/* Copyright (C) 2002 Aladdin Enterprises.  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.
  
  For more information about licensing, please refer to
  http://www.ghostscript.com/licensing/. For information on
  commercial licensing, go to http://www.artifex.com/licensing/ or
  contact Artifex Software, Inc., 101 Lucas Valley Road #110,
  San Rafael, CA  94903, U.S.A., +1(415)492-9861.
*/

/* $Id: gdevpdte.c,v 1.43 2003/08/11 19:14:07 igor Exp $ */
/* Encoding-based (Type 1/2/42) text processing for pdfwrite. */
#include "math_.h"
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gxfcmap.h"
#include "gxfcopy.h"
#include "gxfont.h"
#include "gxfont0.h"
#include "gxfont0c.h"
#include "gxpath.h"		/* for getting current point */
#include "gdevpsf.h"
#include "gdevpdfx.h"
#include "gdevpdfg.h"
#include "gdevpdtx.h"
#include "gdevpdtd.h"
#include "gdevpdtf.h"
#include "gdevpdts.h"
#include "gdevpdtt.h"

private int pdf_char_widths(gx_device_pdf *const pdev,
			    pdf_font_resource_t *pdfont, int ch,
			    gs_font_base *font,
			    pdf_glyph_widths_t *pwidths /* may be NULL */);
private int pdf_encode_string(gx_device_pdf *pdev, const pdf_text_enum_t *penum, 
			      const gs_string *pstr,
			      pdf_font_resource_t **ppdfont);
private int pdf_process_string(pdf_text_enum_t *penum, gs_string *pstr,
			       pdf_font_resource_t *pdfont,
			       const gs_matrix *pfmat,
			       pdf_text_process_state_t *ppts);

/*
 * Encode and process a string with a simple gs_font.
 */
int
pdf_encode_process_string(pdf_text_enum_t *penum, gs_string *pstr,
			  const gs_matrix *pfmat,
			  pdf_text_process_state_t *ppts)
{
    gx_device_pdf *const pdev = (gx_device_pdf *)penum->dev;
    pdf_font_resource_t *pdfont;
    gs_font_base *font;
    int code = 0;

    switch (penum->current_font->FontType) {
    case ft_TrueType:
    case ft_encrypted:
    case ft_encrypted2:
    case ft_user_defined:
	break;
    default:
	return_error(gs_error_rangecheck);
    }
    font = (gs_font_base *)penum->current_font;

    code = pdf_encode_string(pdev, penum, pstr, &pdfont); /* Must not change penum. */
    if (code < 0)
	return code;
    return pdf_process_string(penum, pstr, pdfont, pfmat, ppts);
}

/* 
 * Add char code pair to ToUnicode CMap,
 * creating the CMap on neccessity.
 */
int
pdf_add_ToUnicode(gx_device_pdf *pdev, gs_font *font, pdf_font_resource_t *pdfont, 
		  gs_glyph glyph, gs_char ch)
{   int code;
    gs_char unicode;

    if (glyph == GS_NO_GLYPH)
	return 0;
    unicode = font->procs.decode_glyph((gs_font *)font, glyph);
    if (unicode != GS_NO_CHAR) {
	if (pdfont->cmap_ToUnicode == NULL) {
	    uint num_codes = 256, key_size = 1;
	    
	    if (font->FontType == ft_CID_encrypted) {
		gs_font_cid0 *pfcid = (gs_font_cid0 *)font;

		num_codes = pfcid->cidata.common.CIDCount;
		key_size = 2;
	    } else if (font->FontType == ft_CID_TrueType) {
		gs_font_cid2 *pfcid = (gs_font_cid2 *)font;

		num_codes = pfcid->cidata.common.CIDCount;
		key_size = 2;
	    }
	    code = gs_cmap_ToUnicode_alloc(pdev->pdf_memory, pdfont->rid, num_codes, key_size, 
					    &pdfont->cmap_ToUnicode);
	    if (code < 0)
		return code;
	}
	if (pdfont->cmap_ToUnicode != NULL)
	    gs_cmap_ToUnicode_add_pair(pdfont->cmap_ToUnicode, ch, unicode);
    }
    return 0;
}

/*
 * Given a text string and a simple gs_font, return a font resource suitable
 * for the text string, possibly re-encoding the string.  This
 * may involve creating a font resource and/or adding glyphs and/or Encoding
 * entries to it.
 *
 * Sets *ppdfont.
 */
private int
pdf_encode_string(gx_device_pdf *pdev, const pdf_text_enum_t *penum,
		  const gs_string *pstr,
		  pdf_font_resource_t **ppdfont)
{
    gs_font *font = (gs_font *)penum->current_font;
    pdf_font_resource_t *pdfont = 0;
    gs_font_base *cfont, *ccfont;
    int code, i;

