--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/include/mupdf/fitz/font.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,858 @@
+// Copyright (C) 2004-2025 Artifex Software, Inc.
+//
+// This file is part of MuPDF.
+//
+// MuPDF is free software: you can redistribute it and/or modify it under the
+// terms of the GNU Affero General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// MuPDF 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 Affero General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
+//
+// Alternative licensing terms are available from the licensor.
+// For commercial licensing, see <https://www.artifex.com/> or contact
+// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
+// CA 94129, USA, for further information.
+
+#ifndef MUPDF_FITZ_FONT_H
+#define MUPDF_FITZ_FONT_H
+
+#include "mupdf/fitz/system.h"
+#include "mupdf/fitz/context.h"
+#include "mupdf/fitz/geometry.h"
+#include "mupdf/fitz/buffer.h"
+#include "mupdf/fitz/color.h"
+
+/* forward declaration for circular dependency */
+struct fz_device;
+
+/* Various font encoding tables and lookup functions */
+
+FZ_DATA extern const char *fz_glyph_name_from_adobe_standard[256];
+FZ_DATA extern const char *fz_glyph_name_from_iso8859_7[256];
+FZ_DATA extern const char *fz_glyph_name_from_koi8u[256];
+FZ_DATA extern const char *fz_glyph_name_from_mac_expert[256];
+FZ_DATA extern const char *fz_glyph_name_from_mac_roman[256];
+FZ_DATA extern const char *fz_glyph_name_from_win_ansi[256];
+FZ_DATA extern const char *fz_glyph_name_from_windows_1252[256];
+
+FZ_DATA extern const unsigned short fz_unicode_from_iso8859_1[256];
+FZ_DATA extern const unsigned short fz_unicode_from_iso8859_7[256];
+FZ_DATA extern const unsigned short fz_unicode_from_koi8u[256];
+FZ_DATA extern const unsigned short fz_unicode_from_pdf_doc_encoding[256];
+FZ_DATA extern const unsigned short fz_unicode_from_windows_1250[256];
+FZ_DATA extern const unsigned short fz_unicode_from_windows_1251[256];
+FZ_DATA extern const unsigned short fz_unicode_from_windows_1252[256];
+
+int fz_iso8859_1_from_unicode(int u);
+int fz_iso8859_7_from_unicode(int u);
+int fz_koi8u_from_unicode(int u);
+int fz_windows_1250_from_unicode(int u);
+int fz_windows_1251_from_unicode(int u);
+int fz_windows_1252_from_unicode(int u);
+
+int fz_unicode_from_glyph_name(const char *name);
+int fz_unicode_from_glyph_name_strict(const char *name);
+const char **fz_duplicate_glyph_names_from_unicode(int unicode);
+const char *fz_glyph_name_from_unicode_sc(int unicode);
+
+/**
+ * A text decoder (to read arbitrary encodings and convert to unicode).
+ */
+typedef struct fz_text_decoder fz_text_decoder;
+
+struct fz_text_decoder {
+	// get maximum size estimate of converted text (fast)
+	int (*decode_bound)(fz_text_decoder *dec, unsigned char *input, int n);
+
+	// get exact size of converted text (slow)
+	int (*decode_size)(fz_text_decoder *dec, unsigned char *input, int n);
+
+	// convert text into output buffer
+	void (*decode)(fz_text_decoder *dec, char *output, unsigned char *input, int n);
+
+	// for internal use only; do not touch!
+	void *table1;
+	void *table2;
+};
+
+/* Initialize a text decoder using an IANA encoding name.
+ * See source/fitz/text-decoder.c for the exact list of supported encodings.
+ * Will throw an exception if the requested encoding is not available.
+ *
+ * The following is a subset of the supported encodings (see source/fitz/text-decoder.c for the full list):
+ *   iso-8859-1
+ *   iso-8859-7
+ *   koi8-r
+ *   euc-jp
+ *   shift_jis
+ *   euc-kr
+ *   euc-cn
+ *   gb18030
+ *   euc-tw
+ *   big5
+ */
+void fz_init_text_decoder(fz_context *ctx, fz_text_decoder *dec, const char *encoding);
+
+/**
+	An abstract font handle.
