 are: w0x, w0y, llx, lly, urx, ury, w1x, w1y, vx, vy. */
/* Note that this returns 1 if we just set up the cache device. */
int
gs_setcachedevice2_double(gs_show_enum * penum, gs_state * pgs,
			  const double *pw2)
{
    int code;

    if (gs_rootfont(pgs)->WMode) {
	float vx = pw2[8], vy = pw2[9];
	gs_fixed_point pvxy, dvxy;
	cached_char *cc;

	if ((code = gs_point_transform2fixed(&pgs->ctm, -vx, -vy, &pvxy)) < 0 ||
	  (code = gs_distance_transform2fixed(&pgs->ctm, vx, vy, &dvxy)) < 0
	    )
	    return 0;		/* don't cache */
	if ((code = gs_setcharwidth(penum, pgs, pw2[6], pw2[7])) < 0)
	    return code;
	/* Adjust the origin by (vx, vy). */
	gx_translate_to_fixed(pgs, pvxy.x, pvxy.y);
	code = set_cache_device(penum, pgs, pw2[2], pw2[3], pw2[4], pw2[5]);
	if (code != 1)
	    return code;
	/* Adjust the character origin too. */
	cc = penum->cc;
	cc->offset.x += dvxy.x;
	cc->offset.y += dvxy.y;
    } else {
	code = gs_setcharwidth(penum, pgs, pw2[0], pw2[1]);
	if (code < 0)
	    return code;
	code = set_cache_device(penum, pgs, pw2[2], pw2[3], pw2[4], pw2[5]);
    }
    return code;
}
/* The _float procedure is strictly for backward compatibility. */
int
gs_setcachedevice2_float(gs_show_enum * penum, gs_state * pgs, const float *pw2)
{
    double w2[10];
    int i;

    for (i = 0; i < 10; ++i)
	w2[i] = pw2[i];
    return gs_setcachedevice2_double(penum, pgs, w2);
}

/* Set up the cache device if relevant. */
/* Return 1 if we just set up a cache device. */
/* Used by setcachedevice and setcachedevice2. */
private int
set_cache_device(gs_show_enum * penum, gs_state * pgs, floatp llx, floatp lly,
		 floatp urx, floatp ury)
{
    gs_glyph glyph;

    /* See if we want to cache this character. */
    if (pgs->in_cachedevice)	/* no recursion! */
	return 0;
    pgs->in_cachedevice = 1;	/* disable color/gray/image operators */
    /* We can only use the cache if we know the glyph. */
    glyph = gs_show_current_glyph(penum);
    if (glyph == gs_no_glyph)
	return 0;
    /* We can only use the cache if ctm is unchanged */
    /* (aside from a possible translation). */
    if (penum->can_cache <= 0 || !pgs->char_tm_valid) {
	if_debug2('k', "[k]no cache: can_cache=%d, char_tm_valid=%d\n",
		  penum->can_cache, (int)pgs->char_tm_valid);
	return 0;
    } {
	const gs_font *pfont = pgs->font;
	gs_font_dir *dir = pfont->dir;
	gx_device *dev = gs_currentdevice_inline(pgs);
	int alpha_bits =
	(*dev_proc(dev, get_alpha_bits)) (dev, go_text);
	gs_log2_scale_point log2_scale;
	static const fixed max_cdim[3] =
	{
#define max_cd(n)\
	    (fixed_1 << (arch_sizeof_short * 8 - n)) - (fixed_1 >> n) * 3
	    max_cd(0), max_cd(1), max_cd(2)
#undef max_cd
	};
	ushort iwidth, iheight;
	cached_char *cc;
	gs_fixed_rect clip_box;
	int code;

	/* Compute the bounding box of the transformed character. */
	/* Since we accept arbitrary transformations, the extrema */
	/* may occur in any order; however, we can save some work */
	/* by observing that opposite corners before transforming */
	/* are still opposite afterwards. */
	gs_fixed_point cll, clr, cul, cur, cdim;

	if ((code = gs_distance_transform2fixed(&pgs->ctm, llx, lly, &cll)) < 0 ||
	    (code = gs_distance_transform2fixed(&pgs->ctm, llx, ury, &clr)) < 0 ||
	    (code = gs_distance_transform2fixed(&pgs->ctm, urx, lly, &cul)) < 0 ||
	 (code = gs_distance_transform2fixed(&pgs->ctm, urx, ury, &cur)) < 0
	    )
	    return 0;		/* don't cache */
	{
	    fixed ctemp;

