path: root/base/gstext.c

/* Copyright (C) 2001-2020 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.,  1305 Grant Avenue - Suite 200, Novato,
   CA 94945, U.S.A., +1(415)492-9861, for further information.
*/


/* Driver text interface support */

#include "memory_.h"
#include "gstypes.h"
#include "gdebug.h"
#include "gserrors.h"
#include "gsmemory.h"
#include "gsstruct.h"
#include "gstypes.h"
#include "gxfcache.h"
#include "gxdevcli.h"
#include "gxdcolor.h"		/* for gs_gstate_color_load */
#include "gxfont.h"		/* for init_fstack */
#include "gxpath.h"
#include "gxtext.h"
#include "gzstate.h"
#include "gsutil.h"
#include "gxdevsop.h"

/* GC descriptors */
public_st_gs_text_params();
public_st_gs_text_enum();

static
ENUM_PTRS_WITH(text_params_enum_ptrs, gs_text_params_t *tptr) return 0;
case 0:
if (tptr->operation & TEXT_FROM_STRING) {
    return ENUM_CONST_STRING2(tptr->data.bytes, tptr->size);
}
if (tptr->operation & TEXT_FROM_BYTES)
    return ENUM_OBJ(tptr->data.bytes);
if (tptr->operation & TEXT_FROM_CHARS)
    return ENUM_OBJ(tptr->data.chars);
if (tptr->operation & TEXT_FROM_GLYPHS)
    return ENUM_OBJ(tptr->data.glyphs);
return ENUM_OBJ(NULL);
case 1:
return ENUM_OBJ(tptr->operation & TEXT_REPLACE_WIDTHS ?
                tptr->x_widths : NULL);
case 2:
return ENUM_OBJ(tptr->operation & TEXT_REPLACE_WIDTHS ?
                tptr->y_widths : NULL);
ENUM_PTRS_END
static RELOC_PTRS_WITH(text_params_reloc_ptrs, gs_text_params_t *tptr)
{
    if (tptr->operation & TEXT_FROM_STRING) {
        gs_const_string str;

        str.data = tptr->data.bytes;
        str.size = tptr->size;
        RELOC_CONST_STRING_VAR(str);
        tptr->data.bytes = str.data;
    } else if (tptr->operation & TEXT_FROM_BYTES)
        RELOC_OBJ_VAR(tptr->data.bytes);
    else if (tptr->operation & TEXT_FROM_CHARS)
        RELOC_OBJ_VAR(tptr->data.chars);
    else if (tptr->operation & TEXT_FROM_GLYPHS)
        RELOC_OBJ_VAR(tptr->data.glyphs);
    if (tptr->operation & TEXT_REPLACE_WIDTHS) {
        RELOC_OBJ_VAR(tptr->x_widths);
        RELOC_OBJ_VAR(tptr->y_widths);
    }
}
RELOC_PTRS_END

static ENUM_PTRS_WITH(text_enum_enum_ptrs, gs_text_enum_t *eptr)
{
    if (index == 8) {
        if (eptr->pair != 0)
            ENUM_RETURN(eptr->pair - eptr->pair->index);
        else
            ENUM_RETURN(0);
    }
    index -= 9;
    if (index <= eptr->fstack.depth)
        ENUM_RETURN(eptr->fstack.items[index].font);
    index -= eptr->fstack.depth + 1;
     return ENUM_USING(st_gs_text_params, &eptr->text, sizeof(eptr->text), index);
}
case 0: return ENUM_OBJ(gx_device_enum_ptr(eptr->dev));
case 1: return ENUM_OBJ(gx_device_enum_ptr(eptr->imaging_dev));
ENUM_PTR3(2, gs_text_enum_t, pgs, orig_font, path);
ENUM_PTR3(5, gs_text_enum_t, pdcolor, pcpath, current_font);
ENUM_PTRS_END

static RELOC_PTRS_WITH(text_enum_reloc_ptrs, gs_text_enum_t *eptr)
{
    int i;