+*/
+typedef struct fz_font fz_font;
+
+/**
+	Fonts come in two variants:
+	Regular fonts are handled by FreeType.
+	Type 3 fonts have callbacks to the interpreter.
+*/
+
+/**
+	Retrieve the FT_Face handle
+	for the font.
+
+	font: The font to query
+
+	Returns the FT_Face handle for the font, or NULL
+	if not a freetype handled font. (Cast to void *
+	to avoid nasty header exposure).
+*/
+void *fz_font_ft_face(fz_context *ctx, fz_font *font);
+
+/**
+	Retrieve the Type3 procs
+	for a font.
+
+	font: The font to query
+
+	Returns the t3_procs pointer. Will be NULL for a
+	non type-3 font.
+*/
+fz_buffer **fz_font_t3_procs(fz_context *ctx, fz_font *font);
+
+/* common CJK font collections */
+enum { FZ_ADOBE_CNS, FZ_ADOBE_GB, FZ_ADOBE_JAPAN, FZ_ADOBE_KOREA };
+
+/**
+	Every fz_font carries a set of flags
+	within it, in a fz_font_flags_t structure.
+*/
+typedef struct
+{
+	unsigned int is_mono : 1;
+	unsigned int is_serif : 1;
+	unsigned int is_bold : 1;
+	unsigned int is_italic : 1;
+	unsigned int ft_substitute : 1; /* use substitute metrics */
+	unsigned int ft_stretch : 1; /* stretch to match PDF metrics */
+
+	unsigned int fake_bold : 1; /* synthesize bold */
+	unsigned int fake_italic : 1; /* synthesize italic */
+	unsigned int has_opentype : 1; /* has opentype shaping tables */
+	unsigned int invalid_bbox : 1;
+
+	unsigned int cjk : 1;
+	unsigned int cjk_lang : 2; /* CNS, GB, JAPAN, or KOREA */
+
+	unsigned int embed : 1;
+	unsigned int never_embed : 1;
+} fz_font_flags_t;
+
+/**
+	Retrieve a pointer to the font flags
+	for a given font. These can then be updated as required.
+
+	font: The font to query
+
+	Returns a pointer to the flags structure (or NULL, if
+	the font is NULL).
+*/
+fz_font_flags_t *fz_font_flags(fz_font *font);
+
+/**
+	In order to shape a given font, we need to
+	declare it to a shaper library (harfbuzz, by default, but others
+	are possible). To avoid redeclaring it every time we need to
+	shape, we hold a shaper handle and the destructor for it within
+	the font itself. The handle is initialised by the caller when
+	first required and the destructor is called when the fz_font is
+	destroyed.
+*/
+typedef struct
+{
+	void *shaper_handle;
+	void (*destroy)(fz_context *ctx, void *); /* Destructor for shape_handle */
+} fz_shaper_data_t;
+
+/**
+	Retrieve a pointer to the shaper data
+	structure for the given font.
+
+	font: The font to query.
+
+	Returns a pointer to the shaper data structure (or NULL if
+	font is NULL).
+*/
+fz_shaper_data_t *fz_font_shaper_data(fz_context *ctx, fz_font *font);
+
+/**
+	Retrieve a pointer to the name of the font.
+
+	font: The font to query.
+
+	Returns a pointer to an internal copy of the font name.
+	Will never be NULL, but may be the empty string.
+*/
+const char *fz_font_name(fz_context *ctx, fz_font *font);
+
+/**
+	Query whether the font flags say that this font is bold.
+*/
+int fz_font_is_bold(fz_context *ctx, fz_font *font);
+
+/**
+	Query whether the font flags say that this font is italic.
+*/
+int fz_font_is_italic(fz_context *ctx, fz_font *font);
+
+/**
+	Query whether the font flags say that this font is serif.
+*/
+int fz_font_is_serif(fz_context *ctx, fz_font *font);
+
+/**
+	Query whether the font flags say that this font is monospaced.
+*/
+int fz_font_is_monospaced(fz_context *ctx, fz_font *font);
+
+/**
+	Retrieve the font bbox.
+
+	font: The font to query.
+
+	Returns the font bbox by value; it is valid only if
+	fz_font_flags(font)->invalid_bbox is zero.
