Windows PowerShell command on Get-command Xft

Manual Pages for UNIX Operating System command usage for man Xft

Introduction to Library Functions Xft(3)

NAME

Xft - 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. HEADER FILE

#include

CONSTANTS

XFT_MAJOR

is the major version number of Xft.

XFT_MINOR

is the minor version number of Xft.

XFT_REVISION

is the revision number of Xft.

XFT_VERSION

is XFT_MAJOR times 10000 (ten thousand), plus XFT_MINOR

times 100, plus XFT_REVISION.

XftVersion

is an alias for XFT_VERSION.

The following example illustrates how Xft's version con-

stants 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

DATA TYPES

XftFont

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

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Introduction to Library Functions Xft(3)

and pointers to the Fontconfig character set and pat-

tern associated with the font. The FcCharSet and FcPattern data types are defined by the Fontconfig library.

XftFonts

are populated with any of XftFontOpen(), XftFontOpen-

Name(), XftFontOpenXlfd(), XftFontOpenInfo(), or

XftFontOpenPattern(). XftFontCopy() is used to dupli-

cate XftFonts, and XftFontClose() is used to mark an

XftFont as unused. XftFonts are internally allocated,

reference-counted, and freed by Xft; the programmer

does not ordinarily need to allocate or free storage for them.

XftDrawGlyphs(),

the XftDrawString*() family, XftDrawCharSpec(), and

XftDrawGlyphSpec() use XftFonts to render text to an

XftDraw object, which may correspond to either a core X

drawable or an X Rendering Extension drawable.

XftGlyphExtents()

and the XftTextExtents*() family are used to determine

the extents (maximum dimensions) of an XftFont.

An XftFont's glyph or character coverage can be determined

with XftFontCheckGlyph() or XftCharExists(). XftChar-

Index() returns the XftFont-specific character index

corresponding to a given Unicode codepoint.

XftGlyphRender(),

XftGlyphSpecRender(), XftCharSpecRender(), and the

XftTextRender*() family use XftFonts to draw into X

Rendering Extension Picture structures. Note:

XftDrawGlyphs(), the XftDrawString*() family,

XftDrawCharSpec(), and XftDrawGlyphSpec() provide a

means of rendering fonts that is independent of the availability of the X Rendering Extension on the X server.

XftFontInfo

is an opaque object that stores information about a

font. XftFontInfo structures are created with XftFon-

tInfoCreate(), freed with XftFontInfoDestroy(), and

compared with XftFontInfoEqual(). XftFontInfo objects

are internally allocated and freed by Xft; the program-

mer does not ordinarily need to allocate or free storage for them.

Each XftFontInfo structure in use is associated with a

unique identifier, which can be retrieved with XftFon-

tInfoHash(). An XftFont can be opened based on

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Introduction to Library Functions Xft(3)

XftFontInfo data with XftFontOpenInfo().

XftColor

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 approxi-

mation offered by the X visual in use). The XRender-

Color data type is defined by the X Render Extension library.

XftColorAllocName()

and XftColorAllocValue() request a color allocation

from the X server (if necessary) and initialize the

members of XftColor. XftColorFree() instructs the X

server to free the color currently allocated for an

XftColor.

One an

XftColor has been initialized, XftDrawSrcPicture(),

XftDrawGlyphs(), the XftDrawString*() family,

XftDrawCharSpec(), XftDrawCharFontSpec(),

XftDrawGlyphSpec(), XftDrawGlyphFontSpec(), and

XftDrawRect() may be used to draw various objects using

it.

XftDraw

is an opaque object which holds information used to render to an X drawable using either the core protocol or the X Rendering extension.

XftDraw

objects are created with any of XftDrawCreate() (which

associates an XftDraw with an existing X drawable),

XftDrawCreateBitmap(), or XftDrawCreateAlpha(), and

destroyed with XftDrawDestroy(). The X drawable asso-

ciated with an XftDraw can be changed with

XftDrawChange(). XftDraws are internally allocated and

freed by Xft; the programmer does not ordinarily need

to allocate or free storage for them. The X

Display, Drawable, Colormap, and Visual of an XftDraw

can be queried with XftDrawDisplay(), XftDrawDraw-

able(), XftDrawColormap(), and XftDrawVisual(), respec-

tively. The X Rendering Extension Picture associated

with an XftDraw is returned by XftDrawPicture().

XftCharSpec

typedef struct _XftCharSpec {

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Introduction to Library Functions Xft(3)

FcChar32 ucs4; short x; short y;

} XftCharSpec;

The FcChar32 data type is defined by the Fontconfig library.

XftCharFontSpec

typedef struct _XftCharFontSpec {

XftFont *font;

FcChar32 ucs4; short x; short y;

} XftCharFontSpec;

The FcChar32 data type is defined by the Fontconfig library.

XftGlyphSpec

typedef struct _XftGlyphSpec {

FT_UInt glyph;

short x; short y;

} XftGlyphSpec;

The FT_UInt data type is defined by the FreeType library.

XftGlyphFontSpec

typedef struct _XftGlyphFontSpec {

XftFont *font;

FT_UInt glyph;

short x; short y;

} XftGlyphFontSpec;

The FT_UInt data type is defined by the FreeType library.

FUNCTIONS Opening and Matching Fonts

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.

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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. Determining the Pixel Extents of a Text String 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,

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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 Fontcon-

fig 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,

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Introduction to Library Functions Xft(3)

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. Drawing Strings (and Other Things)

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

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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 sup-

port 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,

XRenderColor *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. The

XRenderColor data type is defined by the X Rendering Exten-

sion library. void

XftDrawRect (XftDraw *d,

XRenderColor *color, int x, int y, unsigned int width, unsigned int height);

XftDrawRect draws a solid rectangle of the specified color,

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Introduction to Library Functions Xft(3)

width, and height at position x, y to Xft drawable d.

COMPATIBILITY

As of version 2, Xft has become relatively stable and is

expected to retain source and binary compatibility in future releases.

Xft does provide a compatibility interface to its previous

major version, Xft 1.x, described below.

Xft 1.x Compatibility Header File

#include

Xft 1.x Compatibility Data Types

XftPattern

holds a set of names with associated value lists; each

name refers to a property of a font. XftPatterns are

used as inputs to the matching code as well as holding information about specific fonts.

XftFontSet

contains a list of XftPatterns. Internally, Xft uses

this data structure to hold sets of fonts. Externally,

Xft returns the results of listing fonts in this for-

mat.

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. AUTHOR Keith Packard

ATTRIBUTES

See attributes(5) for descriptions of the following attri-

butes:

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Introduction to Library Functions Xft(3)

____________________________________________________________

| ATTRIBUTE TYPE | ATTRIBUTE VALUE |

|_____________________________|_____________________________|

| Availability | x11/library/libxft |

|_____________________________|_____________________________|

| Interface Stability | Volatile |

|_____________________________|_____________________________|

| MT-Level | See XInitThreads(3X11) |

|_____________________________|_____________________________|