harvey/sys/src/cmd/gs/src/gxfont.h

/* Copyright (C) 1989, 1995, 1996, 1997, 1999, 2000 Aladdin Enterprises.  All rights reserved.
  
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  she says so in writing.  Refer to the Aladdin Free Public License (the
  "License") for full details.
  
  Every copy of AFPL Ghostscript must include a copy of the License, normally
  in a plain ASCII text file named PUBLIC.  The License grants you the right
  to copy, modify and redistribute AFPL Ghostscript, but only under certain
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  requires that the copyright notice and this notice be preserved on all
  copies.
*/

/*$Id: gxfont.h,v 1.3 2000/11/23 23:23:40 lpd Exp $ */
/* Font object structure */
/* Requires gsmatrix.h, gxdevice.h */

#ifndef gxfont_INCLUDED
#  define gxfont_INCLUDED

#include "gsccode.h"
#include "gsfont.h"
#include "gsnotify.h"
#include "gsuid.h"
#include "gsstype.h"		/* for extern_st */
#include "gxftype.h"

/* A font object as seen by clients. */
/* See the PostScript Language Reference Manual for details. */

#ifndef gs_text_enum_DEFINED
#  define gs_text_enum_DEFINED
typedef struct gs_text_enum_s gs_text_enum_t;
#endif

#ifndef gx_path_DEFINED
#  define gx_path_DEFINED
typedef struct gx_path_s gx_path;
#endif

/*
 * Define flags for font properties (Flags* members in the structure below.)
 *  Currently these must match the ones defined for PDF.
 */
#define FONT_IS_FIXED_WIDTH (1<<0)
/*
 * Define the structure used to return information about the font as a
 * whole.  Currently this structure almost exactly parallels the PDF
 * FontDescriptor.
 *
 * Unless otherwise specified, values are in the font's native character
 * space, scaled as requested by the call to the font_info procedure.
 * Note that Type 1 fonts typically have 1000 units per em, while
 * TrueType fonts typically have 1 unit per em.
 */
typedef struct gs_font_info_s {
    int members;

    /* The following members exactly parallel the PDF FontDescriptor flags. */

#define FONT_INFO_ASCENT 0x0001
    int Ascent;
#define FONT_INFO_AVG_WIDTH 0x0002
    int AvgWidth;
#define FONT_INFO_BBOX 0x0004
    gs_int_rect BBox;		/* computed from outlines, not FontBBox */
#define FONT_INFO_CAP_HEIGHT 0x0008
    int CapHeight;
#define FONT_INFO_DESCENT 0x0010
    int Descent;
#define FONT_INFO_FLAGS 0x0020
    uint Flags;			/* a mask of FONT_IS_ bits */
    uint Flags_requested;	/* client must set this if FLAGS requested */
    uint Flags_returned;
#define FONT_INFO_ITALIC_ANGLE 0x0100
    float ItalicAngle;		/* degrees CCW from vertical */
#define FONT_INFO_LEADING 0x0200
    int Leading;
#define FONT_INFO_MAX_WIDTH 0x0400
    int MaxWidth;
#define FONT_INFO_MISSING_WIDTH 0x0800
    int MissingWidth;
#define FONT_INFO_STEM_H 0x00010000
    int StemH;
#define FONT_INFO_STEM_V 0x00020000
    int StemV;
#define FONT_INFO_UNDERLINE_POSITION 0x00040000
    int UnderlinePosition;
#define FONT_INFO_UNDERLINE_THICKNESS 0x00080000
    int UnderlineThickness;
#define FONT_INFO_X_HEIGHT 0x00100000
    int XHeight;

    /* The following members do NOT appear in the PDF FontDescriptor. */

#define FONT_INFO_COPYRIGHT 0x0040
    gs_const_string Copyright;
#define FONT_INFO_NOTICE 0x0080
    gs_const_string Notice;
#define FONT_INFO_FAMILY_NAME 0x1000
    gs_const_string FamilyName;
#define FONT_INFO_FULL_NAME 0x2000
    gs_const_string FullName;

} gs_font_info_t;