+*/
+fz_rect fz_font_bbox(fz_context *ctx, fz_font *font);
+
+/**
+	Type for user supplied system font loading hook.
+
+	name: The name of the font to load.
+
+	bold: 1 if a bold font desired, 0 otherwise.
+
+	italic: 1 if an italic font desired, 0 otherwise.
+	needs_exact_metrics: 1 if an exact metric match is required for
+	the font requested.
+
+	Returns a new font handle, or NULL if no font found (or on error).
+*/
+typedef fz_font *(fz_load_system_font_fn)(fz_context *ctx, const char *name, int bold, int italic, int needs_exact_metrics);
+
+/**
+	Type for user supplied cjk font loading hook.
+
+	name: The name of the font to load.
+
+	ordering: The ordering for which to load the font (e.g.
+	FZ_ADOBE_KOREA)
+
+	serif: 1 if a serif font is desired, 0 otherwise.
+
+	Returns a new font handle, or NULL if no font found (or on error).
+*/
+typedef fz_font *(fz_load_system_cjk_font_fn)(fz_context *ctx, const char *name, int ordering, int serif);
+
+/**
+	Type for user supplied fallback font loading hook.
+
+	name: The name of the font to load.
+
+	script: UCDN script enum.
+
+	language: FZ_LANG enum.
+
+	serif, bold, italic: boolean style flags.
+
+	Returns a new font handle, or NULL if no font found (or on error).
+*/
+typedef fz_font *(fz_load_system_fallback_font_fn)(fz_context *ctx, int script, int language, int serif, int bold, int italic);
+
+/**
+	Install functions to allow MuPDF to request fonts from the
+	system.
+
+	Only one set of hooks can be in use at a time.
+*/
+void fz_install_load_system_font_funcs(fz_context *ctx,
+	fz_load_system_font_fn *f,
+	fz_load_system_cjk_font_fn *f_cjk,
+	fz_load_system_fallback_font_fn *f_fallback);
+
+/**
+	Attempt to load a given font from the system.
+
+	name: The name of the desired font.
+
+	bold: 1 if bold desired, 0 otherwise.
+
+	italic: 1 if italic desired, 0 otherwise.
+
+	needs_exact_metrics: 1 if an exact metrical match is required,
+	0 otherwise.
+
+	Returns a new font handle, or NULL if no matching font was found
+	(or on error).
+*/
+fz_font *fz_load_system_font(fz_context *ctx, const char *name, int bold, int italic, int needs_exact_metrics);
+
+/**
+	Attempt to load a given font from
+	the system.
+
+	name: The name of the desired font.
+
+	ordering: The ordering to load the font from (e.g. FZ_ADOBE_KOREA)
+
+	serif: 1 if serif desired, 0 otherwise.
+
+	Returns a new font handle, or NULL if no matching font was found
+	(or on error).
+*/
+fz_font *fz_load_system_cjk_font(fz_context *ctx, const char *name, int ordering, int serif);
+
+/**
+	Search the builtin fonts for a match.
+	Whether a given font is present or not will depend on the
+	configuration in which MuPDF is built.
+
+	name: The name of the font desired.
+
+	bold: 1 if bold desired, 0 otherwise.
+
+	italic: 1 if italic desired, 0 otherwise.
+
+	len: Pointer to a place to receive the length of the discovered
+	font buffer.
+
+	Returns a pointer to the font file data, or NULL if not present.
+*/
+const unsigned char *fz_lookup_builtin_font(fz_context *ctx, const char *name, int bold, int italic, int *len);
+
+/**
+	Search the builtin base14 fonts for a match.
+	Whether a given font is present or not will depend on the
+	configuration in which MuPDF is built.
+
+	name: The name of the font desired.
+
+	len: Pointer to a place to receive the length of the discovered
+	font buffer.
+
+	Returns a pointer to the font file data, or NULL if not present.
+*/
+const unsigned char *fz_lookup_base14_font(fz_context *ctx, const char *name, int *len);
+
+/**
+	Search the builtin cjk fonts for a match.
+	Whether a font is present or not will depend on the
+	configuration in which MuPDF is built.
+
+	ordering: The desired ordering of the font (e.g. FZ_ADOBE_KOREA).