    /*
     * In contradiction with pre-7.20 versions of pdfwrite,
     * we never re-encode texts due to possible encoding conflict while font merging.
     */
    code = pdf_obtain_font_resource((const gs_text_enum_t *)penum, pstr, &pdfont);
    if (code < 0)
	return code;
    code = pdf_add_resource(pdev, pdev->substream_Resources, "/Font", (pdf_resource_t *)pdfont);
    if (code < 0)
	return code;

    cfont = pdf_font_resource_font(pdfont, false);
    ccfont = pdf_font_resource_font(pdfont, true);
    for (i = 0; i < pstr->size; ++i) {
	int ch = pstr->data[i];
	pdf_encoding_element_t *pet = &pdfont->u.simple.Encoding[ch];
	gs_glyph glyph =
	    font->procs.encode_char(font, ch, GLYPH_SPACE_NAME);
	gs_glyph copied_glyph;
	gs_const_string gnstr;

	if (glyph == GS_NO_GLYPH || glyph == pet->glyph)
	    continue;
	if (pet->glyph != GS_NO_GLYPH) { /* encoding conflict */
	    return_error(gs_error_rangecheck); 
	    /* Must not happen because pdf_obtain_font_resource
	     * checks for encoding compatibility. 
	     */
	}
	code = font->procs.glyph_name(font, glyph, &gnstr);
	if (code < 0)
	    return code;	/* can't get name of glyph */
	if (font->FontType != ft_user_defined) {
	    /* The standard 14 fonts don't have a FontDescriptor. */
	    code = (pdfont->base_font != 0 ?
		    pdf_base_font_copy_glyph(pdfont->base_font, glyph, (gs_font_base *)font) :
		    pdf_font_used_glyph(pdfont->FontDescriptor, glyph, (gs_font_base *)font));
	    if (code == gs_error_undefined)
		continue;	/* notdef */
	    if (code < 0)
		return code;
	    if (pdfont->base_font == NULL && ccfont != NULL &&
		    (gs_copy_glyph_options(font, glyph, (gs_font *)ccfont, COPY_GLYPH_NO_NEW) != 1 || 
		     gs_copied_font_add_encoding((gs_font *)ccfont, ch, glyph) < 0)) {
		/*
		 * The "complete" copy of the font appears incomplete
		 * due to incrementally added glyphs. Drop the "complete"
		 * copy now and continue with subset font only.
		 *
		 * Note that we need to add the glyph to the encoding of the
		 * "complete" font, because "PPI-ProPag 2.6.1.4 (archivePg)"
		 * creates multiple font copies with reduced encodings
		 * (we believe it is poorly designed),
		 * and we can merge the copies back to a single font (see Bug 686875).
		 * We also check whether the encoding is compatible. 
		 * It must be compatible here due to the pdf_obtain_font_resource 
		 * and ccfont logics, but we want to ensure for safety reason.
		 */
		ccfont = NULL;
		pdf_font_descriptor_drop_complete_font(pdfont->FontDescriptor);
	    }
	    /*
	     * We arbitrarily allow the first encoded character in a given
	     * position to determine the encoding associated with the copied
	     * font.
	     */
	    copied_glyph = cfont->procs.encode_char((gs_font *)cfont, ch,
						    GLYPH_SPACE_NAME);
	    if (glyph != copied_glyph &&
		gs_copied_font_add_encoding((gs_font *)cfont, ch, glyph) < 0
		)
		pet->is_difference = true;
	    pdfont->used[ch >> 3] |= 0x80 >> (ch & 7);
	}
	/*
	 * We always generate ToUnicode for simple fonts, because
	 * we can't detemine in advance, which glyphs the font actually uses.
	 * The decision about writing it out is deferred until pdf_write_font_resource.
	 */
	code = pdf_add_ToUnicode(pdev, font, pdfont, glyph, ch);
	if (code < 0)
	    return code;
	pet->glyph = glyph;
	pet->str = gnstr;
    }
    *ppdfont = pdfont;
    return 0;
}

/*
 * Estimate text bbox.
 */
private int
process_text_estimate_bbox(pdf_text_enum_t *pte, gs_font_base *font,
			  const gs_const_string *pstr,
			  const gs_matrix *pfmat,
			  gs_rect *text_bbox, gs_point *pdpt)
{
    int i;
    int space_char =
	(pte->text.operation & TEXT_ADD_TO_SPACE_WIDTH ?
	 pte->text.space.s_char : -1);
    int WMode = font->WMode;
    int code = 0;
    gs_point total = {0, 0};
    gs_fixed_point origin;
    gs_matrix m;
    int xy_index = pte->xy_index;

