/* Copyright (C) 2001-2006 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 that
   license.  Refer to licensing information at http://www.artifex.com/
   or contact Artifex Software, Inc.,  7 Mt. Lassen Drive - Suite A-134,
   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
*/

/* $Id: gdevpdte.c 11993 2011-01-04 10:48:32Z ken $ */
/* Encoding-based (Type 1/2/42) text processing for pdfwrite. */

#include "math_.h"
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gsutil.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 "gdevpdfo.h"
#include "gdevpdtx.h"
#include "gdevpdtd.h"
#include "gdevpdtf.h"
#include "gdevpdts.h"
#include "gdevpdtt.h"

static 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 */);
static int pdf_process_string(pdf_text_enum_t *penum, gs_string *pstr,
			       const gs_matrix *pfmat,
			       pdf_text_process_state_t *ppts,
			       const gs_glyph *gdata);

/*
 * Process a string with a simple gs_font.
 */
int
pdf_process_string_aux(pdf_text_enum_t *penum, gs_string *pstr,
			  const gs_glyph *gdata, const gs_matrix *pfmat,
			  pdf_text_process_state_t *ppts)
{
    gs_font_base *font = (gs_font_base *)penum->current_font;

    switch (font->FontType) {
    case ft_TrueType:
    case ft_encrypted:
    case ft_encrypted2:
    case ft_user_defined:
	break;
    default:
	return_error(gs_error_rangecheck);
    }
    return pdf_process_string(penum, pstr, pfmat, ppts, gdata);
}

/* 
 * 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, const gs_const_string *gnstr)
{   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 && gnstr != NULL && gnstr->size == 7) {
	if (!memcmp(gnstr->data, "uni", 3)) {
	    static const char *hexdigits = "0123456789ABCDEF";
	    char *d0 = strchr(hexdigits, gnstr->data[3]);
	    char *d1 = strchr(hexdigits, gnstr->data[4]);
	    char *d2 = strchr(hexdigits, gnstr->data[5]);
	    char *d3 = strchr(hexdigits, gnstr->data[6]);

	    if (d0 != NULL && d1 != NULL && d2 != NULL && d3 != NULL)
		unicode = ((d0 - hexdigits) << 12) + ((d1 - hexdigits) << 8) +
			  ((d2 - hexdigits) << 4 ) +  (d3 - hexdigits);
	}
    }
    if (unicode != GS_NO_CHAR) {
	if (pdfont->cmap_ToUnicode == NULL) {
	    /* ToUnicode CMaps are always encoded with two byte keys. See
	     * Technical Note 5411, 'ToUnicode Mapping File Tutorial'
	     * page 3.
	     */
	    /* Unfortunately, the above is not true. See the PDF Reference (version 1.7
	     * p 472 'ToUnicode CMaps'. Even that documentation is incorrect as it
	     * describes codespaceranges, in fact for Acrobat this is irrelevant,
	     * but the bfranges must be one byte for simple fonts. By altering the
	     * key size for CID fonts we can write both consistently correct.
	     */
	    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) {
		key_size = 2;
#if 0
		gs_font_cid2 *pfcid = (gs_font_cid2 *)font;

		num_codes = pfcid->cidata.common.CIDCount;
#else
		/* Since PScript5.dll creates GlyphNames2Unicode with character codes
		   instead CIDs, and with the WinCharSetFFFF-H2 CMap
		   character codes appears from the range 0-0xFFFF (Bug 687954),
		   we must use the maximal character code value for the ToUnicode
		   code count. */
		num_codes = 65536;
#endif
	    }
	    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;
}

typedef struct {
    gx_device_pdf *pdev;
    pdf_resource_type_t rtype;
} pdf_resource_enum_data_t;

static int 
process_resources2(void *client_data, const byte *key_data, uint key_size, const cos_value_t *v)
{
    pdf_resource_enum_data_t *data = (pdf_resource_enum_data_t *)client_data;
    pdf_resource_t *pres = pdf_find_resource_by_resource_id(data->pdev, data->rtype, v->contents.object->id);

    if (pres == NULL)
	return_error(gs_error_unregistered); /* Must not happen. */
    pres->where_used |= data->pdev->used_mask;
    return 0;
}

static int 
process_resources1(void *client_data, const byte *key_data, uint key_size, const cos_value_t *v)
{
    pdf_resource_enum_data_t *data = (pdf_resource_enum_data_t *)client_data;
    static const char *rn[] = {PDF_RESOURCE_TYPE_NAMES};
    int i;

    for (i = 0; i < count_of(rn); i++) {
	if (rn[i] != NULL && !bytes_compare((const byte *)rn[i], strlen(rn[i]), key_data, key_size))
	    break;
    }
    if (i >= count_of(rn))
	return 0;
    data->rtype = i;
    return cos_dict_forall((cos_dict_t *)v->contents.object, data, process_resources2);
}