#define swap(a, b) ctemp = a, a = b, b = ctemp
#define make_min(a, b) if ( (a) > (b) ) swap(a, b)

	    make_min(cll.x, cur.x);
	    make_min(cll.y, cur.y);
	    make_min(clr.x, cul.x);
	    make_min(clr.y, cul.y);
#undef make_min
#undef swap
	}
	/* Now take advantage of symmetry. */
	if (clr.x < cll.x)
	    cll.x = clr.x, cur.x = cul.x;
	if (clr.y < cll.y)
	    cll.y = clr.y, cur.y = cul.y;
	/* Now cll and cur are the extrema of the box. */
	cdim.x = cur.x - cll.x;
	cdim.y = cur.y - cll.y;
	show_set_scale(penum);
	log2_scale.x = penum->log2_suggested_scale.x;
	log2_scale.y = penum->log2_suggested_scale.y;
#ifdef DEBUG
	if (gs_debug_c('k')) {
	    dlprintf6("[k]cbox=[%g %g %g %g] scale=%dx%d\n",
		      fixed2float(cll.x), fixed2float(cll.y),
		      fixed2float(cur.x), fixed2float(cur.y),
		      1 << log2_scale.x, 1 << log2_scale.y);
	    print_ctm("  ", pgs);
	}
#endif
	/*
	 * If the device wants anti-aliased text,
	 * increase the sampling scale to ensure that
	 * if we want N bits of alpha, we generate
	 * at least 2^N sampled bits per pixel.
	 */
	if (alpha_bits > 1) {
	    int more_bits =
	    alpha_bits - (log2_scale.x + log2_scale.y);

	    if (more_bits > 0) {
		if (log2_scale.x <= log2_scale.y) {
		    log2_scale.x += (more_bits + 1) >> 1;
		    log2_scale.y += more_bits >> 1;
		} else {
		    log2_scale.x += more_bits >> 1;
		    log2_scale.y += (more_bits + 1) >> 1;
		}
	    }
	} else if (!OVERSAMPLE || pfont->PaintType != 0) {
	    /* Don't oversample artificially stroked fonts. */
	    log2_scale.x = log2_scale.y = 0;
	}
	if (cdim.x > max_cdim[log2_scale.x] ||
	    cdim.y > max_cdim[log2_scale.y]
	    )
	    return 0;		/* much too big */
	iwidth = ((ushort) fixed2int_var(cdim.x) + 2) << log2_scale.x;
	iheight = ((ushort) fixed2int_var(cdim.y) + 2) << log2_scale.y;
	if_debug3('k', "[k]iwidth=%u iheight=%u dev_cache %s\n",
		  (uint) iwidth, (uint) iheight,
		  (penum->dev_cache == 0 ? "not set" : "set"));
	if (penum->dev_cache == 0) {
	    code = show_cache_setup(penum);
	    if (code < 0)
		return code;
	}
	/*
	 * If we're oversampling (i.e., the temporary bitmap is
	 * larger than the final monobit or alpha array) and the
	 * temporary bitmap is large, use incremental conversion
	 * from oversampled bitmap strips to alpha values instead of
	 * full oversampling with compression at the end.
	 */
	cc = gx_alloc_char_bits(dir, penum->dev_cache,
				(iwidth > MAX_TEMP_BITMAP_BITS / iheight &&
				 log2_scale.x + log2_scale.y > alpha_bits ?
				 penum->dev_cache2 : NULL),
				iwidth, iheight, &log2_scale, alpha_bits);
	if (cc == 0)
	    return 0;		/* too big for cache */
	/* The mins handle transposed coordinate systems.... */
	/* Truncate the offsets to avoid artifacts later. */
	cc->offset.x = fixed_ceiling(-cll.x);
	cc->offset.y = fixed_ceiling(-cll.y);
	if_debug4('k', "[k]width=%u, height=%u, offset=[%g %g]\n",
		  (uint) iwidth, (uint) iheight,
		  fixed2float(cc->offset.x),
		  fixed2float(cc->offset.y));
	if ((code = gs_gsave(pgs)) < 0) {
	    gx_free_cached_char(dir, cc);
	    return code;
	}
	/* Nothing can go wrong now.... */
	penum->cc = cc;
	cc->code = glyph;
	cc->wmode = gs_rootfont(pgs)->WMode;
	cc->wxy = penum->wxy;
	/* Install the device */
	gx_set_device_only(pgs, (gx_device *) penum->dev_cache);
	pgs->ctm_default_set = false;
	/* Adjust the transformation in the graphics context */
	/* so that the character lines up with the cache. */
	gx_translate_to_fixed(pgs,
			      cc->offset.x << log2_scale.x,
			      cc->offset.y << log2_scale.y);
	if ((log2_scale.x | log2_scale.y) != 0)
	    gx_scale_char_matrix(pgs, 1 << log2_scale.x,
				 1 << log2_scale.y);
	/* Set the initial matrix for the cache device. */
	penum->dev_cache->initial_matrix = ctm_only(pgs);
	/* Set the oversampling factor. */
	penum->log2_current_scale.x = log2_scale.x;
	penum->log2_current_scale.y = log2_scale.y;
	/* Reset the clipping path to match the metrics. */
	clip_box.p.x = clip_box.p.y = 0;
	clip_box.q.x = int2fixed(iwidth);
	clip_box.q.y = int2fixed(iheight);
	if ((code = gx_clip_to_rectangle(pgs, &clip_box)) < 0)
	    return code;
	gx_set_device_color_1(pgs);	/* write 1's */
	pgs->in_cachedevice = 2;	/* we are caching */
    }
    penum->width_status = sws_cache;
    return 1;
}

