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XmbTextPerCharExtents

Section: XLIB FUNCTIONS (3)
Updated: libX11 1.6.4
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NAME

XmbTextPerCharExtents, XwcTextPerCharExtents, Xutf8TextPerCharExtents - obtain per-character information for a text string

SYNTAX

: Status XmbTextPerCharExtents(XFontSet font_set, char *string, int num_bytes, XRectangle *ink_array_return, XRectangle *logical_array_return, int array_size, int *num_chars_return, XRectangle *overall_ink_return, XRectangle *overall_logical_return);
: Status XwcTextPerCharExtents(XFontSet font_set, wchar_t *string, int num_wchars, XRectangle *ink_array_return, XRectangle *logical_array_return, int array_size, int *num_chars_return, XRectangle *overall_ink_return, XRectangle *overall_logical_return);
: Status Xutf8TextPerCharExtents(XFontSet font_set, char *string, int num_bytes, XRectangle *ink_array_return, XRectangle *logical_array_return, int array_size, int *num_chars_return, XRectangle *overall_ink_return, XRectangle *overall_logical_return);

ARGUMENTS

array_size: Specifies the size of ink_array_return and logical_array_return. The caller must pass in arrays of this size.
font_set: Specifies the font set.
ink_array_return: Returns the ink dimensions for each character.
logical_array_return: Returns the logical dimensions for each character.
num_bytes: Specifies the number of bytes in the string argument.
num_chars_return: Returns the number of characters in the string argument.
num_wchars: Specifies the number of characters in the string argument.
overall_ink_return: Returns the overall ink extents of the entire string.
overall_logical_return: Returns the overall logical extents of the entire string.
string: Specifies the character string.

DESCRIPTION

The XmbTextPerCharExtents, XwcTextPerCharExtents and Xutf8TextPerCharExtents functions return the text dimensions of each character of the specified text, using the fonts loaded for the specified font set. Each successive element of ink_array_return and logical_array_return is set to the successive character's drawn metrics, relative to the drawing origin of the string and one rectangle for each character in the supplied text string. The number of elements of ink_array_return and logical_array_return that have been set is returned to num_chars_return.

Each element of ink_array_return is set to the bounding box of the corresponding character's drawn foreground color. Each element of logical_array_return is set to the bounding box that provides minimum spacing to other graphical features for the corresponding character. Other graphical features should not intersect any of the logical_array_return rectangles.

Note that an XRectangle represents the effective drawing dimensions of the character, regardless of the number of font glyphs that are used to draw the character or the direction in which the character is drawn. If multiple characters map to a single character glyph, the dimensions of all the XRectangles of those characters are the same.

When the XFontSet has missing charsets, metrics for each unavailable character are taken from the default string returned by XCreateFontSet so that the metrics represent the text as it will actually be drawn. The behavior for an invalid codepoint is undefined.

If the array_size is too small for the number of characters in the supplied text, the functions return zero and num_chars_return is set to the number of rectangles required. Otherwise, the functions return a nonzero value.

If the overall_ink_return or overall_logical_return argument is non-NULL, XmbTextPerCharExtents, XwcTextPerCharExtents and Xutf8TextPerCharExtents return the maximum extent of the string's metrics to overall_ink_return or overall_logical_return, as returned by XmbTextExtents, XwcTextExtents or Xutf8TextExtents.

The function Xutf8TextPerCharExtents is an extension introduced by The XFree86 Project, Inc. in their 4.0.2 release. Its presence is indicated by the macro X_HAVE_UTF8_STRING.