/*
 * Register charproc fonts with the page or substream.
 */
int
pdf_used_charproc_resources(gx_device_pdf *pdev, pdf_font_resource_t *pdfont) 
{
    if (pdfont->where_used & pdev->used_mask)
	return 0;
    pdfont->where_used |= pdev->used_mask;
    if (pdev->CompatibilityLevel >= 1.2)
	return 0;
    if (pdfont->FontType == ft_user_defined) {
	pdf_resource_enum_data_t data;

	data.pdev = pdev;
	return cos_dict_forall(pdfont->u.simple.s.type3.Resources, &data, process_resources1);
    }
    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.
 */
static int
pdf_encode_string_element(gx_device_pdf *pdev, gs_font *font, pdf_font_resource_t *pdfont,
		  gs_char ch, const gs_glyph *gdata)
{
    gs_font_base *cfont, *ccfont;
    int code;
    gs_glyph copied_glyph;
    gs_const_string gnstr;
    pdf_encoding_element_t *pet;
    gs_glyph glyph;

    /*
     * In contradiction with pre-7.20 versions of pdfwrite,
     * we never re-encode texts due to possible encoding conflict while font merging.
     */
    cfont = pdf_font_resource_font(pdfont, false);
    ccfont = pdf_font_resource_font(pdfont, true);
    pet = &pdfont->u.simple.Encoding[ch];
    glyph = (gdata == NULL ? font->procs.encode_char(font, ch, GLYPH_SPACE_NAME)
			   : *gdata);
    if (glyph == GS_NO_GLYPH || glyph == pet->glyph)
	return 0;
    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 < 0 && code != gs_error_undefined)
	    return code;
	if (code == gs_error_undefined) {
	    if (pdev->PDFA || pdev->PDFX) {
		switch (pdev->PDFACompatibilityPolicy) {
		    case 0:
			emprintf(pdev->memory,
                             "Requested glyph not present in source font,\n not permitted in PDF/A, reverting to normal PDF output\n");
			pdev->AbortPDFAX = true;
			pdev->PDFA = false;
			break;
		    case 1:
			emprintf(pdev->memory,
                             "Requested glyph not present in source font,\n not permitted in PDF/A, glyph will not be present in output file\n\n");
			/* Returning an error causees text processing to try and
			 * handle the glyph by rendering to a bitmap instead of
			 * as a glyph in a font. This will eliminate the problem
			 * and the fiel should appear the same as the original.
			 */
			return gs_error_unknownerror;
			break;
		    case 2:
			emprintf(pdev->memory,
                             "Requested glyph not present in source font,\n not permitted in PDF/A, aborting conversion\n");
			/* Careful here, only certain errors will bubble up 
			 * through the text processing.
			 */
			return gs_error_invalidfont;
			break;
		    default:
			emprintf(pdev->memory,
                             "Requested glyph not present in source font,\n not permitted in PDF/A, unrecognised PDFACompatibilityLevel,\nreverting to normal PDF output\n");
			pdev->AbortPDFAX = true;
			pdev->PDFA = false;
			break;
		}
	    }
	    /* PS font has no such glyph. */
	    if (bytes_compare(gnstr.data, gnstr.size, (const byte *)".notdef", 7)) {
		pet->glyph = glyph;
		pet->str = gnstr;
		pet->is_difference = true;
	    }
	} else 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, &gnstr);
    if (code < 0)
	return code;
    pet->glyph = glyph;
    pet->str = gnstr;
    return 0;
}

/*
 * Estimate text bbox.
 */
static 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;

	if (glyph == gs_no_glyph)
	    return_error (gs_error_invalidfont);

	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 && pte->text.operation & TEXT_ADD_TO_SPACE_WIDTH) {
		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;
}