    if (font->FontBBox.p.x == font->FontBBox.q.x ||
	font->FontBBox.p.y == font->FontBBox.q.y)
	return_error(gs_error_undefined);
    code = gx_path_current_point(pte->path, &origin);
    if (code < 0)
	return code;
    m = ctm_only(pte->pis);
    m.tx = fixed2float(origin.x);
    m.ty = fixed2float(origin.y);
    gs_matrix_multiply(pfmat, &m, &m);
    for (i = 0; i < pstr->size; ++i) {
	byte c = pstr->data[i];
	gs_rect bbox;
	gs_point wanted, tpt, p0, p1, p2, p3;
	gs_glyph glyph = font->procs.encode_char((gs_font *)font, c, 
					GLYPH_SPACE_NAME);
	gs_glyph_info_t info;
	int code = font->procs.glyph_info((gs_font *)font, glyph, NULL,
					    GLYPH_INFO_WIDTH0 << WMode,
					    &info);

	if (code < 0)
	    return code;
	gs_point_transform(font->FontBBox.p.x, font->FontBBox.p.y, &m, &p0);
	gs_point_transform(font->FontBBox.p.x, font->FontBBox.q.y, &m, &p1);
	gs_point_transform(font->FontBBox.q.x, font->FontBBox.p.y, &m, &p2);
	gs_point_transform(font->FontBBox.q.x, font->FontBBox.q.y, &m, &p3);
	bbox.p.x = min(min(p0.x, p1.x), min(p1.x, p2.x)) + total.x;
	bbox.p.y = min(min(p0.y, p1.y), min(p1.y, p2.y)) + total.y;
	bbox.q.x = max(max(p0.x, p1.x), max(p1.x, p2.x)) + total.x;
	bbox.q.y = max(max(p0.y, p1.y), max(p1.y, p2.y)) + total.y;
	if (i == 0)
	    *text_bbox = bbox;
	else
	    rect_merge(*text_bbox, bbox);
	if (pte->text.operation & TEXT_REPLACE_WIDTHS) {
	    gs_text_replaced_width(&pte->text, xy_index++, &tpt);
	    gs_distance_transform(tpt.x, tpt.y, &ctm_only(pte->pis), &wanted);
	} else {
	    gs_distance_transform(info.width[WMode].x,
				  info.width[WMode].y,
				  &m, &wanted);
	    if (pte->text.operation & TEXT_ADD_TO_ALL_WIDTHS) {
		gs_distance_transform(pte->text.delta_all.x,
				      pte->text.delta_all.y,
				      &ctm_only(pte->pis), &tpt);
		wanted.x += tpt.x;
		wanted.y += tpt.y;
	    }
	    if (pstr->data[i] == space_char) {
		gs_distance_transform(pte->text.delta_space.x,
				      pte->text.delta_space.y,
				      &ctm_only(pte->pis), &tpt);
		wanted.x += tpt.x;
		wanted.y += tpt.y;
	    }
	}
	total.x += wanted.x;
	total.y += wanted.y;
    }
    *pdpt = total;
    return 0;
}

private void
adjust_first_last_char(pdf_font_resource_t *pdfont, byte *str, int size)
{
    int i;

    for (i = 0; i < size; ++i) {
	int chr = str[i];

	if (chr < pdfont->u.simple.FirstChar)
	    pdfont->u.simple.FirstChar = chr;
	if (chr > pdfont->u.simple.LastChar)
	    pdfont->u.simple.LastChar = chr;
    }
}

/*
 * Internal procedure to process a string in a non-composite font.
 * Doesn't use or set pte->{data,size,index}; may use/set pte->xy_index;
 * may set penum->returned.total_width.  Sets ppts->values.
 *
 * Note that the caller is responsible for re-encoding the string, if
 * necessary; for adding Encoding entries in pdfont; and for copying any
 * necessary glyphs.  penum->current_font provides the gs_font for getting
 * glyph metrics, but this font's Encoding is not used.
 */
private int process_text_return_width(const pdf_text_enum_t *pte,
				      gs_font_base *font,
				      pdf_text_process_state_t *ppts,
				      const gs_const_string *pstr,
				      gs_point *pdpt, int *accepted);
private int
pdf_process_string(pdf_text_enum_t *penum, gs_string *pstr,
		   pdf_font_resource_t *pdfont, const gs_matrix *pfmat,
		   pdf_text_process_state_t *ppts)
{
    gx_device_pdf *const pdev = (gx_device_pdf *)penum->dev;
    gs_font_base *font = (gs_font_base *)penum->current_font;
    const gs_text_params_t *text = &penum->text;
    int code = 0, mask;
    gs_point width_pt;
    gs_rect text_bbox;
    int accepted;

    if (pfmat == 0)
	pfmat = &font->FontMatrix;
    if (text->operation & TEXT_RETURN_WIDTH) {
	code = gx_path_current_point(penum->path, &penum->origin);
	if (code < 0)
	    return code;
    }
    