/* setcharwidth */
/* Note that this returns 1 if the current show operation is */
/* non-displaying (stringwidth or cshow). */
int
gs_setcharwidth(register gs_show_enum * penum, gs_state * pgs,
		floatp wx, floatp wy)
{
    int code;

    if (penum->width_status != sws_none)
	return_error(gs_error_undefined);
    if ((code = gs_distance_transform2fixed(&pgs->ctm, wx, wy, &penum->wxy)) < 0)
	return code;
    /* Check whether we're setting the scalable width */
    /* for a cached xfont character. */
    if (penum->cc != 0) {
	penum->cc->wxy = penum->wxy;
	penum->width_status = sws_cache_width_only;
    } else {
	penum->width_status = sws_no_cache;
    }
    return !SHOW_IS_DRAWING(penum);
}

/* ------ Enumerator ------ */

/* Do the next step of a show (or stringwidth) operation */
int
gs_show_next(gs_show_enum * penum)
{
    return (*penum->continue_proc) (penum);
}

/* Continuation procedures */
private int show_update(P1(gs_show_enum * penum));
private int show_move(P1(gs_show_enum * penum));
private int show_proceed(P1(gs_show_enum * penum));
private int show_finish(P1(gs_show_enum * penum));
private int
continue_show_update(register gs_show_enum * penum)
{
    int code = show_update(penum);

    if (code < 0)
	return code;
    code = show_move(penum);
    if (code != 0)
	return code;
    return show_proceed(penum);
}
private int
continue_show(register gs_show_enum * penum)
{
    return show_proceed(penum);
}
/* For kshow, the CTM or font may have changed, so we have to reestablish */
/* the cached values in the enumerator. */
private int
continue_kshow(register gs_show_enum * penum)
{
    int code = show_state_setup(penum);

    if (code < 0)
	return code;
    return show_proceed(penum);
}

/* Update position */
private int
show_update(register gs_show_enum * penum)
{
    register gs_state *pgs = penum->pgs;
    cached_char *cc = penum->cc;
    int code;

    /* Update position for last character */
    switch (penum->width_status) {
	case sws_none:
	    /* Adobe interpreters assume a character width of 0, */
	    /* even though the documentation says this is an error.... */
	    penum->wxy.x = penum->wxy.y = 0;
	    break;
	case sws_cache:
	    /* Finish installing the cache entry. */
	    /* If the BuildChar/BuildGlyph procedure did a save and a */
	    /* restore, it already undid the gsave in setcachedevice. */
	    /* We have to check for this by comparing levels. */
	    switch (pgs->level - penum->level) {
		default:
		    return_error(gs_error_invalidfont);		/* WRONG */
		case 2:
		    code = gs_grestore(pgs);
		    if (code < 0)
			return code;
		case 1:
		    ;
	    }
	    gx_add_cached_char(pgs->font->dir, penum->dev_cache,
			       cc, gx_lookup_fm_pair(pgs->font, pgs),
			       &penum->log2_current_scale);
	    if (!SHOW_IS_DRAWING(penum) ||
		penum->charpath_flag != cpm_show
		)
		break;
	    /* falls through */
	case sws_cache_width_only:
	    /* Copy the bits to the real output device. */
	    code = gs_grestore(pgs);
	    if (code < 0)
		return code;
	    code = gs_state_color_load(pgs);
	    if (code < 0)
		return code;
	    return gx_image_cached_char(penum, cc);
	case sws_no_cache:
	    ;
    }
    if (penum->charpath_flag != cpm_show) {
	/* Move back to the character origin, so that */
	/* show_move will get us to the right place. */
	code = gx_path_add_point(pgs->show_gstate->path,
				 penum->origin.x, penum->origin.y);
	if (code < 0)
	    return code;
    }
    return gs_grestore(pgs);
}

/* Move to next character */
private int
show_fast_move(gs_state * pgs, gs_fixed_point * pwxy)
{
    int code = gx_path_add_rel_point_inline(pgs->path, pwxy->x, pwxy->y);

