XTextExtents16

Syntax

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;

Arguments

font_struct	Specifies the XFontStruct structure.
string	Specifies the character string.
nchars	Specifies the number of characters in the character string.
direction_return	Returns the value of the direction hint (FontLeftToRight or FontRightToLeft).
font_ascent_return	Returns the font ascent.
font_descent_return	Returns the font descent.
overall_return	Returns the overall size in the specified XCharStruct structure.

Description

The XTextExtents16() function performs the size computation locally and, thereby, avoid the round-trip overhead of XQueryTextExtents() and XQueryTextExtents16(). The function returns 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.

XTextExtents16

Syntax

Arguments

Description

See also