| Xft(3) | Library Functions Manual | Xft(3) |
The following example illustrates how Xft's version constants might be used:
#if (XFT_VERSION >= 20107)
(void) puts("Version 2.1.7 or later of the Xft library is in"
" use.");
#else
(void) printf("Insufficient version of Xft (%d.%d.%d) installed;
" need at least version 2.1.7.\n", XFT_MAJOR,
XFT_MINOR,
XFT_REVISION);
#endif
typedef struct _XftFont {
int ascent;
int descent;
int height;
int max_advance_width;
FcCharSet *charset;
FcPattern *pattern;
} XftFont;
An XftFont is the primary data structure of interest to programmers
using Xft; it contains general font metrics and pointers to the
Fontconfig character set and pattern associated with the font. The
FcCharSet and FcPattern data types are defined by the
Fontconfig library.
typedef struct _XftColor {
unsigned long pixel;
XRenderColor color;
} XftColor;
An XftColor object permits text and other items to be rendered in a
particular color (or the closest approximation offered by the X visual in
use). The XRenderColor data type is defined by the X Render
Extension library.
typedef struct _XftCharSpec {
FcChar32 ucs4;
short x;
short y;
} XftCharSpec;
typedef struct _XftCharFontSpec {
XftFont *font;
FcChar32 ucs4;
short x;
short y;
} XftCharFontSpec;
typedef struct _XftGlyphSpec {
FT_UInt glyph;
short x;
short y;
} XftGlyphSpec;
typedef struct _XftGlyphFontSpec {
XftFont *font;
FT_UInt glyph;
short x;
short y;
} XftGlyphFontSpec;
XftFont *
XftFontOpen (Display *dpy,
int screen,
...);
XftFontOpen takes a list of pattern element triples of the form
field, type, value (terminated with a NULL), matches that
pattern against the available fonts, and opens the matching font, sizing it
correctly for screen number screen on display dpy. The
Display data type is defined by the X11 library. Returns NULL if no
match is found.
Example:
font = XftFontOpen (dpy, screen,
XFT_FAMILY, XftTypeString, "charter",
XFT_SIZE, XftTypeDouble, 12.0,
NULL);
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.
XftFont *
XftFontOpenName (Display *dpy,
int screen,
unsigned char *name);
XftFontOpenName behaves as XftFontOpen does, except that it takes
a Fontconfig pattern string (which is passed to the Fontconfig library's
FcNameParse() function).
XftFont *
XftFontOpenXlfd (Display *dpy,
int screen,
unsigned char *xlfd)
XftFontOpenXlfd behaves as XftFontOpen does, except that it takes
a string containing an X Logical Font Description (XLFD).
FcPattern *
XftFontMatch (Display *dpy,
int screen,
FcPattern *pattern,
FcResult *result);
Also used internally by the XftFontOpen* functions, XftFontMatch
can also be used directly to determine the Fontconfig font pattern resulting
from an Xft font open request. The FcPattern and FcResult data
types are defined by the Fontconfig library.
void
XftTextExtents8 (Display *dpy,
XftFont *font,
FcChar8 *string,
int len,
XGlyphInfo *extents);
XftTextExtents8 computes the pixel extents on display dpy of no
more than len glyphs of a string consisting of eight-bit
characters when drawn with font, storing them in extents. The
FcChar8 data type is defined by the Fontconfig library, and the
XGlyphInfo data type is defined by the X Rendering Extension library.
void
XftTextExtents16 (Display *dpy,
XftFont *font,
FcChar16 *string,
int len,
XGlyphInfo *extents);
XftTextExtents16 computes the pixel extents on display dpy of no
more than len glyphs of a string consisting of sixteen-bit
characters when drawn with font, storing them in extents. The
FcChar16 data type is defined by the Fontconfig library, and the
XGlyphInfo data type is defined by the X Rendering Extension library.
void
XftTextExtents32 (Display *dpy,
XftFont *font,
FcChar32 *string,
int len,
XGlyphInfo *extents);
XftTextExtents32 computes the pixel extents on display dpy of no
more than len glyphs of a string consisting of thirty-two-bit
characters when drawn with font, storing them in extents. The
FcChar32 data type is defined by the Fontconfig library, and the
XGlyphInfo data type is defined by the X Rendering Extension library.