    if (penum->pis->text_rendering_mode != 3 && !(text->operation & TEXT_DO_NONE)) {
	/*
	 * Acrobat Reader can't handle text with huge coordinates,
	 * so skip the text if it is outside the clip bbox
	 * (Note : it ever fails with type 3 fonts).
	 */
	code = process_text_estimate_bbox(penum, font, (gs_const_string *)pstr, pfmat, 
					  &text_bbox, &width_pt);
	if (code == 0) {
	    gs_fixed_rect clip_bbox;
	    gs_rect rect;

	    gx_cpath_outer_box(penum->pcpath, &clip_bbox);
	    rect.p.x = fixed2float(clip_bbox.p.x);
	    rect.p.y = fixed2float(clip_bbox.p.y);
	    rect.q.x = fixed2float(clip_bbox.q.x);
	    rect.q.y = fixed2float(clip_bbox.q.y);
	    rect_intersect(rect, text_bbox);
	    if (rect.p.x > rect.q.x || rect.p.y > rect.q.y) {
		penum->index += pstr->size;
		goto finish;
	    }
	}
    } else {
	/* We have no penum->pcpath. */
    }

    /*
     * Note that pdf_update_text_state sets all the members of ppts->values
     * to their current values.
     */
    code = pdf_update_text_state(ppts, penum, pdfont, pfmat);
    if (code > 0) {
	/* Try not to emulate ADD_TO_WIDTH if we don't have to. */
	if (code & TEXT_ADD_TO_SPACE_WIDTH) {
	    if (!memchr(pstr->data, penum->text.space.s_char, pstr->size))
		code &= ~TEXT_ADD_TO_SPACE_WIDTH;
	}
    }
    if (code < 0)
	return code;
    mask = code;

    if (text->operation & TEXT_REPLACE_WIDTHS)
	mask |= TEXT_REPLACE_WIDTHS;

    /*
     * The only operations left to handle are TEXT_DO_DRAW and
     * TEXT_RETURN_WIDTH.
     */
    if (mask == 0) {
	/*
	 * If any character has real_width != Width, we have to process
	 * the string character-by-character.  process_text_return_width
	 * will tell us what we need to know.
	 */
	if (!(text->operation & (TEXT_DO_DRAW | TEXT_RETURN_WIDTH)))
	    return 0;
	code = process_text_return_width(penum, font, ppts,
					 (gs_const_string *)pstr,
					 &width_pt, &accepted);
	if (code < 0)
	    return code;
	if (code == 0) {
	    /* No characters with redefined widths -- the fast case. */
	    if (text->operation & TEXT_DO_DRAW || penum->pis->text_rendering_mode == 3) {
		code = pdf_append_chars(pdev, pstr->data, accepted,
					width_pt.x, width_pt.y, false);
		if (code < 0)
		    return code;
		adjust_first_last_char(pdfont, pstr->data + penum->index, accepted);
		penum->index += accepted;
	    } else if (text->operation & TEXT_DO_NONE)
		penum->index += accepted;
	} else {
	    /* Use the slow case.  Set mask to any non-zero value. */
	    mask = TEXT_RETURN_WIDTH;
	}
    }
    if (mask) {
	/* process_text_modify_width destroys text parameters, save them now. */
        int index0 = penum->index, xy_index = penum->xy_index;
	gs_text_params_t text = penum->text;
	int xy_index_step = (penum->text.x_widths != NULL && /* see gs_text_replaced_width */
			     penum->text.x_widths == penum->text.y_widths ? 2 : 1);
	
	if (penum->text.x_widths != NULL) {
	    penum->text.x_widths += xy_index * xy_index_step;
	}
	if (penum->text.y_widths != NULL)
	    penum->text.y_widths += xy_index * xy_index_step;
	penum->xy_index = 0;
	code = process_text_modify_width(penum, (gs_font *)font, ppts,
					 (gs_const_string *)pstr,
					 &width_pt);
	if (penum->text.x_widths != NULL)
	    penum->text.x_widths -= xy_index * xy_index_step;
	if (penum->text.y_widths != NULL)
	    penum->text.y_widths -= xy_index * xy_index_step;
	penum->xy_index += xy_index;
	adjust_first_last_char(pdfont, pstr->data, penum->index);
	penum->text = text;
	penum->index += index0;
	if (code < 0)
	    return code;
    }


finish:
    /* Finally, return the total width if requested. */
    if (!(text->operation & TEXT_RETURN_WIDTH))
	return 0;
    if (text->operation & TEXT_DO_NONE) {
	/* stringwidth needs to transform to user space. */
	gs_point p;

	gs_distance_transform_inverse(width_pt.x, width_pt.y, &ctm_only(penum->pis), &p);
	penum->returned.total_width.x += p.x;
	penum->returned.total_width.y += p.y;
    } else
	penum->returned.total_width = width_pt;
    return gx_path_add_point(penum->path,
			     penum->origin.x + float2fixed(width_pt.x),
			     penum->origin.y + float2fixed(width_pt.y));
}