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;
    }
}

int
pdf_shift_text_currentpoint(pdf_text_enum_t *penum, gs_point *wpt)
{
    gs_state *pgs;
    extern_st(st_gs_state);

    if (gs_object_type(penum->dev->memory, penum->pis) != &st_gs_state) {
	/* Probably never happens. Not sure though. */
	return_error(gs_error_unregistered);
    }
    pgs = (gs_state *)penum->pis;
    return gs_moveto_aux(penum->pis, gx_current_path(pgs),
			      fixed2float(penum->origin.x) + wpt->x, 
			      fixed2float(penum->origin.y) + wpt->y);
}

/*
 * 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.
 */
static 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, const gs_glyph *gdata,
				      gs_point *pdpt, int *accepted);
static int
pdf_process_string(pdf_text_enum_t *penum, gs_string *pstr,
		   const gs_matrix *pfmat,
		   pdf_text_process_state_t *ppts, const gs_glyph *gdata)
{
    gx_device_pdf *const pdev = (gx_device_pdf *)penum->dev;
    gs_font_base *font = (gs_font_base *)penum->current_font;
    pdf_font_resource_t *pdfont;
    const gs_text_params_t *text = &penum->text;
    int code = 0, mask;
    gs_point width_pt;
    int accepted;

    code = pdf_obtain_font_resource(penum, pstr, &pdfont);
    if (code < 0)
	return code;
    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 (text->size == 0)
	return 0;
    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).
	 */
	gs_rect text_bbox = {{0, 0}, {0, 0}};

	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, gdata,
					 &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, 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.operation & TEXT_REPLACE_WIDTHS) ? 0 :
			     penum->text.x_widths == penum->text.y_widths ? 2 : 1);
	/* A glyphshow takes a shortcut by storing the single glyph directly into
	 * penum->text.data.d_glyph. However, process_text_modify_width
	 * replaces pte->text.data.bytes (these two are part of a union) with
	 * pstr->data, which is not valid for a glyphshow because it alters
	 * the glyph value store there. If we make a copy of the single glyph, 
	 * it all works correctly.then 
	 */
	gs_glyph gdata_i, *gdata_p = (gs_glyph *)gdata;
	if (penum->text.operation & TEXT_FROM_SINGLE_GLYPH) {
	    gdata_i = *gdata;
	    gdata_p = &gdata_i;
	}

	if (penum->text.operation & TEXT_REPLACE_WIDTHS) {
	    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, (const gs_glyph *)gdata_p, false);
	if (penum->text.operation & TEXT_REPLACE_WIDTHS) {
	    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 pdf_shift_text_currentpoint(penum, &width_pt);
}

/*
 * 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.
 */
static 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, NULL);
	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, NULL);
	}
	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) {
	    if (!(pdfont->used[ch >> 3] & 0x80 >> (ch & 7)))
		return gs_error_undefined; /* The charproc was not accumulated. */
	    if (!pdev->charproc_just_accumulated &&
		!(pdfont->u.simple.s.type3.cached[ch >> 3] & 0x80 >> (ch & 7))) {
		 /* The charproc uses setcharwidth. 
		    Need to accumulate again to check for a glyph variation. */
		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];
	    pwidths->replaced_v = 0;
	} 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;
}

/*
 * Convert glyph widths (.Width.xy and .real_widths.xy) from design to PDF text space
 * Zero-out one of Width.xy.x/y per PDF Ref 5.3.3 "Text Space Details"
 */
static void
pdf_char_widths_to_uts(pdf_font_resource_t *pdfont /* may be NULL for non-Type3 */,
		       pdf_glyph_widths_t *pwidths)
{
    if (pdfont && pdfont->FontType == ft_user_defined) {
	gs_matrix *pmat = &pdfont->u.simple.s.type3.FontMatrix;

	pwidths->Width.xy.x *= pmat->xx; /* formula simplified based on wy in glyph space == 0 */
	pwidths->Width.xy.y  = 0.0; /* WMode == 0 for PDF Type 3 fonts */
	gs_distance_transform(pwidths->real_width.xy.x, pwidths->real_width.xy.y, pmat, &pwidths->real_width.xy);
    } else {
	/*
	 * For other font types:
	 * - PDF design->text space is a simple scaling by 0.001.
	 * - The Width.xy.x/y that should be zeroed-out per 5.3.3 "Text Space Details" is already 0.
	 */
	pwidths->Width.xy.x /= 1000.0;
	pwidths->Width.xy.y /= 1000.0;
	pwidths->real_width.xy.x /= 1000.0;
	pwidths->real_width.xy.y /= 1000.0;
    }
}

