XTextExtents(3X11)                   SysV                   XTextExtents(3X11)



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

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


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


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

     XQueryTextExtents16(display, font_ID, string, nchars, direction_return,
     font_ascent_return,
                             font_descent_return, overall_return)
           Display *display;
           XID font_ID;
           XChar2b *string;
           int nchars;
           int *direction_return;
           int *font_ascent_return, *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 a pointer to 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.

     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
     XTextWidth(3X11)
     Xlib - C Language X Interface