    RELOC_USING(st_gs_text_params, &eptr->text, sizeof(eptr->text));
    eptr->dev = gx_device_reloc_ptr(eptr->dev, gcst);
    eptr->imaging_dev = gx_device_reloc_ptr(eptr->imaging_dev, gcst);
    RELOC_PTR3(gs_text_enum_t, pgs, orig_font, path);
    RELOC_PTR3(gs_text_enum_t, pdcolor, pcpath, current_font);
    if (eptr->pair != NULL)
        eptr->pair = (cached_fm_pair *)RELOC_OBJ(eptr->pair - eptr->pair->index) +
                             eptr->pair->index;
    for (i = 0; i <= eptr->fstack.depth; i++)
        RELOC_PTR(gs_text_enum_t, fstack.items[i].font);
}
RELOC_PTRS_END

/* Begin processing text. */
int
gx_device_text_begin(gx_device * dev, gs_gstate * pgs,
                     const gs_text_params_t * text, gs_font * font,
                     gx_path * path,	/* unless DO_NONE & !RETURN_WIDTH */
                     const gx_device_color * pdcolor,	/* DO_DRAW */
                     const gx_clip_path * pcpath,	/* DO_DRAW */
                     gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    if (TEXT_PARAMS_ARE_INVALID(text))
        return_error(gs_error_rangecheck);
    {
        gx_path *tpath =
            ((text->operation & TEXT_DO_NONE) &&
             !(text->operation & TEXT_RETURN_WIDTH) ? 0 : path);
        const gx_clip_path *tcpath =
            (text->operation & TEXT_DO_DRAW ? pcpath : 0);

        /* A high level device need to know an initial device color
           for accumulates a charstring of a Type 3 font.
           Since the accumulation may happen while stringwidth.
           we pass the device color unconditionally. */
        return dev_proc(dev, text_begin)
            (dev, pgs, text, font, tpath, pdcolor, tcpath, mem, ppte);
    }
}

/*
 * Initialize a newly created text enumerator.  Implementations of
 * text_begin must call this just after allocating the enumerator.
 */
static int
gs_text_enum_init_dynamic(gs_text_enum_t *pte, gs_font *font)
{
    uint operation = pte->text.operation;
    bool propagate_charpath = (operation & TEXT_DO_DRAW) != 0;

    pte->current_font = font;
    pte->index = 0;
    pte->xy_index = 0;
    pte->FontBBox_as_Metrics2.x = pte->FontBBox_as_Metrics2.y = 0;
    pte->pair = 0;
    pte->device_disabled_grid_fitting = 0;
    pte->outer_CID = GS_NO_GLYPH;
    pte->single_byte_space = false;
    pte->cc = NULL;

    /* We need to set the charpath_flag, as the PCL interpreter calls the
     * graphics lib to do some measurement operations, which relies on the
     * charpath_flag. See bug 700577 for more details. */
    if (operation & TEXT_DO_ANY_CHARPATH)
        pte->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 :
             operation & TEXT_DO_CHARWIDTH ? cpm_charwidth :
             cpm_show /* can't happen */ );
    else
        pte->charpath_flag =
        (propagate_charpath ? (pte->pgs ? pte->pgs->in_charpath : 0) : cpm_show);
    pte->is_pure_color = pte->pgs ? gs_color_writes_pure(pte->pgs) : 0;

    return font->procs.init_fstack(pte, font);
}
int
gs_text_enum_init(gs_text_enum_t *pte, const gs_text_enum_procs_t *procs,
                  gx_device *dev, gs_gstate *pgs,
                  const gs_text_params_t *text, gs_font *font, gx_path *path,
                  const gx_device_color *pdcolor, const gx_clip_path *pcpath,
                  gs_memory_t *mem)
{
    int code;

    pte->text = *text;
    pte->dev = dev;
    pte->imaging_dev = NULL;
    pte->pgs = pgs;
    pte->orig_font = font;
    pte->path = path;
    pte->pdcolor = pdcolor;
    pte->pcpath = pcpath;
    pte->memory = mem;
    pte->procs = procs;
#ifdef DEBUG
    pte->text_enum_id = gs_next_text_enum_id(font);
#else
    pte->text_enum_id = 0;
#endif
    pte->enum_client_data = NULL;
    /* text_begin procedure sets rc */
    /* init_dynamic sets current_font */

    pte->log2_scale.x = pte->log2_scale.y = 0;
    /* init_dynamic sets index, xy_index, fstack */
    code = gs_text_enum_init_dynamic(pte, font);
    if (code >= 0)
        rc_increment(dev);
    return code;
}

gs_text_enum_t *
gs_text_enum_alloc(gs_memory_t * mem, gs_gstate * pgs, client_name_t cname)
{
    gs_text_enum_t *penum;

    rc_alloc_struct_1(penum, gs_text_enum_t, &st_gs_text_enum, mem,
                      return 0, cname);
    penum->rc.free = rc_free_text_enum;