/*
 * Compute the total text width (in user space).  Return 1 if any
 * character had real_width != Width, otherwise 0.
 */
static 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, const gs_glyph *gdata,
			  gs_point *pdpt, int *accepted)
{
    int i;
    gs_point w;
    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;
    gx_device_pdf *pdev = (gx_device_pdf *)pte->dev;
    pdf_font_resource_t *pdfont;

    code = pdf_attached_font_resource(pdev, (gs_font *)font, &pdfont, NULL, NULL, NULL, NULL);
    if (code < 0)
	return code;
    for (i = 0, w.x = w.y = 0; i < pstr->size; ++i) {
	pdf_glyph_widths_t cw; /* in PDF text space */
	gs_char ch = pstr->data[i];

	{  const gs_glyph *gdata_i = (gdata != NULL ? gdata + i : 0);

	    code = pdf_encode_string_element(pdev, (gs_font *)font, pdfont, ch, gdata_i);
	    if (code < 0)
		return code;
	}
	if (font->FontType == ft_user_defined &&
	    (i > 0 || !pdev->charproc_just_accumulated) &&
	    !(pdfont->u.simple.s.type3.cached[ch >> 3] & (0x80 >> (ch & 7))))
	    code = gs_error_undefined;
	else 
	    code = pdf_char_widths((gx_device_pdf *)pte->dev,
	                           ppts->values.pdfont, ch, font,
				   &cw);
	if (code < 0) {
	    if (i)
		break;
	    *accepted = 0;
	    return code;
	}
	pdf_char_widths_to_uts(pdfont, &cw);
	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 * ppts->values.size, w.y * ppts->values.size,
			  &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;
}

#define RIGHT_SBW 1 /* Old code = 0, new code = 1. */
#if !RIGHT_SBW
/*
 * Retrieve glyph origing shift for WMode = 1 in design units.
 */
static 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;
    }
}
#endif

/*
 * 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.
 * 
 * Destroys the text parameters in *pte. 
 * The caller must restore them.
 */
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, const gs_glyph *gdata, bool composite)
{
    gx_device_pdf *const pdev = (gx_device_pdf *)pte->dev;
    int space_char =
	(pte->text.operation & TEXT_ADD_TO_SPACE_WIDTH ?
	 pte->text.space.s_char : -1);
    gs_point start, total;
    pdf_font_resource_t *pdfont3 = NULL;
    int code;

    if (font->FontType == ft_user_defined) {
	code = pdf_attached_font_resource(pdev, font, &pdfont3, NULL, NULL, NULL, NULL);
        if (code < 0)
	    return code;

    }
    pte->text.data.bytes = pstr->data;
    pte->text.size = pstr->size;
    pte->index = 0;
    pte->text.operation &= ~TEXT_FROM_ANY;
    pte->text.operation |= TEXT_FROM_STRING;
    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, then converted to PDF text space */
	gs_point did, wanted, tpt;	/* user space */
	gs_point v = {0, 0}; /* design space */
	gs_char chr;
	gs_glyph glyph;
	int index = pte->index;
	gs_text_enum_t pte1 = *(gs_text_enum_t *)pte;
	int FontType;
#if RIGHT_SBW
	bool use_cached_v = true;
#endif
	byte composite_type3_text[1];

	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;

	    if (subfont->FontType == ft_user_defined) {
		pdf_font_resource_t *pdfont;

		FontType = subfont->FontType;
		code = pdf_attached_font_resource(pdev, subfont, 
			    &pdfont, NULL, NULL, NULL, NULL);
		if (code < 0)
		    return code;
		chr = pdf_find_glyph(pdfont, glyph);
		composite_type3_text[0] = (byte)chr;
		code = pdf_char_widths((gx_device_pdf *)pte->dev,
				       ppts->values.pdfont, chr, (gs_font_base *)subfont,
				       &cw);
	    } else {
		pdf_font_resource_t *pdsubf = ppts->values.pdfont->u.type0.DescendantFont;

		FontType = pdsubf->FontType;
		code = pdf_glyph_widths(pdsubf, font->WMode, glyph, subfont, &cw, 
		    pte->cdevproc_callout ? pte->cdevproc_result : NULL);
	    }
	} else {/* must be a base font */
	    const gs_glyph *gdata_i = (gdata != NULL ? gdata + pte->index : 0);