    /* If the current position is out of range, don't try to move. */
    if (code == gs_error_limitcheck && pgs->clamp_coordinates)
	code = 0;
    return code;
}
private int
show_move(register gs_show_enum * penum)
{
    register gs_state *pgs = penum->pgs;

    if (SHOW_IS_XYCSHOW(penum)) {
	penum->continue_proc = continue_show;
	return gs_show_move;
    }
    if (SHOW_IS_ADD_TO_ALL(penum))
	gs_rmoveto(pgs, penum->text.delta_all.x, penum->text.delta_all.y);
    if (SHOW_IS_ADD_TO_SPACE(penum)) {
	gs_char chr = penum->current_char;
	int fdepth = penum->fstack.depth;

	if (fdepth > 0) {
	    /* Add in the shifted font number. */
	    uint fidx = penum->fstack.items[fdepth].index;

	    switch (((gs_font_type0 *) (penum->fstack.items[fdepth - 1].font))->data.FMapType) {
		case fmap_1_7:
		case fmap_9_7:
		    chr += fidx << 7;
		    break;
		default:
		    chr += fidx << 8;
	    }
	}
	if (chr == penum->text.space.s_char)
	    gs_rmoveto(pgs, penum->text.delta_space.x,
		       penum->text.delta_space.y);
    }
    /* wxy is in device coordinates */
    {
	int code = show_fast_move(pgs, &penum->wxy);

	if (code < 0)
	    return code;
    }
    /* Check for kerning, but not on the last character. */
    if (SHOW_IS_DO_KERN(penum) && penum->index < penum->text.size) {
	penum->continue_proc = continue_kshow;
	return gs_show_kern;
    }
    return 0;
}
/* Process next character */
private int
show_proceed(register gs_show_enum * penum)
{
    register gs_state *pgs = penum->pgs;
    gs_font *pfont;
    cached_fm_pair *pair = 0;
    gs_font *rfont =
    (penum->fstack.depth < 0 ? pgs->font : penum->fstack.items[0].font);
    int wmode = rfont->WMode;

    font_proc_next_char((*next_char)) = rfont->procs.next_char;
    font_proc_next_glyph((*next_glyph)) = rfont->procs.next_glyph;
#define next_char_glyph(penum, pchr, pglyph)\
    (next_char == 0 ? (*next_glyph)(penum, pchr, pglyph) :\
     (*(pglyph) = gs_no_glyph, (*next_char)(penum, pchr)))
    gs_char chr;
    gs_glyph glyph;
    int code;
    cached_char *cc;
    gx_device *dev = gs_currentdevice_inline(pgs);
    int alpha_bits = (*dev_proc(dev, get_alpha_bits)) (dev, go_text);

    if (penum->charpath_flag == cpm_show && SHOW_IS_DRAWING(penum)) {
	code = gs_state_color_load(pgs);
	if (code < 0)
	    return code;
    }
  more:			/* Proceed to next character */
    pfont = (penum->fstack.depth < 0 ? pgs->font :
	     penum->fstack.items[penum->fstack.depth].font);
    /* can_cache >= 0 allows us to use cached characters, */
    /* even if we can't make new cache entries. */
    if (penum->can_cache >= 0) {
	/* Loop with cache */
	for (;;) {
	    switch ((code = next_char_glyph(penum, &chr, &glyph))) {
		default:	/* error */
		    return code;
		case 2:	/* done */
		    return show_finish(penum);
		case 1:	/* font change */
		    pfont = penum->fstack.items[penum->fstack.depth].font;
		    pgs->char_tm_valid = false;
		    show_state_setup(penum);
		    pair = 0;
		    /* falls through */
		case 0:	/* plain char */
		    /*
		     * We don't need to set penum->current_char in the
		     * normal cases, but it's needed for widthshow,
		     * kshow, and one strange client, so we may as well
		     * do it here.
		     */
		    penum->current_char = chr;
		    if (glyph == gs_no_glyph) {
			glyph = (*penum->encode_char) (penum, pfont, &chr);
			penum->current_char = chr;
			if (glyph == gs_no_glyph) {
			    cc = 0;
			    goto no_cache;
			}
		    }
		    if (pair == 0)
			pair = gx_lookup_fm_pair(pfont, pgs);
		    cc = gx_lookup_cached_char(pfont, pair, glyph, wmode,
					       alpha_bits);
		    if (cc == 0) {
			/* Character is not in cache. */
			/* If possible, try for an xfont before */
			/* rendering from the outline. */
			if (pfont->ExactSize == fbit_use_outlines ||
			    pfont->PaintType == 2
			    )
			    goto no_cache;
			if (pfont->BitmapWidths) {
			    cc = gx_lookup_xfont_char(pgs, pair, chr,
				     glyph, &pfont->procs.callbacks, wmode);
			    if (cc == 0)
				goto no_cache;
			} else {
			    if (!SHOW_IS_DRAWING(penum) != 0 ||
				penum->charpath_flag != cpm_show
				)
				goto no_cache;
			    /* We might have an xfont, but we still */
			    /* want the scalable widths. */
			    cc = gx_lookup_xfont_char(pgs, pair, chr,
				     glyph, &pfont->procs.callbacks, wmode);
			    /* Render up to the point of */
			    /* setcharwidth or setcachedevice, */
			    /* just as for stringwidth. */
			    /* This is the only case in which we can */
			    /* to go no_cache with cc != 0. */
			    goto no_cache;
			}
		    }
		    /* Character is in cache. */
		    /* We might be doing .charboxpath or stringwidth; */
		    /* check for these now. */
		    if (penum->charpath_flag != cpm_show) {
			/* This is .charboxpath.  Get the bounding box */
			/* and append it to a path. */
			gx_path box_path;
			gs_fixed_point pt;
			fixed llx, lly, urx, ury;