    /* Initialize pointers for GC */
    penum->text.operation = 0;  /* no pointers relevant */
    penum->dev = 0;
    penum->pgs = pgs;
    penum->fapi_log2_scale.x = penum->fapi_log2_scale.y = -1;
    penum->fapi_glyph_shift.x = penum->fapi_glyph_shift.y = 0;
    penum->fstack.depth = -1;
    return penum;
}

/*
 * Copy the dynamically changing elements from one enumerator to another.
 * This is useful primarily for enumerators that sometimes pass the
 * operation to a subsidiary enumerator.
 */
void
gs_text_enum_copy_dynamic(gs_text_enum_t *pto, const gs_text_enum_t *pfrom,
                          bool for_return)
{
    int depth = pfrom->fstack.depth;

    pto->current_font = pfrom->current_font;
    pto->index = pfrom->index;
    pto->bytes_decoded = pfrom->bytes_decoded;
    pto->xy_index = pfrom->xy_index;
    pto->fstack.depth = depth;
    pto->FontBBox_as_Metrics2 = pfrom->FontBBox_as_Metrics2;
    pto->pair = pfrom->pair;
    pto->device_disabled_grid_fitting = pfrom->device_disabled_grid_fitting;
    pto->outer_CID = pfrom->outer_CID;
    if (depth >= 0)
        memcpy(pto->fstack.items, pfrom->fstack.items,
               (depth + 1) * sizeof(pto->fstack.items[0]));
    if (for_return) {
        pto->cmap_code = pfrom->cmap_code;
        pto->returned = pfrom->returned;
    }
}

/* Begin processing text based on a graphics state. */
int
gs_text_begin(gs_gstate * pgs, const gs_text_params_t * text,
              gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gx_clip_path *pcpath = 0;
    int code;
    gs_overprint_params_t op_params = { 0 };
    bool op_active = dev_proc(pgs->device, dev_spec_op)(pgs->device, gxdso_overprint_active, NULL, 0);
    bool text_op_fill = ((pgs->overprint || (!pgs->overprint && op_active)) &&
        (pgs->text_rendering_mode == 0));
    bool text_op_stroke = ((pgs->stroke_overprint || (!pgs->stroke_overprint && op_active)) &&
        (pgs->text_rendering_mode == 1));

    /*
     * Detect nocurrentpoint now, even if the string is empty, for Adobe
     * compatibility.
     */
    if (text->operation & (TEXT_DO_DRAW | TEXT_DO_ANY_CHARPATH)) {
        if (!pgs->current_point_valid)
            return_error(gs_error_nocurrentpoint);
    }
    /* Detect zero FontNatrix now for Adobe compatibility with CET tests.
       Note that matrixe\\ces like [1 0 0 0 0 0] are used in comparefiles
       to compute a text width.
       Note : FontType 3 throws error in setcachedevice. */
    if (pgs->font->FontType != ft_user_defined &&
        pgs->font->FontType != ft_PDF_user_defined &&
        pgs->font->FontType != ft_GL2_stick_user_defined &&
        pgs->font->FontType != ft_PCL_user_defined &&
        pgs->font->FontMatrix.xx == 0 && pgs->font->FontMatrix.xy == 0 &&
        pgs->font->FontMatrix.yx == 0 && pgs->font->FontMatrix.yy == 0)
        return_error(gs_error_undefinedresult); /* sic! : CPSI compatibility */
    if (text->operation & TEXT_DO_DRAW) {
        code = gx_effective_clip_path(pgs, &pcpath);
        if (code < 0)
            return code;
    }
    /* We must load device color even with no TEXT_DO_DRAW,
       because a high level device accumulates a charstring
       of a Type 3 font while stringwidth.
       Unfortunately we can't effectively know a leaf font type here,
       so we load the color unconditionally . */
    /* Processing a text object operation */
    ensure_tag_is_set(pgs, pgs->device, GS_TEXT_TAG);	/* NB: may unset_dev_color */

    code = gx_set_dev_color(pgs);
    if (code != 0)
        return code;
    code = gs_gstate_color_load(pgs);
    if (code < 0)
        return code;

    if (text_op_stroke) {
        if_debug0m(gs_debug_flag_overprint, pgs->memory,
            "[overprint] Stroke Text Overprint\n");
        code = gs_do_set_overprint(pgs);
        if (code < 0)
            return code;
    } else if (text_op_fill) {
        if_debug0m(gs_debug_flag_overprint, pgs->memory,
            "[overprint] Fill Text Overprint\n");
        code = gs_do_set_overprint(pgs);
        if (code < 0)
            return code;
    }

