XFT
全名:『 X FreeType interface library 』
簡要說明:
XFT 是一組處理 FreeType 字型的函式庫,函式庫內容可分為兩大類:
* 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.
- 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. Externally, 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, Xft-
TypeString, "charter", XFT_SIZE, XftTypeDouble,
12.0);
This opens the charter font at 12 points. The point size is automati-
cally converted to the correct pixel size based on the resolution of
the monitor.
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 render 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.
講這麼多...您一定看得霧煞煞..沒關係...我也不是很了解,您要問的答案在底下:
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 program 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"
;
edit : FIELD-NAME ASSIGN expr SEMI
;
STRINGs are double-quote delimited. FIELD-NAMEs are identifiers,
ASSIGN is one of "=", "+=" or "=+". expr can contain the usual arith-
metic 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 configuration parame-
ters from the indicated file. "includeif" doesn't elicit a complaint
if the file doesn't exist. If the file name begins with a '~' charac-
ter, it refers to a path relative to the home directory of the user.
If the tests in a "match" statement all match a user-specified pattern,
the pattern will be edited with the specified 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.
所以..簡單的說 XftConfig 就是 XFT 提供的設定介面...