			code = gx_path_current_point(pgs->path, &pt);
			if (code < 0)
			    return code;
			llx = fixed_rounded(pt.x - cc->offset.x) +
			    int2fixed(penum->ftx);
			lly = fixed_rounded(pt.y - cc->offset.y) +
			    int2fixed(penum->fty);
			urx = llx + int2fixed(cc->width),
			    ury = lly + int2fixed(cc->height);
			gx_path_init_local(&box_path, pgs->memory);
			code =
			    gx_path_add_rectangle(&box_path, llx, lly,
						  urx, ury);
			if (code >= 0)
			    code =
				gx_path_add_char_path(pgs->show_gstate->path,
						      &box_path,
						      penum->charpath_flag);
			if (code >= 0)
			    code = gx_path_add_point(pgs->path, pt.x, pt.y);
			gx_path_free(&box_path, "show_proceed(box path)");
			if (code < 0)
			    return code;
		    } else if (SHOW_IS_DRAWING(penum)) {
			code = gx_image_cached_char(penum, cc);
			if (code < 0)
			    return code;
			else if (code > 0) {
			    cc = 0;
			    goto no_cache;
			}
		    }
		    if (SHOW_IS_SLOW(penum)) {
			/* Split up the assignment so that the */
			/* Watcom compiler won't reserve esi/edi. */
			penum->wxy.x = cc->wxy.x;
			penum->wxy.y = cc->wxy.y;
			code = show_move(penum);
		    } else
			code = show_fast_move(pgs, &cc->wxy);
		    if (code) {
			/* Might be kshow, so store the state. */
			penum->current_glyph = glyph;
			return code;
		    }
	    }
	}
    } else {
	/* Can't use cache */
	switch ((code = next_char_glyph(penum, &chr, &glyph))) {
	    default:
		return code;
	    case 2:
		return show_finish(penum);
	    case 1:
		pfont = penum->fstack.items[penum->fstack.depth].font;
		show_state_setup(penum);
	    case 0:
		;
	}
	penum->current_char = chr;
	if (glyph == gs_no_glyph) {
	    glyph = (*penum->encode_char) (penum, pfont, &chr);
	    penum->current_char = chr;
	}
	cc = 0;
    }
  no_cache:
    /*
     * We must call the client's rendering code.  Normally,
     * we only do this if the character is not cached (cc = 0);
     * however, we also must do this if we have an xfont but
     * are using scalable widths.  In this case, and only this case,
     * we get here with cc != 0.  penum->current_char has already
     * been set, but not penum->current_glyph.
     */
    penum->current_glyph = glyph;
    if ((code = gs_gsave(pgs)) < 0)
	return code;
    /* Set the font to the current descendant font. */
    pgs->font = pfont;
    /* Reset the in_cachedevice flag, so that a recursive show */
    /* will use the cache properly. */
    pgs->in_cachedevice = 0;
    /* Reset the sampling scale. */
    penum->log2_current_scale.x = penum->log2_current_scale.y = 0;
    /* Set the charpath data in the graphics context if necessary, */
    /* so that fill and stroke will add to the path */
    /* rather than having their usual effect. */
    pgs->in_charpath = penum->charpath_flag;
    pgs->show_gstate =
	(penum->show_gstate == pgs ? pgs->saved : penum->show_gstate);
    pgs->stroke_adjust = false;	/* per specification */
    {
	gs_fixed_point cpt;
	gx_path *ppath = pgs->path;

	if ((code = gx_path_current_point_inline(ppath, &cpt)) < 0)
	    goto rret;
	penum->origin.x = cpt.x;
	penum->origin.y = cpt.y;
	/* Normally, char_tm is valid because of show_state_setup, */
	/* but if we're in a cshow, it may not be. */
	gs_currentcharmatrix(pgs, NULL, true);
#if 1				/*USE_FPU <= 0 */
	if (pgs->ctm.txy_fixed_valid && pgs->char_tm.txy_fixed_valid) {
	    fixed tx = pgs->ctm.tx_fixed;
	    fixed ty = pgs->ctm.ty_fixed;

	    gs_settocharmatrix(pgs);
	    cpt.x += pgs->ctm.tx_fixed - tx;
	    cpt.y += pgs->ctm.ty_fixed - ty;
	} else
#endif
	{
	    double tx = pgs->ctm.tx;
	    double ty = pgs->ctm.ty;
	    double fpx, fpy;

