XFT(3)XFT(3)NAMEXFT - X FreeType interface library
DESCRIPTION
Xft is a simple library designed to interface the FreeType
rasterizer with the X Rendering Extension. This manual
page barely scratches the surface of this library.
DATATYPES
XftPattern holds a set of names with associated value
lists; each name refers to a property of a font. XftPat-
terns are used as inputs to the matching code as well as
holding information about specific fonts.
XftFont contains general font metrics and a pointer to
either the core XFontStruct data or a structure holding
FreeType and X Render Extension data.
XftFontStruct contains information about FreeType fonts
used with the X Render Extension.
XftFontSet contains a list of XftPatterns. Internally Xft
uses this data structure to hold sets of fonts. Exter-
nally, Xft returns the results of listing fonts in this
format.
XftObjectSet holds a set of names and is used to specify
which fields from fonts are placed in the the list of
returned patterns when listing fonts.
XftDraw is an opaque object which holds information used
to render to an X drawable using either core protocol or
the X Rendering extension.
FUNCTIONS
XftFont *
XftFontOpen (Display *dpy, int screen, ...);
XftFontOpen takes a list of pattern elements of the form
(field, type, value) terminated with a 0, matches that
pattern against the available fonts and opens the matching
font.
Example:
font = XftFontOpen (dpy, scr,
XFT_FAMILY, XftTypeString, "charter",
XFT_SIZE, XftTypeDouble, 12.0);
This opens the charter font at 12 points. The point size
is automatically converted to the correct pixel size based
on the resolution of the monitor.
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void
XftTextExtents8 (Display *dpy,
XftFont *font,
unsigned char *string,
int len,
XGlyphInfo *extents);
XftTextExtents8 computes the pixel extents of "string"
when drawn with "font".
XftDraw *
XftDrawCreate (Display *dpy,
Drawable drawable,
Visual *visual,
Colormap colormap);
XtDrawCreate creates a structure that can be used to ren-
der text and rectangles to the screen.
void
XftDrawString8 (XftDraw *d,
XRenderColor *color,
XftFont *font,
int x,
int y,
unsigned char *string,
int len);
XftDrawString8 draws "string" using "font" in "color" at
"x, y".
void
XftDrawRect (XftDraw *d,
XRenderColor *color,
int x,
int y,
unsigned int width,
unsigned int height);
XftDrawRect fills a solid rectangle in the specified
color.
XftConfig
The XftConfig file contains configuration information for
the Xft library consisting of directories to look at for
font information as well as instructions on editing pro-
gram specified font patterns before attempting to match
the available fonts.
config : "dir" STRING
| "include" STRING
| "includeif" STRING
| "match" tests "edit" edits
;
test : qual FIELD-NAME COMPARE CONSTANT
;
qual : "any"
| "all"
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;
edit : FIELD-NAME ASSIGN expr SEMI
;
STRINGs are double-quote delimited. FIELD-NAMEs are iden-
tifiers, ASSIGN is one of "=", "+=" or "=+". expr can
contain the usual arithmetic operators and can include
FIELD-NAMEs.
"dir" adds a directory to the list of places Xft will look
for fonts. There is no particular order implied by the
list; Xft treats all fonts about the same.
"include" and "includeif" cause Xft to load more configu-
ration parameters from the indicated file. "includeif"
doesn't elicit a complaint if the file doesn't exist. If
the file name begins with a '~' character, it refers to a
path relative to the home directory of the user.
If the tests in a "match" statement all match a user-spec-
ified pattern, the pattern will be edited with the speci-
fied instructions.
Where ASSIGN is "=", the matching value in the pattern
will be replaced by the given expression. "+="/"=+" will
prepend/append a new value to the list of values for the
indicated field.
RESTRICTIONS
Xft will probably change radically in the future; weak
attempts will be made to retain some level of source-file
compatibility.
AUTHOR
Keith Packard, member of the XFree86 Project, Inc.
XFree86 Version 1.0 3