    /* If overprint is true, push the compositor action to set the op device state */
    if ((pgs->overprint  && pgs->text_rendering_mode == 0) ||
        (pgs->stroke_overprint && pgs->text_rendering_mode == 1) ||
        op_active) {
        gx_device* dev = pgs->device;
        cmm_dev_profile_t* dev_profile;

        dev_proc(dev, get_profile)(dev, &dev_profile);
        if (dev_profile->sim_overprint && 
            (dev_profile->device_profile[GS_DEFAULT_DEVICE_PROFILE]->data_cs == gsCMYK ||
             dev_profile->device_profile[GS_DEFAULT_DEVICE_PROFILE]->data_cs == gsNCHANNEL)) {
            if (pgs->text_rendering_mode == 0) {
                op_params.op_state = OP_STATE_FILL;
                gs_gstate_update_overprint(pgs, &op_params);
            } else if (pgs->text_rendering_mode == 1) {
                op_params.op_state = OP_STATE_STROKE;
                gs_gstate_update_overprint(pgs, &op_params);
            }
        }
    }

    pgs->device->sgr.stroke_stored = false;
    return gx_device_text_begin(pgs->device, pgs,
                                text, pgs->font, pgs->path,
                                gs_currentdevicecolor_inline(pgs),
                                pcpath, mem, ppte);
}

/*
 * Update the device color to be used with text (because a kshow or
 * cshow procedure may have changed the current color).
 */
int
gs_text_update_dev_color(gs_gstate * pgs, gs_text_enum_t * pte)
{
    /*
     * The text enumerator holds a device color pointer, which may be a
     * null pointer or a pointer to the same device color as the graphic
     * state points to. In the former case the text is not to be
     * rendered, and hence of no interest here. In the latter case the
     * update of the graphic state color will update the text color as
     * well.
     */
    /* Processing a text object operation */
    ensure_tag_is_set(pgs, pgs->device, GS_TEXT_TAG);	/* NB: may unset_dev_color */

    if (pte->pdcolor != 0) {
        int code = gx_set_dev_color(pgs);
        if (code != 0)
            return code;
    }
    return 0;
}

static inline uint text_do_draw(gs_gstate * pgs)
{
    return (pgs->text_rendering_mode == 3 ?
        TEXT_DO_NONE | TEXT_RENDER_MODE_3 : TEXT_DO_DRAW);
}

/* Begin PostScript-equivalent text operations. */
int
gs_show_begin(gs_gstate * pgs, const byte * str, uint size,
              gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;

    text.operation = TEXT_FROM_STRING | text_do_draw(pgs) | TEXT_RETURN_WIDTH;
    text.data.bytes = str, text.size = size;
    return gs_text_begin(pgs, &text, mem, ppte);
}
int
gs_ashow_begin(gs_gstate * pgs, double ax, double ay, const byte * str, uint size,
               gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;

    text.operation = TEXT_FROM_STRING | TEXT_ADD_TO_ALL_WIDTHS |
        text_do_draw(pgs) | TEXT_RETURN_WIDTH;
    text.data.bytes = str, text.size = size;
    text.delta_all.x = ax;
    text.delta_all.y = ay;
    return gs_text_begin(pgs, &text, mem, ppte);
}
int
gs_widthshow_begin(gs_gstate * pgs, double cx, double cy, gs_char chr,
                   const byte * str, uint size,
                   gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;

    text.operation = TEXT_FROM_STRING | TEXT_ADD_TO_SPACE_WIDTH |
        text_do_draw(pgs) | TEXT_RETURN_WIDTH;
    text.data.bytes = str, text.size = size;
    text.delta_space.x = cx;
    text.delta_space.y = cy;
    text.space.s_char = chr;
    return gs_text_begin(pgs, &text, mem, ppte);
}
int
gs_awidthshow_begin(gs_gstate * pgs, double cx, double cy, gs_char chr,
                    double ax, double ay, const byte * str, uint size,
                    gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;