	    gs_settocharmatrix(pgs);
	    fpx = fixed2float(cpt.x) + (pgs->ctm.tx - tx);
	    fpy = fixed2float(cpt.y) + (pgs->ctm.ty - ty);
#define f_fits_in_fixed(f) f_fits_in_bits(f, fixed_int_bits)
	    if (!(f_fits_in_fixed(fpx) && f_fits_in_fixed(fpy))) {
		gs_note_error(code = gs_error_limitcheck);
		goto rret;
	    }
	    cpt.x = float2fixed(fpx);
	    cpt.y = float2fixed(fpy);
	}
	gs_newpath(pgs);
	code = show_origin_setup(pgs, cpt.x, cpt.y,
				 penum->charpath_flag);
	if (code < 0)
	    goto rret;
    }
    penum->width_status = sws_none;
    penum->continue_proc = continue_show_update;
    /* Try using the build procedure in the font. */
    /* < 0 means error, 0 means success, 1 means failure. */
    penum->cc = cc;		/* set this now for build procedure */
    code = (*pfont->procs.build_char) (penum, pgs, pfont, chr, glyph);
    if (code < 0) {
	discard(gs_note_error(code));
	goto rret;
    }
    if (code == 0) {
	code = show_update(penum);
	if (code < 0)
	    goto rret;
	/* Note that show_update does a grestore.... */
	code = show_move(penum);
	if (code)
	    return code;	/* ... so don't go to rret here. */
	goto more;
    }
    /*
     * Some BuildChar procedures do a save before the setcachedevice,
     * and a restore at the end.  If we waited to allocate the cache
     * device until the setcachedevice, we would attempt to free it
     * after the restore.  Therefore, allocate it now.
     */
    if (penum->dev_cache == 0) {
	code = show_cache_setup(penum);
	if (code < 0)
	    goto rret;
    }
    return gs_show_render;
    /* If we get an error while setting up for BuildChar, */
    /* we must undo the partial setup. */
  rret:gs_grestore(pgs);
    return code;
#undef next_char_glyph
}

/* Finish show or stringwidth */
private int
show_finish(gs_show_enum * penum)
{
    gs_state *pgs = penum->pgs;
    int code, rcode;

    gs_show_enum_release(penum, NULL);
    if (!SHOW_IS_STRINGWIDTH(penum))
	return 0;
    /* Save the accumulated width before returning, */
    /* and undo the extra gsave. */
    code = gs_currentpoint(pgs, &penum->width);
    rcode = gs_grestore(pgs);
    return (code < 0 ? code : rcode);
}

/* Return the current character for rendering. */
gs_char
gs_show_current_char(const gs_show_enum * penum)
{
    return penum->current_char;
}

/* Return the current glyph for rendering. */
gs_glyph
gs_show_current_glyph(const gs_show_enum * penum)
{
    return penum->current_glyph;
}

/* Return the width of the just-enumerated character (for cshow). */
int
gs_show_current_width(const gs_show_enum * penum, gs_point * ppt)
{
    return gs_idtransform(penum->pgs,
			  fixed2float(penum->wxy.x),
			  fixed2float(penum->wxy.y), ppt);
}

/* Return the just-displayed character for kerning. */
gs_char
gs_kshow_previous_char(const gs_show_enum * penum)
{
    return penum->current_char;
}

/* Return the about-to-be-displayed character for kerning. */
gs_char
gs_kshow_next_char(const gs_show_enum * penum)
{
    return penum->text.data.bytes[penum->index];
}

/* ------ Miscellaneous accessors ------ */

/* Return the current font for cshow. */
gs_font *
gs_show_current_font(const gs_show_enum * penum)
{
    return (penum->fstack.depth < 0 ? penum->pgs->font :
	    penum->fstack.items[penum->fstack.depth].font);
}

/* Restore the current font after cshow. */
int
gs_show_restore_font(const gs_show_enum * penum)
{
    int fdepth = penum->fstack.depth;

    if (fdepth >= 0) {
	gs_state *pgs = penum->pgs;

	gs_setfont(pgs, penum->fstack.items[0].font);
	pgs->font = penum->fstack.items[fdepth].font;
    }
    return 0;
}

/* Return the charpath mode. */
gs_char_path_mode
gs_show_in_charpath(const gs_show_enum * penum)
{
    return penum->charpath_flag;
}

/* Return the accumulated width for stringwidth. */
void
gs_show_width(const gs_show_enum * penum, gs_point * ppt)
{
    *ppt = penum->width;
}

/* 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 meaningful just before calling gs_setcharwidth or */
/* gs_setcachedevice[2]. */
/* Note that we can't do this if the procedure has done any extra [g]saves. */
bool
gs_show_width_only(const gs_show_enum * penum)
{
    /* penum->cc will be non-zero iff we are calculating */
    /* the scalable width for an xfont character. */
    return ((!SHOW_IS_DRAWING(penum) || penum->cc != 0) &&
	    penum->pgs->level == penum->level + 1);
}

/* ------ Internal routines ------ */

/* Initialize a show enumerator. */
private int
show_setup(register gs_show_enum * penum, gs_state * pgs, const char *str,
	   uint size, uint operation, bool propagate_charpath)
{
    int code;
    gs_font *pfont;

