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XTextExtents(3)                 XLIB FUNCTIONS                 XTextExtents(3)

NAME
       XTextExtents, XTextExtents16, XQueryTextExtents, XQueryTextExtents16 -
       compute or query text extents

SYNTAX
       int XTextExtents(XFontStruct *font_struct, _Xconst char *string, int
              nchars, int *direction_return, int *font_ascent_return, int
              *font_descent_return, XCharStruct *overall_return);

       int XTextExtents16(XFontStruct *font_struct, _Xconst XChar2b *string,
              int nchars, int *direction_return, int *font_ascent_return, int
              *font_descent_return, XCharStruct *overall_return);

       int XQueryTextExtents(Display *display, XID font_ID, _Xconst char
              *string, int nchars, int *direction_return, int
              *font_ascent_return, int *font_descent_return, XCharStruct
              *overall_return);

       int XQueryTextExtents16(Display *display, XID font_ID, _Xconst XChar2b
              *string, int nchars, int *direction_return, int
              *font_ascent_return, int *font_descent_return, XCharStruct
              *overall_return);

ARGUMENTS
       direction_return
                 Returns the value of the direction hint (FontLeftToRight or
                 FontRightToLeft).

       display   Specifies the connection to the X server.

       font_ID   Specifies either the font ID or the GContext ID that contains
                 the font.

       font_ascent_return
                 Returns the font ascent.

       font_descent_return
                 Returns the font descent.

       font_struct
                 Specifies the XFontStruct structure.

       nchars    Specifies the number of characters in the character string.

       string    Specifies the character string.

       overall_return
                 Returns the overall size in the specified XCharStruct
                 structure.

DESCRIPTION
       The XTextExtents and XTextExtents16 functions perform the size
       computation locally and, thereby, avoid the round-trip overhead of
       XQueryTextExtents and XQueryTextExtents16.  Both functions return an
       XCharStruct structure, whose members are set to the values as follows.

       The ascent member is set to the maximum of the ascent metrics of all
       characters in the string.  The descent member is set to the maximum of
       the descent metrics.  The width member is set to the sum of the
       character-width metrics of all characters in the string.  For each
       character in the string, let W be the sum of the character-width
       metrics of all characters preceding it in the string.  Let L be the
       left-side-bearing metric of the character plus W.  Let R be the right-
       side-bearing metric of the character plus W.  The lbearing member is
       set to the minimum L of all characters in the string.  The rbearing
       member is set to the maximum R.

       For fonts defined with linear indexing rather than 2-byte matrix
       indexing, each XChar2b structure is interpreted as a 16-bit number with
       byte1 as the most significant byte.  If the font has no defined default
       character, undefined characters in the string are taken to have all
       zero metrics.

       The XQueryTextExtents and XQueryTextExtents16 functions return the
       bounding box of the specified 8-bit and 16-bit character string in the
       specified font or the font contained in the specified GC.  These
       functions query the X server and, therefore, suffer the round-trip
       overhead that is avoided by XTextExtents and XTextExtents16.  Both
       functions return a XCharStruct structure, whose members are set to the
       values as follows.

       The ascent member is set to the maximum of the ascent metrics of all
       characters in the string.  The descent member is set to the maximum of
       the descent metrics.  The width member is set to the sum of the
       character-width metrics of all characters in the string.  For each
       character in the string, let W be the sum of the character-width
       metrics of all characters preceding it in the string.  Let L be the
       left-side-bearing metric of the character plus W.  Let R be the right-
       side-bearing metric of the character plus W.  The lbearing member is
       set to the minimum L of all characters in the string.  The rbearing
       member is set to the maximum R.

       For fonts defined with linear indexing rather than 2-byte matrix
       indexing, each XChar2b structure is interpreted as a 16-bit number with
       byte1 as the most significant byte.  If the font has no defined default
       character, undefined characters in the string are taken to have all
       zero metrics.

       Characters with all zero metrics are ignored.  If the font has no
       defined default_char, the undefined characters in the string are also
       ignored.

       XQueryTextExtents and XQueryTextExtents16 can generate BadFont and
       BadGC errors.

DIAGNOSTICS
       BadFont   A value for a Font or GContext argument does not name a
                 defined Font.

       BadGC     A value for a GContext argument does not name a defined
                 GContext.

SEE ALSO
       XLoadFont(3), XTextWidth(3)
       Xlib - C Language X Interface

X Version 11                     libX11 1.8.6                  XTextExtents(3)