    text.operation = TEXT_FROM_STRING |
        TEXT_ADD_TO_ALL_WIDTHS | TEXT_ADD_TO_SPACE_WIDTH |
        text_do_draw(pgs) | TEXT_RETURN_WIDTH;
    text.data.bytes = str, text.size = size;
    text.delta_space.x = cx;
    text.delta_space.y = cy;
    text.space.s_char = chr;
    text.delta_all.x = ax;
    text.delta_all.y = ay;
    return gs_text_begin(pgs, &text, mem, ppte);
}
int
gs_kshow_begin(gs_gstate * pgs, const byte * str, uint size,
               gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;

    /* Detect degenerate CTM now for Adobe compatibility with CET 13-12-4. */
    if (pgs->ctm.xx * pgs->ctm.yy - pgs->ctm.yx * pgs->ctm.xy == 0)
        return_error(gs_error_undefinedresult); /* sic! : CPSI compatibility */
    text.operation = TEXT_FROM_STRING | text_do_draw(pgs) | TEXT_INTERVENE |
        TEXT_RETURN_WIDTH;
    text.data.bytes = str, text.size = size;
    return gs_text_begin(pgs, &text, mem, ppte);
}

/* Retrieve text params from enumerator. */
gs_text_params_t *
gs_get_text_params(gs_text_enum_t *pte)
{
    return &pte->text;
}

int
gs_xyshow_begin(gs_gstate * pgs, const byte * str, uint size,
                const float *x_widths, const float *y_widths,
                uint widths_size, gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;
    uint widths_needed;
    int code;

    text.operation = TEXT_FROM_STRING | TEXT_REPLACE_WIDTHS |
        text_do_draw(pgs) | TEXT_RETURN_WIDTH;
    text.data.bytes = str, text.size = size;
    text.x_widths = x_widths;
    text.y_widths = y_widths;
    text.widths_size = widths_size;

    /*
     * Check that the widths array is large enough.  gs_text_replaced_width
     * checks this step-by-step, but Adobe's interpreters check it ahead of
     * time, and for CET compliance, we must also.  This is very easy for
     * font types that always have 8-bit characters, but for others, we
     * must use the font's next_char_glyph procedure to determine how many
     * characters there are in the string.
     */
    code = gs_text_count_chars(pgs, &text, mem);
    if (code < 0)
        return code;
    widths_needed = code;
    if (x_widths && y_widths)
        widths_needed <<= 1;
    if (widths_size < widths_needed)
        return_error(gs_error_rangecheck);
    return gs_text_begin(pgs, &text, mem, ppte);
}

static void
setup_FontBBox_as_Metrics2 (gs_text_enum_t * pte, gs_font * pfont)
{
    /* When we exec a operator like `show' that has a a chance to get
       a glyph from a char, we can set FontBBox_as_Metrics2 in
       gschar0.c:gs_type0_next_char_glyph.  In other hand, when we
       exec a operator like `glyphshow' that get a glyph directly from
       an input file, gschar0.c:gs_type0_next_char_glyph is exec'ed.
       For the later case, we set up FontBBox_as_Metrics2 with using
       this procedure.. */
    if (pfont->FontType == ft_CID_encrypted
        || pfont->FontType == ft_CID_TrueType)
        pte->FontBBox_as_Metrics2 = ((gs_font_base *)pfont)->FontBBox.q;
}

int
gs_glyphshow_begin(gs_gstate * pgs, gs_glyph glyph,
                   gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;
    int result;

    text.operation = TEXT_FROM_SINGLE_GLYPH | text_do_draw(pgs) | TEXT_RETURN_WIDTH;
    text.data.d_glyph = glyph;
    text.size = 1;
    result = gs_text_begin(pgs, &text, mem, ppte);
    if (result == 0)
      setup_FontBBox_as_Metrics2(*ppte, pgs->font);
    return result;
}
int
gs_cshow_begin(gs_gstate * pgs, const byte * str, uint size,
               gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;

    text.operation = TEXT_FROM_STRING | TEXT_DO_NONE | TEXT_INTERVENE;
    text.data.bytes = str, text.size = size;
    return gs_text_begin(pgs, &text, mem, ppte);
}
int
gs_stringwidth_begin(gs_gstate * pgs, const byte * str, uint size,
                     gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;