/*
 * Define the structure used to return information about a glyph.
 */
typedef struct gs_glyph_info_s {
    int members;		/* mask of which members are valid */
#define GLYPH_INFO_WIDTH0 1
#define GLYPH_INFO_WIDTH GLYPH_INFO_WIDTH0
#define GLYPH_INFO_WIDTH1 2	/* must be WIDTH0 << 1 */
#define GLYPH_INFO_WIDTHS (GLYPH_INFO_WIDTH0 | GLYPH_INFO_WIDTH1)
    gs_point width[2];		/* width for WMode 0/1 */
#define GLYPH_INFO_BBOX 4
    gs_rect bbox;
#define GLYPH_INFO_NUM_PIECES 8
    int num_pieces;		/* # of pieces if composite, 0 if not */
#define GLYPH_INFO_PIECES 16
    gs_glyph *pieces;		/* pieces are stored here: the caller must */
				/* preset pieces if INFO_PIECES is set. */
} gs_glyph_info_t;

/* Define the "object" procedures of fonts. */

typedef struct gs_font_procs_s {

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

    /*
     * Define any special handling of gs_definefont.
     * We break this out so it can be different for composite fonts.
     */

#define font_proc_define_font(proc)\
  int proc(P2(gs_font_dir *, gs_font *))
    font_proc_define_font((*define_font));

    /*
     * Define any special handling of gs_makefont.
     * We break this out so it can be different for composite fonts.
     */

#define font_proc_make_font(proc)\
  int proc(P4(gs_font_dir *, const gs_font *, const gs_matrix *, gs_font **))
    font_proc_make_font((*make_font));

    /*
     * Get information about the font, as specified by the members mask.
     * Disregard the FontMatrix: scale the font as indicated by *pscale
     * (pscale=NULL means no scaling).  Set info->members to the members
     * that are actually returned.  Note that some member options require
     * the caller to preset some of the elements of info.  Note also that
     * this procedure may return more information than was requested.
     */

#define font_proc_font_info(proc)\
  int proc(P4(gs_font *font, const gs_point *pscale, int members,\
	      gs_font_info_t *info))
    font_proc_font_info((*font_info));

    /*
     * Determine whether this font is the "same as" another font in the ways
     * specified by the mask.  The returned value is a subset of the mask.
     * This procedure is allowed to be conservative (return false in cases
     * of uncertainty).  Note that this procedure does not test the UniqueID
     * or FontMatrix.
     */

#define FONT_SAME_OUTLINES 1
#define FONT_SAME_METRICS 2
#define FONT_SAME_ENCODING 4

#define font_proc_same_font(proc)\
  int proc(P3(const gs_font *font, const gs_font *ofont, int mask))
    font_proc_same_font((*same_font));

    /* ------ Glyph-level procedures ------ */

    /* Map a character code to a glyph.  Some PostScript fonts use both
     * names and indices to identify glyphs: for example, in PostScript Type
     * 42 fonts, the Encoding array maps character codes to glyph names, and
     * the CharStrings dictionary maps glyph names to glyph indices.  In
     * such fonts, the glyph_space argument determines which type of glyph
     * is returned.
     */

#define font_proc_encode_char(proc)\
  gs_glyph proc(P3(gs_font *, gs_char, gs_glyph_space_t))
    font_proc_encode_char((*encode_char));

    /*
     * Get the next glyph in an enumeration of all glyphs defined by the
     * font.  index = 0 means return the first one; a returned index of 0
     * means the enumeration is finished.  The glyphs are enumerated in
     * an unpredictable order.
     */

#define font_proc_enumerate_glyph(proc)\
  int proc(P4(gs_font *font, int *pindex, gs_glyph_space_t glyph_space,\
	      gs_glyph *pglyph))
    font_proc_enumerate_glyph((*enumerate_glyph));

    /*
     * Get information about a glyph, as specified by the members mask.
     * pmat = NULL means get the scalable values; non-NULL pmat means get
     * the scaled values.  Set info->members to the members that are
     * actually returned.  Return gs_error_undefined if the glyph doesn't
     * exist in the font; calling glyph_info with members = 0 is an
     * efficient way to find out whether a given glyph exists.  Note that
     * some member options require the caller to preset some of the elements
     * of info.  Note also that this procedure may return more information
     * than was requested.
     */

#define font_proc_glyph_info(proc)\
  int proc(P5(gs_font *font, gs_glyph glyph, const gs_matrix *pmat,\
	      int members, gs_glyph_info_t *info))
    font_proc_glyph_info((*glyph_info));

