/* Copyright (C) 2002 Aladdin Enterprises.  All rights reserved.
  
  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License version 2
  as published by the Free Software Foundation.


  This software is provided AS-IS with no warranty, either express or
  implied. That is, this program is distributed in the hope that it will 
  be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  59 Temple Place, Suite 330, Boston, MA, 02111-1307.
  
  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: gdevpdtf.h,v 1.8 2002/09/15 13:21:09 igor Exp $ */
/* Font and CMap resource structure and API for pdfwrite */

#ifndef gdevpdtf_INCLUDED
#  define gdevpdtf_INCLUDED

#include "gdevpdtx.h"

/* ================ Types and structures ================ */

/* ---------------- Font resources ---------------- */

/*
 * pdfwrite manages several different flavors of font resources:
 *
 *  Those that have neither a FontDescriptor nor a base_font:
 *	Type 0 (composite) fonts
 *  Those that have no FontDescriptor, but do have a base_font:
 *	Standard 14 fonts
 *  Those that have a FontDescriptor but no base_font:
 *	Type 3 bitmap fonts
 *  Those that have a FontDescriptor with a base_font:
 *	Type 1 / Type 2 fonts
 *	Type 42 (TrueType) fonts
 *	CIDFontType 0 (Type 1/2) CIDFonts
 *	CIDFontType 2 (TrueType) CIDFonts
 */
/*
 * Font names in PDF files have caused an enormous amount of trouble, so we
 * document specifically how they are handled in each structure.
 *
 * The PDF Reference specifies the BaseFont of a font resource as follows,
 * depending on the font type:
 *
 *   Type 0 - if the descendant font is CIDFontType 0, the descendant font
 *     name followed by a hyphen and the CMap name (the value of Encoding,
 *     if a name, otherwise the CMapName from the CMap); if the descendant
 *     font is CIDFontType 2, the descendant font name.
 *
 *   Type 1 - "usually" the same as the FontName in the base font.
 *
 *   MM Type 1 - if embedded, the same as Type 1; if not embedded, spaces
 *     in the font name are replaced with underscores.
 *
 *   Type 3 - not used.
 *
 *   TrueType - initially, the PostScript name from the 'name' table in
 *     the font; if none, the "name by which the font is known in the host
 *     operating system".  Spaces are removed.  Then, under circumstances
 *     not defined, the string ",Bold", ",Italic", or ",BoldItalic" is
 *     appended if the font has the corresponding style properties.
 *     [We do not do this: we simply use the key_name or font_name.]
 *
 *   CIDFontType 0 - "usually" the same as the CIDFontName in the base font.
 *
 *   CIDFontType 2 - the same as TrueType.
 *
 * In addition, the BaseFont has a XXXXXX+ prefix if the font is a subset
 * (whether embedded or not).
 *
 * We would like to compute the BaseFont at the time that we create the font
 * resource object.  The font descriptor (which is needed to provide
 * information about embedding) and the base font are both available at that
 * time.  Unfortunately, the information as to whether the font will be
 * subsetted is not available.  Therefore, we do compute the BaseFont from
 * the base font name when the font resource is created, to allow checking
 * for duplicate names and for standard font names, but we compute it again
 * after writing out the base font.
 */

#ifndef gs_cmap_DEFINED
#  define gs_cmap_DEFINED
typedef struct gs_cmap_s gs_cmap_t;
#endif

#ifndef gs_font_type0_DEFINED
#  define gs_font_type0_DEFINED
typedef struct gs_font_type0_s gs_font_type0;
#endif

#ifndef pdf_base_font_DEFINED
#  define pdf_base_font_DEFINED
typedef struct pdf_base_font_s pdf_base_font_t;
#endif

#ifndef pdf_font_descriptor_DEFINED
#  define pdf_font_descriptor_DEFINED
typedef struct pdf_font_descriptor_s pdf_font_descriptor_t;
#endif

/*
 * The write_contents procedure is set by the implementation when the
 * font resource is created.  It is called after generic code has opened
 * the resource object and written the Type, BaseFont (if any),
 * FontDescriptor reference (if any), ToUnicode CMap reference (if any),
 * and additional dictionary entries (if any).
 * The write_contents procedure must write any remaining entries specific
 * to the FontType, followed by the closing ">>", and then call
 * pdf_end_separate.  The reason for this division of function is to allow
 * the write_contents procedure to write additional objects that the
 * resource object references, after closing the resource object.
 */
typedef int (*pdf_font_write_contents_proc_t)
     (gx_device_pdf *, pdf_font_resource_t *);