    text.operation = TEXT_FROM_STRING | TEXT_DO_NONE | TEXT_RETURN_WIDTH;
    text.data.bytes = str, text.size = size;
    return gs_text_begin(pgs, &text, mem, ppte);
}
int
gs_charpath_begin(gs_gstate * pgs, const byte * str, uint size, bool stroke_path,
                  gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;

    text.operation = TEXT_FROM_STRING | TEXT_RETURN_WIDTH |
        (stroke_path ? TEXT_DO_TRUE_CHARPATH : TEXT_DO_FALSE_CHARPATH);
    text.data.bytes = str, text.size = size;
    return gs_text_begin(pgs, &text, mem, ppte);
}
int
gs_charboxpath_begin(gs_gstate * pgs, const byte * str, uint size,
                bool stroke_path, gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;

    text.operation = TEXT_FROM_STRING | TEXT_RETURN_WIDTH |
        (stroke_path ? TEXT_DO_TRUE_CHARBOXPATH : TEXT_DO_FALSE_CHARBOXPATH);
    text.data.bytes = str, text.size = size;
    return gs_text_begin(pgs, &text, mem, ppte);
}
int
gs_glyphpath_begin(gs_gstate * pgs, gs_glyph glyph, bool stroke_path,
                   gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;
    int result;

    text.operation = TEXT_FROM_SINGLE_GLYPH | TEXT_RETURN_WIDTH |
        (stroke_path ? TEXT_DO_TRUE_CHARPATH : TEXT_DO_FALSE_CHARPATH);
    text.data.d_glyph = glyph;
    text.size = 1;
    result = gs_text_begin(pgs, &text, mem, ppte);
    if (result == 0)
      setup_FontBBox_as_Metrics2(*ppte, pgs->font);
    return result;
}
int
gs_glyphwidth_begin(gs_gstate * pgs, gs_glyph glyph,
                    gs_memory_t * mem, gs_text_enum_t ** ppte)
{
    gs_text_params_t text;
    int result;

    text.operation = TEXT_FROM_SINGLE_GLYPH | TEXT_DO_NONE | TEXT_RETURN_WIDTH;
    text.data.d_glyph = glyph;
    text.size = 1;
    result = gs_text_begin(pgs, &text, mem, ppte);
    if (result == 0)
      setup_FontBBox_as_Metrics2(*ppte, pgs->font);
    return result;
}

/* Restart processing with different parameters. */
int
gs_text_restart(gs_text_enum_t *pte, const gs_text_params_t *text)
{
    gs_text_enum_t tenum;

    tenum = *pte;
    tenum.text = *text;
    gs_text_enum_init_dynamic(&tenum, pte->orig_font);
    setup_FontBBox_as_Metrics2(pte, pte->orig_font);
    return gs_text_resync(pte, &tenum);
}

/*
 * Resync text processing with new parameters and string position.
 */
int
gs_text_resync(gs_text_enum_t *pte, const gs_text_enum_t *pfrom)
{
    return pte->procs->resync(pte, pfrom);
}

/* Process text after 'begin'. */
int
gs_text_process(gs_text_enum_t * pte)
{
    return pte->procs->process(pte);
}

/* Access elements of the enumerator. */
gs_font *
gs_text_current_font(const gs_text_enum_t *pte)
{
    return pte->current_font;
}
gs_char
gs_text_current_char(const gs_text_enum_t *pte)
{
    return pte->returned.current_char;
}
gs_char
gs_text_next_char(const gs_text_enum_t *pte)
{
    const uint operation = pte->text.operation;

    if (pte->index >= pte->text.size)
        return gs_no_char;	/* rangecheck */
    if (operation & (TEXT_FROM_STRING | TEXT_FROM_BYTES))
        return pte->text.data.bytes[pte->index];
    if (operation & TEXT_FROM_CHARS)
        return pte->text.data.chars[pte->index];
    return gs_no_char;		/* rangecheck */
}
gs_glyph
gs_text_current_glyph(const gs_text_enum_t *pte)
{
    return pte->returned.current_glyph;
}
int
gs_text_total_width(const gs_text_enum_t *pte, gs_point *pwidth)
{
    *pwidth = pte->returned.total_width;
    return 0;
}

