REF XExtent A.Schoter, August 1991
COPYRIGHT University of Sussex 1991. All Rights Reserved.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<<<<<<<< >>>>>>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<<<<<<<< X EXTENT >>>>>>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<<<<<<<< >>>>>>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
The procedures described in this REF file shadow their equivalent C
functions for extent handling and related functions.
---------------------
1 List of procedures
---------------------
The procedures below are made available by doing:
œ uses xlib, XExtent;
For details see:
œ Xlib - C Language X Interface,
œ MIT X Consortium Standard,
œ X Version 11, Release 4
œ
œ Copyright (C) 1985, 1986, 1987, 1988, 1989 Massachusetts
œ Institute of Technology, Cambridge, Massachusetts, and
œ Digital Equipment Corporation, Maynard, Massachusetts.
XSizeHints [typedef]
This data structure provides information on the raster size.
œ typedef struct {
œ long flags;
œ int x, y;
œ int width, height;
œ int min_width, min_height;
œ int max_width, max_height;
œ int width_inc, height_inc;
œ struct {
œ int x;
œ int y;
œ } min_aspect, max_aspect;
} XSizeHints;
flags marks which fields in this structure are defined; x and y
within the substructure are the numerator and denominator
respectively.
XCharStruct [typedef]
This data structure provides information on the character font
metric.
œ typedef struct {
œ short lbearing;
œ short rbearing;
œ short width;
œ short ascent;
œ short descent;
œ unsigned short attributes;
} XCharStruct;
lbearing and rbearing are the origin to the left edge and origin
to the right edge of the raster respectively; width is the
amount to advance to the next character's origin; ascent and
descent are the baseline to the top edge and baseline to the
bottom edge of the raster repectively; attributes allow for
flags to be assigned per character.
XFontProp [typedef]
This structure allows for the association of arbitrary
information with fonts.
œ typedef struct {
œ Atom name;
œ unsigned long card32;
} XFontProp;
XFontStruct [typedef]
This structure contains information about a font.
œ typedef struct {
œ XExtData *ext_data;
œ Font fid;
œ unsigned direction;
œ unsigned min_char_or_byte2;
œ unsigned max_char_or_byte2;
œ unsigned min_byte1;
œ unsigned max_byte1;
œ Bool all_chars_exist;
œ unsigned default_char;
œ int n_properties;
œ XFontProp *properties;
œ XCharStruct min_bounds;
œ XCharStruct max_bounds;
œ XCharStruct *per_char;
œ int ascent;
œ int descent;
} XFontStruct;
ext_data is a hook to hang extension data on; fid is the font ID
for the given font; direction provides a hint about the
direction the font is painted; min_char_or_byte2 and
max_char_or_byte2 are the first and last character respectively;
min_byte1 and max_byte1 are the first and last row that exist
respectively; all_chars_exist is a flag indicating whether all
characters have non-zero size; default_char is the character to
print for undefined characters; n_properties is a count of the
number of additional properties, and properties is a pointer to
an array of additional properties; min_bounds and max_bounds are
the minimum and maximum bounds over all existing characters
respectively; per_char provides first character to last
character information; ascent and descent provide information
about the extent above and below the baseline for spacing.
--- C.x/x/pop/ref/XExtent
--- Copyright University of Sussex 1991. All rights reserved.