+
+	len: Pointer to a place to receive the length of the discovered
+	font buffer.
+
+	Returns a pointer to the font file data, or NULL if not present.
+*/
+const unsigned char *fz_lookup_cjk_font(fz_context *ctx, int ordering, int *len, int *index);
+
+/**
+	Search the builtin cjk fonts for a match for a given language.
+	Whether a font is present or not will depend on the
+	configuration in which MuPDF is built.
+
+	lang: Pointer to a (case sensitive) language string (e.g.
+	"ja", "ko", "zh-Hant" etc).
+
+	len: Pointer to a place to receive the length of the discovered
+	font buffer.
+
+	subfont: Pointer to a place to store the subfont index of the
+	discovered font.
+
+	Returns a pointer to the font file data, or NULL if not present.
+*/
+const unsigned char *fz_lookup_cjk_font_by_language(fz_context *ctx, const char *lang, int *len, int *subfont);
+
+/**
+	Return the matching FZ_ADOBE_* ordering
+	for the given language tag, such as "zh-Hant", "zh-Hans", "ja", or "ko".
+*/
+int fz_lookup_cjk_ordering_by_language(const char *name);
+
+/**
+	Search the builtin noto fonts for a match.
+	Whether a font is present or not will depend on the
+	configuration in which MuPDF is built.
+
+	script: The script desired (e.g. UCDN_SCRIPT_KATAKANA).
+
+	lang: The language desired (e.g. FZ_LANG_ja).
+
+	len: Pointer to a place to receive the length of the discovered
+	font buffer.
+
+	Returns a pointer to the font file data, or NULL if not present.
+*/
+const unsigned char *fz_lookup_noto_font(fz_context *ctx, int script, int lang, int *len, int *subfont);
+
+/**
+	Search the builtin noto fonts specific symbol fonts.
+	Whether a font is present or not will depend on the
+	configuration in which MuPDF is built.
+*/
+const unsigned char *fz_lookup_noto_math_font(fz_context *ctx, int *len);
+const unsigned char *fz_lookup_noto_music_font(fz_context *ctx, int *len);
+const unsigned char *fz_lookup_noto_symbol1_font(fz_context *ctx, int *len);
+const unsigned char *fz_lookup_noto_symbol2_font(fz_context *ctx, int *len);
+const unsigned char *fz_lookup_noto_emoji_font(fz_context *ctx, int *len);
+const unsigned char *fz_lookup_noto_boxes_font(fz_context *ctx, int *len);
+
+/**
+	Look up the Noto font file name for a given script.
+	From the returned font stem, you can look for Noto fonts on the system in the form:
+		Noto(Sans|Serif)${STEM}-Regular.(otf|ttf)
+*/
+const char *fz_lookup_noto_stem_from_script(fz_context *ctx, int script, int language);
+const char *fz_lookup_script_name(fz_context *ctx, int script, int language);
+
+/**
+	Try to load a fallback font for the
+	given combination of font attributes. Whether a font is
+	present or not will depend on the configuration in which
+	MuPDF is built.
+
+	script: The script desired (e.g. UCDN_SCRIPT_KATAKANA).
+
+	language: The language desired (e.g. FZ_LANG_ja).
+
+	serif: 1 if serif desired, 0 otherwise.
+
+	bold: 1 if bold desired, 0 otherwise.
+
+	italic: 1 if italic desired, 0 otherwise.
+
+	Returns a new font handle, or NULL if not available.
+*/
+fz_font *fz_load_fallback_font(fz_context *ctx, int script, int language, int serif, int bold, int italic);
+
+/**
+	Create a new (empty) type3 font.
+
+	name: Name of font (or NULL).
+
+	matrix: Font matrix.
+
+	Returns a new font handle, or throws exception on
+	allocation failure.
+*/
+fz_font *fz_new_type3_font(fz_context *ctx, const char *name, fz_matrix matrix);
+
+/**
+	Create a new font from a font file in memory.
+
+	Fonts created in this way, will be eligible for embedding by default.
+
+	name: Name of font (leave NULL to use name from font).
+
+	data: Pointer to the font file data.
+
+	len: Length of the font file data.
+
+	index: Which font from the file to load (0 for default).