    /* Set rest of common members. */
    penum->text.operation = operation;
    penum->text.data.bytes = (const byte *)str;		/* avoid signed chars */
    penum->text.size = size;
    penum->index = 0;
    /* Set other members. */
    gx_set_dev_color(pgs);
    pfont = pgs->font;
    penum->pgs = pgs;
    penum->level = pgs->level;
    if (operation & TEXT_DO_ANY_CHARPATH)
	penum->charpath_flag =
	    (operation & TEXT_DO_FALSE_CHARPATH ? cpm_false_charpath :
	     operation & TEXT_DO_TRUE_CHARPATH ? cpm_true_charpath :
	     operation & TEXT_DO_FALSE_CHARBOXPATH ? cpm_false_charboxpath :
	     operation & TEXT_DO_TRUE_CHARBOXPATH ? cpm_true_charboxpath :
	     cpm_show /* can't happen */ );
    else
	penum->charpath_flag =
	    (propagate_charpath ? pgs->in_charpath : cpm_show);
    penum->dev_cache = 0;
    penum->dev_cache2 = 0;
    penum->dev_null = 0;
    penum->cc = 0;
    penum->continue_proc = continue_show;
    code = (*pfont->procs.init_fstack) (penum, pfont);
    if (code < 0)
	return code;
    penum->can_cache =		/* show_state_setup may reset */
	(penum->charpath_flag == cpm_show ? 1 : -1);
    code = show_state_setup(penum);
    if (code < 0)
	return code;
    penum->show_gstate =
	(propagate_charpath && (pgs->in_charpath != 0) ?
	 pgs->show_gstate : pgs);
    return 0;
}

/* Initialize the gstate-derived parts of a show enumerator. */
/* We do this both when starting the show operation, */
/* and when returning from the kshow callout. */
private int
show_state_setup(gs_show_enum * penum)
{
    gs_state *pgs = penum->pgs;
    gx_clip_path *pcpath;
    const gs_font *pfont;

    if (penum->fstack.depth <= 0) {
	pfont = pgs->font;
	gs_currentcharmatrix(pgs, NULL, 1);	/* make char_tm valid */
    } else {
	/* We have to concatenate the parent's FontMatrix as well. */
	gs_matrix mat;
	const gx_font_stack_item *pfsi =
	&penum->fstack.items[penum->fstack.depth];

	pfont = pfsi->font;
	gs_matrix_multiply(&pfont->FontMatrix,
			   &pfsi[-1].font->FontMatrix, &mat);
	gs_setcharmatrix(pgs, &mat);
    }
    /* Skewing or non-rectangular rotation are not supported. */
    if (!CACHE_ROTATED_CHARS &&
	(is_fzero2(pgs->char_tm.xy, pgs->char_tm.yx) ||
	 is_fzero2(pgs->char_tm.xx, pgs->char_tm.yy))
	)
	penum->can_cache = 0;
    if (penum->can_cache >= 0 &&
	gx_effective_clip_path(pgs, &pcpath) >= 0
	) {
	gs_fixed_rect cbox;

	gx_cpath_inner_box(pcpath, &cbox);
	/* Since characters occupy an integral number of pixels, */
	/* we can (and should) round the inner clipping box */
	/* outward rather than inward. */
	penum->ibox.p.x = fixed2int_var(cbox.p.x);
	penum->ibox.p.y = fixed2int_var(cbox.p.y);
	penum->ibox.q.x = fixed2int_var_ceiling(cbox.q.x);
	penum->ibox.q.y = fixed2int_var_ceiling(cbox.q.y);
	gx_cpath_outer_box(pcpath, &cbox);
	penum->obox.p.x = fixed2int_var(cbox.p.x);
	penum->obox.p.y = fixed2int_var(cbox.p.y);
	penum->obox.q.x = fixed2int_var_ceiling(cbox.q.x);
	penum->obox.q.y = fixed2int_var_ceiling(cbox.q.y);
#if 1				/*USE_FPU <= 0 */
	if (pgs->ctm.txy_fixed_valid && pgs->char_tm.txy_fixed_valid) {
	    penum->ftx = (int)fixed2long(pgs->char_tm.tx_fixed -
					 pgs->ctm.tx_fixed);
	    penum->fty = (int)fixed2long(pgs->char_tm.ty_fixed -
					 pgs->ctm.ty_fixed);
	} else {
#endif
	    double fdx = pgs->char_tm.tx - pgs->ctm.tx;
	    double fdy = pgs->char_tm.ty - pgs->ctm.ty;

#define int_bits (arch_sizeof_int * 8 - 1)
	    if (!(f_fits_in_bits(fdx, int_bits) &&
		  f_fits_in_bits(fdy, int_bits))
		)
		return_error(gs_error_limitcheck);
#undef int_bits
	    penum->ftx = (int)fdx;
	    penum->fty = (int)fdy;
	}
    }
    penum->encode_char = pfont->procs.encode_char;
    return 0;
}