/*
 * Get the widths (unmodified and possibly modified) of a given character
 * in a simple font.  May add the widths to the widths cache (pdfont->Widths
 * and pdf_font_cache_elem::real_widths).  Return 1 if the widths were not cached.
 */
private int
pdf_char_widths(gx_device_pdf *const pdev,
		pdf_font_resource_t *pdfont, int ch, gs_font_base *font,
		pdf_glyph_widths_t *pwidths /* may be NULL */)
{
    pdf_glyph_widths_t widths;
    int code;
    byte *glyph_usage;
    double *real_widths;
    int char_cache_size, width_cache_size;
    pdf_font_resource_t *pdfont1;

    code = pdf_attached_font_resource(pdev, (gs_font *)font, &pdfont1, 
				&glyph_usage, &real_widths, &char_cache_size, &width_cache_size);
    if (code < 0)
	return code;
    if (pdfont1 != pdfont)
	return_error(gs_error_unregistered); /* Must not happen. */
    if (ch < 0 || ch > 255)
	return_error(gs_error_rangecheck);
    if (ch >= width_cache_size)
	return_error(gs_error_unregistered); /* Must not happen. */
    if (pwidths == 0)
	pwidths = &widths;
    if (font->FontType != ft_user_defined && real_widths[ch] == 0) {
	/* Might be an unused char, or just not cached. */
	gs_glyph glyph = pdfont->u.simple.Encoding[ch].glyph;

	code = pdf_glyph_widths(pdfont, font->WMode, glyph, (gs_font *)font, pwidths);
	if (code < 0)
	    return code;
	if (font->WMode != 0 && code > 0 && !pwidths->replaced_v) {
	    /*
	     * The font has no Metrics2, so it must write
	     * horizontally due to PS spec.
	     * Therefore we need to fill the Widths array,
	     * which is required by PDF spec.
	     * Take it from WMode==0.
	     */
	    code = pdf_glyph_widths(pdfont, 0, glyph, (gs_font *)font, pwidths);
	}
	if (pwidths->replaced_v) {
	    pdfont->u.simple.v[ch].x = pwidths->real_width.v.x - pwidths->Width.v.x;
	    pdfont->u.simple.v[ch].y = pwidths->real_width.v.y - pwidths->Width.v.y;
	} else
	    pdfont->u.simple.v[ch].x = pdfont->u.simple.v[ch].y = 0;
	if (code == 0) {
	    pdfont->Widths[ch] = pwidths->Width.w;
	    real_widths[ch] = pwidths->real_width.w;
	}
    } else {
	if (font->FontType == ft_user_defined && 
		!(pdfont->used[ch >> 3] & 0x80 >> (ch & 7)))
	    return gs_error_undefined;
	pwidths->Width.w = pdfont->Widths[ch];
	pwidths->Width.v = pdfont->u.simple.v[ch];
	if (font->FontType == ft_user_defined) {
	    pwidths->real_width.w = real_widths[ch * 2];
	    pwidths->Width.xy.x = pwidths->Width.w;
	    pwidths->Width.xy.y = 0;
	    pwidths->real_width.xy.x = real_widths[ch * 2 + 0];
	    pwidths->real_width.xy.y = real_widths[ch * 2 + 1];
	} else if (font->WMode) {
	    pwidths->real_width.w = real_widths[ch];
	    pwidths->Width.xy.x = 0;
	    pwidths->Width.xy.y = pwidths->Width.w;
	    pwidths->real_width.xy.x = 0;
	    pwidths->real_width.xy.y = pwidths->real_width.w;
	} else {
	    pwidths->real_width.w = real_widths[ch];
	    pwidths->Width.xy.x = pwidths->Width.w;
	    pwidths->Width.xy.y = 0;
	    pwidths->real_width.xy.x = pwidths->real_width.w;
	    pwidths->real_width.xy.y = 0;
	}
	code = 0;
    }
    return code;
}

/*
 * Compute the total text width (in user space).  Return 1 if any
 * character had real_width != Width, otherwise 0.
 */
private int
process_text_return_width(const pdf_text_enum_t *pte, gs_font_base *font,
			  pdf_text_process_state_t *ppts,
			  const gs_const_string *pstr,
			  gs_point *pdpt, int *accepted)
{
    int i;
    gs_point w;
    double scale;
    gs_point dpt;
    int num_spaces = 0;
    int space_char =
	(pte->text.operation & TEXT_ADD_TO_SPACE_WIDTH ?
	 pte->text.space.s_char : -1);
    int widths_differ = 0, code;