/*
 * Define an element of an Encoding.  The element is unused if glyph ==
 * GS_NO_GLYPH.
 */
typedef struct pdf_encoding_element_s {
    gs_glyph glyph;
    gs_const_string str;
    bool is_difference;		/* true if must be written in Differences */
} pdf_encoding_element_t;
#define private_st_pdf_encoding1() /* gdevpdtf.c */\
  gs_private_st_const_strings1(st_pdf_encoding1,\
    pdf_encoding_element_t, "pdf_encoding_element_t",\
    pdf_encoding1_enum_ptrs, pdf_encoding1_reloc_ptrs, str)
#define private_st_pdf_encoding_element() /* gdevpdtf.c */\
  gs_private_st_element(st_pdf_encoding_element, pdf_encoding_element_t,\
    "pdf_encoding_element_t[]", pdf_encoding_elt_enum_ptrs,\
    pdf_encoding_elt_reloc_ptrs, st_pdf_encoding1)

/*
 * Widths are the widths in the outlines: this is what PDF interpreters
 * use, and what will be written in the PDF file.  real_widths are the
 * widths possibly modified by Metrics[2] and CDevProc: these define the
 * actual advance widths of the characters in the PostScript text.
 */
struct pdf_font_resource_s {
    pdf_resource_common(pdf_font_resource_t);
    font_type FontType;		/* copied from font, if any */
    pdf_font_write_contents_proc_t write_contents;
    gs_string BaseFont;		/* (not used for Type 3) */
    pdf_font_descriptor_t *FontDescriptor; /* (not used for Type 0, Type 3, */
				/* or standard 14 fonts) */
    /*
     * Currently, the base_font and copied_font members are only used for
     * the standard 14 fonts, which do not have a FontDescriptor.
     * Eventually we may decide to use them for other types as well.
     */
    pdf_base_font_t *base_font;	/* == FontDescriptor->base_font */
    gs_font_base *copied_font;	/* == base_font->copied */
    uint count;			/* # of chars/CIDs */
    double *Widths;		/* [count] (not used for Type 0) */
    byte *used;			/* [ceil(count/8)] bitmap of chars/CIDs used */
				/* (not used for Type 0 or Type 3) */
    pdf_resource_t *ToUnicode;	/* CMap (not used for CIDFonts) */
    union {

	struct /*type0*/ {

	    pdf_font_resource_t *DescendantFont; /* CIDFont */
	    /*
	     * The Encoding_name must be long enough to hold either the
	     * longest standard CMap name defined in the PDF Reference,
	     * or the longest reference to an embedded CMap (# 0 R).
	     */
	    char Encoding_name[max( /* standard name or <id> 0 R */
		      17,	/* /UniJIS-UCS2-HW-H */
		      sizeof(long) * 8 / 3 + 1 + 4 /* <id> 0 R */
		      ) + 1	/* \0 terminator */
	    ];
	    gs_const_string CMapName; /* copied from the original CMap, */
				/* or references the table of standard names */
	    bool cmap_is_standard;
	    int WMode;		/* of CMap */

	} type0;

	struct /*cidfont*/ {

	    /* [D]W[2] is Widths. */
	    long CIDSystemInfo_id; /* (written when font is allocated) */
	    ushort *CIDToGIDMap; /* (CIDFontType 2 only) [count] */
 	    gs_id glyphshow_font_id;

	} cidfont;

	struct /*simple*/ {

	    int FirstChar, LastChar; /* 0 <= FirstChar <= LastChar <= 255 */
	    /*
	     * The BaseEncoding can only be ENCODING_INDEX_WINANSI,
	     * ENCODING_INDEX_MACROMAN, ENCODING_INDEX_MACEXPERT, or -1.
	     */
	    gs_encoding_index_t BaseEncoding;
	    pdf_encoding_element_t *Encoding; /* [256], not for Type 3 */
	    gs_point *v; /* [256], glyph origin for WMode 1 */

	    union {

		struct /*type1*/ {
		    bool is_MM_instance;
		} type1;

		struct /*truetype*/ {
		    /*
		     * No extra info needed, but the ANSI standard doesn't
		     * allow empty structs.
		     */
		    int _dummy;
		} truetype;

		struct /*type3*/ {
		    gs_int_rect FontBBox;
		    pdf_char_proc_t *char_procs;
		    int max_y_offset;
		} type3;

	    } s;

	} simple;

    } u;
};
/* The GC descriptor for resource types must be public. */
#define public_st_pdf_font_resource() /* gdevpdtf.c */\
  gs_public_st_composite(st_pdf_font_resource, pdf_font_resource_t,\
    "pdf_font_resource_t", pdf_font_resource_enum_ptrs,\
    pdf_font_resource_reloc_ptrs)

/*
 * Define the possible embedding statuses of a font.
 */
typedef enum {
    FONT_EMBED_STANDARD,	/* 14 standard fonts */
    FONT_EMBED_NO,
    FONT_EMBED_YES
} pdf_font_embed_t;