		/* gdata is NULL when composite == true, or the text isn't a single byte.  */
	    code = pdf_encode_string_element(pdev, font, ppts->values.pdfont, chr, gdata_i);
	    FontType = font->FontType;
	    if (code >= 0) {
		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, NULL);
		    use_cached_v = false; /* Since we have no chr and don't call pdf_char_widths. */
		} 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 RIGHT_SBW
	if (composite || !use_cached_v) {
	    if (cw.replaced_v) {
		v.x = cw.real_width.v.x - cw.Width.v.x;
		v.y = cw.real_width.v.y - cw.Width.v.y;
	    }
	} else
	    v = ppts->values.pdfont->u.simple.v[chr];
	if (font->WMode) {
	    /* With WMode 1 v-vector is (WMode 1 origin) - (WMode 0 origin).
	       The glyph shifts in the opposite direction.  */
	    v.x = - v.x;
	    v.y = - v.y;
	} else {
	    /* With WMode 0 v-vector is (Metrics sb) - (native sb).
	       The glyph shifts in same direction.  */
	}
	/* pdf_glyph_origin is not longer used. */
#else
	if ((pte->text.operation & TEXT_FROM_SINGLE_GLYPH) ||
	    (pte->text.operation & TEXT_FROM_GLYPHS)) {
	    v.x = v.y = 0;
	} else if (composite) {
	    if (cw.replaced_v) {
		v.x = cw.real_width.v.x - cw.Width.v.x;
		v.y = cw.real_width.v.y - cw.Width.v.y;
	    }
	} else
	    pdf_glyph_origin(ppts->values.pdfont, chr, font->WMode, &v);
#endif
	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;
#if RIGHT_SBW
	    glyph_origin_shift.x = v.x * scale0;
	    glyph_origin_shift.y = v.y * scale0;
#else
	    glyph_origin_shift.x = - v.x * scale0;
	    glyph_origin_shift.y = - v.y * scale0;
#endif
	    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,
				  &font->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;
	    }
	}
	pdf_char_widths_to_uts(pdfont3, &cw); /* convert design->text space */
	if (pte->text.operation & (TEXT_DO_DRAW | TEXT_RENDER_MODE_3)) {
	    gs_distance_transform(cw.Width.xy.x * ppts->values.size,
				  cw.Width.xy.y * ppts->values.size,
				  &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;
	    }
	    if (composite && FontType == ft_user_defined)
		code = pdf_append_chars(pdev, composite_type3_text, 1, did.x, did.y, composite);
	    else
		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 * ppts->values.size,
				  cw.real_width.xy.y * ppts->values.size,
				  &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 && pte->text.operation & TEXT_ADD_TO_SPACE_WIDTH) {
		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;
	}
	pdev->charproc_just_accumulated = false;
    }
    *pdpt = total;
    return 0;
}

/*
 * 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 *penum = (pdf_text_enum_t *)pte;
    int code;
    gs_string str;
    pdf_text_process_state_t text_state;
    const gs_glyph *gdata = NULL;

    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);
    } 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;
	}
    } 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 or outlines.
	 *
	 * 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.
	 */
	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)
		break;
	    count += char_code_length;
	    if (operation & TEXT_INTERVENE)
		break; /* Just do one character. */
	}
	if (i < size) {
	    pdf_font_resource_t *pdfont; 

	    str.data = buf;
	    str.size = size;
	    code = pdf_obtain_font_resource_unencoded(penum, &str, &pdfont, gdata);
	    if (code < 0) {
		/* 
		 * pdf_text_process will fall back 
		 * to default implementation.
		 */
		return code;
	    }
	    count = size;
	}
	/*  So far we will use TEXT_FROM_STRING instead
	    TEXT_FROM_*_GLYPH*. Since we used a single 
	    byte encoding, the character index appears invariant
	    during this substitution.
	 */
    } else
	return_error(gs_error_rangecheck);
    str.data = buf;
    if (count > 1 && (operation & TEXT_INTERVENE)) {
	/* Just do one character. */
	str.size = 1;
	code = pdf_process_string_aux(penum, &str, gdata, NULL, &text_state);
	if (code >= 0) {
	    pte->returned.current_char = buf[0];
	    code = TEXT_PROCESS_INTERVENE;
	}
    } else {
	str.size = count;
	code = pdf_process_string_aux(penum, &str, gdata, NULL, &text_state);
    }
    return code;
}