    if (font->FontType == ft_user_defined) {
	code = font_orig_scale((gs_font *)font, &scale);
	if (code < 0)
	    return code;
	scale *= ppts->values.size;
    } else
	scale = 0.001 * ppts->values.size;
    for (i = 0, w.x = w.y = 0; i < pstr->size; ++i) {
	pdf_glyph_widths_t cw;

	code = pdf_char_widths((gx_device_pdf *)pte->dev,
	                           ppts->values.pdfont, pstr->data[i], font,
				   &cw);
	if (code < 0) {
	    if (i)
		break;
	    *accepted = 0;
	    return code;
	}
	w.x += cw.real_width.xy.x;
	w.y += cw.real_width.xy.y;
	if (cw.real_width.xy.x != cw.Width.xy.x ||
	    cw.real_width.xy.y != cw.Width.xy.y
	    )
	    widths_differ = 1;
	if (pstr->data[i] == space_char)
	    ++num_spaces;
    }
    *accepted = i;
    gs_distance_transform(w.x * scale, w.y * scale,
			  &ppts->values.matrix, &dpt);
    if (pte->text.operation & TEXT_ADD_TO_ALL_WIDTHS) {
	int num_chars = *accepted;
	gs_point tpt;

	gs_distance_transform(pte->text.delta_all.x, pte->text.delta_all.y,
			      &ctm_only(pte->pis), &tpt);
	dpt.x += tpt.x * num_chars;
	dpt.y += tpt.y * num_chars;
    }
    if (pte->text.operation & TEXT_ADD_TO_SPACE_WIDTH) {
	gs_point tpt;

	gs_distance_transform(pte->text.delta_space.x, pte->text.delta_space.y,
			      &ctm_only(pte->pis), &tpt);
	dpt.x += tpt.x * num_spaces;
	dpt.y += tpt.y * num_spaces;
    }
    *pdpt = dpt;

    return widths_differ;
}

/*
 * Retrieve glyph origing shift for WMode = 1 in design units.
 */
private void 
pdf_glyph_origin(pdf_font_resource_t *pdfont, int ch, int WMode, gs_point *p)
{
    /* For CID fonts PDF viewers provide glyph origin shift automatically.
     * Therefore we only need to do for non-CID fonts.
     */
    switch (pdfont->FontType) {
	case ft_encrypted:
	case ft_encrypted2:
	case ft_TrueType:
	case ft_user_defined:
	    *p = pdfont->u.simple.v[ch];
	    break;
	default:
	    p->x = p->y = 0;
	    break;
    }
}

/*
 * Emulate TEXT_ADD_TO_ALL_WIDTHS and/or TEXT_ADD_TO_SPACE_WIDTH,
 * and implement TEXT_REPLACE_WIDTHS if requested.
 * Uses and updates ppts->values.matrix; uses ppts->values.pdfont.
 */
int
process_text_modify_width(pdf_text_enum_t *pte, gs_font *font,
			  pdf_text_process_state_t *ppts,
			  const gs_const_string *pstr,
			  gs_point *pdpt)
{
    gx_device_pdf *const pdev = (gx_device_pdf *)pte->dev;
    double scale;
    int space_char =
	(pte->text.operation & TEXT_ADD_TO_SPACE_WIDTH ?
	 pte->text.space.s_char : -1);
    int code = 0;
    gs_point start, total;
    bool composite = (ppts->values.pdfont->FontType == ft_composite);

    if (font->FontType == ft_user_defined) {
	code = font_orig_scale((gs_font *)font, &scale);
	if (code < 0)
	    return code;
	scale *= ppts->values.size;
    } else
	scale = 0.001 * ppts->values.size;
    pte->text.data.bytes = pstr->data;
    pte->text.size = pstr->size;
    pte->index = 0;
    start.x = ppts->values.matrix.tx;
    start.y = ppts->values.matrix.ty;
    total.x = total.y = 0;	/* user space */
    /*
     * Note that character widths are in design space, but text.delta_*
     * values and the width value returned in *pdpt are in user space,
     * and the width values for pdf_append_chars are in device space.
     */
    for (;;) {
	pdf_glyph_widths_t cw;	/* design space */
	gs_point did, wanted, tpt;	/* user space */
	gs_point v = {0, 0}; /* design space */
	gs_char chr;
	gs_glyph glyph;
	int code, index = pte->index;
	gs_text_enum_t pte1 = *(gs_text_enum_t *)pte;
	int FontType;

	code = pte1.orig_font->procs.next_char_glyph(&pte1, &chr, &glyph);
	if (code == 2) { /* end of string */
	    gs_text_enum_copy_dynamic((gs_text_enum_t *)pte, &pte1, true);
	    break;
	}
	if (code < 0)
	    return code;
	if (composite) { /* from process_cmap_text */
	    gs_font *subfont = pte1.fstack.items[pte1.fstack.depth].font;
	    pdf_font_resource_t *pdsubf = ppts->values.pdfont->u.type0.DescendantFont;