+
+	use_glyph_box: 1 if we should use the glyph bbox, 0 otherwise.
+
+	Returns new font handle, or throws exception on error.
+*/
+fz_font *fz_new_font_from_memory(fz_context *ctx, const char *name, const unsigned char *data, int len, int index, int use_glyph_bbox);
+
+/**
+	Create a new font from a font file in a fz_buffer.
+
+	Fonts created in this way, will be eligible for embedding by default.
+
+	name: Name of font (leave NULL to use name from font).
+
+	buffer: Buffer to load from.
+
+	index: Which font from the file to load (0 for default).
+
+	use_glyph_box: 1 if we should use the glyph bbox, 0 otherwise.
+
+	Returns new font handle, or throws exception on error.
+*/
+fz_font *fz_new_font_from_buffer(fz_context *ctx, const char *name, fz_buffer *buffer, int index, int use_glyph_bbox);
+
+/**
+	Create a new font from a font file.
+
+	Fonts created in this way, will be eligible for embedding by default.
+
+	name: Name of font (leave NULL to use name from font).
+
+	path: File path to load from.
+
+	index: Which font from the file to load (0 for default).
+
+	use_glyph_box: 1 if we should use the glyph bbox, 0 otherwise.
+
+	Returns new font handle, or throws exception on error.
+*/
+fz_font *fz_new_font_from_file(fz_context *ctx, const char *name, const char *path, int index, int use_glyph_bbox);
+
+/**
+	Create a new font from one of the built-in fonts.
+*/
+fz_font *fz_new_base14_font(fz_context *ctx, const char *name);
+fz_font *fz_new_cjk_font(fz_context *ctx, int ordering);
+fz_font *fz_new_builtin_font(fz_context *ctx, const char *name, int is_bold, int is_italic);
+
+/**
+	Control whether a given font should be embedded or not when writing.
+*/
+void fz_set_font_embedding(fz_context *ctx, fz_font *font, int embed);
+
+/**
+	Add a reference to an existing fz_font.
+
+	font: The font to add a reference to.
+
+	Returns the same font.
+*/
+fz_font *fz_keep_font(fz_context *ctx, fz_font *font);
+
+/**
+	Drop a reference to a fz_font, destroying the
+	font when the last reference is dropped.
+
+	font: The font to drop a reference to.
+*/
+void fz_drop_font(fz_context *ctx, fz_font *font);
+
+/**
+	Set the font bbox.
+
+	font: The font to set the bbox for.
+
+	xmin, ymin, xmax, ymax: The bounding box.
+*/
+void fz_set_font_bbox(fz_context *ctx, fz_font *font, float xmin, float ymin, float xmax, float ymax);
+
+/**
+	Return a bbox for a given glyph in a font.
+
+	font: The font to look for the glyph in.
+
+	gid: The glyph to bound.
+
+	trm: The matrix to apply to the glyph before bounding.
+
+	Returns rectangle by value containing the bounds of the given
+	glyph.
+*/
+fz_rect fz_bound_glyph(fz_context *ctx, fz_font *font, int gid, fz_matrix trm);
+
+/**
+	Determine if a given glyph in a font
+	is cacheable. Certain glyphs in a type 3 font cannot safely
+	be cached, as their appearance depends on the enclosing
+	graphic state.
+
+	font: The font to look for the glyph in.
+
+	gif: The glyph to query.
+
+	Returns non-zero if cacheable, 0 if not.
+*/
+int fz_glyph_cacheable(fz_context *ctx, fz_font *font, int gid);
+
+/**
+	Run a glyph from a Type3 font to
+	a given device.
+
+	font: The font to find the glyph in.
+
+	gid: The glyph to run.
+
+	trm: The transform to apply.
+
+	dev: The device to render onto.
+*/
+void fz_run_t3_glyph(fz_context *ctx, fz_font *font, int gid, fz_matrix trm, struct fz_device *dev);
+
+/**
+	Return the advance for a given glyph.
+
+	font: The font to look for the glyph in.
+
+	glyph: The glyph to find the advance for.
+
+	wmode: 1 for vertical mode, 0 for horizontal.
+
+	Returns the advance for the glyph.