    /*
     * Append the outline for a glyph to a path, with the glyph origin
     * at the current point.  pmat is as for glyph_width.  The outline
     * does include a final moveto for the advance width.
     */

#define font_proc_glyph_outline(proc)\
  int proc(P4(gs_font *font, gs_glyph glyph, const gs_matrix *pmat,\
	      gx_path *ppath))
    font_proc_glyph_outline((*glyph_outline));

    /* ------ Glyph rendering procedures ------ */

    /*
     * Define any needed procedure for initializing the composite
     * font stack in a show enumerator.  This is a no-op for
     * all but composite fonts.
     */

#define font_proc_init_fstack(proc)\
  int proc(P2(gs_text_enum_t *, gs_font *))
    font_proc_init_fstack((*init_fstack));

    /*
     * Define the font's algorithm for getting the next character or glyph
     * from a string being shown.  This is trivial, except for composite
     * fonts.  Returns 0 if the current (base) font didn't change, 1 if it
     * did change, 2 if there are no more characters, or an error code.
     *
     * This procedure may set either *pchar to gs_no_char or *pglyph to
     * gs_no_glyph, but not both.
     */

#define font_proc_next_char_glyph(proc)\
  int proc(P3(gs_text_enum_t *pte, gs_char *pchar, gs_glyph *pglyph))
    font_proc_next_char_glyph((*next_char_glyph));

    /*
     * Define a client-supplied BuildChar/BuildGlyph procedure.
     * The gs_char may be gs_no_char (for BuildGlyph), or the gs_glyph
     * may be gs_no_glyph (for BuildChar), but not both.  Return 0 for
     * success, 1 if the procedure was unable to render the character
     * (but no error occurred), <0 for error.
     */

#define font_proc_build_char(proc)\
  int proc(P5(gs_text_enum_t *, gs_state *, gs_font *, gs_char, gs_glyph))
    font_proc_build_char((*build_char));

    /* Callback procedures for external font rasterizers */
    /* (see gsccode.h for details.) */

    gx_xfont_callbacks callbacks;

} gs_font_procs;

/* Default font-level font procedures in gsfont.c */
font_proc_define_font(gs_no_define_font);
font_proc_make_font(gs_no_make_font);
font_proc_make_font(gs_base_make_font);
font_proc_font_info(gs_default_font_info);
font_proc_same_font(gs_default_same_font);
font_proc_same_font(gs_base_same_font);
/* Default glyph-level font procedures in gsfont.c */
font_proc_encode_char(gs_no_encode_char);
font_proc_enumerate_glyph(gs_no_enumerate_glyph);
font_proc_glyph_info(gs_default_glyph_info);
font_proc_glyph_outline(gs_no_glyph_outline);
/* Default glyph rendering procedures in gstext.c */
font_proc_init_fstack(gs_default_init_fstack);
font_proc_next_char_glyph(gs_default_next_char_glyph);
font_proc_build_char(gs_no_build_char);
/* Default procedure vector in gsfont.c */
extern const gs_font_procs gs_font_procs_default;

/* The font names are only needed for xfont lookup and high-level output. */
typedef struct gs_font_name_s {
#define gs_font_name_max 47	/* must be >= 40 */
    /* The +1 is so we can null-terminate for debugging printout. */
    byte chars[gs_font_name_max + 1];
    uint size;
} gs_font_name;