	    FontType = pdsubf->FontType;
	    code = pdf_glyph_widths(pdsubf, font->WMode, glyph, subfont, &cw);
	} else {/* must be a base font */
	    FontType = font->FontType;
	    if (chr == GS_NO_CHAR && glyph != GS_NO_GLYPH) {
		/* glyphshow, we have no char code. Bug 686988.*/
		code = pdf_glyph_widths(ppts->values.pdfont, font->WMode, glyph, font, &cw);
	    } else 
		code = pdf_char_widths((gx_device_pdf *)pte->dev,
				       ppts->values.pdfont, chr, (gs_font_base *)font,
				       &cw);
	}
	if (code < 0) {
	    if (index > 0)
		break;
	    return code;
	}
	gs_text_enum_copy_dynamic((gs_text_enum_t *)pte, &pte1, true);
	if (composite) {
	    if (cw.replaced_v) {
		v.x = cw.Width.v.x - cw.real_width.v.x;
		v.y = cw.Width.v.y - cw.real_width.v.y;
	    }
	} else
	    pdf_glyph_origin(ppts->values.pdfont, chr, font->WMode, &v);
	if (v.x != 0 || v.y != 0) {
	    gs_point glyph_origin_shift;
	    double scale0;

	    if (FontType == ft_TrueType || FontType == ft_CID_TrueType)
		scale0 = (float)0.001;
	    else
		scale0 = 1;
	    glyph_origin_shift.x = -v.x * scale0;
	    glyph_origin_shift.y = -v.y * scale0;
	    gs_distance_transform(glyph_origin_shift.x, glyph_origin_shift.y,
				  &font->FontMatrix, &glyph_origin_shift);
	    if (composite) {
		gs_font *subfont = pte->fstack.items[pte->fstack.depth].font;

		gs_distance_transform(glyph_origin_shift.x, glyph_origin_shift.y,
				      &subfont->FontMatrix, &glyph_origin_shift);
	    }
	    gs_distance_transform(glyph_origin_shift.x, glyph_origin_shift.y,
				  &ctm_only(pte->pis), &glyph_origin_shift);
	    if (glyph_origin_shift.x != 0 || glyph_origin_shift.y != 0) {
		ppts->values.matrix.tx = start.x + total.x + glyph_origin_shift.x;
		ppts->values.matrix.ty = start.y + total.y + glyph_origin_shift.y;
		code = pdf_set_text_state_values(pdev, &ppts->values);
		if (code < 0)
		    break;
	    }
	}
	if (pte->text.operation & TEXT_DO_DRAW) {
	    gs_distance_transform(cw.Width.xy.x * scale,
				  cw.Width.xy.y * scale,
				  &ppts->values.matrix, &did);
	    gs_distance_transform((font->WMode ? 0 : ppts->values.character_spacing),
				  (font->WMode ? ppts->values.character_spacing : 0),
				  &ppts->values.matrix, &tpt);
	    did.x += tpt.x;
	    did.y += tpt.y;
	    if (chr == space_char) {
		gs_distance_transform((font->WMode ? 0 : ppts->values.word_spacing),
				      (font->WMode ? ppts->values.word_spacing : 0),
				      &ppts->values.matrix, &tpt);
		did.x += tpt.x;
		did.y += tpt.y;
	    }
	    code = pdf_append_chars(pdev, pstr->data + index, pte->index - index, did.x, did.y, composite);
	    if (code < 0)
		break;
	} else
	    did.x = did.y = 0;
	if (pte->text.operation & TEXT_REPLACE_WIDTHS) {
	    gs_point dpt;

	    code = gs_text_replaced_width(&pte->text, pte->xy_index++, &dpt);
	    if (code < 0)
		return_error(gs_error_unregistered);
	    gs_distance_transform(dpt.x, dpt.y, &ctm_only(pte->pis), &wanted);
	} else {
	    gs_distance_transform(cw.real_width.xy.x * scale,
				  cw.real_width.xy.y * scale,
				  &ppts->values.matrix, &wanted);
	    if (pte->text.operation & TEXT_ADD_TO_ALL_WIDTHS) {
		gs_distance_transform(pte->text.delta_all.x,
				      pte->text.delta_all.y,
				      &ctm_only(pte->pis), &tpt);
		wanted.x += tpt.x;
		wanted.y += tpt.y;
	    }
	    if (chr == space_char) {
		gs_distance_transform(pte->text.delta_space.x,
				      pte->text.delta_space.y,
				      &ctm_only(pte->pis), &tpt);
		wanted.x += tpt.x;
		wanted.y += tpt.y;
	    }
	}
	total.x += wanted.x;
	total.y += wanted.y;
	if (wanted.x != did.x || wanted.y != did.y) {
	    ppts->values.matrix.tx = start.x + total.x;
	    ppts->values.matrix.ty = start.y + total.y;
	    code = pdf_set_text_state_values(pdev, &ppts->values);
	    if (code < 0)
		break;
	}
    }
    *pdpt = total;
    return code;
}