+*/
+float fz_advance_glyph(fz_context *ctx, fz_font *font, int glyph, int wmode);
+
+/**
+	Find the glyph id for a given unicode
+	character within a font.
+
+	font: The font to look for the unicode character in.
+
+	unicode: The unicode character to encode.
+
+	Returns the glyph id for the given unicode value, or 0 if
+	unknown.
+*/
+int fz_encode_character(fz_context *ctx, fz_font *font, int unicode);
+
+/**
+	Encode character, preferring small-caps variant if available.
+
+	font: The font to look for the unicode character in.
+
+	unicode: The unicode character to encode.
+
+	Returns the glyph id for the given unicode value, or 0 if
+	unknown.
+*/
+int fz_encode_character_sc(fz_context *ctx, fz_font *font, int unicode);
+
+/**
+	Encode character.
+
+	Either by direct lookup of glyphname within a font, or, failing
+	that, by mapping glyphname to unicode and thence to the glyph
+	index within the given font.
+
+	Returns zero for type3 fonts.
+*/
+int fz_encode_character_by_glyph_name(fz_context *ctx, fz_font *font, const char *glyphname);
+
+/**
+	Find the glyph id for
+	a given unicode character within a font, falling back to
+	an alternative if not found.
+
+	font: The font to look for the unicode character in.
+
+	unicode: The unicode character to encode.
+
+	script: The script in use.
+
+	language: The language in use.
+
+	out_font: The font handle in which the given glyph represents
+	the requested unicode character. The caller does not own the
+	reference it is passed, so should call fz_keep_font if it is
+	not simply to be used immediately.
+
+	Returns the glyph id for the given unicode value in the supplied
+	font (and sets *out_font to font) if it is present. Otherwise
+	an alternative fallback font (based on script/language) is
+	searched for. If the glyph is found therein, *out_font is set
+	to this reference, and the glyph reference is returned. If it
+	cannot be found anywhere, the function returns 0.
+*/
+int fz_encode_character_with_fallback(fz_context *ctx, fz_font *font, int unicode, int script, int language, fz_font **out_font);
+
+/**
+	Find the name of a glyph
+
+	font: The font to look for the glyph in.
+
+	glyph: The glyph id to look for.
+
+	buf: Pointer to a buffer for the name to be inserted into.
+
+	size: The size of the buffer.
+
+	If a font contains a name table, then the name of the glyph
+	will be returned in the supplied buffer. Otherwise a name
+	is synthesised. The name will be truncated to fit in
+	the buffer.
+*/
+void fz_get_glyph_name(fz_context *ctx, fz_font *font, int glyph, char *buf, int size);
+
+/**
+	Retrieve font ascender in ems.
+*/
+float fz_font_ascender(fz_context *ctx, fz_font *font);
+
+/**
+	Retrieve font descender in ems.
+*/
+float fz_font_descender(fz_context *ctx, fz_font *font);
+
+/**
+	Retrieve the MD5 digest for the font's data.
+*/
+void fz_font_digest(fz_context *ctx, fz_font *font, unsigned char digest[16]);
+
+/* Implementation details: subject to change. */
+
+void fz_decouple_type3_font(fz_context *ctx, fz_font *font, void *t3doc);
+
+/**
+	map an FT error number to a
+	static string.
+
+	err: The error number to lookup.
+
+	Returns a pointer to a static textual representation
+	of a freetype error.
+*/
+const char *ft_error_string(int err);
+int ft_char_index(void *face, int cid);
+int ft_name_index(void *face, const char *name);
+
+/**
+	Internal functions for our Harfbuzz integration
+	to work around the lack of thread safety.
+*/
+
+/**
+	Lock against Harfbuzz being called
+	simultaneously in several threads. This reuses
+	FZ_LOCK_FREETYPE.
+*/
+void fz_hb_lock(fz_context *ctx);
+
+/**
+	Unlock after a Harfbuzz call. This reuses
+	FZ_LOCK_FREETYPE.
+*/
+void fz_hb_unlock(fz_context *ctx);
+
+/**
+	Callback for use in font cmap enumeration.
+*/
+typedef void (fz_cmap_callback)(fz_context *ctx, void *opaque, unsigned long ucs, unsigned int gid);
+
+/**
+	Enumerate a cmap using a callback.
