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X11R7.4 - man page for xcreatefontset (x11r4 section 3)

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XCreateFontSet(3)			  XLIB FUNCTIONS			XCreateFontSet(3)

NAME
       XCreateFontSet, XFreeFontSet - create and free an international text drawing font set

SYNTAX
       XFontSet XCreateFontSet(Display *display, char *base_font_name_list, char ***miss-
	      ing_charset_list_return, int *missing_charset_count_return, char
	      **def_string_return);

       void XFreeFontSet(Display *display, XFontSet font_set);

ARGUMENTS
       display	 Specifies the connection to the X server.

       base_font_name_list
		 Specifies the base font names.

       def_string_return
		 Returns the string drawn for missing charsets.

       font_set  Specifies the font set.

       missing_charset_count_return
		 Returns the number of missing charsets.

       missing_charset_list_return
		 Returns the missing charsets.

DESCRIPTION
       The XCreateFontSet function creates a font set for the specified display.  The font set is
       bound to the current locale when XCreateFontSet is called.  The font set may be used in
       subsequent calls to obtain font and character information and to image text in the locale
       of the font set.

       The base_font_name_list argument is a list of base font names that Xlib uses to load the
       fonts needed for the locale.  The base font names are a comma-separated list.  The string
       is null-terminated and is assumed to be in the Host Portable Character Encoding; other-
       wise, the result is implementation-dependent.  White space immediately on either side of a
       separating comma is ignored.

       Use of XLFD font names permits Xlib to obtain the fonts needed for a variety of locales
       from a single locale-independent base font name.  The single base font name should name a
       family of fonts whose members are encoded in the various charsets needed by the locales of
       interest.

       An XLFD base font name can explicitly name a charset needed for the locale.  This allows
       the user to specify an exact font for use with a charset required by a locale, fully con-
       trolling the font selection.

       If a base font name is not an XLFD name, Xlib will attempt to obtain an XLFD name from the
       font properties for the font.  If this action is successful in obtaining an XLFD name, the
       XBaseFontNameListOfFontSet function will return this XLFD name instead of the client-sup-
       plied name.

       Xlib uses the following algorithm to select the fonts that will be used to display text
       with the XFontSet.

       For each font charset required by the locale, the base font name list is searched for the
       first appearance of one of the following cases that names a set of fonts that exist at the
       server:

       o    The first XLFD-conforming base font name that specifies the required charset or a
	    superset of the required charset in its CharSetRegistry and CharSetEncoding fields.
	    The implementation may use a base font name whose specified charset is a superset of
	    the required charset, for example, an ISO8859-1 font for an ASCII charset.

       o    The first set of one or more XLFD-conforming base font names that specify one or more
	    charsets that can be remapped to support the required charset.  The Xlib implementa-
	    tion may recognize various mappings from a required charset to one or more other
	    charsets and use the fonts for those charsets.  For example, JIS Roman is ASCII with
	    tilde and backslash replaced by yen and overbar; Xlib may load an ISO8859-1 font to
	    support this character set if a JIS Roman font is not available.

       o    The first XLFD-conforming font name or the first non-XLFD font name for which an XLFD
	    font name can be obtained, combined with the required charset (replacing the CharSe-
	    tRegistry and CharSetEncoding fields in the XLFD font name).  As in case 1, the
	    implementation may use a charset that is a superset of the required charset.

       o    The first font name that can be mapped in some implementation-dependent manner to one
	    or more fonts that support imaging text in the charset.

       For example, assume that a locale required the charsets:

       ISO8859-1
       JISX0208.1983
       JISX0201.1976
       GB2312-1980.0

       The user could supply a base_font_name_list that explicitly specifies the charsets, ensur-
       ing that specific fonts are used if they exist.	For example:

       "-JIS-Fixed-Medium-R-Normal--26-180-100-100-C-240-JISX0208.1983-0,-JIS-Fixed-Medium-R-Normal--26-180-100-100-C-120-JISX0201.1976-0,-GB-Fixed-Medium-R-Normal--26-180-100-100-C-240-GB2312-1980.0,-Adobe-Courier-Bold-R-Normal--25-180-75-75-M-150-ISO8859-1"

       Alternatively, the user could supply a base_font_name_list that omits the charsets, let-
       ting Xlib select font charsets required for the locale.	For example:

       "-JIS-Fixed-Medium-R-Normal--26-180-100-100-C-240,-JIS-Fixed-Medium-R-Normal--26-180-100-100-C-120,-GB-Fixed-Medium-R-Normal--26-180-100-100-C-240,-Adobe-Courier-Bold-R-Normal--25-180-100-100-M-150"

       Alternatively, the user could simply supply a single base font name that allows Xlib to
       select from all available fonts that meet certain minimum XLFD property requirements.  For
       example:

       "-*-*-*-R-Normal--*-180-100-100-*-*"

       If XCreateFontSet is unable to create the font set, either because there is insufficient
       memory or because the current locale is not supported, XCreateFontSet returns NULL, miss-
       ing_charset_list_return is set to NULL, and missing_charset_count_return is set to zero.
       If fonts exist for all of the charsets required by the current locale, XCreateFontSet
       returns a valid XFontSet, missing_charset_list_return is set to NULL, and miss-
       ing_charset_count_return is set to zero.

       If no font exists for one or more of the required charsets, XCreateFontSet sets miss-
       ing_charset_list_return to a list of one or more null-terminated charset names for which
       no font exists and sets missing_charset_count_return to the number of missing fonts.  The
       charsets are from the list of the required charsets for the encoding of the locale and do
       not include any charsets to which Xlib may be able to remap a required charset.

       If no font exists for any of the required charsets or if the locale definition in Xlib
       requires that a font exist for a particular charset and a font is not found for that
       charset, XCreateFontSet returns NULL.  Otherwise, XCreateFontSet returns a valid XFontSet
       to font_set.

       When an Xmb/wc drawing or measuring function is called with an XFontSet that has missing
       charsets, some characters in the locale will not be drawable.  If def_string_return is
       non-NULL, XCreateFontSet returns a pointer to a string that represents the glyphs that are
       drawn with this XFontSet when the charsets of the available fonts do not include all font
       glyphs required to draw a codepoint.  The string does not necessarily consist of valid
       characters in the current locale and is not necessarily drawn with the fonts loaded for
       the font set, but the client can draw and measure the default glyphs by including this
       string in a string being drawn or measured with the XFontSet.

       If the string returned to def_string_return is the empty string (""), no glyphs are drawn,
       and the escapement is zero.  The returned string is null-terminated.  It is owned by Xlib
       and should not be modified or freed by the client.  It will be freed by a call to XFree-
       FontSet with the associated XFontSet.  Until freed, its contents will not be modified by
       Xlib.

       The client is responsible for constructing an error message from the missing charset and
       default string information and may choose to continue operation in the case that some
       fonts did not exist.

       The returned XFontSet and missing charset list should be freed with XFreeFontSet and
       XFreeStringList, respectively.  The client-supplied base_font_name_list may be freed by
       the client after calling XCreateFontSet.

       The XFreeFontSet function frees the specified font set.	The associated base font name
       list, font name list, XFontStruct list, and XFontSetExtents, if any, are freed.

SEE ALSO
       XExtentsofFontSet(3X11), XFontsOfFontSet(3X11), XFontSetExtents(3X11)
       Xlib - C Language X Interface

X Version 11				   libX11 1.2.1 			XCreateFontSet(3)
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