ncurses 6.3 - patch 20220625

[ncurses.git] / man / curs_bkgd.3x

diff --git a/man/curs_bkgd.3x b/man/curs_bkgd.3x
index 2c3d3d4fee93d8663cfa031a4c06927e3d14107e..f9199ce077bb6741303246b3c80482ee37b255bd 100644 (file)
--- a/man/curs_bkgd.3x
+++ b/man/curs_bkgd.3x
@@ -27,7 +27,7 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
-.\" $Id: curs_bkgd.3x,v 1.34 2022/02/12 20:06:41 tom Exp $
+.\" $Id: curs_bkgd.3x,v 1.35 2022/06/25 21:55:45 tom Exp $
 .de bP
 .ie n  .IP \(bu 4
 .el    .IP \(bu 2
@@ -52,15 +52,18 @@
 .br
 .SH DESCRIPTION
 .SS bkgdset
-The \fBbkgdset\fP and \fBwbkgdset\fP routines manipulate the
-background of the named window.
-The window background is a \fBchtype\fP consisting of
-any combination of attributes (i.e., rendition) and a character.
+The \fBbkgdset\fP and \fBwbkgdset\fP routines
+set the \fIbackground\fP for a window.
+A window's background is a \fBchtype\fP consisting of
+any combination of attributes (i.e., rendition) and a character:
+.bP
 The attribute part of the background is combined (OR'ed) with all non-blank
 characters that are written into the window with \fBwaddch\fP.
+.bP
 Both the character and attribute parts of the background are combined with
-the blank characters.
-The background becomes a property of the
+blank characters that are written into the window.
+.PP
+The background becomes a property of each
 character and moves with the character through any scrolling and
 insert/delete line/character operations.
 .PP
@@ -94,6 +97,11 @@ For each cell in the window, whether or not it is blank:
 The library first compares the \fIcharacter\fP,
 and if it matches the current character part of the background,
 it replaces that with the new background character.
+.IP
+When \fBbkgdset\fP is used to set the background character,
+that does not update each cell in the window.
+A subsequent call to \fBbkgd\fP will only modify the \fIcharacter\fP in
+cells which match the current background character.
 .bP
 The library then checks if the cell uses color,
 i.e., its color pair value is nonzero.
@@ -114,7 +122,7 @@ the library updates only the non-color attributes,
 first removing those which may have come from the current background,
 and then adding attributes from the new background.
 .PP
-If the background's character value is zero, a space is assumed.
+If the background's character value is zero (0), a space is assumed.
 .PP
 If the terminal does not support color,
 or if color has not been started with \fBstart_color\fP,