/* Assuming REPLACE_WIDTHS is set, return the width of the i'th character. */
int
gs_text_replaced_width(const gs_text_params_t *text, uint index,
                       gs_point *pwidth)
{
    const float *x_widths = text->x_widths;
    const float *y_widths = text->y_widths;

    if (x_widths == y_widths) {
        if (x_widths) {
            index *= 2;
            if (index + 1 >= text->widths_size)
                return_error(gs_error_rangecheck);
            pwidth->x = x_widths[index];
            pwidth->y = x_widths[index + 1];
        }
        else
            pwidth->x = pwidth->y = 0;
    } else {
        if (index >= text->widths_size)
            return_error(gs_error_rangecheck);
        pwidth->x = (x_widths ? x_widths[index] : 0.0);
        pwidth->y = (y_widths ? y_widths[index] : 0.0);
    }
    return 0;
}

/* Determine whether only the width is needed. */
bool
gs_text_is_width_only(const gs_text_enum_t * pte)
{
    return pte->procs->is_width_only(pte);
}

/* Return the width of the current character. */
int
gs_text_current_width(const gs_text_enum_t * pte, gs_point *pwidth)
{
    return pte->procs->current_width(pte, pwidth);
}

/* Set text metrics and optionally enable caching. */
int
gs_text_set_cache(gs_text_enum_t * pte, const double *values,
                  gs_text_cache_control_t control)
{
    return pte->procs->set_cache(pte, values, control);
}
int
gs_text_setcharwidth(gs_text_enum_t * pte, const double wxy[2])
{
    return pte->procs->set_cache(pte, wxy, TEXT_SET_CHAR_WIDTH);
}
int
gs_text_setcachedevice(gs_text_enum_t * pte, const double wbox[6])
{
    return pte->procs->set_cache(pte, wbox, TEXT_SET_CACHE_DEVICE);
}
int
gs_text_setcachedevice2(gs_text_enum_t * pte, const double wbox2[10])
{
    return pte->procs->set_cache(pte, wbox2, TEXT_SET_CACHE_DEVICE2);
}

/* Retry processing the last character without caching. */
int
gs_text_retry(gs_text_enum_t * pte)
{
    return pte->procs->retry(pte);
}

/* Release the text processing structures. */
void
gx_default_text_release(gs_text_enum_t *pte, client_name_t cname)
{
    rc_decrement_only(pte->dev, cname);
    rc_decrement_only(pte->imaging_dev, cname);
}
void
rc_free_text_enum(gs_memory_t * mem, void *obj, client_name_t cname)
{
    gs_text_enum_t *pte = obj;

    pte->procs->release(pte, cname);
    rc_free_struct_only(mem, obj, cname);
}
void
gs_text_release(gs_text_enum_t * pte, client_name_t cname)
{
    rc_decrement_only(pte, cname);
}

/* ---------------- Default font rendering procedures ---------------- */

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

/* Default next-glyph procedure. */
int
gs_default_next_char_glyph(gs_text_enum_t *pte, gs_char *pchr, gs_glyph *pglyph)
{
    if (pte->index >= pte->text.size)
        return 2;
    if (pte->text.operation & (TEXT_FROM_STRING | TEXT_FROM_BYTES)) {
        /* ordinary string */
        *pchr = pte->text.data.bytes[pte->index];
        if (pte->outer_CID != GS_NO_GLYPH)
            *pglyph = pte->outer_CID;
        else
            *pglyph = GS_NO_GLYPH;
    } else if (pte->text.operation & TEXT_FROM_SINGLE_GLYPH) {
        /* glyphshow or glyphpath */
        *pchr = gs_no_char;
        *pglyph = pte->text.data.d_glyph;
    } else if (pte->text.operation & TEXT_FROM_GLYPHS) {
        *pchr = gs_no_char;
        *pglyph = pte->text.data.glyphs[pte->index];
    } else if (pte->text.operation & TEXT_FROM_SINGLE_CHAR) {
        *pchr = pte->text.data.d_char;
        *pglyph = GS_NO_GLYPH;
    } else if (pte->text.operation & TEXT_FROM_CHARS) {
        *pchr = pte->text.data.chars[pte->index];
        *pglyph = GS_NO_GLYPH;
    } else
        return_error(gs_error_rangecheck); /* shouldn't happen */
    pte->index++;
    return 0;
}

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