+*/
+void fz_enumerate_font_cmap(fz_context *ctx, fz_font *font, fz_cmap_callback *cb, void *opaque);
+
+/**
+	Ensure that a font has its ascender/descender values calculated
+	from the actual bbox of the glyphs.
+
+	Note, that we combine the declared values from the font (or the
+	default values if those are not present) with the actual bbox to
+	get the final result. So this can only cause ascender/descender
+	to move further apart!
+*/
+void fz_calculate_font_ascender_descender(fz_context *ctx, fz_font *font);
+
+typedef enum
+{
+	FZ_ASCDESC_FROM_FONT,
+	FZ_ASCDESC_DEFAULT,
+	FZ_ASCDESC_FROM_BOUNDS
+} fz_ascdesc_source;
+
+#define FZ_MAX_TRUSTWORTHY_ASCENT 8
+#define FZ_MAX_TRUSTWORTHY_DESCENT -2
+
+struct fz_font
+{
+	int refs;
+	char name[32];
+	fz_buffer *buffer;
+
+	fz_font_flags_t flags;
+
+	void *ft_face; /* has an FT_Face if used */
+	fz_shaper_data_t shaper_data;
+
+	fz_matrix t3matrix;
+	void *t3resources;
+	fz_buffer **t3procs; /* has 256 entries if used */
+	struct fz_display_list **t3lists; /* has 256 entries if used */
+	float *t3widths; /* has 256 entries if used */
+	unsigned short *t3flags; /* has 256 entries if used */
+	void *t3doc; /* a pdf_document for the callback */
+	void (*t3run)(fz_context *ctx, void *doc, void *resources, fz_buffer *contents, struct fz_device *dev, fz_matrix ctm, void *gstate, fz_default_colorspaces *default_cs, void *fill_gstate, void *stroke_gstate);
+	void (*t3freeres)(fz_context *ctx, void *doc, void *resources);
+
+	fz_rect bbox;	/* font bbox is used only for t3 fonts */
+
+	float ascender;
+	float descender;
+	fz_ascdesc_source ascdesc_src;
+
+	int glyph_count;
+
+	/* per glyph bounding box cache. */
+	fz_rect **bbox_table;
+	int use_glyph_bbox;
+
+	/* substitute metrics */
+	int width_count;
+	short width_default; /* in 1000 units */
+	short *width_table; /* in 1000 units */
+
+	/* cached glyph metrics */
+	float **advance_cache;
+
+	/* cached encoding lookup */
+	uint16_t *encoding_cache[256];
+
+	/* cached md5sum for caching */
+	int has_digest;
+	unsigned char digest[16];
+
+	/* Which font to use in a collection. */
+	int subfont;
+};
+
+void fz_ft_lock(fz_context *ctx);
+
+void fz_ft_unlock(fz_context *ctx);
+
+/* Internal function. Must be called with FT_ALLOC_LOCK
+ * held. Returns 1 if this thread (context!) already holds
+ * the freeetype lock. */
+int fz_ft_lock_held(fz_context *ctx);
+
+/* Internal function: Extract a ttf from the ttc that underlies
+ * a given fz_font. Caller takes ownership of the returned
+ * buffer.
+ */
+fz_buffer *fz_extract_ttf_from_ttc(fz_context *ctx, fz_font *font);
+
+/* Internal function: Given a ttf in a buffer, create a subset
+ * ttf in a new buffer that only provides the required gids.
+ * Caller takes ownership of the returned buffer.
+ *
+ * EXPERIMENTAL AND VERY SUBJECT TO CHANGE.
+ */
+fz_buffer *fz_subset_ttf_for_gids(fz_context *ctx, fz_buffer *orig, int *gids, int num_gids, int symbolic, int cidfont);
+
+/* Internal function: Given a cff in a buffer, create a subset
+ * cff in a new buffer that only provides the required gids.
+ * Caller takes ownership of the returned buffer.
+ *
+ * EXPERIMENTAL AND VERY SUBJECT TO CHANGE.
+ */
+fz_buffer *fz_subset_cff_for_gids(fz_context *ctx, fz_buffer *orig, int *gids, int num_gids, int symbolic, int cidfont);
+
+#endif