/* ---------------- Global structures ---------------- */

/*
 * Define a structure for keeping track of the (unique) resource for
 * each standard font.  Note that standard fonts do not have descriptors:
 * the base_font and copied_font members of the font resource provide the
 * necessary information.
 */
typedef struct pdf_standard_font_s {
    pdf_font_resource_t *pdfont;
    gs_matrix orig_matrix;	/* ****** do we need this? */
} pdf_standard_font_t;
#define private_st_pdf_standard_font() /* gdevpdtf.c */\
  gs_private_st_ptrs1(st_pdf_standard_font, pdf_standard_font_t,\
    "pdf_standard_font_t", pdf_std_font_enum_ptrs, pdf_std_font_reloc_ptrs,\
    pdfont)
#define private_st_pdf_standard_font_element() /* gdevpdtf.c */\
  gs_private_st_element(st_pdf_standard_font_element, pdf_standard_font_t,\
    "pdf_standard_font_t[]", pdf_std_font_elt_enum_ptrs,\
    pdf_std_font_elt_reloc_ptrs, st_pdf_standard_font)

/*
 * There is a single instance (per device) of a structure that tracks global
 * information about outline fonts.  It is defined here, rather than
 * opaquely in the implementation file, because the text processing code
 * needs access to it.
 */

/*typedef struct pdf_outline_fonts_s pdf_outline_fonts_t;*/  /* gdevpdtx.h */
struct pdf_outline_fonts_s {
    pdf_standard_font_t *standard_fonts; /* [PDF_NUM_STANDARD_FONTS] */
};
#define private_st_pdf_outline_fonts() /* gdevpdtf.c */\
  gs_private_st_ptrs1(st_pdf_outline_fonts, pdf_outline_fonts_t,\
    "pdf_outline_fonts_t", pdf_outline_fonts_enum_ptrs,\
    pdf_outline_fonts_reloc_ptrs, standard_fonts)

/* ================ Procedures ================ */

/* ---------------- Font resources ---------------- */

/*
 * Allocate and initialize bookkeeping for outline fonts.
 */
pdf_outline_fonts_t *pdf_outline_fonts_alloc(gs_memory_t *mem);

/*
 * Return the standard fonts array.
 */
pdf_standard_font_t *pdf_standard_fonts(const gx_device_pdf *pdev);

/*
 * Allocate specific types of font resource.
 */
int pdf_font_type0_alloc(gx_device_pdf *pdev, pdf_font_resource_t **ppfres,
			 gs_id rid, pdf_font_resource_t *DescendantFont);
int pdf_font_type3_alloc(gx_device_pdf *pdev, pdf_font_resource_t **ppfres,
			 pdf_font_write_contents_proc_t write_contents);
int pdf_font_std_alloc(gx_device_pdf *pdev, pdf_font_resource_t **ppfres,
		       gs_id rid, gs_font_base *pfont, int index);
int pdf_font_simple_alloc(gx_device_pdf *pdev, pdf_font_resource_t **ppfres,
			  gs_id rid, pdf_font_descriptor_t *pfd);
int pdf_font_cidfont_alloc(gx_device_pdf *pdev, pdf_font_resource_t **ppfres,
			   gs_id rid, pdf_font_descriptor_t *pfd);

/*
 * Return the (copied, subset) font associated with a font resource.
 * If this font resource doesn't have a descriptor (Type 0, Type 3, or
 * standard 14), return 0.
 */
gs_font_base *pdf_font_resource_font(const pdf_font_resource_t *pdfont);

/*
 * Determine the embedding status of a font.  If the font is in the base
 * 14, store its index (0..13) in *pindex and its similarity to the base
 * font (as determined by the font's same_font procedure) in *psame.
 * (pindex and/or psame may be NULL.)
 */
pdf_font_embed_t pdf_font_embed_status(gx_device_pdf *pdev, gs_font *font,
				       int *pindex,
				       gs_glyph *glyphs, int num_glyphs);

/*
 * Compute the BaseFont of a font according to the algorithm described
 * above.
 */
int pdf_compute_BaseFont(gx_device_pdf *pdev, pdf_font_resource_t *pdfont);

/*
 * Close the text-related parts of a document, including writing out font
 * and related resources.
 */
int pdf_close_text_document(gx_device_pdf *pdev); /* in gdevpdtw.c */

/* ---------------- CMap resources ---------------- */

/*
 * Allocate a CMap resource.
 */
int pdf_cmap_alloc(gx_device_pdf *pdev, const gs_cmap_t *pcmap,
		   pdf_resource_t **ppres /* CMap */);

/*
 * Add a CID-to-GID mapping to a CIDFontType 2 font resource.
 */
int pdf_font_add_cid_to_gid(pdf_font_resource_t *pdfont, uint cid, uint gid);

#endif /* gdevpdtf_INCLUDED */