/* Set the suggested oversampling scale for character rendering. */
private void
show_set_scale(gs_show_enum * penum)
{
    /*
     * Decide whether to oversample.
     * We have to decide this each time setcachedevice is called.
     */
    const gs_state *pgs = penum->pgs;

    if (penum->charpath_flag == cpm_show &&
	SHOW_IS_DRAWING(penum) &&
	gx_path_is_void_inline(pgs->path) &&
    /* Oversampling rotated characters doesn't work well. */
	(is_fzero2(pgs->char_tm.xy, pgs->char_tm.yx) ||
	 is_fzero2(pgs->char_tm.xx, pgs->char_tm.yy))
	) {
	const gs_font_base *pfont = (gs_font_base *) pgs->font;
	gs_fixed_point extent;
	int code = gs_distance_transform2fixed(&pgs->char_tm,
				  pfont->FontBBox.q.x - pfont->FontBBox.p.x,
				  pfont->FontBBox.q.y - pfont->FontBBox.p.y,
					       &extent);

	if (code >= 0) {
	    int sx =
	    (extent.x == 0 ? 0 :
	     any_abs(extent.x) < int2fixed(25) ? 2 :
	     any_abs(extent.x) < int2fixed(60) ? 1 :
	     0);
	    int sy =
	    (extent.y == 0 ? 0 :
	     any_abs(extent.y) < int2fixed(25) ? 2 :
	     any_abs(extent.y) < int2fixed(60) ? 1 :
	     0);

	    /* If we oversample at all, make sure we do it */
	    /* in both X and Y. */
	    if (sx == 0 && sy != 0)
		sx = 1;
	    else if (sy == 0 && sx != 0)
		sy = 1;
	    penum->log2_suggested_scale.x = sx;
	    penum->log2_suggested_scale.y = sy;
	    return;
	}
    }
    /* By default, don't scale. */
    penum->log2_suggested_scale.x =
	penum->log2_suggested_scale.y = 0;
}

/* Set up the cache device and related information. */
/* Note that we always allocate both cache devices, */
/* even if we only use one of them. */
private int
show_cache_setup(gs_show_enum * penum)
{
    gs_state *pgs = penum->pgs;
    gs_memory_t *mem = pgs->memory;
    gx_device_memory *dev =
    gs_alloc_struct(mem, gx_device_memory, &st_device_memory,
		    "show_cache_setup(dev_cache)");
    gx_device_memory *dev2 =
    gs_alloc_struct(mem, gx_device_memory, &st_device_memory,
		    "show_cache_setup(dev_cache2)");

    if (dev == 0 || dev2 == 0) {
	gs_free_object(mem, dev2, "show_cache_setup(dev_cache2)");
	gs_free_object(mem, dev, "show_cache_setup(dev_cache)");
	return_error(gs_error_VMerror);
    }
    /*
     * We only initialize the device for the sake of the GC,
     * (since we have to re-initialize it as either a mem_mono
     * or a mem_abuf device before actually using it) and also
     * to set its memory pointer.
     */
    gs_make_mem_mono_device(dev, mem, gs_currentdevice_inline(pgs));
    penum->dev_cache = dev;
    penum->dev_cache2 = dev2;
    /* Initialize dev2 for the sake of the GC. */
    *dev2 = *dev;
    /* Account for the extra references from the enumerator. */
    rc_increment(dev);
    rc_increment(dev2);
    return 0;
}

/* Set the character origin as the origin of the coordinate system. */
/* Used before rendering characters, and for moving the origin */
/* in setcachedevice2 when WMode=1. */
private int
show_origin_setup(gs_state * pgs, fixed cpt_x, fixed cpt_y,
		  gs_char_path_mode charpath_flag)
{
    if (charpath_flag == cpm_show) {
	/* Round the translation in the graphics state. */
	/* This helps prevent rounding artifacts later. */
	cpt_x = fixed_rounded(cpt_x);
	cpt_y = fixed_rounded(cpt_y);
    }
    /*
     * BuildChar procedures expect the current point to be undefined,
     * so we omit the gx_path_add_point with ctm.t*_fixed.
     */
    return gx_translate_to_fixed(pgs, cpt_x, cpt_y);
}

/* Default fstack initialization procedure. */
int
gs_default_init_fstack(gs_show_enum * penum, gs_font * pfont)
{
    penum->fstack.depth = -1;
    return 0;
}

/* Default next-character procedure. */
int
gs_default_next_char(gs_show_enum * penum, gs_char * pchr)
{
    gs_glyph ignore_glyph;

    return gs_default_next_glyph(penum, pchr, &ignore_glyph);
}

/* Default next-glyph procedure. */
int
gs_default_next_glyph(gs_show_enum * penum, gs_char * pchr, gs_glyph * pglyph)
{
    if (penum->index == penum->text.size)
	return 2;
    *pchr = penum->text.data.bytes[penum->index++];
    *pglyph = gs_no_glyph;
    return 0;
}
