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XTextExtents(3X11)	       XLIB FUNCTIONS		   XTextExtents(3X11)



NAME
  XTextExtents, XTextExtents16, XQueryTextExtents, XQueryTextExtents16 - com-
  pute 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 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 char-
  acters in the string.	 The descent member is set to the maximum of the des-
  cent 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, unde-
  fined 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 char-
  acters in the string.	 The descent member is set to the maximum of the des-
  cent 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, unde-
  fined 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(3X11), XTextWidth(3X11)
  Xlib - C Language X Interface
























































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