/*
 * Define a generic font.  We include PaintType and StrokeWidth here because
 * they affect rendering algorithms outside the Type 1 font machinery.
 *
 * ****** NOTE: If you define any subclasses of gs_font, you *must* define
 * ****** the finalization procedure as gs_font_finalize.  Finalization
 * ****** procedures are not automatically inherited.
 */
#define gs_font_common\
	gs_font *next, *prev;		/* chain for original font list or */\
					/* scaled font cache */\
	gs_memory_t *memory;		/* allocator for this font */\
	gs_font_dir *dir;		/* directory where registered */\
	bool is_resource;\
	gs_notify_list_t notify_list;	/* clients to notify when freeing */\
	gs_id id;			/* internal ID (no relation to UID) */\
	gs_font *base;			/* original (unscaled) base font */\
	void *client_data;		/* additional client data */\
	gs_matrix FontMatrix;\
	font_type FontType;\
	bool BitmapWidths;\
	fbit_type ExactSize, InBetweenSize, TransformedChar;\
	int WMode;			/* 0 or 1 */\
	int PaintType;			/* PaintType for Type 1/4/42 fonts, */\
					/* 0 for others */\
	float StrokeWidth;		/* StrokeWidth for Type 1/4/42 */\
					/* fonts (if present), 0 for others */\
	gs_font_procs procs;\
	/* We store both the FontDirectory key (key_name) and, */\
	/* if present, the FontName (font_name). */\
	gs_font_name key_name, font_name
/*typedef struct gs_font_s gs_font; *//* in gsfont.h and other places */
struct gs_font_s {
    gs_font_common;
};

extern_st(st_gs_font);		/* (abstract) */
struct_proc_finalize(gs_font_finalize);  /* public for concrete subclasses */
#define public_st_gs_font()	/* in gsfont.c */\
  gs_public_st_complex_only(st_gs_font, gs_font, "gs_font",\
    0, font_enum_ptrs, font_reloc_ptrs, gs_font_finalize)
#define st_gs_font_max_ptrs (st_gs_notify_list_max_ptrs + 5)

#define private_st_gs_font_ptr()	/* in gsfont.c */\
  gs_private_st_ptr(st_gs_font_ptr, gs_font *, "gs_font *",\
    font_ptr_enum_ptrs, font_ptr_reloc_ptrs)
#define st_gs_font_ptr_max_ptrs 1

extern_st(st_gs_font_ptr_element);
#define public_st_gs_font_ptr_element()	/* in gsfont.c */\
  gs_public_st_element(st_gs_font_ptr_element, gs_font *, "gs_font *[]",\
    font_ptr_element_enum_ptrs, font_ptr_element_reloc_ptrs, st_gs_font_ptr)

/* Allocate and minimally initialize a font. */
/* Does not set: FontMatrix, FontType, key_name, font_name. */
gs_font *
  gs_font_alloc(P5(gs_memory_t *mem, gs_memory_type_ptr_t pstype,
		   const gs_font_procs *procs, gs_font_dir *dir,
		   client_name_t cname));

/*
 * Register/unregister a client for notification by a font.  Currently
 * the clients are only notified when a font is freed.  Note that any
 * such client must unregister itself when *it* is freed.
 */
int gs_font_notify_register(P3(gs_font *font, gs_notify_proc_t proc,
			       void *proc_data));
int gs_font_notify_unregister(P3(gs_font *font, gs_notify_proc_t proc,
				 void *proc_data));

/* Define a base (not composite) font. */
#define gs_font_base_common\
	gs_font_common;\
	gs_rect FontBBox;\
	gs_uid UID;\
	gs_encoding_index_t encoding_index;\
	gs_encoding_index_t nearest_encoding_index  /* (may be >= 0 even if */\
						/* encoding_index = -1) */
#ifndef gs_font_base_DEFINED
#  define gs_font_base_DEFINED
typedef struct gs_font_base_s gs_font_base;
#endif
struct gs_font_base_s {
    gs_font_base_common;
};

extern_st(st_gs_font_base);
#define public_st_gs_font_base()	/* in gsfont.c */\
  gs_public_st_suffix_add1_final(st_gs_font_base, gs_font_base,\
    "gs_font_base", font_base_enum_ptrs, font_base_reloc_ptrs,\
    gs_font_finalize, st_gs_font, UID.xvalues)
#define st_gs_font_base_max_ptrs (st_gs_font_max_ptrs + 1)

/* Allocate and minimally initialize a base font. */
/* Does not set: same elements as gs_alloc_font. */
gs_font_base *
  gs_font_base_alloc(P5(gs_memory_t *mem, gs_memory_type_ptr_t pstype,
			const gs_font_procs *procs, gs_font_dir *dir,
			client_name_t cname));

/*
 * Test whether a glyph is the notdef glyph for a base font.
 * The test is somewhat adhoc: perhaps this should be a virtual procedure.
 */
bool gs_font_glyph_is_notdef(P2(gs_font_base *bfont, gs_glyph glyph));

#endif /* gxfont_INCLUDED */