aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorRichard M. Stallman2002-09-14 17:36:44 +0000
committerRichard M. Stallman2002-09-14 17:36:44 +0000
commitbbf77fe8902e0ae9467b679071302d82ed28d1bd (patch)
treefdb20936db0ef51d4490868f74b25376e4842428
parentbf2a6c399cf5f48ba47eaa5133c009a271e98401 (diff)
downloademacs-bbf77fe8902e0ae9467b679071302d82ed28d1bd.tar.gz
emacs-bbf77fe8902e0ae9467b679071302d82ed28d1bd.zip
Correct the explanation of glyphs and glyph table.
-rw-r--r--lispref/display.texi50
1 files changed, 29 insertions, 21 deletions
diff --git a/lispref/display.texi b/lispref/display.texi
index 0d4cfd88f76..acbabfcb2e9 100644
--- a/lispref/display.texi
+++ b/lispref/display.texi
@@ -3380,17 +3380,36 @@ are defined in the library @file{disp-table}.
3380@cindex glyph 3380@cindex glyph
3381 A @dfn{glyph} is a generalization of a character; it stands for an 3381 A @dfn{glyph} is a generalization of a character; it stands for an
3382image that takes up a single character position on the screen. Glyphs 3382image that takes up a single character position on the screen. Glyphs
3383are represented in Lisp as integers, just as characters are. 3383are represented in Lisp as integers, just as characters are. Normally
3384Emacs finds glyphs in the display table (@pxref{Display Tables}).
3385
3386 A glyph can be @dfn{simple} or it can be defined by the @dfn{glyph
3387table}. A simple glyph is just a way of specifying a character and a
3388face to output it in. The glyph code for a simple glyph, mod 524288,
3389is the character to output, and the glyph code divided by 524288
3390specifies the face number (@pxref{Face Functions}) to use while
3391outputting it. (524288 is
3392@ifnottex
33932**19.)
3394@end ifnottex
3395@tex
3396$2^{19}$.)
3397@end tex
3398@xref{Faces}.
3384 3399
3385@cindex glyph table 3400 On character terminals, you can set up a @dfn{glyph table} to define
3386 The meaning of each integer, as a glyph, is defined by the glyph 3401the meaning of glyph codes. The glyph codes is the value of the
3387table, which is the value of the variable @code{glyph-table}. 3402variable @code{glyph-table}.
3388 3403
3389@defvar glyph-table 3404@defvar glyph-table
3390The value of this variable is the current glyph table. It should be a 3405The value of this variable is the current glyph table. It should be a
3391vector; the @var{g}th element defines glyph code @var{g}. If the value 3406vector; the @var{g}th element defines glyph code @var{g}.
3392is @code{nil} instead of a vector, then all glyphs are simple (see 3407
3393below). The glyph table is not used on windowed displays. 3408If a glyph code is greater than or equal to the length of the glyph
3409table, that code is automatically simple. If the value of
3410@code{glyph-table} is @code{nil} instead of a vector, then all glyphs
3411are simple. The glyph table is not used on graphical displays, only
3412on character terminals. On graphical displays, all glyphs are simple.
3394@end defvar 3413@end defvar
3395 3414
3396 Here are the possible types of elements in the glyph table: 3415 Here are the possible types of elements in the glyph table:
@@ -3403,24 +3422,13 @@ but not under a window system.
3403 3422
3404@item @var{integer} 3423@item @var{integer}
3405Define this glyph code as an alias for glyph code @var{integer}. You 3424Define this glyph code as an alias for glyph code @var{integer}. You
3406can use an alias to specify a face code for the glyph; see below. 3425can use an alias to specify a face code for the glyph and use a small
3426number as its code.
3407 3427
3408@item @code{nil} 3428@item @code{nil}
3409This glyph is simple. The glyph code mod 524288 is the character to 3429This glyph is simple.
3410output, and the glyph code divided by 524288 specifies the face number
3411(@pxref{Face Functions}) to use while outputting it. (524288 is
3412@ifnottex
34132**19.)
3414@end ifnottex
3415@tex
3416$2^{19}$.)
3417@end tex
3418@xref{Faces}.
3419@end table 3430@end table
3420 3431
3421 If a glyph code is greater than or equal to the length of the glyph
3422table, that code is automatically simple.
3423
3424@defun create-glyph string 3432@defun create-glyph string
3425@tindex create-glyph 3433@tindex create-glyph
3426This function returns a newly-allocated glyph code which is set up to 3434This function returns a newly-allocated glyph code which is set up to