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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;
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.