/*
 * Get character code from a glyph code.
 * An usage of this function is very undesirable,
 * because a glyph may be unlisted in Encoding.
 */
int 
pdf_encode_glyph(gs_font_base *bfont, gs_glyph glyph0,
	    byte *buf, int buf_size, int *char_code_length)
{
    gs_char c;

    *char_code_length = 1;
    if (*char_code_length > buf_size) 
	return_error(gs_error_rangecheck); /* Must not happen. */
    for (c = 0; c < 255; c++) {
	gs_glyph glyph1 = bfont->procs.encode_char((gs_font *)bfont, c, 
		    GLYPH_SPACE_NAME);
	if (glyph1 == glyph0) {
	    buf[0] = (byte)c;
	    return 0;
	}
    }
    return_error(gs_error_rangecheck); /* Can't encode. */
}

/* ---------------- Type 1 or TrueType font ---------------- */

/*
 * Process a text string in a simple font.
 */
int
process_plain_text(gs_text_enum_t *pte, void *vbuf, uint bsize)
{
    byte *const buf = vbuf;
    uint count;
    uint operation = pte->text.operation;
    pdf_text_enum_t *const penum = (pdf_text_enum_t *)pte;
    int code;
    gs_string str;
    bool encoded;
    pdf_text_process_state_t text_state;

    if (operation & (TEXT_FROM_STRING | TEXT_FROM_BYTES)) {
	count = pte->text.size - pte->index;
	if (bsize < count)
	    return_error(gs_error_unregistered); /* Must not happen. */
	memcpy(buf, (const byte *)pte->text.data.bytes + pte->index, count);
	encoded = false;
    } else if (operation & (TEXT_FROM_CHARS | TEXT_FROM_SINGLE_CHAR)) {
	/* Check that all chars fit in a single byte. */
	const gs_char *cdata;
	int i;

	if (operation & TEXT_FROM_CHARS) {
	    cdata = pte->text.data.chars;
	    count = (pte->text.size - pte->index);
	} else {
	    cdata = &pte->text.data.d_char;
	    count = 1;
	}
	if (bsize < count * sizeof(gs_char))
	    return_error(gs_error_unregistered); /* Must not happen. */
	for (i = 0; i < count; ++i) {
	    gs_char chr = cdata[pte->index + i];

	    if (chr & ~0xff)
		return_error(gs_error_rangecheck);
	    buf[i] = (byte)chr;
	}
	encoded = false;
    } else if (operation & (TEXT_FROM_GLYPHS | TEXT_FROM_SINGLE_GLYPH)) {
	/*
	 * Since PDF has no analogue of 'glyphshow',
	 * we try to encode glyphs with the current
	 * font's encoding. If the current font has no encoding,
	 * or the encoding doesn't contain necessary glyphs,
	 * the text will be represented with a Type 3 font with bitmaps.
	 *
	 * When we fail with encoding (136-01.ps is an example),
	 * we could locate a PDF font resource or create a new one
	 * with same outlines and an appropriate encoding.
	 * Also we could change .notdef entries in the
	 * copied font (assuming that document designer didn't use
	 * .notdef for a meanful printing).
	 * fixme: Not implemented yet.
	 */
	const gs_glyph *gdata;
	gs_font *font = pte->current_font;
	uint size;
	int i;

	if (operation & TEXT_FROM_GLYPHS) {
	    gdata = pte->text.data.glyphs;
	    size = pte->text.size - pte->index;
	} else {
	    gdata = &pte->text.data.d_glyph;
	    size = 1;
	}
	if (!pdf_is_simple_font(font))
	    return_error(gs_error_unregistered); /* Must not happen. */
	count = 0;
	for (i = 0; i < size; ++i) {
	    gs_glyph glyph = gdata[pte->index + i];
	    int char_code_length;

	    code = pdf_encode_glyph((gs_font_base *)font, glyph, 
			 buf + count, size - count, &char_code_length);
	    if (code < 0) {
		/* 
		 * pdf_text_process will fall back 
		 * to default implementation.
		 */
		return code;
	    }
	    count += char_code_length;
	}
	encoded = true;
    } else
	return_error(gs_error_rangecheck);
    str.data = buf;
    if (count > 1 && (pte->text.operation & TEXT_INTERVENE)) {
	/* Just do one character. */
	str.size = 1;
	code = pdf_encode_process_string(penum, &str, NULL, &text_state);
	if (code >= 0) {
	    pte->returned.current_char = buf[0];
	    code = TEXT_PROCESS_INTERVENE;
	}
    } else {
	str.size = count;
	code = pdf_encode_process_string(penum, &str, NULL, &text_state);
    }
    return code;
}