void
XftTextExtentsUtf8 (Display *dpy,
XftFont *font,
FcChar8 *string,
int len,
XGlyphInfo *extents);
XftTextExtentsUtf8 computes the pixel extents on display dpy of no
more than len bytes of a UTF-8 encoded string when drawn with
font, storing them in extents. The XGlyphInfo data type
is defined by the X Rendering Extension library.
void
XftTextExtentsUtf16 (Display *dpy,
XftFont *font,
FcChar8 *string,
FcEndian endian,
int len,
XGlyphInfo *extents);
XftTextExtentsUtf16 computes the pixel extents on display dpy of
no more than len bytes of a UTF-16LE- or UTF-16BE-encoded string
when drawn with font, storing them in extents. The endianness of
string must be specified in endian. The FcEndian data
type is defined by the Fontconfig library, and the XGlyphInfo data type
is defined by the X Rendering Extension library.
void
XftGlyphExtents (Display *dpy,
XftFont *font,
FT_UInt *glyphs,
int nglyphs,
XGlyphInfo *extents);
Also used internally by the XftTextExtents* functions,
XftGlyphExtents computes the pixel extents on display dpy of no
more than nglyphs in the array glyphs drawn with font,
storing them in extents. The FT_UInt data type is defined by the
FreeType library, and the XGlyphInfo data type is defined by the X
Rendering Extension library.
XftDraw *
XftDrawCreate (Display *dpy,
Drawable drawable,
Visual *visual,
Colormap colormap);
XftDrawCreate creates a structure that can be used to render text and
rectangles using the specified drawable, visual, and
colormap on display. The Drawable, Visual, and
Colormap data types are defined by the X11 library.
XftDraw *
XftDrawCreateBitmap (Display *dpy,
Pixmap bitmap);
XftDrawCreateBitmap behaves as XftDrawCreate, except it uses an X
pixmap of color depth 1 instead of an X drawable. The Pixmap data type
is defined by the X11 library.
XftDraw *
XftDrawCreateAlpha (Display *dpy,
Pixmap pixmap,
int depth);
XftDrawCreateAlpha behaves as XftDrawCreate, except it uses an X
pixmap of color depth depth instead of an X drawable. The Pixmap
data type is defined by the X11 library.
void
XftDrawChange (XftDraw *draw,
Drawable drawable);
XftDrawChange changes the X drawable association of the existing Xft draw
object draw from its current value to drawable.
Display * XftDrawDisplay (XftDraw *draw);XftDrawDisplay returns a pointer to the display associated with the Xft draw object draw.
Drawable XftDrawDrawable (XftDraw *draw);XftDrawDrawable returns the X drawable associated with the Xft draw object draw.
Colormap XftDrawColormap (XftDraw *draw);XftDrawColormap returns the colormap associatied with the Xft draw object draw.
Visual * XftDrawVisual (XftDraw *draw);XftDrawVisual returns a pointer to the visual associated with the Xft draw object draw.
Picture XftDrawPicture (XftDraw *draw);XftDrawPicture returns the picture associated with the Xft draw object draw. If the the X server does not support the X Rendering Extension, 0 is returned.
Picture
XftDrawSrcPicture (XftDraw *draw,
XftColor *color);
This function is never called if the X server doesn't support the X Rendering
Extension; instead, XftGlyphCore is used.
void XftDrawDestroy (XftDraw *draw);XftDrawDestroy destroys draw (created by one of the XftCreate functions) and frees the memory that was allocated for it.
void
XftDrawString8 (XftDraw *d,
XftColor *color,
XftFont *font,
int x,
int y,
unsigned char *string,
int len);
XftDrawString8 draws no more than len glyphs of string to
Xft drawable d using font in color at position
x, y.
void
XftDrawRect (XftDraw *d,
XftColor *color,
int x,
int y,
unsigned int width,
unsigned int height);
XftDrawRect draws a solid rectangle of the specified color,
width, and height at position x, y to Xft drawable
d.
Xft does provide a compatibility interface to its previous major version, Xft 1.x, described below.
| X Version 11 |